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Merging connectivity rules and large-scale condition assessment improves conservation adequacy in river systems
Journal of Applied Ecology
Abstract
Conservation adequacy is defined as the ability of conservation measures to sustain biodiversity. Although river network connectivity is important for maintaining key ecological processes and ensuring persistence of biodiversity, it also facilitates the propagation of threats along river networks, which may compromise the sustainability of freshwater biodiversity and therefore conservation adequacy. This study aims to introduce two modifications to river conservation planning related to connectivity and catchment condition that together can improve the adequacy of the priority areas identified. This will establish an operational framework for end‐users, such as policy makers and NGO s.
We operationalize the connectivity framework that has recently emerged in systematic river conservation planning by using a GIS coding system for catchment location in the conservation software package marxan . Additionally, we use a landscape measure of catchment disturbance to direct the conservation plan to the least‐disturbed area while still meeting targets for the conservation of fish species used as surrogates for overall biodiversity in our study catchment, the D aly R iver in northern A ustralia. This proxy for condition aggregates information on land‐use, extractive industries, point‐source pollution, and water infrastructure.
We successfully modelled the distribution of 39 fish species based on GIS ‐derived landscape descriptors (most important descriptors were; discharge, distance to river mouth, geology and conductivity).
Results from the systematic planning analysis identified a portfolio of watersheds that delivered close to optimal upstream protection with around 4700 stream kilometres (30% of the total network). When using upstream disturbance as an extra penalty, most of the network stayed intact; however, a replacement area was found for a major tributary, which only added an extra 1% of the stream network to the total area.
Synthesis and applications . Improving conservation adequacy by accounting for upstream connectivity and condition using this easy‐to‐implement framework and software package has the potential to facilitate further application of systematic methods in river conservation planning. Furthermore, integrating condition as a discounting factor can also improve conservation adequacy in a broad range of environments (including terrestrial and marine), while not necessarily increasing the management costs.
... Incorporating connectivity is therefore crucial for effective conservation of migrants (Cabeza, 2003;van Teeffelen et al., 2006;Martin et al., 2007;Klaassen et al., 2008;Beger et al., 2010;Sheehy et al., 2010;Hermoso et al., 2012a;Hermoso et al., 2012b;Linke et al., 2012;Iwamura et al., 2013;Langhans et al., 2014;Runge et al., 2014a;Nicol et al., 2015). ...
... Conservation planning for migratory shorebirds in the EAAF requires methods that can simultaneously account for connectivity (Cabeza, 2003;van Teeffelen et al., 2006;Martin et al., 2007;Klaassen et al., 2008;Beger et al., 2010;Hermoso et al., 2012a;Hermoso et al., 2012b;Linke et al., 2012;Iwamura et al., 2013;Langhans et al., 2014;Runge et al., 2014a;Nicol et al., 2015) and uncertainty (McDonald-Madden et al., 2008;Wintle et al., 2010;Keith et al., 2011;McDonald-Madden et al., 2011). Finding local, national and international solutions for managing migratory shorebirds is no trivial pursuit. ...
... Conservation plans that account for connectivity repeatedly outperform plans that do not (Sheehy et al., 2011b;Hermoso et al., 2012a;Linke et al., 2012;Iwamura et al., 2014;Runge et al., 2014a;Nicol et al., 2015), yet more than 90% of the world's migratory birds are inadequately protected across their annual cycle . ...
... The DSS and the underlying data must also be detailed enough to give an acceptable level of (un)certainty in the results [19]. Similarly, the concept of longitudinal connectivity has to be included in the planning process and has been successfully applied with DSSs designed for conservation planning [20,21], and for some catchmentbased water quality models such as eWater Source [22]. ...
... Simulated annealing is an optimization routine that has been applied to resource allocation [35], conservation planning tools [20,21] and planning catchment erosion mitigation [15]. Simulated annealing is a probabilistic technique for finding the global optimum in a search space. ...
Supplying safe, secure, and reliable drinking water is a growing challenge particularly in regions where catchments have diverse land uses, rapidly growing populations, and are subject to increasing weather extremes such as in the subtropics. Catchments represent the first barrier in providing ecosystem services for water quality protection and bulkwater suppliers are therefore investing in mitigation measures to reduce risk to drinking water quality for consumers. This paper presents an approach to combine data on erosion processes, pathogenic bacteria and protozoa from several sources, determine the highest risks from these hazards and identify an optimum portfolio of intervention activities that provide maximum risk reduction at water treatment plants (WTP) for a given budget using a simulated annealing optimizer. The approach is demonstrated in a catchment with six WTPs servicing small rural to urban populations. The catchment is predominantly used for agriculture. Results show that drinking water risk from protozoa can be reduced for most WTPs for moderate investment budget, while bacteria risk reduction requires significantly larger budget due to the greater number of significant source sites relative to protozoa. Total suspended sediment loads remain a very high risk to most of the WTPs due to the large extent of channel and gully erosion and landslides. A map of priority areas and associated suite of interventions are produced to guide on groundwork.
... There are several assumptions inherent in the analyses presented here and we highlight the lack of information on connectivity or cost in these prioritizations. First, we did not consider connectivity between sites or different parts of the population, which can be an important aspect of spatial conservation planning for migratory species (Moilanen and Moilanen 2005, Martin et al. 2007, Linke et al. 2012, Iwamura et al. 2013, Runge et al. 2014, Hewson et al. 2016, Brown et al. 2017, D'Aloia et al. 2017, Dhanjal-Adams et al. 2017). There are quantitative strategies for incorporating connectivity into spatial prioritizations (Beger et al. 2010a, b, Daigle et al. 2018, and these strategies have been used in some marine and freshwater prioritizations (Hermoso et al. 2011, Linke et al. 2012, Magris et al. 2014, Schill et al. 2015. ...
... First, we did not consider connectivity between sites or different parts of the population, which can be an important aspect of spatial conservation planning for migratory species (Moilanen and Moilanen 2005, Martin et al. 2007, Linke et al. 2012, Iwamura et al. 2013, Runge et al. 2014, Hewson et al. 2016, Brown et al. 2017, D'Aloia et al. 2017, Dhanjal-Adams et al. 2017). There are quantitative strategies for incorporating connectivity into spatial prioritizations (Beger et al. 2010a, b, Daigle et al. 2018, and these strategies have been used in some marine and freshwater prioritizations (Hermoso et al. 2011, Linke et al. 2012, Magris et al. 2014, Schill et al. 2015. However, for most bird species, information on connectivity is not available, so the analysis presented here aligns with the level of information most often used for conservation planning. ...
Most spatial conservation planning for wide‐ranging or migratory species is constrained by poor knowledge of species’ spatiotemporal dynamics and is only based on static species’ ranges. However, species have substantial variation in abundance across their range and migratory species have important spatiotemporal population dynamics. With growing ecological data and advancing analytics, both of these can be estimated and incorporated into spatial conservation planning. However, there is limited information on the degree to which including this information affects conservation planning. We compared the performance of systematic conservation prioritizations for different scenarios based on varying the input species’ distributions by ecological metric (abundance distributions versus range maps) and temporal sampling resolution (weekly, monthly, or quarterly). We used the example of a community of 41 species of migratory shorebirds that breed in North America, and we used eBird data to produce weekly estimates of species’ abundances and ranges. Abundance distributions at a monthly or weekly resolution led to prioritizations that most efficiently protected species throughout the full annual cycle. Conversely, spatial prioritizations based on species’ ranges required more sites and left most species insufficiently protected for at least part of their annual cycle. Prioritizations with only quarterly species ranges were very inefficient as they needed to target 40% of species’ ranges to include 10% of populations. We highlight the high value of abundance information for spatial conservation planning, which leads to more efficient and effective spatial prioritization for conservation. Overall, we provide evidence that spatial conservation planning for wide‐ranging migratory species is most robust and efficient when informed by species’ abundance information from the full annual cycle.
... LCP [33,34], however, has been widely applied to improve existing reserve networks while considering biodiversity patterns [10,[35][36][37][38][39]. Though LCP is a well-rounded approach for preserving the natural value of terrestrial [10,[36][37][38]40], marine [41,42], and freshwater [43,44] ecosystems, its main purpose is for locating, designing, and managing protected areas within a landscape [45]. Recently, interest in spatially quantitative systematic conservation approaches has been growing, as evidenced by the increased applications of Figure 1. ...
... LCP [33,34], however, has been widely applied to improve existing reserve networks while considering biodiversity patterns [10,[35][36][37][38][39]. Though LCP is a well-rounded approach for preserving the natural value of terrestrial [10,[36][37][38]40], marine [41,42], and freshwater [43,44] ecosystems, its main purpose is for locating, designing, and managing protected areas within a landscape [45]. Recently, interest in spatially quantitative systematic conservation approaches has been growing, as evidenced by the increased applications of computer-based software modeling tools such as Marxan [46] and Zonation [47] which both implement target-based planning algorithms as their primary planning method [48]. ...
Sustainable conservation aims to ensure the sustained conservation of landscape multi-functionality which in turn requires ensuring ecosystem service (ES) and habitat quality (HQ) sustainability with inclusive landscape-scale conservation planning. This study proposes a landscape conservation planning (LCP) framework for landscape-scale ES-HQ conservation and sustainability. Spatially explicit hotspots for five ESs and HQs are identified via InVEST and LISA software. Spatiotemporal changes in ES-HQ hotspots, in terms of stability and resilience, are delineated. The Zonation technique is applied to prioritize areas for conservation based on ES-HQ hotspot stability and resilience maps. High priority conservation areas are identified and are used as reserve area inputs for land use modeling with CLUE-S software to simulate future land use change under climate change scenarios. This study reports that varied rainfall and climate are major driving factors of ES-HQ sustainability disturbance in the study area. Furthermore, our proposed conservation Strategy 2 demonstrates that a larger extent of landscape multi-functionality can be sustained when the existing conservation area includes the total area of identified ES-HQ resilient hotspots. This study effectively identifies the stability and resiliency of ES-HQ hotspot areas affected by disturbances for high priority landscape conservation requirements to ensure ES-HQ sustainability and landscape multi-functionality in the study area.
... We attribute this to a general absence of hydrological regimes and connectivity features in terrestrial delineations. Since terrestrial bioregions are not adequate descriptors for aquatic ecosystems, many authors have argued for a nationally consistent classification of Australian rivers (Kingsford & Nevill, 2006;Linke et al., 2012). We agree with Belbin and Williams (2016) that more effort is needed to define custom spatial predictors that capture landscape function relevant to aquatic ecosystems for modelling to better inform conservation assessment. ...
... Most protected areas only partially protect freshwater systems (e.g. rare species habitat) and often fail to address key ecological processes, such as whole catchment integration and connectivity (Darwall et al., 2011;Dudgeon et al., 2006;Linke et al., 2012). ...
... space for time substitution) as well as those focussed on the dynamics over extended time within fewer locations (see Magoulick, 2000;Matthews & Marsh-Matthews, 2003). As part of a larger study on the environmental water requirements of freshwater fishes of the perennial Daly River in northern Australia (see Chan et al., 2012;Jackson et al., 2014;Linke et al., 2012;Stewart-Koster et al., 2011), we sampled a range of locations biannually for up to 10 years. Water resource use in this river is most likely to impact on the dry season flow regime of the perennial main channel and the study accordingly focussed on sites located in this part of the basin (Chan et al., 2012). ...
... Linke et al., 2012), extensively distributed across northern Australia and characteristic of intermittent streams across the region(Warfe et al., 2013). These included rainbowfish (M. ...
Intermittent rivers make up a large portion of the global river network and are the dominant river type in northern Australia. Increased pressure is being placed on such systems, and a better understanding of their ecology is needed. We examined, over a 7-year period, the fish fauna of the intermittent Fergusson River, a major tributary of the Daly River of the northern Australia. Changes in habitat structure with the onset of the dry season involved contraction of the riffle/run/pool habitat to a single refugial pool, the size of which was determined by antecedent wet season hydrology. The fishes present comprised a subset of species present within the Daly River main channel and consisted of the most widely distributed of northern Australia's freshwater fishes. The Fergusson River provides suitable spawning habitat for species during the wet season (e.g. Hephaestus fuliginosus, Leiopotherapon unicolor and Neosilurus catfishes) and during the dry season for a different set of species (e.g. Amniataba percoides, Melanotaenia australis and Glossogobius aureus). Little year-to-year variation in assemblage structure was observed early in the dry season, whereas interannual variation in late dry season assemblages was substantial. Dry season recruitment imparted some of the interannual variability in assemblage structure recorded between late dry season samples. Piscivorous fishes were an important, but temporally variable, component of the assemblage present in the late dry season refugial habitat, and predation was potentially another important source of variation in assemblage structure.
... Protected areas are considered as a mainstay of biodiversity conservation as well as contributing to human well-being (Gaston et al., 2008). In rivers, the most effective conservation strategy is proposed to be framed at the basin scale (Allan et al., 1997;Saunders et al., 2002;Linke et al., 2012). This framework considers that basins are biogeographic units (Doadrio, 1988;Reyjol et al., 2007), and that rivers are linear systems through which major threats to freshwater diversity such as pollution can easily propagate (Allan et al., 1997;Nel et al., 2007). ...
... The efficacy of common fish catching methods (electrofishing) is also higher in small than in large rivers (Bohlin et al., 1989). However, the design of fluvial reserves is complex and requires the selection of multiple protected zones with different management regimes (Linke et al., 2008(Linke et al., , 2012Hermoso et al., 2016). Nonetheless, we believe that the design of new protected areas should not change the focus on the management of hydrological regimes and sewage discharges at the basin scale, as this is the most effective way to conserve fluvial diversity. ...
Global freshwater biodiversity is declining at unprecedented rates while non-native species are expanding. Examining diversity patterns across variable river conditions can help develop better management strategies. However, many indicators can be used to determine the conservartion value of aquatic communities, and little is known of how well they correlate to each other in making diagnostics, including when testing for the efficacy of protected areas. Using an extensive data set (99,700km(2), n=530 sites) across protected and unprotected river reaches in 15 catchments of NE Spain, we examine correlations among 20 indicators of conservation value of fish communities, including the benefits they provide to birds and threatened mammals and mussels. Our results showed that total native fish abundance or richness correlated reasonably well with many native indicators. However, the lack of a strong congruence led modelling techniques to identify different river attributes for each indicator of conservation value. Overall, tributaries were identified as native fish refugees, and nutrient pollution, salinization, low water velocity and poor habitat structure as major threats to the native biota. We also found that protected areas offered limited coverage to major components of biodiversity, including rarity, threat and host-parasite relationships, even though values of non-native indicators were notably reduced. In conclusion, restoring natural hydrological regimes and water chemical status is a priority to stem freshwater biodiversity loss in this region. A complementary action can be the protection of tributaries, but more studies examining multiple components of diversity are necessary to fully test their potential as fluvial reserves in Mediterranean climate areas.
... First, freshwater systems have been described as hierarchically nested (Frissell et al., 1986) such that no single level of the hierarchy can represent all elements. Second, the highly connected nature of freshwater systems (which may include fluvial, lacustrine, palustrine and estuary areas) makes them particularly vulnerable to fragmentation (Fagan, 2002), and upstream/downstream influences (Fausch et al., 2002) (see sections re clauses 3 and 6), such that the ability of the species and ecosystems to persist needs to be accounted for in conjunction with ensuring adequate representation across the catchment (Dudgeon et al., 2006; Nel et al., 2009 Nel et al., , 2011 Linke et al., 2012). Third, freshwater ecosystems are highly dynamic and evolving systems (Stiassny et al., 2010); for example, rivers change course and features, pools are filled with sediment to become marshes. ...
... Planning for connectivity is especially important for adaptation to ecosystem change as a result of climate change (see previous section on clause 5). There are methods available to account for the specific needs of freshwater systems in conservation planning, such as longitudinal (Linke et al., 2007; Moilanen et al., 2008; Hermoso et al., 2011) and lateral (Hermoso et al., 2012) connectivity. However, these methods have been used rarely to inform on-the-ground implementation of conservation. ...
Protected areas, although often terrestrially focused and less frequently designed to protect freshwater resources, can be extremely important for conserving freshwater biodiversity and supporting human water security necessary for people to survive and thrive.
This study measured the quantity of water that is being provided by protected areas to areas downstream, and how threatened protected areas are in terms of their water provision.
Building on a Freshwater Provision Index, the numbers of people who live downstream from these protected areas around the world were then assessed. The same process was applied to areas where there are no protected areas.
Protected areas deliver 20% of the global total of approximately 40 000 km ³ year ⁻¹ of continental runoff. More than one‐quarter of water provisions supplied by the world's protected areas are exposed to low levels of threat and less than 10% are exposed to high levels of threat; this is compared with higher levels of threat for provisions from non‐protected areas, where nearly one quarter of the provisions are exposed to high threat and only 10% are exposed to low threat.
Nearly two‐thirds of the global population is living downstream of the world's protected areas as potential users of freshwater provisions supplied by these areas. Despite the overall large volume of low‐threat water supplied by protected areas, globally 80% of the downstream human community users receive water from upstream protected areas under high threat, and no continent has less than 59% of its downstream users receiving water from upstream protected areas under high threat.
Globally, increased attention to reduce the threats to fresh water in areas under protection, as well as designation and management of additional areas, are needed to safeguard freshwater flows, and support biodiversity conservation and the provision of freshwater ecosystem services.
Copyright © 2016 John Wiley & Sons, Ltd.
... The development of technologies to capture data at very high spatial and temporal resolutions is making it possible to move from the conceptual theories of patterns and processes in riverscapes to the testing and practice of such theories (Carbonneau et al. 2012). GIS and RS now provide the possibility of assessing river systems at broader spatial scales and hence incorporate condition assessment into conservation planning (Linke et al. 2012). These advances, however, are highly dependent on data availability. ...
... Merging species modeling with systematic conservation planning in river landscapes has provided a successful end user model conservation planning package (Linke et al. 2012). However to achieve this level of information data at multiple scales is essential for floodplain river systems in the Bolivian Amazon. ...
Tropical freshwater fish communities are increasingly under threat from anthropogenic pressures, particularly alteration to the hydrological regime (e.g. via deforestation and mining within the watershed and in-stream impoundments) which defines the extent and characteristics of in-channel and floodplain habitats for fishes. The ecological consequences of altered hydrology for tropical floodplain ecosystems are likely to be major declines in fish abundance and diversity, lower food web connectivity, reduced microhabitat availability for reproduction and refuge, modified migration patterns and consequently reduced ecosystem services, e.g. fishery resource. Evidence of change is lacking and the current species inventory approaches of collecting fish-related data do not consider spatial (i.e. river-floodplain distances) and temporal (i.e. flood water levels) gradients that are known to largely influence fish communities present in floodplain waterbodies. In the context of increasing threats, fish diversity and community declines are real and require suitable methodological approaches to combine available information and an informed analysis of likely change before actions are irreversible. Bolivian rivers are relatively undisturbed compared to other tropical rivers, however, plans for hydropower and increased deforestation and mining in the region could have devastating effects on the hydrological patterns and the dependent biodiversity. This review aims to summarise the current knowledge of floodplain freshwater fishes using Bolivian rivers as the example, identify the gaps that exist in the science and to propose a landscape ecology approach to integrate pattern and process understanding of the river-floodplain mosaic to fill knowledge gaps in an appropriate way towards the conservation of fish resources.
... We used the proportion of each subcatchment under intensive human uses (Appendix S3) as an estimate of threat intensity. This estimate was used as a penalty in the prioritization process similar to Linke et al. (2012), where we tried to avoid the allocation of any zone in highly degraded areas whenever possible. ...
... This approach also helps refine management recommendations from simple binary solutions, where only an indication on conservation priority areas is provided (e.g. Linke et al., 2012), to more specific information on the particular contribution to conservation objectives of each zone and the type of management it should receive. In combination, this increase in efficiency and refinement in recommendations could help unlock the necessary expansion of Natura 2000 to adequately cover freshwater conservation needs in the Iberian Peninsula (Hermoso et al., 2015c). ...
Aim
Conservation management in freshwater systems requires addressing some key ecological processes to warrant functional and effective protected areas. There are systematic planning methods available to address these needs, but they often result in large areas identified as priority for strict protection, which might constrain their implementation. Considering multiple zones with different management regimes might provide a more flexible and practical solution to this problem, though this approach remains poorly used in freshwater systems. We evaluate the use of a multizone approach to enhance protection of freshwater biodiversity and ecological processes in a large reserve network, Natura 2000.
Location
Iberian Peninsula.
Methods
We tested three scenarios of freshwater conservation planning: (1) a protection‐only approach based on areas identified using Marxan; (2) a more flexible approach where multiple management zones are considered using Marxan with Zones, both accounting for Natura 2000; and (3) a third one similar to (2) but ignoring Natura 2000. The three scenarios were compared considering their effectiveness in representing all species. We also evaluated the role of Natura 2000 within the management zones identified and the effect of these areas.
Results
We found that although there was only an 8% reduction in total area required to complement Natura 2000 under the multizone approach compared to the protection‐only approach, the refinement of conservation recommendations under different management zones can reduce the area needed for strict protection by 62%. Considering Natura 2000 compromised the efficiency of solutions while only one‐third of its extent was selected under the strict protection zone.
Main conclusions
The refinement in management recommendations and resulting improvement in efficiency achieved by using the multizone approach could help unlock the needed expansion of Natura 2000 to adequately cover freshwater conservation needs in the Iberian Peninsula and other areas where similar issues have been highlighted.
... Global Ecology and Biogeography, © 2016 John Wiley & Sons Ltd correlation of the selection frequency outputs and compared it with that of a solution that includes all 34 tracks. To further examine the increased inclusion of telemetry tracks, we used a Bray-Curtis dissimilarity matrix method as described in Linke et al. (2012) and displayed our results in a dendrogram. This method compared the Marxan best solution outputs (the solution with the lowest objective function score) when run with different numbers of tracks. ...
... When there is only a short widow of time to act for threatened species it is critical that decision makers invest and act in those areas that will be most effective at ensuring species persistence (Bottrill et al., 2008). A B C D Figure 5 Dendrogram comparing the dissimilarity of solutions (Bray-Curtis dissimilarity matrix method; Linke et al., 2012) with increasing numbers of tracks. Each node on the dendrogram represents the number of tracks (0, 5, 10, 15, 20, 25, 30, and 34 tracks) used in the analysis and the repetition letter (each number of tracks was run 10 times each, represented by letters a-j). ...
Aim
Conservation plans often struggle to account for connectivity in spatial prioritization approaches for the protection of migratory species. Protection of such species is challenging because their movements may be uncertain and variable, span vast distances, cross international borders and traverse land and sea habitats. Often we are faced with small samples of information from various sources and the collection of additional data can be costly and time‐consuming. Therefore it is important to evaluate what degree of spatial information provides sufficient results for directing management actions. Here we develop and evaluate an approach that incorporates habitat and movement information to advance the conservation of migratory species. We test our approach using information on threatened loggerhead sea turtles ( C aretta caretta ) in the M editerranean.
Location
The M editerranean S ea.
Methods
We use Marxan, a spatially explicit decision support tool, to select priority conservation areas. Four approaches with increasing amounts of information about the loggerhead sea turtle are compared, ranging from (1) the broad distribution, (2) multiple habitat types that represent foraging, nesting and inter‐nesting habitats, (3) mark–recapture movement information to (4) telemetry‐derived migration tracks.
Results
We find that spatial priorities for sea turtle conservation are sensitive to the information used in the prioritization process. Setting conservation targets for migration tracks altered the location of conservation priorities, indicating that conservation plans designed without such data would miss important sea turtle habitat. We discover that even a small number of tracks make a significant contribution to a spatial conservation plan if those tracks are substantially different.
Main conclusions
This study presents a novel approach to improving spatial prioritization for conserving migratory species. We propose that future telemetry studies tailor their efforts towards conservation prioritization needs, meaning that spatially dispersed samples rather than just large numbers should be obtained. This work highlights the valuable information that telemetry research contributes to the conservation of migratory species.
... Thus, it leads to a continuous struggle for policymakers to design targeted and site-specific conservation plans for snow trout. Although, various protection amendments for freshwater biodiversity have been implemented at the global level (Linke et al. 2012;Heino et al. 2016). ...
Fish are a significant component of the aquatic environment and are crucial in supporting and maintaining the entire ecological system, thereby making freshwater systems more resilient and sustainable. The structure of a fish community is influenced by biotic interactions and abiotic variables. In recent years, spanning from the last 5 to 10 years, conservationists and commercial fishermen have reported a significant decline in freshwater fisheries. The decline can be attributed to several factors, including the introduction of exotic species, construction of dams, anthropogenic activities, illegal fishing, and overfishing. Schizothorax richardsonii, is a highly valued freshwater fish, inhabiting the foothills of the Himalayan regions. The declines of S. richardsonii in the Himalayan region are more than 90% in some areas and the predicted overall reduction is inferred to be around 50% with similar rates. Withstanding all the variations in biotic and abiotic factors, the species is expanding its range of altitude and evolving according to the climate-driven shifts in the Himalayas and apparently, its current distributional range would be lost over time. In Indo-Himalayan ranges, there is a lack of conservative measures and as a result, despite its ecological importance, snow trout has been given a vulnerable status by IUCN 2020. This review aims to provide descriptive biology and discuss the anthropogenic impact on the population structure of snow trout and its conservation.
... [22][23][24] Considering conservation costs and human disturbances in the conservation planning model could minimize financial loss and avoid significant disturbances in conservation areas to promote conservation success in a more cost-efficient manner. [32][33][34] Therefore, a systematic conservation planning approach that considers species richness, distribution range, conservation costs, and human disturbances is necessary to optimize the current network of PAs. ...
To meet the challenge of biodiversity loss and reach the targets of the proposed Post-2020 Global Biodiversity Framework, the Chinese government updated the list of national key protected wildlife in 2021 and has been continually expanding the protected areas (PAs). However, the status of protected wildlife in PAs remains unclear. In this study, we conducted a national assessment of the status of protected wildlife and suggested an optimization plan to overcome these shortcomings. From 1988 to 2021, the number of protected species almost doubled, and the area of PAs increased by 2.4 times, covering over 92.8% of the protected species. Nonetheless, 70.8% of the protected species are still not effectively protected by PAs, with some having less than 10% of their habitat included in PAs. Despite the significant addition of amphibians and reptiles to the latest protection list, they are the fewest species and are the least covered by PAs compared to birds and mammals. To fix these gaps, we systematically optimized the current PAs network by adding another 10.0% of China’s land area as PAs, which resulted in 37.6% coverage of protected species’ habitats in PAs. Additionally, 26 priority areas were identified. Our research aimed to identify gaps in current conservation policies and suggest optimization solutions to facilitate wildlife conservation planning in China. In general, updating the list of key protected wildlife species and systematically optimizing PA networks are essential and applicable to other countries facing biodiversity loss.
... The incorporation of connectivity metrics in cross-realm conservation planning can be challenging (Hermoso et al., 2021). A common approach is the identification of cross-realm threats and the location of conservation areas in regions that are less affected by them (Linke et al., 2012). Another approach is the incorporation of different types of connectivity between realms into spatial conservation prioritization (Beger et al., 2010). ...
In the past years, efforts have been made to include connectivity metrics in conservation planning in order to promote and enhance well-connected systems of protected areas. Connectivity is particularly important for species that rely on more than one realm during their daily or life cycle (multi-realm species). However, conservation plans for the protection of multi-realm species usually involve a single realm, excluding other realms from the prioritization process. Here, we demonstrate an example of cross-realm conservation planning application for the island of Cyprus by taking into account the terrestrial and marine realms and their interface (i.e. coast). Operating within a data-poor context, we use functional connectivity metrics to identify priority areas for the conservation of six multi-realm species, by setting conservation targets simultaneously for the terrestrial and marine realms. MARXAN decision-support tool was used for the identification of the priority areas.
Four scenarios were developed to evaluate the impacts of including connectivity in the prioritization process and the effectiveness of the existing coastal/marine protected areas in the achievement of the conservation targets set for the species. All scenarios considered land and sea anthropogenic uses as surrogate costs to influence the prioritization process.
Our findings show an increase in the area of the reserve network and, therefore, the cost, when connectivity is included, whilst reducing the total boundary length. Furthermore, the current reserve network fails to achieve conservation targets, particularly for the marine part, which has a substantially smaller protection coverage than the terrestrial part.
We conclude that focus should be given in the expansion of the current coastal/marine reserve network following a cross-realm conservation approach. This approach is not only relevant for the conservation of multi-realm species, but also for islandscapes, in particular, where the interdependence between the hinterland and the coast is larger and therefore the magnitude of the impacts generated in one realm and affects the other.
... Here, we propose seven main points that should be specifically considered in joint river conservation and restoration planning, using functioning meta-systems as key background idea. While some of these ideas on river conservation and river restoration have been considered in other regions (Hermoso et al., 2016;Linke et al., 2012), we emphasize the peculiarities of boreal and Arctic catchments and river systems, including pronounced seasonality of temperature and flooding (Rolls et al., 2018), as well as low human population densities over large areas (Anderson, 2009). We also point out a lack of research when it comes to joint conservation and restoration rather than focusing on these topics on their own. ...
1. Freshwater ecosystems and their biota are more seriously threatened than their marine and terrestrial counterparts. A solution to halt increasing negative impacts of anthropogenic development would be to reconsider the basics of nature conservation (i.e. protection of pristine and near-pristine areas) and restoration (i.e. returning an impacted site to as natural condition as possible) through inclusion of the knowledge on abiotic and biotic dynamics of rivers draining pristine catchments. In boreal and Arctic regions, such comparisons are still possible because in addition to harbouring strongly modified drainage basins, some of the most natural drainage basins are also situated in these high-latitude areas.
2. A suitable approach for simultaneous planning of joint river conservation and restoration would be to (i) examine how well different kinds of rivers are covered by existing protected area networks and (ii) to restore parts of degraded rivers to facilitate colonization by aquatic and riparian organisms that have found havens in existing protected areas. This joint approach is a two-way road, as conservation and restoration benefit from each other by allowing river networks to facilitate movements of organisms and matter, thereby mimicking natural riverine meta-systems in anthropogeni-cally modified drainage basins, with restored sites acting as stepping-stones between protected areas.
3. We argue that existing policy instruments should consider the fact that river ecosystems are spatially and temporally dynamic meta-systems. These characteristics should be given due attention in conservation and restoration rather than relying on a static approach where a snapshot classification of river reaches is thought to be enough without considering underlying ecological dynamics. Taking ecological dynamics into account would contribute to sustainable management and maintenance of biodiversity and ecosystem services.
... For riverine connectivity we used asymmetric connectivity based on freshwater sub-catchment connections, as detailed in Linke et al. (2012). For marine connectivity, we included shared boundaries of marine planning units, as this is the standard method for including connectivity in marine conservation planning. ...
There is a growing recognition that conservation strategies should be designed accounting for cross-realm connections, such as freshwater connections to land and sea, to ensure effectiveness of marine spatial protection and minimize perverse outcomes of changing land-use. Yet, examples of integration across realms are relatively scarce, with most targeting priorities in a single realm, such as marine or freshwater, while minimizing threats originating in terrestrial ecosystems. To date, no study has optimized priorities across multiple realms to produce a spatially explicit integrated conservation plan that simultaneously accounts for multiple human activities at a national scale. This represents a major gap in the application of existing cross-realm planning theory. We present a national scale conservation framework for selecting protected areas using a case study of Papua New Guinea (PNG) that integrates multiple systems and ecological connectivity to account for cross-realm benefits and minimize threats of land-use and climate change. The relative importance of both the forests and inshore reef environments to PNG subsistence and commercial livelihoods emphasizes the importance of considering the connections between the land and sea. The plan was commissioned by the PNG Conservation and Environment Protection Authority and identifies a comprehensive set of priorities that meet conservation targets in both the land and sea. Our national-scale prioritization framework is useful for agencies and managers looking to implement actions given multiple objectives, including watershed management and biodiversity protection, and ensures actions are efficient and effective across the land and sea.
... Des exemples sont disponibles de la façon d'intégrer efficacement la connectivité dans toutes ses dimensions : longitudinale (Hermoso et al., 2011), latérale (Hermoso et al., 2012a), verticale (Nel et al., 2011) et temporelle (Hermoso et al., 2012b), dans des cadres de planification systématique de la conservation, qui aideront à concevoir des aires protégées écologiquement fonctionnelles du point de vue de l'eau douce. Des progrès ont également été réalisés dans l'intégration des menaces et des processus de dégradation dans la planification de la conservation, afin d'éviter les efforts de conservation dans des zones où l'existence de menaces ou leur propagation pourrait compromettre la persistance de la biodiversité (par exemple, Moilanen et al., 2011 ;Linke et al., 2012). ...
... Recent developments in systematic conservation planning for rivers include methods to incorporate longitudinal, lateral (river to floodplain), vertical (surface-groundwater) and temporal connectivity as well as accounting for threatening processes that may compromise biodiversity protection Linke et al., 2012), including climate change (Pittock et al., 2008). The hydrological connectivity between lentic and lotic environments also requires special attention in PA design and management, and forms a central pillar of the Integrated Lake Basin Management (ILBM) Platform Process (Arthington et al.,Chapter 8,this volume). ...
Key messages:
• Five high level ecological principles common to all freshwater ecosystems are presented. Although they have different ramifications for each ecosystem type these principles are fundamental to the design and management of all freshwater Protected Areas (PAs) and the conservation of aquatic
biodiversity.
• A universal guiding principle for PA management is that the entire catchment with its land, water, biogeochemical resources and processes is the ideal unit to be protected and managed. Where full protection is not possible, the catchment needs to be managed in a sustainable way that minimises threats
and impacts from non-reserved lands. Protected area management that fails to recognise and address the threats and pressures arising in the catchment risks loss of environmental quality, species diversity and ecological resilience.
• The flow of water is one of five dynamic environmental regimes that regulate much of the structure and functioning of every running water ecosystem and many aspects of lentic and groundwater systems. The naturally dynamic flow regime plays a critical role in sustaining native biodiversity and ecosystem integrity in streams and rivers. Likewise the characteristics
and variability of lentic (lakes and estuaries) and subsurface water regimes are critical to their dynamics, management and conservation.
• The spatial and temporal connectivity patterns and processes of aquatic ecosystems in their natural state are important elements for consideration in PA design and management. Connectivity in rivers is defined in three spatial dimensions: longitudinal (upstream–downstream), lateral (interactions between channel and riparian/floodplain systems), and vertical (connections between the surface and groundwater systems), with temporal dynamics influencing all spatial dimensions of connectivity. Thus minimising the impacts of dams and levee banks as barriers, and changes to water flows, is crucial for conservation. The hydrological connectivity between lakes, streams, estuaries and subsurface environments also requires special attention in PA design and management, and forms a central pillar of Integrated Lake Basin Management (ILBM).
• A primary goal of biodiversity conservation is to delineate PAs that conserve species-rich habitats and vital resources, important species radiations and the greatest number of threatened endemic species. Significant interbasin differences in biodiversity and levels of endemism mean a lack of ‘substitutability’ among freshwater habitat units, adding to the complexity of freshwater biodiversity conservation. The tools of systematic conservation planning lend themselves to identification of the most beneficial options for biodiversity protection.
•Freshwater species have long histories of exposure and adaptation to variable environmental conditions and extremes (e.g., drought and flood cycles), conferring resistance and resilience at the individual, community and ecosystems levels. Maintaining catchment integrity, natural flow and standing water regimes, the spatial and temporal dimensions of connectivity,
and native biodiversity hotspots will help to maintain the ecological resilience of aquatic systems in protected areas, and support societal adaptations to shifting environmental and climatic regimes.
... The methodology proposed in this work can be of interest and has enough flexibility to be applied to other regulated Alpine river systems, especially where restoration measures are constrained by relevant limitations in the available financial resources, and where complex, more detailed decision support systems (e.g., Klauer et al., 2015;Linke et al., 2012) are not applicable. The Sarca River case study presents similar pressures and data availability to other Alpine rivers (e.g., see Carolli et al., 2017). ...
We discuss the prioritization of river reaches to be selected for restoration measures under the constraints of financial resource limitation. We propose and apply a simple approach based on the quantification of major hydro-morphological alterations and the critical comparison with locally proposed restoration actions. The available hydro-morphological and ecological data for the approach do not go beyond the requirements posed by the implementation of the EU Water Framework and Floods Directives. We describe an example that refers to a heavily regulated Alpine river (Sarca River, NE Italy). The results indicate hydropower facilities as a key source of hydrological alteration, with sediment retention and grade control structures on lateral tributaries playing an additional relevant role in reducing sediment supply. The frequency and duration of sediment-transporting floods have dramatically decreased, and the bed sediment composition has been markedly altered and become highly compacted. Habitat improvement has been achieved after the implementation of minimum environmental flows. The comparison between the results of the hydro-morphological indicators and the locally proposed restoration actions highlights that reaches with lower degree of hydro-morphological alterations do not coincide with the areas chosen for the locally planned actions, which often miss considerations of the relevant spatial scales. In a context of limited available financial resources and data compared to other flagship river restoration projects in the European Alps, the present work suggests viable options for the choice of target restoration reaches.
... Hydrological connectivity can be regarded as a physical variable explaining the distribution of available habitats in the wetland network (Freeman et al. 2007;Linke et al. 2012). Understanding how macrobenthos communities respond to gradients of wetland network connectivity is important for the practical management of estuarine wetland ecosystems. ...
The abundant estuarine wetlands supported by the complex river network in the Pearl River Delta are under intense anthropogenic influence, which threatens the local ecosystem. This paper examines the benthic macroinvertebrate diversity and abundance within the Pearl River Estuary through a field study. Fieldwork, based on the integral index of connectivity (IIC) of the wetland network, was carried out in the Pearl River Estuary. The responses of macroinvertebrate metrics to the integral connectivity gradient in the wetland network were examined. Statistical analyses (CCA) revealed that the benthic abundance in high-hydrological-connectivity riverine habitats was clearly distinct from that in low-connectivity habitats. Statistical analysis demonstrated that the diversity and abundance of the macrobenthos populations were determined by the integral connectivity of the wetland network. A non-linear model was developed to depict the relationship between macroinvertebrate diversity and network connectivity. Thus, conservation efforts in estuarine wetlands should focus on the macroinvertebrate diversity response in wetland patches with specific connectivity characteristics in the wetland network of the Pearl River Delta.
... large-scale assessments of the environmental conditions of watersheds or river networks and has already been used to support systematic classification efforts at sub-basin and river reach scales 18,19 and to measure the 'free-flowing' status of all rivers globally 20 . Other key applications in ecological sciences include species distribution modelling and conservation planning [21][22][23][24] . We also imagine advances in macro-ecology, such as exploring life history traits or environmental drivers, as other global databases containing functional ecological parameters become available that can be combined with HydroATLAS. ...
The HydroATLAS database provides a standardized compendium of descriptive hydro-environmental information for all watersheds and rivers of the world at high spatial resolution. Version 1.0 of HydroATLAS offers data for 56 variables, partitioned into 281 individual attributes and organized in six categories: hydrology; physiography; climate; land cover & use; soils & geology; and anthropogenic influences. HydroATLAS derives the hydro-environmental characteristics by aggregating and reformatting original data from well-established global digital maps, and by accumulating them along the drainage network from headwaters to ocean outlets. The attributes are linked to hierarchically nested sub-basins at multiple scales, as well as to individual river reaches, both extracted from the global HydroSHEDS database at 15 arc-second (~500 m) resolution. The sub-basin and river reach information is offered in two companion datasets: BasinATLAS and RiverATLAS. The standardized format of HydroATLAS ensures easy applicability while the inherent topological information supports basic network functionality such as identifying up- and downstream connections. HydroATLAS is fully compatible with other products of the overarching HydroSHEDS project enabling versatile hydro-ecological assessments for a broad user community.
... Existen ejemplos de cómo incorporar de manera eficaz todas las dimensiones de la conectividad -longitudinal(Hermoso et al., 2011), lateral(Hermoso et al., 2012a), vertical(Nel et al., 2011) y temporal(Hermoso et al., 2012b)-dentro de marcos sistemáticos para la planeación de la conservación, lo cual ayuda a diseñar áreas protegidas que sean ecológicamente funcionales desde el punto de vista del agua dulce. También se han visto avances en la integración de las amenazas y los procesos de degradación en la planeación de la conservación, de tal manera que se evite la asignación de esfuerzos de conservación en áreas donde la existencia de amenazas o su propagación pueda comprometer la persistencia de la biodiversidad (por ejemplo,Moilanen et al., 2011;Linke et al., 2012).La planeación para lograr la persistencia de la biodiversidad al mantener la resiliencia ecológica requiere considerar los factores políticos y socioeconómicos que influyen en los sistemas acuáticos. Los aspectos sociales(Knight et al., 2011) y políticos(Faleiro y Loyola, 2013) de la conservación desempeñan un papel importante en el éxito o el fracaso de un plan. ...
... went beyond accounting only for longitudinal connectivity in conservation prioritization to include connections between subcatchments that were not hydrologically connected. Their prioritization accounted for connections between wetlands, giving explicit consideration to acces- sibility of wetlands by waterbirds and turtles(Hermoso, Kennard, & Linke, 2012).Although hydrological connections to wetlands and floodplains have been addressed in conservation guidelines since the 1980s, they have hardly been considered in systematic planning. Ausseil,Chadderton, Gerbeaux, Stephens, and Leathwick (2010)andLourival, Drechsler, Watts, Game, and Possingham (2011)applied systematic planning principles to determine priority areas for different types of wetlands; however, neither study provided adequate consideration of the spatial location of wetlands.Lourival et al. (2011)accounted for connections between wetlands a posteriori after priority catchments were identified, but a priori inclusion of connectivity between ecosystem units, such as wetlands or aquifers, results in more efficient conservation solutions(Linke, Turak, Asmyhr, & Hose, 2019). ...
... Yet such spatially explicit information on reef condition is lacking for much of the marine environment, which necessitates the use of surrogate information such as reef extent or bioregionalizations to make decisions about where to allocate resources (e.g., Fernandes et al., 2005;Green et al., 2014;Beger et al., 2015;Jumin et al., 2017). Some studies have used threats as a proxy for ecosystem condition (García Molinos et al., 2017;Linke et al., 2012;Tallis, Ferdaña, & Gray, 2008). While this may be feasible at smaller scales, large regional prioritizations most often rely on broadly classified morphological features derived from remotely sensed data, and representation is achieved by specifying proportions of each habitat or substrate type to capture their associated biodiversity (Young & Carr, 2015). ...
Aim
Mega‐diverse coral reef ecosystems are declining globally, necessitating conservation prioritizations to protect biodiversity and ecosystem services of sites with high functional integrity to promote persistence. In practice however, the design of marine‐protected area (MPA) systems often relies on broad classifications of habitat class and size, making the tacit assumption that all reefs are of comparable condition. We explored the impact of this assumption through a novel, pragmatic approach for incorporating variability in coral cover in a large‐scale regional spatial prioritization plan.
Location
The Coral Triangle.
Methods
We developed a spatially explicit predictive model of hard coral cover based on freely available macro‐ecological data to generate a complete regional map of coral cover as a proxy for reef condition. We then incorporate this information in spatial conservation prioritization software Marxan to design an MPA system that meets specific conservation objectives.
Results
We discover prioritizations using area‐based representation of reef habitat alone may overestimate the conservation benefit, defined as the amount of hard coral cover protected, by up to 64%. We find substantial differences in conservation priorities and an overall increase in habitat quality metrics when accounting for predicted coral cover.
Main conclusions
This study shows that including habitat condition in a large‐scale marine spatial prioritization is feasible within time and resource constraints, and calls for increased implementation, and evaluation, of such ecologically relevant planning approaches to enhance potential conservation effectiveness.
... Building from our approach taken in this paper, we recognize some important next steps that could be taken in future evaluation efforts that may be highly effective for freshwaters. First, incorporating connectivity measures represents one potential improvement (Linke et al., 2012;Thieme et al., 2016). Evaluating the degree to which anthropogenic barriers such as dams may fragment and/or affect access to protected freshwaters would provide key information for conservation (Hermoso, Filipe, Segurado, & Beja, 2018). ...
Aim
To assess the effectiveness of protected areas in two catchment scales (local and network) in conserving regionally common fluvial fishes using modelled species distributions.
Location
Conterminous United States.
Methods
A total of 150 species were selected that were geographically widespread, abundant, non‐habitat specialists and native within nine large ecoregions. Species distribution models were developed using boosted regression trees, and modelled distributions were assessed for protection status under two alternatives: lands strictly managed for biodiversity (Highly Restricted Use) and those allowing multiple uses (Multiple Use), with protection target levels (i.e., the amount of protected area required for protection) for local and network catchments being developed from ecoregion‐based urban and agricultural land use thresholds from fish responses.
Results
Overall, less than 2% of fluvial catchments in the conterminous USA are meeting both local and network catchment protection target levels under the Highly Restricted Use alternative, whereas 16% of catchments met protection levels for the Multiple Use alternative, with protection largely concentrated in the western USA. For common native species distributions within ecoregions, only one species had >10% of streams meeting combined local and network catchment protection target levels under the Highly Restricted Use alternative, whereas 50 distributions (~14% of species distribution models) met this level under the Multiple Use alternative.
Main conclusions
Even for fishes considered widespread and abundant, protection levels are lacking, particularly when considering only lands that are actively managed for biodiversity. Given the increasing intensification of anthropogenic activities and substantial uncertainty associated with climate change, considering the conservation status for all species, including those currently considered common, is warranted.
... Designing efficient and effective conservation area networks in freshwaters needs to account for the spatial hierarchies of fluvial ecosystems and the necessity to consider different sources of connectivity (28). This is important because disturbances such as pollution, flow alteration, and the spread of introduced species are easily propagated through hydrological networks and seriously affect the biodiversity apparently protected within the reserved area (29). ...
The river Nile flows across 11 African countries, supporting millions of human livelihoods, and holding globally important biodiversity and endemism yet remains underprotected. No basin-wide spatial conservation planning has been attempted to date, and the importance of coordinated conservation planning for the Nile’s biodiversity remains unknown. We address these gaps by creating a basin-wide conservation plan for the Nile’s freshwater fish. We identify priority areas for conservation action and compare cross-boundary collaboration scenarios for achieving biodiversity conservation targets, accounting for river connectivity. We found that collaborative conservation efforts are crucial for reducing conservation costs, saving 34% of costs compared to an uncoordinated, business-as-usual scenario. While most Nile basin countries benefit from coordinating conservation planning, costs and benefits are unequally distributed. We identify “hot spots” consistently selected as conservation priority areas across all collaboration scenarios, and provide a framework for improving return on conservation investment for large and complex river systems globally.
... Criticisms of early conservation planning tools were largely based on the lack of including ecological function. This has even been remediated in simple conservation algorithms (Moilanen et al. 2008;Hermoso et al. 2011;Linke et al. 2012) that can now include connectivity, as well as accounting for disturbance and condition. Later developments include different management actions in still reasonably simple parameterisation frameworks (Watts et al. 2009;Moilanen et al. 2011), although note that including connectivity in zoning algorithms is not trivial . ...
In this chapter we review techniques that managers may use to respond to climate change. First, modelling the impacts of climate change on freshwater ecosystems are discussed. While hydro-climatic projections can be used their imprecision requires the selection of robust adaptation options that provide benefits under a range of possible climate outcomes. Second, contested concepts for managing freshwater ecosystems and resources are summarised, and we conclude that they may be used to develop and implement cross- sectoral policies that sustain freshwater ecosystems. Third, options for climate change adaptation for freshwater ecosystems recommends application of six principles, emphasising: accommodation of change; application of ecological and socio-economic targets across multiple scales; maintaining connectivity, conservation of refugia, and representative habitats; initial implementation of no- and low- regret adaptation interventions; agreeing on thresholds for ecological change that trigger new management interventions; and scientific monitoring and evaluation. We conclude by considering how to manage the negative impacts and seize positive synergies in climate change responses: conservation advocates must engage with agriculture, energy, and water resources sectors if freshwater ecosystems are to be incorporated in their decisions.
... Longitudinal position in the drainage network was inferred for all the sample sites by measuring the distance to the river mouth at the Atlantic Ocean. This variable can be used as a simple proxy descriptor of topography (Pusey & Kennard 1996;Linke et al. 2012), and was measured using Geographic Information System (QGIS 2.8.1-Wien) software by inserting geographical coordinates of the sample sites along with Mampituba network vector data. In addition, local environmental data of each site were obtained at site-scale for descriptive purposes, including stretch length, width, depth, velocity and elevation (Table 1). ...
Although longitudinal position is recognized as a major predictor of fish assemblage structure in stream ecosystems, how mesohabitat type interacts with longitudinal position to drive different spatial and temporal patterns in fish assemblages is still unknown. We investigated adjacent pool and riffle mesohabitats in a paired sampling design along the longitudinal gradient of a coastal subtropical drainage in Brazil. We tested whether the structure of fish assemblages of contrasting mesohabitat types respond similarly to position along the longitudinal riverine axis. Mesohabitat type by itself was by far the most important predictor of fish assemblage composition in multivariate models. Nektonic characid species were predominant in pools while benthic loricariids were most abundant in riffles. However, the interaction between longitudinal position and mesohabitat explained an additional significant proportion of the variation in fish assemblage composition. Changes in species composition with longitudinal position differed between riffles and pools. Models for predicting descriptors of assemblage structure revealed that fish abundance and spatial beta diversity responded strongly to the interaction between mesohabitat type and longitudinal position. Specifically, downstream fish abundance increased more for pools than for riffles. Spatial beta diversity showed opposite trends between pools and riffles along the longitudinal gradient, indicating that the combination and strength of niche and dispersal processes are different between these mesohabitat types. In summary, pool and riffle mesohabitats maintain fish assemblages that are taxonomically and functionally different and that respond differently to longitudinal position. Considering pool and riffle assemblages separately in modeling fish assemblage patterns can contribute greatly to our understanding of human modifications and other mechanisms driving spatial and temporal variation of fish assemblages within stream networks. © 2018 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany.
... In addition, the area of each subcatchment was used as a surrogate for cost (Ban & Klein, 2009) to minimize the total area to be managed for the differ- ent purposes, thereby indirectly minimizing the potential management and opportunity costs. Alternative surrogates for cost commonly used include estimates of human disturbance or river integrity ( Linke et al., 2012). In these cases, it is assumed that highly degraded areas would be less suitable for conservation purposes and should be avoided. ...
• Integrating ecosystem services (ESs) in landscape planning can help to identify conservation opportunities by finding co‐benefits between biodiversity conservation and the maintenance of regulating and cultural ecosystem services. The adequate integration of ESs needs careful consideration of potential trade‐offs, however, especially between provisioning services and biodiversity conservation (e.g. the potentially negative consequences of agricultural water extraction within areas important for the maintenance of biodiversity). These trade‐offs have been overlooked in systematic spatial planning to date, especially in freshwater systems.
• marxan with zones was used to identify priority areas for the conservation of freshwater biodiversity (139 species of freshwater fish, turtles, and waterbirds) and the provision of freshwater ESs in the Daly River, northern Australia. Four different surrogates for ESs were mapped, including those potentially incompatible with conservation goals (i.e. groundwater provision for agriculture and recreational fisheries) and those that are more compatible with conservation (i.e. flood regulation by riparian forests; provision of perennial water). The spatial allocation of multiple management zones was prioritized: (i) three conservation zones, aiming to represent freshwater biodiversity and compatible ESs to enhance co‐benefits; and (ii) two production zones, where access to provisioning ESs could be granted. The representation of ESs obtained when using the multi‐zoning approach was compared with that achieved with a single management zone approach. The comparison was performed across different representation targets.
• Different results were found with low and high targets for ESs. With low targets (<25% of all ESs), the multi‐zoning approach achieved up to 53% more co‐benefits than the single‐zone approach. With high targets (>25% of all ESs), the trade‐offs avoided were more evident, with up to 56% less representation of incompatible ESs within conservation zones.
• Multi‐zone planning could help decision makers respond better to the increasingly complex catchment management context, caused by an increasing demand for provisioning services and a diminishing availability of resources, as well as manage and plan for challenges in other realms facing similar problems.
... using graph theory and optimization techniques (Erős et al., 2011;Neeson et al., 2015;King et al., 2017). A separate strand of research has focused on applying reserve selection methods (Moilanen et al., 2008;Newbold & Siikamäki, 2009;Linke et al., 2012, Hermoso et al., 2017 to the design of freshwater conservation networks. Within this latter group, connectivity, when it has been considered, is incorporated in a fairly simplistic manner by trying to ensure that selected areas (usually subcatchments) are spatially adjacent. ...
Spatial prioritization tools provide a means of finding efficient trade‐offs between biodiversity protection and the delivery of ecosystem services. Although a large number of prioritization approaches have been proposed in the literature, most are specifically designed for terrestrial systems. When applied to river ecosystems, they often fail to adequately account for the essential role that landscape connectivity plays in maintaining both biodiversity and ecosystem services. This is particularly true of longitudinal connectivity, which in many river catchments is highly altered by the presence of dams, stream‐road crossings, and other artificial structures.
We propose a novel framework for coordinating river conservation and connectivity restoration. As part of this, we formulate an optimization model for deciding which subcatchments to designate for ecosystem services and which to include in a river protected area (RPA) network, while also deciding which existing river barriers to remove in order to maximize longitudinal connectivity within the RPA network. In addition to constraints on the size and makeup of the RPA network, the model also considers the suitability of sites for conservation, based on a biological integrity index, and connectivity to multiple habitat types. We demonstrate the usefulness of our approach using a case study involving four managed river catchments located in Hungary.
Results show that large increases in connectivity‐weighted habitat can be achieved through targeted selection of barrier removals and that the benefits of barrier removal are strongly depend on RPA network size. We find that (i) highly suboptimal solutions are produced if habitat conservation planning and connectivity restoration are done separately and (ii) RPA acquisition provides substantially greater marginal benefits than barrier removal given limited resources.
Synthesis and applications . Finding a balance between conservation and ecosystem services provision should give more consideration to connectivity restoration planning, especially in multi‐use riverscapes. We present the first modelling framework to directly integrate and optimize river conservation and connectivity restoration planning. This framework can help conservation managers to account better for connectivity, resulting in more effective catchment scale maintenance of biological integrity and ecosystem services delivery.
... One of the main challenges for freshwater systematic conservation planning (FWSCP) is how to deal with the hierarchical structure and connectedness (both longitudinal and lateral) of the aquatic network , which have motivated freshwater ecologists and conservationists to adapt methodologies and find new analytical tools and models. Moreover, spatial prioritization algorithms were adapted to take into account the connectivity (Moilanen et al., 2008;Hermoso et al., 2011Hermoso et al., , 2012, and the anthropogenic pressure (in the form of catchment disturbance) to be more realistically represented and efficiently evaluated (Esselman and Allan, 2011;Linke et al., 2012). ...
Large protected areas have been created in Brazilian Amazon intending to safeguard as much of its biodiversity as possible. Despite these intentions, such megareserves were created predominantly focusing on terrestrial organisms and ecosystems. Here, we assessed the ability of the current Brazilian Amazon protected areas network to efficiently safeguard its stream- welling fish fauna. Ecological niche models were built for 138 stream fish species using MaxEnt software. We performed a gap analysis and spatial prioritization under three different Amazon protected areas scenarios: (1) strictly protected areas (SPAs) only; (2) SPA plus sustainable use areas (SPA +SUA); and (3) SPA +SUA plus indigenous territories (SPA+ SUA +IT). The species were classified according to their distribution range size and required representation targets. widespread species usually had lower area under the curve (AUC) and true skill statistics (TSS) values, which would be expected for large and heterogeneous areas such as the Amazon. Only partial gap species were found, with 20% to 90% of required representation targets included in PAs, which was not enough for a complete protection. Most of the officially protected areas in the Brazilian Amazon do not correspond to areas with high direct conservation values for stream fishes, once the priority areas for these species conservation were outside the PAs, leaving a high portion of the regional vertebrate fauna inadequately protected. We conclude that fishes and other freshwater organisms and habitats should be explicitly included during systematic conservation planning in order to thoroughly protect the Brazilian Amazon biodiversity.
... Cost shown in equation (1) represents the cost of preserving each planning unit. This is not necessarily the monetary value of a land parcel or stream section, but can also be any relative social (Adams, Mills, Jupiter, & Pressey, 2011), economic (Christensen, Ferdaña, & Steenbeek, 2009) or ecological (Linke et al., 2012) measure of cost, or a combination thereof (Game & Grantham, 2008). Given our interest in exploring the effect of incorporating trophic structure, we used a constant baseline cost across the study area (all the planning units were assigned a cost of 1) similar to Hermoso, Kennard, and Linke (2012). ...
Systematic conservation planning has become a standard approach globally, but prioritization of conservation efforts hardly considers species traits in decision making. This can be important for species persistence and thus adequacy of the conservation plan. Here, we developed and validated a novel approach of incorporating trophic information into a systematic conservation planning framework. We demonstrate the benefits of this approach using fish data from Europe's second largest river, the Danube. Our results show that adding trophic information leads to a different spatial configuration of priority areas at no additional cost. This can enhance identification of priority refugia for species in the lower position of the trophic web while simultaneously identifying areas that represent a more diverse species pool. Our methodological approach to incorporating species traits into systematic conservation planning is generally applicable, irrespective of realm, geographical area, and species composition and can potentially lead to more adequate conservation plans.
... In a broad sense, freshwater ecosystems encompass all riverine and nonriverine inland water bodies including rivers, lakes, wetlands, underground water and estuaries ( Nel et al., 2009), in which the riverine and nonriverine freshwaters are hydrologically connected with each other. The persistence of freshwater ecosystems and associated biodiversity thus depends on the connectivity to maintain ecological processes throughout this complex connected system ( Linke et al., 2012). However, the prevailing freshwater conservation planning has largely focused on riverine systems ( Ward et al., 2002;Higgins et al., 2005;Nel et al., 2007;Sowa et al., 2007;Linke et al., 2007;Moilanen et al., 2008;Fullerton et al., 2010;Turak et al., 2011), nonriverine freshwater habitats such as floodplain wetlands and lakes have either received limited consideration ( Thieme et al., 2007;Ausseil et al., 2011), or have only been treated as peripheral terrestrial features regardless of their connectedness with riverine freshwater systems (with a few exceptions, see Michel et al., 2009). ...
Freshwater ecosystems encompass all inland water bodies, in which riverine and nonriverine freshwaters are linked through hydrological connectivity within a catchment. However, riverine and nonriverine freshwaters have often been assessed separately and their interdependence and connection has not been considered appropriately in prevailing freshwater conservation planning. To address the representation and persistence of freshwater ecosystems in conservation assessment, we integrated riverine and nonriverine freshwater wetlands as broad-scale conservation surrogates and incorporated longitudinal, lateral and vertical connectivity rules in a conservation planning for the freshwater wetlands in the North China Plain (NCP). We also considered interbasin connectivity by incorporating conservation features of key transferring nodes of the South-to-North Water Diversion Project (SNWD) in the NCP to safeguard their unique ecosystem services of regulating interbasin freshwater. Three scenarios (i.e., 2D, 3D and interbasin scenario) were developed by incorporating different multiple conservation targets, and their spatial priorities and cost-efficiency in freshwater conservation were compared. We applied systematic conservation framework and modified Marxan to accommodate these multidirectional and interbasin connectivity targets in our freshwater conservation assessment. The results indicated that the existing conservation system covered approximately 20% of the freshwater wetlands in the NCP, and there were still considerable conservation gaps that need to be filled. The optimal scenarios could substantially improve the representation, complementarity and persistence for the conservation of freshwater ecosystems, but would not significantly increased overall costs. The framework developed by our research has the potential to facilitate further application of systematic methods in freshwater conservation and rehabilitation planning at multiple scales.
... Compared to other models that integrate habitat dynamics of riparian trees (Van Looy et al., 2005;Stella et al., 2010;Harper et al., 2011;Scott et al., 2013), we add a spatial component of population dynamics in the river network with the metapopulation model. This integrated spatial population dynamics modelling is moreover proposed for identifying crucial network connections (Artzy-Randrup and Stone, 2010), network structure influence to extinction risks (Ashcroft et al., 2012;Linke et al., 2012;Webb and Padgham, 2013) and metapopulation persistence in relation to habitat quality and connectivity (Gilroy et al., 2014). Over the Loire basin we clearly identify zones and subcatchments with limited persistence and resilience for these species. ...
Floodplain landscapes are highly fragmented by river regulation resulting in habitat degradation and flood regime perturbation, posing risks to population persistence. Climate change is expected to pose supplementary risks in this context of fragmented landscapes, and especially for river systems adaptation management programs are developed. The association of habitat quality and quantity with the landscape dynamics and resilience to human-induced disturbances is still poorly understood in the context of species survival and colonization processes, but essential to prioritize conservation and restoration actions. We present a modelling approach that elucidates network connectivity and landscape dynamics in spatial and temporal context to identify vital corridors and conservation priorities in the Loire river and its tributaries. Alteration of flooding and flow regimes is believed to be critical to population dynamics in river ecosystems. Still, little is known of critical levels of alteration both spatially and temporally. We applied metapopulation modelling approaches for a dispersal-limited tree species, white elm; and a recruitment-limited tree species, black poplar. In different model steps the connectivity and natural dynamics of the river landscape are confronted with physical alterations (dams/dykes) to species survival and then future scenarios for climatic changes and potential adaptation measures are entered in the model and translated in population persistence over the river basin. For the two tree species we highlighted crucial network zones in relation to habitat quality and connectivity. Where the human impact model already shows currently restricted metapopulation development, climate change is projected to aggravate this persistence perspective substantially. For both species a significant drawback to the basin population is observed, with 1/3 for elm and ¼ for poplar after 25 years already. But proposed adaptation measures prove effective to even bring metapopulation strength and persistence up to a level above the current level.
... Recent developments in systematic conservation planning for rivers include methods to incorporate longitudinal, lateral (river to floodplain), vertical (surface-groundwater) and temporal connectivity as well as accounting for threatening processes that may compromise biodiversity protection (Linke et al., 2012) including climate change (Pittock et al., 2008). Planning and legislation for conservation reserves also has to consider the socio-economic landscape and identify opportunities for maximum protection of biodiversity within the constraints of catchment land-use, river infrastructure, human activities and climate change. ...
Despite the disparities in size and volume of marine and freshwater realms, a strikingly similar number of species is found in each – with 15 150 Actinopterygian fishes in fresh water and 14 740 in the marine realm. Their ecological and societal values are widely recognized yet many marine and freshwater fishes increasingly risk local, regional or global extinction.
The prevailing threats in aquatic systems are habitat loss and degradation, invasive species, pollution, over‐exploitation and climate change. Unpredictable synergies with climate change greatly complicate the impacts of other stressors that threaten many marine and freshwater fishes.
Isolated and fragmented habitats typically present the most challenging environments for small, specialized freshwater and marine fishes, whereas overfishing is by far the greatest threat to larger marine and freshwater species. Species that migrate within or between freshwater and marine realms may face high catchability in predictable migration bottlenecks, and degradation of breeding habitat, feeding habitat or the intervening migration corridors.
Conservation reserves are vital to protect species‐rich habitats, important radiations, and threatened endemic species. Integration of processes that connect terrestrial, freshwater and marine protected areas promises more effective conservation outcomes than disconnected reserves. Diadromous species in particular require more attention in aquatic restoration and conservation planning across disparate government agencies.
Human activities and stressors that increasingly threaten freshwater and marine fishes must be curbed to avoid a wave of extinctions. Freshwater recovery programmes range from plans for individual species to recovery of entire basin faunas. Reducing risks to threatened marine species in coastal habitats also requires conservation actions at multiple scales. Most of the world's larger economically important fisheries are relatively well‐monitored and well‐managed but there are urgent needs to curb fishing mortality and minimize catch of the most endangered species in both realms.
Copyright © 2016 John Wiley & Sons, Ltd.
... Recent developments in systematic conservation planning for rivers include methods to incorporate longitudinal, lateral (river to floodplain), vertical (surface-groundwater) and temporal connectivity as well as accounting for threatening processes that may compromise biodiversity protection (Linke et al., 2012) including climate change (Pittock et al., 2008). Planning and legislation for conservation reserves also has to consider the socio-economic landscape and identify opportunities for maximum protection of biodiversity within the constraints of catchment land-use, river infrastructure, human activities and climate change. ...
... By accounting for connectivity in the identification of priority areas we also minimised the potential negative effects of propagation of threats along the river network into priority areas, which could compromise the persistence of biodiversity. Our approach avoided the allocation of priority areas for conservation downstream from highly degraded areas as demonstrated by Linke et al. (2012). Both processes are key to maintenance of freshwater ecosystems and persistence of biodiversity. ...
1. Accounting for genetic diversity and evolutionary processes has long been recognised as an important goal in conservation planning. However, because genetic data are often lacking, surrogate approaches are widely used. Few studies have, however, assessed the capacity of surrogate data, such as higher taxonomic levels (e.g., species distributions) to portray intraspecific genetic diversity.
2. Here, we contrast conservation plans based on traditional species distribution data, with those derived from intraspecific genetic data for a smaller subset of species; both using freshwater fish in northern Australia. We modelled the spatial distribution of 46 species and intraspecific genetic diversity within four common species. We then identified priority areas for conservation using both datasets and evaluated the extent to which solutions obtained from species distribution data portrayed genetic diversity.
3. We found that genetic diversity could be adequately represented within priority areas identified using species distribution data, even at low conservation targets and for species with complex genetic structure. However, this was only true when using the entire fish community (i.e. all 46 species). In contrast, a substantial component of the genetic structure would not be represented in conservation priority areas when using a subset of species.
4. Our results have important implications for the use of surrogates for genetic diversity in conservation planning. Sufficient genetic diversity might be represented in conservation priority areas by including a broad range of species with distributions ranging from common to rare elements in the community in the prioritisation analyses. We recommend focusing on improving accuracy of data on species distributions to reduce uncertainties in conservation recommendations derived from commission and omission errors, to avoid misuse of limited conservation funds and potential failure of conservation practice.
... First, freshwater systems have been described as hierarchically nested (Frissell et al., 1986) such that no single level of the hierarchy can represent all elements. Second, the highly connected nature of freshwater systems (which may include fluvial, lacustrine, palustrine and estuary areas) makes them particularly vulnerable to fragmentation (Fagan, 2002), and upstream/downstream influences (Fausch et al., 2002) (see sections re clauses 3 and 6), such that the ability of the species and ecosystems to persist needs to be accounted for in conjunction with ensuring adequate representation across the catchment (Dudgeon et al., 2006;Nel et al., 2009Nel et al., , 2011Linke et al., 2012). Third, freshwater ecosystems are highly dynamic and evolving systems (Stiassny et al., 2010); for example, rivers change course and features, pools are filled with sediment to become marshes. ...
The Strategic Plan for Biodiversity (2011–2020), adopted at the 10th meeting of the Conference of the Parties to the Convention on Biological Diversity, sets 20 Aichi Biodiversity Targets to be met by 2020 to address biodiversity loss and ensure its sustainable and equitable use. Aichi Biodiversity Target 11 describes what an improved conservation network would look like for marine, terrestrial and inland water areas, including freshwater ecosystems.
To date, there is no comprehensive assessment of what needs to be achieved to meet Target 11 for freshwater biodiversity. Reports on implementation often fail to consider explicitly freshwater ecosystem processes and habitats, the pressures upon them, and therefore the full range of requirements and actions needed to sustain them.
Here the current progress and key gaps for meeting Aichi Target 11 are assessed by exploring the implications of each of its clauses for freshwater biodiversity.
Concerted action on Aichi Biodiversity Target 11 for freshwater biodiversity by 2020 is required in a number of areas: a robust baseline is needed for each of the clauses described here at national and global scales; designation of new protected areas or expansion of existing protected areas to cover known areas of importance for biodiversity and ecosystem services, and a representative sample of biodiversity; use of Other Effective Area‐Based Conservation Measures (OECMs) in places where designating a protected area is not appropriate; and promoting and implementing better management strategies for fresh water in protected areas that consider its inherent connectivity, contextual vulnerability, and required human and technical capacity.
Considering the specific requirements of freshwater systems through Aichi Biodiversity Target 11 has long‐term value to the Sustainable Development Goals discussions and global conservation policy agenda into the coming decades.
Copyright © 2016 John Wiley & Sons, Ltd.
... Robust conservation planning should follow a systematic approach that considers four criteria (Possingham et al. 2006): (1) comprehensiveness (inclusion of the full range of species, processes and ecosystems); (2) representativeness (complete representation of the conservation target within the area); (3) adequacy (adequate representation in order to maintain long-term viability); and (4) efficiency (minimising costs while maximising conservation value). Systematic conservation planning approaches are increasingly applied to freshwater ecosystems ( Khoury et al. 2011;Linke et al. 2011;Turak and Linke 2011;), incorporating longitudinal connectivity ( Hermoso et al. 2012), condition ( Linke et al. 2012) and spatiotemporal complexities of water availability ). ...
Australia has diverse wetlands with multiple threats. We reviewed knowledge about the extent of wetlands, representativeness, impacts and threats to integrity and options for effective conservation. Natural Australian wetlands cover an estimated 33 266 245 ha (4.4%), with 55% palustrine (floodplains and swamps), followed by 31% lakes, 10% estuarine systems, and 5% rivers and creeks. The Lake Eyre (1.1%), Murray–Darling (0.73%), Tanami–Timor Sea Coast (0.71%) and the Carpentaria Coast (0.55%) drainage divisions have more wetlands, also reflected in the distributions among states and territories. Ramsar sites and wetlands in protected areas were generally biased towards the southern continent. Overall representation of mapped wetlands was good for lacustrine (40.6%) and estuarine (34.4%), fair for riverine (16.8%), but inadequate for palustrine (10.8%) wetlands. Within drainage divisions, representation varied considerably, with shortfalls from the Aichi target of 17%. Agriculture, urbanisation, poll
... However, coarse spatial data on landscape stressors or other proxies can be substituted for fi eld data on actual stream habitat condition when necessary (e.g. Hermoso et al. , 2011 ;Linke et al. , 2012 ). Explicit consideration of economic costs and political constraints will, in most cases, yield more cost-effective recommendations than prioritisatio n analyses that do not account for these real-world issues (e.g. ...
Migratory fi shes are natural wonders. For many people, the term migratory fi sh evokes images of salmon audaciously jumping at waterfalls as they return to their own riverine birthplace to spawn after years of growth in the ocean, but freshwater fi shes actually show a broad spectrum of migration strategies. Migratory fi shes include small species – three-spined sticklebacks that spawn in coastal streams around the northern Pacifi c and gobies that move from the ocean into tropical island streams by climbing waterfalls (McDowall, 1988) – as well as some of the largest freshwater fi shes in the world, such as the Mekong dog-eating catfi sh and the Chinese paddlefi sh (Stone, 2007). Aside from migratory habits, these species have few shared characteristics; they encompass numerous evolutionary lineages, enormous differences in life history , and every possible direction and distance of migration. Biologists treat migratory freshwater fi shes as a functional group because their life-history strategy revolves around long-distance movement between ecosystems in a perilous quest to take advantage of both high-quality breeding sites and bountiful feeding areas. As humans have physically blocked fi sh migrations, degraded breeding and feeding grounds and relentlessly harvested migrants for their fl esh and roe, many populations have declined or been extirpated. This chapter will provide an overview of fundamental and applied research that is helping to guide efforts to conserve migratory freshwater fi shes. For practical purposes, we defi ne migratory behaviour as the synchronized movement of a substantial proportion of a population between Conservation of Freshwater Fishes , eds P. Closs, M. Krkosek and J. D. Olden. Published by Cambridge University Press.
... There are examples of how to effectively incorporate connectivity in all its dimensions-longitudinal (Hermoso et al. 2011), lateral (Hermoso et al. 2012a), vertical (Nel et al. 2011) and temporal (Hermoso et al. 2012b)-into systematic conservation planning frameworks, which help design protected areas that are ecologically functional from a freshwater point of view. There also have been advances in integrating threats and degradation processes into conservation planning, to avoid the allocation of conservation efforts in areas where the existence of threats or their propagation could compromise the persistence of biodiversity (for example, Moilanen et al. 2011;Linke et al. 2012). ...
The constant pressure of anthropogenic activities has generated that the cloud forest fragments (BN) have an island pattern surrounded by a matrix of socioeconomic activities. The conservation of this ecosystem is key due to its high biological diversity that it represents in relation to its territorial extension in Mexico and globally. The objective of this work is to analyze the changes in the vegetation cover and the structural connectivity of the BN in the 1995-2018 period in the Transversal Volcanic System of the state of Michoacán from the visual interpretation of Orthophotos and Spot satellite images. Landscape metrics were applied to later carry out their comparative analysis. The results obtained show that the BN coverage lost an area of 9,038 ha in 23 years, with a global deforestation rate between 1995- 2018 of -1.4%. Regarding the structural connectivity, the BN was observed an increase in the number of patches, increasing from 628 in 1995 to 762 in 2018, as well as the density of patches going from 2.1 to 3.6 ha for the same period. This reflects that the BN has fragmented considerably, in addition to rapidly losing its original surface. It is essential to generate data and information that contribute to the construction of strategies that increase the connectivity of the landscape in the BN fragments, guaranteeing the survival of wild species, through actions aimed at conserving biodiversity in the long term and reducing the fragmentation and isolation of ecosystems.
This concluding chapter contains a comparative overview of the state of fish resources, fisheries, and management models in the inland waters of the Western Balkans. The aim was to find a possible sustainable solution for freshwater fisheries under increasingly diverse anthropogenic stressors on the environment and ecosystems, as well as ongoing climate changes. Likely, a single model approach is not possible because of the heterogeneity of ecological and social conditions, even in such a relatively small area. However, the ecosystem approach could be a common basis for the integral management of water and water resources. This approach must be strictly scientifically and socially acceptable to balance sustainable use and conservation under different conditions.
This chapter contains a brief overview of the development of models for assessing the sustainability and conservation priorities for fish, fish resources, and inland water habitats in Serbia and the region. The basic version of the ES–HIPPO model consists of two elements. The first, Ecological Specialization (ES), reflects the level of taxon specialization in relation to habitat, diet, reproduction strategy, life cycle, body size, degree of endemism, and degree of isolation. The second factor, “HIPPO,” refers to the impact of factors such as H-habitat alterations, I-invasive species, P-pollution, P-human population growth, and O-overexploitation on populations in the spatial and temporal dimensions. From the general model, advanced models were developed: ES–HIPPOfish intended for assessing the viability of fish species that are important for fishing, ES–HIPPOcrayfish to assess the sustainability of decapod crustacean populations, and the latest version of ESE–HIPPOriverbasin to assess the degree of habitat conservation for a sustainable fish community in a river basin.
• Groundwater has very rarely been included in modern systematic conservation planning methods that identify key areas for protection of aquatic organisms.
• Three conservation plans were developed for aquatic ecosystems in the Hunter Valley, NSW, Australia using the planning software Marxan: one model for rivers and wetlands and two that consider groundwater ecosystems. The first of these groundwater inclusive models included aquifers in the initial planning process; the second retrofitted groundwater onto an existing conservation plan.
• The results demonstrate that, if groundwater protection was included at the planning stage, the overall land that was needed only increased marginally. When included, groundwater protection led to an emphasis on groundwater recharge zones. A posteriori inclusion of GW protections, however, yielded a 30% increase in surface area needing protection.
• We conclude that groundwater can be included in conservation planning but it is much more efficient to do so at the beginning of the planning process.
• The next step is to refine the planning methods by including data on groundwater‐dependent organisms, either by genetic means or novel statistical techniques, and hence using a direct biotic signal instead of environmental surrogates.
Marxan is reserve selection software that was developed to identify efficient, near-optimal spatial solutions to conservation planning. Here we describe its basic mechanisms and introduce previous studies to outline the program's use and potential applications. Marxan seeks sets of planning units to achieve a given conservation goal at minimum cost based on the principle of complementarity. It uses a wide array of conservation targets, including genetic diversity and habitat types as surrogates, in addition to species. We introduce previous studies focused on reserve selection under future climate or land-use change and on evaluating priority areas by considering trade-offs between biodiversity conservation and ecosystem services. We also review research on priority areas for the reintroduction, restoration, and management of invasive species. Marxan depends on user-specified ecological and socioeconomic parameters and, therefore, may be subject to bias. Nevertheless, Marxan can suggest spatially explicit solutions based on conservation targets and given costs, facilitating the effective investment of monetary or human resources and aiding consensus among stakeholders and decision makers.
• The Alaskan Matanuska‐Susitna Basin (MSB) provides habitat for all five Pacific salmon species, and their large seasonal spawning runs are important both ecologically and economically. However, the encroachment of human development through urbanization and extractive industries poses a serious risk to salmon habitat in the MSB.
• Using systematic conservation planning techniques, different methods of incorporating anthropogenic risks were assessed to determine how to conserve salmon habitat in the area cost‐effectively.
• The consequences of four distinct conservation scenarios were quantified: no consideration either of urbanization or extractive industries (‘Risk ignored’ scenario); accounting for the risk of urbanization, and avoiding conservation in all areas rich in fossil fuels (‘Urbanization accounted, all extraction avoided’ scenario); accounting for urbanization and oil and gas development, but avoiding conservation in coal‐rich areas (‘Urbanization accounted, coal areas avoided’ scenario); and accounting for all anthropogenic risks to habitat, and allowing conservation in oil, gas, or coal‐rich areas (‘All risks accounted’ scenario). To compare conservation success and resilience, the impacts of these risks were estimated using Monte Carlo simulations. The final cost of each solution was then divided by the number of conservation targets met to determine a return on investment.
• Results from scenarios that avoided all extractive activities, or only coal, suggest that conservation targets cannot be met simply by avoiding areas rich in fossil fuels, and these scenarios resulted in lower returns on investment than those in which risks from extraction were incorporated into the solution.
• By developing a method for setting priorities that are economically based, this study provides a method for local managers and conservation groups to identify conservation opportunities in MSB river basins.
Riverine biological communities are highly resilient to extreme flood and/or drying disturbance regimes that would otherwise be destructive because these organisms can recolonise from upstream, floodplain or hyporheic refugia when suitable conditions return. Healthy rivers require a high degree of connectivity to support complex life cycles of many lotic organisms and associated ecosystem functioning. Similarly, connectivity is required for appropriate geophysical functioning; permitting flux of water and sediment that drives channel-forming and ecological processes. Ecological and geophysical processes have operated in this temporal and spatial patchwork of disturbance and recovery pre-Anthropocene. Human impacts are increasing constraints on river and floodplain connectivity, severing many natural pathways, and degrading river ecosystem functioning. River restoration seeks to re-establish some of those biological and physical connections to enhance some level of system health. However, increasing sediment connectivity may be detrimental to river health in some instances. Strongly connected catchments can transmit excessive quantities of sediment from inappropriate land management, detrimental invasive species can spread more widely, and many ecosystem processes can exceed positive feedback control. Simply restoring connectivity will not necessarily lead to healthy river ecosystems. River management requires a greater understanding of how and when connectivity can and should be restored. While current thinking is often that greater connectivity is better, we illustrate with examples from New Zealand rivers that this is not always the case. The benefits and costs of maintaining or restoring river connectivity need to be given as much attention as the restoration and maintenance of river systems per se.
Executive Summary
There is much interest in ‘developing’ Northern Australia with a parallel commitment to “caring
for the unique Australian landscape” (Department of Prime Minister and Cabinet 2014).
However, trying to decide how to ‘develop’ and ‘protect’ simultaneously is a non-trivial task.
There are many modelling tools: integrated models, frameworks, and decision support tools
that can generate information to inform such decisions, but they are so numerous that it is
difficult to determine which are best suited to inform different decisions. The aim of this project
was thus to create a resource to help (potential) ‘end users’ (practitioners) to assess:
- the availability and suitability of particular tools; and/or
- the feasibility of using, developing, and maintaining different types of tools
to support planning and development decisions across Northern Australia.
We first conducted a very broad-scale review of literature on the numerous different models,
modelling approaches, to ‘scope’ our work, determining which types of tools should be included
in the review and clarifying what we mean by the phrase integrated decision support tool (IDST)
(Section 2.1). For the purposes of this project, we decided an IDST must satisfy all of the
following criteria:
1) It must integrate data from both the ‘natural’ and the ‘human’ realms.
2) It must do more than simply ‘describe’ ‘visualise’, collate or disseminate information; it
must generate its own sets of ‘predictions’ and/or ‘decisions’.
3) There must be applied examples of these models, populated with regionally relevant
data (i.e. the IDST must be more than a conceptual diagram or a ‘method’ such as a
particular type of statistical analysis).
Using insights from the literature to assess the availability and suitability of various tools, we
identified three broad categories of IDSTs, namely: those originating from within the
biophysical sciences; the social and economic sciences; and the mathematical/computing
sciences (Section 2.2). In our further analysis of those categories of IDSTs (Section 2.3), we
recognized three sub-categories within each borad category. They could be differentiated
according to a range of factors such as the focus of model (e.g. on aquatic species,
hydrological systems, economics, or interactions between systems), the spatial and temporal
scale of data used within the models, and the techniques used to analyse data within the
models (Table 2). We discussed each of those sub-categories in more detail, critically
evaluated and assessed their strengths and limitations, and summarised the “Technical
Specifications” of each of the nine different sub-categories of IDSTs (Appendix 1Appendix
1Appendix 1).
The feasibility of using, developing, and maintaining different types of tools was assessed next.
For each of nine sub-categories of IDSTs we identified case study examples of their application
in Northern Australia (Appendix 2). Where we were unable to find examples of Northern
Australian applications, we sought examples that had been applied elsewhere in the world but
in contexts similar to that of Northern Australia (i.e. with relatively intact ecosystems, significant
Indigenous populations and ‘development’ largely focused around industries that are reliant
upon natural resources).
To further assess the feasibility of using, developing, and maintaining IDSTs we developed
questionnaires and interviewed relevant northern ‘stakeholders’ (creaters of, and potential
users of, IDSTs) (Section 3). Using a snow-ball sampling technique, we obtained interviews
from 40 current and potential IDST ‘users’ (30 of whom had used an IDST) and from 17 model
‘builders’. Amongst other things, these interviews highlighted that decision-makers use a
variety of different methods to collate information, with IDSTs being rated as generally more
‘useful’ than public meetings and internet surveys, but often less useful than private
consultations, negotiation and consensus seeking approaches. Tools that displayed outputs
visually were often considered to be the most useful and the most able to influence policy. Our
model ‘builder’ interviews highlighted, most importantly, the vast time (several years) and
resources (several millions of dollars) required to build the larger (coupled) systems models. It
was also noted that a number of “off the shelf” models, that could be tailored for specific region,
landscape or industry with much less resources and within less time, exist.
Overall, our project highlighted that a useful way in which to think about ‘which type of model’
is best fit for purpose is to consider first one’s primary objective (often determined by job/role),
using that objective to provide a first-round ‘filter’. For example, many of the early IDSTs
developed by biophysical scientists, had as their primary goal, that of protecting key species
at minimum ‘cost’, so end users who have a primary goal or a legislative requirement to protect
aspects of the natural realm (e.g. conservation of a species), may find that the models which
have been developed by biophysical scientists are likely to be most useful. That said, our more
detailed discussion of IDSTs (Sections 2.3.2.1 to 2.3.4.3), highlights that each sub-category of
IDST is most suited to different decision-making contexts. Importantly, some of the IDSTs
which have been developed within a particular disciplinary group are also able to generate
information that is useful to those whose primary objective is somewhat different to that
normally addressed by researshers within that group. For example, systems models,
hydrological models and bioeconomic models often involve deep integration, and thus help
foster understanding about the way in which different parts of the human system interact with
the natural system; it is not only the systems models which can do this. Similarly, although
hydrological models focus primarily on the biophysical (hydrological) system, their objective is
often largely anthropogenic – namely to determine how much water it is ‘safe’ to extract for
use in an economic system. As such, having a primary objective that is linked to the
environment (e.g. wanting to conserve a species), does not necessarily mean that it will only
be the models that have been developed by biophysical scientists that are likely to be useful.
One needs to focus more clearly on the question at hand.
To guide decision-makers through the complex labyrinth of model choices discussed in this
report, we thus developed a stylised representation (flowchart) of the types of questions
addressed by each of our nine-subcategories of models (Figure 17). This flowchart shows how
those questions link to (stylised) primary objectives of decision-makers, while also synthesising
stakeholder perceptions regarding the ease of understanding of model outputs, and the likely
resources (human, financial and time) required for model development or application.
The conservation of freshwater ecosystems has lagged behind that of marine and terrestrial ecosystems and often requires the integration of large‐scale approaches and transboundary considerations. This study aims to set the foundations of a spatial conservation strategy by identifying the most important catchments for the conservation of freshwater biodiversity in Europe.
Using data on 1296 species of fish, mollusc, odonate and aquatic plant, and the key biodiversity area criteria (species Red List status, range restriction and uniqueness of species assemblages), we identified a network of Critical Catchments for the conservation of freshwater biodiversity. Applying spatial prioritisation, we show how the prioritised network differs from the ideal case of protecting all Critical Catchments and how it changes when protected areas are included, and we also identify gaps between the prioritised network and existing protected areas.
Critical Catchments ( n = 8423) covered 45% of the area of Europe, with 766 qualifying (‘trigger’) species located primarily in southern Europe. The prioritised network, limited to 17% of the area of Europe, comprised 3492 catchments mostly in southern and eastern Europe and species targets were met for at least 96% of the trigger species.
We found the majority of Critical Catchments to be inadequately covered by protected areas. However, our prioritised network presents a possible solution to augment protected areas to meet policy targets while also achieving good species coverage.
Policy implications . While Critical Catchments cover almost half of Europe, priority catchments are mostly in southern and eastern Europe where the current level of protection is not sufficient. This study presents a foundation for a Europe‐wide systematic conservation plan to ensure the persistence of freshwater biodiversity. Our study provides a powerful new tool for optimising investment on the conservation of freshwater biodiversity and for meeting targets set forth in international biodiversity policies, conventions and strategies.
The aim of this study is to create a two-tiered assessment combining restoration and conservation, both needed for biodiversity management. The first tier of this approach assesses the condition of a site using a standard bioassessment method, AUSRIVAS, to determine whether significant loss of biodiversity has occurred because of human activity. The second tier assesses the conservation value of sites that were determined to be unimpacted in the first step against a reference database. This ensures maximum complementarity without having to set a priori target areas. Using the reference database, we assign site-specific and comparable coefficients for both restoration (Observed/Expected taxa with >50% probability of occurrence) and conservation values (O/E taxa with Keywords: biodiversity assessment; conservation; predictive models; restoration; rivers Document Type: Research Article DOI: http://dx.doi.org/10.1023/A:1024614610232 Affiliations: Cooperative Research Centre for Freshwater Ecology, University of Canberra, Canberra 2601, Australia Publication date: June 1, 2003 $(document).ready(function() { var shortdescription = $(".originaldescription").text().replace(/\\&/g, '&').replace(/\\, '<').replace(/\\>/g, '>').replace(/\\t/g, ' ').replace(/\\n/g, ''); if (shortdescription.length > 350){ shortdescription = "" + shortdescription.substring(0,250) + "... more"; } $(".descriptionitem").prepend(shortdescription); $(".shortdescription a").click(function() { $(".shortdescription").hide(); $(".originaldescription").slideDown(); return false; }); }); Related content In this: publication By this: publisher In this Subject: Biology By this author: Linke, Simon ; Norris, Richard GA_googleFillSlot("Horizontal_banner_bottom");
1. Freshwater conservation has received less attention than its terrestrial or marine counterparts. Given the accelerated rate of change and intensive human use that freshwater ecosystems are submitted to, it is urgent to focus more attention on fresh waters. Existing conservation planning tools – such as Marxan – need to be modified to account for the special nature of these systems. Connectivity plays a key role in freshwater ecosystems. Threats are mediated along river corridors, and the condition of the entire catchment influences river biodiversity downstream. This needs to be considered in conservation planning.
2. The probabilities of occurrence of nine native freshwater fish species in a Mediterranean river basin, obtained from Multivariate Adaptive Regression Splines‐ Generalized Linear Model (MARS‐GLM) models, were used as features to develop spatial conservation priorities. The priorities accounted for complementarity and spatial design issues.
3. To deal with the connected nature of rivers, we modified Marxan’s boundary length penalty, avoiding the selection of isolated planning units and forcing the inclusion of closer upstream areas. We introduced ‘virtual boundaries’ between non‐headwater stream segments and added distance‐weighted penalties to the overall connectivity cost (CP) when stream segments upstream of the selected planning units are not selected.
4. This approach to prioritising connectivity is concordant with ecological theory, as it considers the natural and roughly exponential decay of upstream influences with distance. It accounts for the natural capacity of rivers to mitigate impacts when designing reserves. When connectivity was not emphasised, Marxan prioritised natural corridors for longitudinal movements. In contrast, whole sub‐basins were prioritised when connectivity was emphasised. Changing the relative emphasis on connectivity substantially changed the spatial prioritisation; our conservation investment could move from one basin to another.
5. Our novel approach to dealing with directional connectivity enables managers of freshwater systems to set ecologically meaningful spatial conservation priorities.
1. Protected area networks for river ecosystems must account for the highly connected nature of river habitats and the fact that conditions in distant locations can influence downstream habitats and biota. We used Marxan conservation planning software to address the unique constraints of reserve design in river ecosystems and structure a reserve network to overcome key challenges to freshwater conservation.
2. The range limits of 63 fish species in Mesoamerica were predicted and used in Marxan to design a network of conservation focal areas that encompasses 15% of the range of each species in areas with low risk of environmental degradation. Upstream risk intensity was estimated by propagating landscape-based sources of stress downstream along the direction of flow in GIS. We constrained Marxan solutions to account for basin divides, and we defined critical management zones to include important habitats that contribute to species persistence and mitigate threats.
3. The proposed reserve network encompassed 11% of the study area, half of which was contained within existing protected areas. Our exercise also identified important gaps in protection. Because terrestrial-based environmental risks were propagated through the river network and considered in the solution, focal areas were constrained to catchments with low levels of upstream human activity. Addition of critical management zones – riparian buffers and fish migration corridors – expanded the network area by one-fifth.
4. Our application of Marxan allowed longitudinal connectivity and topographic barriers to species movement to be considered. Adding critical management zones expanded the size of the reserve network, but is crucial to the network’s conservation efficacy. We call for an evaluation of the added management capacity needed to conserve critical management zones and suggest ways to further improve the reserve design process.
Community-level approaches to biological conservation are now recognized as a major advance in most current single-species conservation and management practices. Existing approaches for modeling bio- logical communities, have limited utility, however, because they commonly examine community metrics ( e.g., species richness, assemblage “types” ) and consequently do not consider the identity of the species that compose the community. This is a critical shortcoming because the functional differences among species ultimately translate into the differential vulnerability of biological communities to natural and human-related environmental change. To address this concern I present a novel, species-specific approach to modeling communities using a multiresponse, artificial neural network. This provides an analytical approach that facilitates the development of a single, integrative model that predicts the entire species membership of a community while still respecting differences in the functional relationship between each species and its environment. I used temperate-lake fish communities to illustrate the utility of this modeling approach and found that predictions of community composition by the neural network were highly concordant with observed compositions of the 286 study lakes. Average similarity between observed and predicted community composition was 80% ( 22 out of the 27 species correctly classified ), and the model predicted a significant portion of the community composition in 91% of the lakes. I discuss the importance of the lake habitat variables for predicting community composition and explore the spatial distribution of model predictions in light of recent species invasions. The proposed modeling approach provides a powerful, quantitative tool for developing community predictive models that explicitly consider species membership, and thus each species' functional role in the community. Such models will contribute significantly to the study and conservation of biological communities.
Resumen: La conservación biológica a nivel de comunidad se reconoce actualmente como un importante avance en la mayoría de las prácticas actuales de conservación y manejo de una especie. Sin embargo, los enfoques actuales al modelaje tienen una utilidad limitada ya que, por lo general, consideran medidas de las comunidades ( por ejemplo, la riqueza de especies, “tipos” de ensamblaje” ) sin considerar así la identidad de las especies que integran la comunidad. Esta es una limitación crucial dado que las diferencias funcionales entre especies se traducen, en última instancia, en una vulnerabilidad diferencial de las comunidades biológicas a cambios ambientales naturales y antropogénicos. Para atender esta preocupación, presento un enfoque novedoso especie – específica al modelaje de comunidades utilizando una red neural artificial y de respuestas múltiples. Este enfoque proporciona una aproximación analítica que facilita el desarrollo de un solo modelo integrativo que predice el total de especies que integran una comunidad, respetando a su vez las diferencias en la relación funcional entre cada especie y su ambiente. Utilicé comunidades de peces en lagos templados para ejemplificar la utilidad de este modelo y pude determinar que las predicciones en cuanto a la composición de la comunidad usando la red neural eran altamente concordantes con las composiciones observadas de los 286 lagos estudiados. La similitud promedio entre la composición observada y la predicha fue del 80% ( 22 de 27 especies correctamente clasificadas ), y el modelo predijo una porción significativa de la comunidad en 91% de los lagos. Se discute la importancia de las variables del hábitat lacustre para predecir la composición de la comunidad y la distribución espacial de las predicciones del modelo es explorada a la luz de recientes invasiones de especies. La aproximación propuesta proporciona una poderosa herramienta cuantitativa para desarrollar modelos predictivos que consideran explícitamente las especies integrantes de una comunidad ( y por lo tanto, la función de cada especie en la comunidad ). Tales modelos contribuirán significativamente al estudio y a la conservación de comunidades biológicas.
1. Management of whole rivers and river catchments requires a comprehensive set of information about river condition and use, both existing and historical, and the links between them at regional, state or national scales. This paper outlines a new approach to the assessment of river condition, using a small team was able to assess 210 000 km of rivers across more than 3 million km2 of Australia in little more than a year.
2. The approach was driven by a hierarchical model of river function, which assumed that broad-scale catchment characteristics affect local hydrology, habitat features, water quality and, ultimately, aquatic biota. The model provided the basis for selecting important ecologically relevant features that indices should represent. For each reach of each river we derived a biological index and an environmental index based on measures quantifying catchment and hydrological condition, and habitat and water quality condition. Data came from existing state and national databases, satellite images, site measurements and process models.
3. All indices were calculated as deviation from a reference condition, were range-standardised and were divided into equivalent bands of condition. Amalgamation of index components and of sub-indices was determined by consideration of their ecological effects; for example, general degradation might be additive, but toxic effects of one component would override all others.
4. Several internal and external validation methods were employed, with the all-important validation of the final assessments undertaken by comparison with a similar index based on locally measured data.
5. The environmental assessment classified 14% of reaches as largely unmodified, 67% as moderately modified and 19% as substantially modified by human impacts. The biological assessment based on site assessments and modelled data using invertebrates indicated that 70% of reaches were equivalent to reference condition and that 30% were significantly impaired. Catchment disturbance, elevated sediment and nutrient loads, and habitat degradation all contributed to these results. These impacts have all occurred during the last 200 years (post-European settlement).
6. Partly as a result of the assessments of this study the Australian Government has begun to adopt a more environmentally sustainable approach to broad-scale water management.
1. Traditionally the assessment of river water quality has been based solely on the measurement of physical, chemical and some biological characteristics. While these measurements may be efficient for regulating effluent discharges and protecting humans, they are not very useful for large‐scale management of catchments or for assessing whether river ecosystems are being protected.
2. Measurements of aquatic biota, to identify structural or functional integrity of ecosystems, have recently gained acceptance for river assessment. Empirical evidence from studies of river ecosystems under stress suggests that a small group of biological ecosystem‐level indicators can assess river condition. However, physical and chemical features of the environment affect these indicators, the structure and function of which may be changed by human activities.
3. The term ‘river health’, applied to the assessment of river condition, is often seen as being analogous with human health, giving many a sense of understanding. Unfortunately, the meaning of ‘river health’ remains obscure. It is not clear what aspects of river health sets of ecosystem‐level indicators actually identify, nor how physical, chemical and biological characteristics may be integrated into measures rather than just observations of cause and effect.
4. Increased examination of relationships between environmental variables that affect aquatic biota, such as habitat structure, flow regime, energy sources, water quality and biotic interactions and biological condition, are required in the study of river health.
SUMMARY 1. The prediction of species distributions is of primary importance in ecology and conservation biology. Statistical models play an important role in this regard; however, researchers have little guidance when choosing between competing methodologies because few comparative studies have been conducted.
2. We provide a comprehensive comparison of traditional and alternative techniques for predicting species distributions using logistic regression analysis, linear discriminant analysis, classification trees and artificial neural networks to model: (1) the presence/absence of 27 fish species as a function of habitat conditions in 286 temperate lakes located in south-central Ontario, Canada and (2) simulated data sets exhibiting deterministic, linear and non-linear species response curves.
3. Detailed evaluation of model predictive power showed that approaches produced species models that differed in overall correct classification, specificity (i.e. ability to correctly predict species absence) and sensitivity (i.e. ability to correctly predict speciespresence) and in terms of which of the study lakes they correctly classified. Onaverage, neural networks outperformed the other modelling approaches, although all approaches predicted species presence/absence with moderate to excellent success.
4. Based on simulated non-linear data, classification trees and neural networks greatly outperformed traditional approaches, whereas all approaches exhibited similar correct classification rates when modelling simulated linear data.
5. Detailed evaluation of model explanatory insight showed that the relative importance of the habitat variables in the species models varied among the approaches, where habitat variable importance was similar among approaches for some species and very different for others.
6. In general, differences in predictive power (both correct classification rate and identity of the lakes correctly classified) among the approaches corresponded with differences in habitat variable importance, suggesting that non-linear modelling approaches (i.e. classification trees and neural networks) are better able to capture and model complex, non-linear patterns found in ecological data. The results from the comparisons using simulated data further support this notion.
7. By employing parallel modelling approaches with the same set of data and focusing on comparing multiple metrics of predictive performance, researchers can begin to choose predictive models that not only provide the greatest predictive power, but also best fit the proposed application.
Multivariate predictive models are widely used tools for assessment of aquatic ecosystem health and models have been successfully
developed for the prediction and assessment of aquatic macroinvertebrates, diatoms, local stream habitat features and fish.
We evaluated the ability of a modelling method based on the River InVertebrate Prediction and Classification System (RIVPACS)
to accurately predict freshwater fish assemblage composition and assess aquatic ecosystem health in rivers and streams of
south-eastern Queensland, Australia. The predictive model was developed, validated and tested in a region of comparatively
high environmental variability due to the unpredictable nature of rainfall and river discharge. The model was concluded to
provide sufficiently accurate and precise predictions of species composition and was sensitive enough to distinguish test
sites impacted by several common types of human disturbance (particularly impacts associated with catchment land use and associated
local riparian, in-stream habitat and water quality degradation). The total number of fish species available for prediction
was low in comparison to similar applications of multivariate predictive models based on other indicator groups, yet the accuracy
and precision of our model was comparable to outcomes from such studies. In addition, our model developed for sites sampled
on one occasion and in one season only (winter), was able to accurately predict fish assemblage composition at sites sampled
during other seasons and years, provided that they were not subject to unusually extreme environmental conditions (e.g. extended
periods of low flow that restricted fish movement or resulted in habitat desiccation and local fish extinctions).
The assessment of the ecological status of freshwater ecosystems is a key issue for many international laws such as the Water Framework Directive (WFD) in light of the actual impoverished status of these ecosystems. Different multimetric approaches have been successfully developed in different freshwater environments. However, multimetric indices are difficult to apply to Mediterranean rivers basins, characterized by freshwater fish communities very low in species richness and support a high number of endemics with generalist and opportunistic life strategies. Here we follow a site-specific approach to develop an adaptation of the multimetric procedure usually used in Indices of Biotic Integrity (IBI), resulting in the Index of Community Integrity (ICI). We modeled the presence–absence of 10 native freshwater fish species from the Guadiana River basin using the Assessment of Nearest Neighbor Analyses (ANNA) model, to assess the deviation of the observed and expected community composition at reference condition. ANNA, which is a multi-species model, allowed incorporating in the index some rare species, though not all of them present in the basin. Deviations were transformed into probabilities of belonging to a reference site and species by species measures were then integrated in a final score. The use of presence–absence only data reduces potential errors associated with estimations of species’ abundance and its seasonal changes, which is especially important in Mediterranean environments. The ICI was sensitive to both habitat degradation and the degree of dominance of non-native species within the freshwater fish community (or biotic perturbation), which have been traditionally overlooked in IBIs, but was unresponsive to natural sources of variation. Given the site-specific nature and the simplicity of the index that we propose here, we expect it to be applicable to other Mediterranean basins for which predictive models can be produced.
Artificial neural networks (ANNs) are receiving greater attention in the ecological sciences as a powerful statistical modeling technique; however, they have also been labeled a “black box” because they are believed to provide little explanatory insight into the contributions of the independent variables in the prediction process. A recent paper published in Ecological Modelling [Review and comparison of methods to study the contribution of variables in artificial neural network models, Ecol. Model. 160 (2003) 249–264] addressed this concern by providing a comprehensive comparison of eight different methodologies for estimating variable importance in neural networks that are commonly used in ecology. Unfortunately, comparisons of the different methodologies were based on an empirical dataset, which precludes the ability to establish generalizations regarding the true accuracy and precision of the different approaches because the true importance of the variables is unknown. Here, we provide a more appropriate comparison of the different methodologies by using Monte Carlo simulations with data exhibiting defined (and consequently known) numeric relationships. Our results show that a Connection Weight Approach that uses raw input-hidden and hidden-output connection weights in the neural network provides the best methodology for accurately quantifying variable importance and should be favored over the other approaches commonly used in the ecological literature. Average similarity between true and estimated ranked variable importance using this approach was 0.92, whereas, similarity coefficients ranged between 0.28 and 0.74 for the other approaches. Furthermore, the Connection Weight Approach was the only method that consistently identified the correct ranked importance of all predictor variables, whereas, the other methods either only identified the first few important variables in the network or no variables at all. The most notably result was that Garson’s Algorithm was the poorest performing approach, yet is the most commonly used in the ecological literature. In conclusion, this study provides a robust comparison of different methodologies for assessing variable importance in neural networks that can be generalized to other data and from which valid recommendations can be made for future studies.
Using the 160,000-km2 drainage basin of the Madre de Dios and Orthon rivers in the southwest Amazon as a test case, we piloted an approach for large-scale conservation planning for freshwater systems characterized by a near-complete lack of biological and physical data. We used newly available spatial and remote sensing datasets, including spaceborne optical and radar observations, and new techniques of spatial data analysis to generate subbasin (⩾100 km2), stream, and floodplain and wetland habitat classifications. We then generated a preliminary plan for a network of conservation areas to protect the most intact examples of representative habitat types while maximizing longitudinal and lateral connectivity. Proposed additions for freshwater conservation complement existing reserves and build on earlier conservation planning efforts for terrestrial ecosystems. In the resulting integrated plan, at least 20% of the area of each major freshwater habitat type is represented and two continuous corridors exist from the mouth of the Madre de Dios to its headwaters in the Andes. In total, we highlighted 84 currently unprotected subbasins to fulfill our representation and connectivity goals. About two-thirds of these subbasins were considered relatively undisturbed and are identified as Level I (critical management zones) or Level II (indigenous territories), whereas one-third are potentially degraded and thus were designated as Level III (threat mitigation zones). This exercise provides an example of how newly available remote-sensing datasets and analytical tools may be used to advance freshwater conservation planning, particularly in data-poor regions.
The process of designing protected areas to represent all ecosystems in an area adequately is becoming increasingly sophisticated. To date freshwater aquatic ecosystems have seldom been considered in this process. How much of a difference does it make when they are considered as well?This study examined the conservation of riverine biodiversity within 17 assessment units contained by the catchment areas of five perennial rivers flowing through Kruger National Park and two seasonal rivers that are largely contained within this park. Physical river types, fish species and invertebrate families or genera were used as surrogates of riverine biodiversity. Conservation planning software was used to select an optimal set of planning units to represent and maintain riverine biodiversity.The current spatial configuration of Kruger National Park, largely an accident of history, is particularly poor when assessed against the objective of conserving riverine biodiversity. Several alternative layouts are examined. These options are theoretical since there is little current opportunity to reassign land uses in the region. This study shows that substantially improved layouts for both riverine and terrestrial biodiversity are possible, under the constraint of the same total area under protection. The study also shows that even these optimal layouts are only partially successful in efforts to conserve fully representative samples of riverine biodiversity. Because of the longitudinal connectivity of rivers, conservation strategies that extend beyond protected areas are essential. Explicit conservation visions, targets and strategies need to be included in integrated water resource management plans.Based on the results of this study, nine recommendations are provided for increasing the effectiveness of current and future protected areas in conserving riverine biodiversity. These are to use systematic conservation planning to make biodiversity benefits explicit; mend the disconnect between terrestrial and freshwater conservation; use multiple surrogates wherever possible; be strategic about the collection and management of primary data; strive for maximum hydrologic connectivity; resist development pressure; foster good relationships across park fences; where relevant, pursue multi-national cooperation at the basin scale; and engage the value debate and resolve awareness and capacity constraints.
In this study, relationships between flow variation across multiple temporal scales and the distribution and abundance of three fish species, western rainbowfish Melanotaenia australis, sooty grunter Hephaestus fuliginosus and barramundi Lates calcarifer were examined at eight sampling reaches in the Daly River, Northern Territory, Australia. Discharge was highly seasonal during the study period of 2006-2010 with a distinct wet-dry discharge pattern. Significant catchment-wide correlations were identified between species abundance and hydrologic variables across several scales describing the magnitude and variability of flow. A Bayesian hierarchical model which accounted for >80% of variation in abundances for all species and age classes (i.e. juvenile and adult), identified the extent to which the influence of short-term flow variation was dependent upon the historical flow regime. There were distinct ontogenetic differences in these relationships for H. fuliginosus, with variability of recent flows having a negative effect on juveniles which was stronger at locations with higher historical mean daily flow. Lates calcarifer also displayed ontogenetic differences in relationships to flow variation with adults showing a positive association with increase in recent flows and juveniles showing a negative one. The effect of increased magnitude of wet-season flows on M. australis was negative in locations with lower historical mean daily flow but positive in locations with higher historical mean daily flow. The results highlighted how interactions between multiple scales of flow variability influence the abundance of fish species according to their life-history requirements.
1. The importance of hydrologic variability for shaping the biophysical attributes and functioning of riverine ecosystems is well recognised by ecologists and water resource managers. In addition to the ecological dependences of flow for aquatic organisms, human societies modify natural flow regimes to provide dependable ecological services, including water supply, hydropower generation, flood control, recreation and navigation. Management of scarce water resources needs to be based on sound science that supports the development of environmental flow standards at the regional scale.
2. Hydrological classification has long played an essential role in the ecological sciences for understanding geographic patterns of riverine flow variability and exploring its influence on biological communities, and more recently, has been identified as a critical process in environmental flow assessments.
3. We present the first continental‐scale classification of hydrologic regimes for Australia based on 120 metrics describing ecologically relevant characteristics of the natural hydrologic regime derived from discharge data for 830 stream gauges. Metrics were calculated from continuous time series (15–30 years of record constrained within a 36‐year period) of mean daily discharge data, and classification was undertaken using a fuzzy partitional method – Bayesian mixture modelling.
4. The analysis resulted in the most likely classification having 12 classes of distinctive flow‐regime types differing in the seasonal pattern of discharge, degree of flow permanence (i.e. perennial versus varying degrees of intermittency), variations in flood magnitude and frequency and other aspects of flow predictability and variability. Geographic, climatic and some catchment topographic factors were generally strong discriminators of flow‐regime classes. The geographical distribution of flow‐regime classes showed varying degrees of spatial cohesion, with stream gauges from certain flow‐regime classes often being non‐contiguously distributed across the continent. These results support the view that spatial variation in hydrology is determined by interactions among climate, geology, topography and vegetation at multiple spatial and temporal scales. Decision trees were also developed to provide the ability to determine the natural flow‐regime class membership of new stream gauges based on their key environmental and/or hydrological characteristics.
5. The need to recognise hydrologic variation at multiple spatial scales is an important first step to setting regional‐scale environmental flow management strategies. We expect that the classification produced here can underpin the development of a greater understanding of flow‐ecology relationships in Australia, and management efforts aimed at prescribing environmental flows for riverine restoration and conservation.
This paper describes the relative influence of (i) landscape scale environmental and hydrological factors, (ii) local scale environmental conditions including recent flow history, and (iii) spatial effects (proximity of sites to one another), on the spatial and temporal variation in local freshwater fish assemblages in the Mary River, south-eastern Queensland, Australia. Using canonical correspondence analysis, each of the three sets of variables explained similar amounts of variation in fish assemblages (ranging from 44 to 52%). Variation in fish assemblages was partitioned into eight unique components: pure environmental, pure spatial, pure temporal, spatially structured environmental variation, temporally structured environmental variation, spatially structured temporal variation, the combined spatial/temporal component of environmental variation and unexplained variation. The total variation explained by these components was 65%. The combined spatial/temporal/environmental component explained the largest component (30%) of the total variation in fish assemblages, whereas pure environmental (6%), temporal (9%) and spatial (2%) effects were relatively unimportant. The high degree of intercorrelation between the three different groups of explanatory variables indicates that our understanding of the importance to fish assemblages of hydrological variation (often highlighted as the major structuring force in river systems) is dependent on the environmental context in which this role is examined. Yes Yes
Despite the demonstrated utility of the Australian River Assessment Scheme (AUSRIVAS) to provide national-scale information on the biological condition of rivers, there is no commensurate scheme that can provide standardised information on physical habitat. Existing habitat assessment methods are not suitable for implementation on a national scale, so we present a new habitat assessment protocol that incorporates favorable elements of existing methods. Habitat Predictive Modelling forms the basis for the protocol because it can predict the occurrence of local-scale features from large-scale data, uses the reference condition concept, can be modified to incorporate a range of biologically and geomorphologically relevant variables, and employs a rapid survey approach. However, the protocol has been augmented with geomorphological variables and incorporates principles of hierarchy and geomorphological river zonation. There are four sequential components to the implementation of the protocol: reference site selection, data collection, predictive model construction and assessment of test sites using the predictive models. Once implemented, the habitat assessment protocol will provide a standardised tool for the assessment of river habitat condition at a variety of governance levels.
Broadening the scope of conservation efforts to protect entire communities provides several advantages over the current species-specific focus, yet ecologists have been hampered by the fact that predictive modeling of multiple species is not directly amenable to traditional statistical approaches. Perhaps the greatest hurdle in community-wide modeling is that communities are composed of both co-occurring groups of species and species arranged independently along environmental gradients. Therefore, commonly used "short-cut" methods such as the modeling of so-called "assemblage types" are problematic. Our study demonstrates the utility of a multiresponse artificial neural network (MANN) to model entire community membership in an integrative yet species-specific manner. We compare MANN to two traditional approaches used to predict community composition: (1) a species-by-species approach using logistic regression analysis (LOG) and (2) a "classification-then-modeling" approach in which sites are classified into assemblage "types" (here we used two-way indicator species analysis and multiple discriminant analysis [MDA]). For freshwater fish assemblages of the North Island, New Zealand, we found that the MANN outperformed all other methods for predicting community composition based on multiscaled descriptors of the environment. The simple-matching coefficient comparing predicted and actual species composition was, on average, greatest for the MANN (91%), followed by MDA (85%), and LOG (83%). Mean Jaccard's similarity (emphasizing model performance for predicting species' presence) for the MANN (66%) exceeded both LOG (47%) and MDA (46%). The MANN also correctly predicted community composition (i.e., a significant proportion of the species membership based on a randomization procedure) for 82% of the study sites compared to 54% (MDA) and 49% (LOG), resulting in the MANN correctly predicting community composition in a total of 311 sites and an additional 117 sites (n = 379), on average, compared to LOG and MDA. The MANN also provided valuable explanatory power by simultaneously quantifying the nature of the relationships between the environment and both individual species and the entire community (composition and richness), which is not readily available from traditional approaches. We discuss how the MANN approach provides a powerful quantitative tool for conservation planning and highlight its potential for biomonitoring programs that currently depend on modeling discrete assemblage types to assess aquatic ecosystem health.
Systematic conservation planning typically requires specification of quantitative representation targets for biodiversity surrogates such as species, vegetation types, and environmental parameters. Targets are usually specified either as the minimum total area in a conservation-area network in which a surrogate must be present or as the proportion of a surrogate's existing spatial distribution required to be in the network. Because the biological basis for setting targets is often unclear, a better understanding of how targets affect selection of conservation areas is needed. We studied how the total area of conservation-area networks depends on percentage targets ranging from 5% to 95%. We analyzed 12 data sets of different surrogate distributions from 5 regions: Korea, Mexico, Québec, Queensland, and West Virginia. To assess the effect of spatial resolution on the target-area relationship, we also analyzed each data set at 7 spatial resolutions ranging from 0.01° × 0.01° to 0.10° × 0.10°. Most of the data sets showed a linear relationship between representation targets and total area of conservation-area networks that was invariant across changes in spatial resolution. The slope of this relationship indicated how total area increased with target level, and our results suggest that greater surrogate representation requires significantly more area. One data set exhibited a highly nonlinear relationship. The results for this data set suggest a new method for setting targets on the basis of the functional form of target-area relationships. In particular, the method shows how the target-area relationship can provide a rationale for setting targets solely on the basis of distributional information about surrogates.
1. Owing to intensive human use, freshwaters are among the most seriously threatened and modified environments on the planet. Their poor condition and the risk to services that humans need from these ecosystems make their rehabilitation a priority. However, many previous studies have reported the poor performance of many rehabilitation activities.
2. Here, we analyse reasons for this poor performance, focussing on the planning of rehabilitation activities, and propose a new approach. We argue that the failure to include driving factors at a scale adequate to capture the ecological processes involved, together with an insufficient incorporation of socio-economic aspects, is a key factor leading the poor performance of many rehabilitation activities.
3. We propose a new approach, ‘systematic rehabilitation planning’, that brings together advances made in conservation planning (cost-effectiveness analysis) and ecosystem science (understanding the complexity of ecosystem processes). This enables planning to be done at the catchment scale, and the trade-offs between various rehabilitation actions to be integrated and prioritised.
4. Finally, it is important, given the constraints imposed by a lack of knowledge, that the planning process is part of an adaptive cycle where it can benefit from and consolidate the experience gained during the implementation and monitoring stages.
Abstract Real patterns of ecological connectivity are seldom explicitly or systematically accounted for systematic conservation planning, in part because commonly used decision support systems can only capture simplistic notions of connectivity. Conventionally, the surrogates used to represent connectivity in conservation plans have assumed the connection between two sites to be symmetric in strength. In reality, ecological linkages between sites are rarely symmetric and often strongly asymmetric. Here, we develop a novel formulation that enabled us to incorporate asymmetric connectivity into the conservation decision support system Marxan. We illustrate this approach using hypothetical examples of a river catchment and a group of reefs, and then apply it to case studies in the Snowy River catchment and Great Barrier Reef, Australia. We show that incorporating asymmetric ecological connectivity in systematic reserve design leads to solutions that more effectively capture connectivity patterns, relative to either ignoring connectivity or assuming symmetric connectivity.
Worldwide increasing pressure on the marine environment requires integrated and ecosystem-based management, and a sound understanding of cumulative impacts of human pressure. As yet, the quantification of risk of cumulative impact remains a difficult task in practice. We developed a geospatial modelling framework to group data on the spatial distribution and intensity of human activities by generic pressure. The impact of those pressures was mapped by accounting for the sensitivity of UK marine landscapes to those pressures. With the help of GIS-based multi-criteria analysis, we developed 4 different scenarios to quantify risk of cumulative impacts that accounted for different importance of ranked pressures (equal, linear and logistic decrease), including a simulated expert consultation. Finally, we assessed the sensitivity of the scenario outcomes to changes to input parameters and compared model outcomes. The risk assessment framework exposed both a wide range of possible modelled scenarios and uncertainties, but all scenarios revealed similar locations with an increased risk of cumulative impacts. Results showed that the logistic weighting scheme was very sensitive to changes in the importance and ranking of pressures in comparison to the linear weighting scheme. For marine planning the use of a weighting scheme with more constrained values should be used in conjunction with a sensitivity analysis to determine the order of input parameters. Once a more comprehensive geodatabase becomes available our standardised framework can be applied to support both the development of sustainable marine plans in practise and the prioritisation of different uses.
The realization of conservation goals requires strategies for managing
whole landscapes including areas allocated to both production and protection.
Reserves alone are not adequate for nature conservation but they are the cornerstone
on which regional strategies are built. Reserves have two main roles. They
should sample or represent the biodiversity of each region and they should
separate this biodiversity from processes that threaten its persistence. Existing
reserve systems throughout the world contain a biased sample of biodiversity,
usually that of remote places and other areas that are unsuitable for commercial
activities. A more systematic approach to locating and designing reserves
has been evolving and this approach will need to be implemented if a large
proportion of today's biodiversity is to exist in a future of increasing numbers
of people and their demands on natural resources.
ABSTRACTA vast scientific literature has been devoted to identifying the best way to represent biodiversity for conservation in the last decade. Methods exist for deciding how to use scarce information and avoid omission and commission errors. The effect of these errors on reserve efficiency does not arise only from the accuracy of data representing conservation features, as usually considered. There are also several underlying assumptions associated with the type of data used that might affect accuracy of conservation decision-making and compromise achievement of conservation objectives.Here the effects of two management scenarios on selection of priority areas for conservation are explored. The spatial distribution of 10 native freshwater fish species in an Iberian basin under present-day and reference conditions were modelled and priority areas for both scenarios using the same spatial and cost constraints were identified.Priority areas identified under the present-day scenario reflected the up-to-date spatial distribution of species and avoided the selection of highly perturbed and costly areas. The isolated spatial distribution of native populations imposed by the current perturbation status limited the spatial connectivity between priority areas under the present-day scenario. Most importantly for the achievement of conservation objectives, priority areas selected under both scenarios did not overlap.Given that the reference scenario was based on potential presence of native species the actual representation of species would be overestimated if consideration were not given to restoring reference conditions (high commission errors). Based on results obtained it is recommended that planners give more consideration to the current perturbation status when identifying priority areas for conservation. Copyright © 2011 John Wiley & Sons, Ltd.
1. We review recent advances in systematic conservation planning in fresh waters. Most modern systematic planning approaches are based on the CARE principles: comprehensiveness, adequacy, representativeness and efficiency. Efficiency is usually provided by a complementarity-based strategy, aiming to select new conservation areas in the light of previously protected features. These strategies have to be modified to account for the connected nature of rivers.
2. Choice of surrogates for conservation features depends on the scale of the assessment, as well as the available expertise and resources. Ideally, real information about taxa or processes – extrapolated by models – ensures that target features are protected. Where this is not feasible, it is critical that the choice of environmental surrogates is informed by target biota or processes.
3. Setting adequacy targets – the most challenging aspect in planning – needs to be evaluated in a freshwater-specific context, as species–area relationships and the distribution of diversity differ in dendritic networks. Adequately designed conservation plans also need to consider upstream land use and catchment disturbances. Recent studies have largely addressed longitudinal connectivity either by setting rules to protect adjacent subcatchments (or even the entire catchment upstream), or by considering the magnitude of disturbance upstream of selected planning units. Very few studies have addressed lateral and vertical connectivity in a systematic way.
4. To implement freshwater conservation plans, we recommend adopting a recently proposed hierarchical protection strategy, from ‘freshwater focal areas’ that contain the actual features to be protected to mixed-use ‘catchment management zones’. Stakeholder involvement is crucial, especially in the large multi-use areas upstream and in the surrounding catchment.
5. We conclude that conservation planning using CARE principles is the only efficient way forward. This special issue shows significant efforts are under way to adapt freshwater-specific adequacy, connectivity and implementation issues in conservation planning. However, a more holistic research investment is required to link freshwater, terrestrial and marine ecosystems.
1. We identified priority sites for freshwater conservation in the Upper Mississippi River (UMR) basin using a coarse- and fine-filter approach to defining biodiversity elements as building blocks. Fine-filter species included federally listed threatened and endangered, imperilled, declining, endemic, disjunct and wide-ranging species. We had species data for over 1300 individual occurrences of species and communities identified as fine-filter elements. The coarse-filter elements are ecosystems (‘Aquatic Ecological Systems’) defined using physical attributes of streams and lakes, and stratified to represent key zoogeographical and physiographical gradients.
2. We used relative ecosystem integrity, species population viability and expert opinion to generate an initial ‘portfolio’ of 600 freshwater areas of biodiversity significance representing the best examples of the species and ecosystem elements. Representation targets were met for all ecosystem types and for an average of 45% for species groups.
3. The application of a coarse- and fine-filter approach to identify biodiversity conservation priorities in the UMR demonstrates the contribution of each component – even in an area with relatively rich fine-filter data. For a large assessment area, data, even if plentiful, will be uneven, and community-level diversity is not catalogued. Thus, the coarse filter allows for greater confidence that a broad suite of species and key environmental gradients are captured in a conservation portfolio, while fine-filter data provide greater confidence that species of conservation and management interest are addressed adequately.
1. The progression of approaches in systematic conservation planning from representation to representation and persistence has greatly enhanced its potential applicability to freshwaters. However, conceptual frameworks that consolidate principles for incorporating persistence into freshwater conservation planning are still lacking.
2. We present four key principles to consider when planning for the persistence of freshwater biodiversity: selecting ecosystems of high ecological integrity; incorporating connectivity; incorporating areas important to population persistence; and identifying additional natural processes that can be mapped.
3. The practicalities of gathering data and conducting the conservation plan to address these principles are explored here using a case study in the Olifants/Doorn Water Management Area, South Africa. Spatial layers are developed for depicting ecological integrity, sub-catchment boundaries, riparian zones and wetlands, high water-yield areas and patterns of groundwater discharge and recharge.
4. These data are used to develop a conservation area network that supports both representation and persistence of freshwater biodiversity. Although the planning region is relatively data rich by global standards, several data deficiencies were identified. We suggest ways of using environmental surrogates to address data deficiencies, improving confidence in these surrogates by combining them wherever possible with existing field data and expert knowledge.
5. We also recommend methods to achieve spatial efficiency by simultaneously designing for representation and persistence of freshwater biodiversity. Spatial efficiency can be achieved in different ways when using a conservation planning algorithm and a multiple-use zoning strategy.
6. The allocation of multiple-use zones aligns closely with the objectives of integrated water resources management and land use planning. Given the practicalities at local levels of planning, we recommend using multiple-use zones in the design phase, rather than merely at the end once the design is complete.
This paper reports the development and application of two Bayesian Network models to assist decision making on the environmental flows required to maintain the ecological health of the Daly River (Northern Territory, Australia). Currently, the Daly River is unregulated, with only a small volume of water extracted annually for agriculture. However, there is considerable pressure for further agricultural development in the catchment, particularly with demand for extra water extraction during the dry season (May–November).
The abundances of two fish species—barramundi ( Lates calcarifer ) and sooty grunter ( Hephaestus fuliginosus )—were chosen as the ecological endpoints for the models, which linked dry season flows to key aspects of the biology of each species. Where available, data were used to define flow–fish habitat relationships, but most of the relationships were defined by expert opinion because of a lack of quantified ecological knowledge.
Recent field data on fish abundances were used to validate the models and gave prediction errors of 20–30%. The barramundi model indicated that the adult sub‐population was key to overall fish abundance, with this sub‐population particularly impacted by the timing of abstraction (early vs. late dry season). The sooty grunter model indicated that the juvenile sub‐population dominated the overall abundance and that this was primarily due to the amount of hydraulically suitable riffle habitat. If current extraction entitlements were fully utilized, the models showed there would be significant impacts on the populations of these two fish species, with the probability of unacceptable abundances increasing to 43% from 25% for sooty grunter and from 36% for barramundi under natural conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Until recently the objectives of tropical river management were narrowly construed: the development imperative drove resource policy. During recent decades, community attitudes to river and water management have changed considerably and the national program of water reform, the National Water Initiative, is accelerating alterations to the way that water is used, managed and priced. A broader range of values and imperatives is now influencing water resource management policy. Not least is the concern over the ecological impacts and economic inefficiencies of the large-scale hydrological schemes that once excited the public's imagination. This paper reports on a recent study of social and economic values of tropical rivers conducted by the authors for an Australian statutory research and development corporation. The study shows that the values associated with tropical rivers have changed and diversified over time with growing societal awareness of the contribution made by unregulated, healthy river systems to human wellbeing and cultural identity. As a consequence of substantial social change, tropical river management must now contend with a more complex array of societal values and water management objectives.
A comprehensive reference system for the Earth's river basins is proposed as a support to river basin management, global change research, and the pursuit of sustainable development. A natural system for delineation and codification of basins is presented which is based upon topographic control and the topology of the river network. These characteristics make the system well suited for implementation and use with digital elevation models (DEMs) and geographic information systems. A demon-stration of these traits is made with the 30-arcsecond GTOPO30 DEM for North America. The system has additional appeal owing to its economy of digits and the topological information that they carry. This is illustrated through presentation of comparisons with USGS hydrologic unit codes and demonstration of the use of code numbers to reveal dependence or independence of water use activities within a basin. 1999 Elsevier Science B.V. All rights reserved.
This study has adapted a complementarity-based area-selection method to estimate conservation value/irreplaceability for river systems. Irreplaceability represents the likelihood that an area will be required as part of a conservation system that achieves all conservation targets. We adapt this measure – often used in marine or terrestrial planning – to consider whole-of-catchment protection in a riverine setting. After dividing the Australian state of Victoria into 1854 subcatchments, we successfully modelled distributions of 400 benthic macroinvertebrate taxa using generalized additive models. We calculated the minimum area required to protect all taxa using three different heuristic selection algorithms. The algorithms were modified to consider the entire upstream catchment for any subcatchment. A summed rarity algorithm, corrected for upstream area, proved to be the most efficient, requiring 100 000 hectares less total catchment area to represent all taxa than the second most efficient algorithm. We calculated irreplaceability by running the algorithm 1000 times and randomly removing 90% of the catchments in each run. From this analysis, we estimated two metrics: Fs (the frequency of selection) and average c (average contribution to conservation targets). Four groups of catchments were identified: (i) catchments that have high contributions and are always or very frequently selected; (ii) catchments that have high contributions and are infrequently selected; (iii) catchments that are always or very frequently selected but contribute few taxa; and (iv) catchments that are infrequently selected and contribute few taxa. Synthesis and applications. For the first time, a complementarity-based algorithm has been adapted to a riverine setting. This algorithm acknowledges the connected nature of rivers by considering not only the local assemblages, but also upstream areas that need to be protected. We demonstrated that using standard algorithms in these connected systems would lead to two mistakes, namely: (i) not all taxa would be covered by reserves that were buffered from potential human disturbances upstream; and (ii) the standard algorithms would not lead to the most efficient solution, potentially costing additional millions of dollars to any conservation scheme. We therefore recommend the use of our algorithm or a similar riverine adaptation of reserve design algorithms to ensure adequate and efficient conservation planning.
Abstract – We developed classification/multiple discriminant analysis models to predict fish assemblage structure and tested whether the predictive power of these models varied with discharge variability. Models developed for assemblages characterized by the density of component species for two rivers with low discharge variability had better predictive power than did models developed for two rivers of higher variability. Similar distinction between rivers of differing flow variability was not evident for models based on assemblages characterized by the presence or absence of component species. Factors such as the within-river level of beta diversity, location of study sites relative to the river mouth and the degree of covariation in species' occurrence appeared important determinants of predictive power in these models. Randomization tests (Mantel tests) were used to determine the degree of association between site by site association matrices generated for fish assemblage structure (both density and presence/absence) and habitat structure (catchment, physical, microhabitat or a combination). This approach revealed that in most cases, catchment-related variables explained almost as much of the variation in assemblage structure as variables related to in-stream habitat structure and that greater association was detected for comparisons based on presence/absence rather than density data. The addition of in-stream habitat variables to catchment-related variables usually resulted in explaining the greatest amount of variation. These data suggest that most of the structure observed in the fish assemblages of the study rivers was a result of the effect of regional or catchment factors in determining which species were present at an individual site and that local factors were then important in determining the abundance of the component species. It is at this level that the effects of regional differences in discharge variability were expressed. Although significantly different from random for all comparisons, Mantel's tests revealed that a substantial amount of variation in the fish assemblage data sets could not be explained by the abiotic (habitat) data sets. It is suggested that the assemblages in question did not represent unit discrete assemblages but were composed of species varying along individual environmental gradients. Predictive models may be better achieved by modelling the distribution and abundance of individual species rather than assemblages.†
1. Systematic conservation planning is a process widely used in terrestrial and marine environments. A principal goal is to establish a network of protected areas representing the full variety of species or ecosystems. We suggest considering three key attributes of a catchment when planning for aquatic conservation: irreplaceability, condition and vulnerability.
2. Based on observed and modelled distributions of 367 invertebrates in the Australian state of Victoria, conservation value was measured by calculating an irreplaceability coefficient for 1854 subcatchments. Irreplaceability indicates the likelihood of any subcatchment being needed to achieve conservation targets. We estimated it with a bootstrapped heuristic reserve design algorithm, which included upstream–downstream connectivity rules. The selection metric within the algorithm was total summed rarity, corrected for protected area.
3. Condition was estimated using a stressor gradient approach in which two classes of geographical information system Layers were summarised using principal components analysis. The first class was disturbance measures such as nutrient and sediment budgets, salinisation and weed cover. The second class was land use layers, including classes of forestry, agricultural and urban use. The main gradient, explaining 56% of the variation, could be characterised as agricultural disturbance. Seventy-five per cent of the study area was classified as disturbed.
4. Our definition of vulnerability was the likelihood of a catchment being exposed to a land use that degrades its condition. This was estimated by comparing land capability and current land use. If land was capable of supporting a land use that would have a more degrading effect on a river than its current tenure, it was classified vulnerable (66% of the study area). 79% of catchments contained more then 50% vulnerable land.
5. When integrating the three measures, two major groups of catchments requiring urgent conservation measures were identified. Seven per cent of catchments were highly irreplaceable, highly vulnerable but in degraded condition. These catchments were flagged for restoration. While most highly irreplaceable catchments in good condition were already protected, 2.5% of catchments in this category are on vulnerable land. These are priority areas for assigning river reserves.
1. The ability of many introduced fish species to thrive in degraded aquatic habitats and their potential to impact on aquatic ecosystem structure and function suggest that introduced fish may represent both a symptom and a cause of decline in river health and the integrity of native aquatic communities.
2. The varying sensitivities of many commonly introduced fish species to degraded stream conditions, the mechanism and reason for their introduction and the differential susceptibility of local stream habitats to invasion because of the environmental and biological characteristics of the receiving water body, are all confounding factors that may obscure the interpretation of patterns of introduced fish species distribution and abundance and therefore their reliability as indicators of river health.
3. In the present study, we address the question of whether alien fish (i.e. those species introduced from other countries) are a reliable indicator of the health of streams and rivers in south-eastern Queensland, Australia. We examine the relationships of alien fish species distributions and indices of abundance and biomass with the natural environmental features, the biotic characteristics of the local native fish assemblages and indicators of anthropogenic disturbance at a large number of sites subject to varying sources and intensities of human impact.
4. Alien fish species were found to be widespread and often abundant in south-eastern Queensland rivers and streams, and the five species collected were considered to be relatively tolerant to river degradation, making them good candidate indicators of river health. Variation in alien species indices was unrelated to the size of the study sites, the sampling effort expended or natural environmental gradients. The biological resistance of the native fish fauna was not concluded to be an important factor mediating invasion success by alien species. Variation in alien fish indices was, however, strongly related to indicators of disturbance intensity describing local in-stream habitat and riparian degradation, water quality and surrounding land use, particularly the amount of urban development in the catchment.
5. Potential confounding factors that may influence the likelihood of introduction and successful establishment of an alien species and the implications of these factors for river bioassessment are discussed. We conclude that the potentially strong impact that many alien fish species can have on the biological integrity of natural aquatic ecosystems, together with their potential to be used as an initial basis to find out other forms of human disturbance impacts, suggest that some alien species (particularly species from the family Poeciliidae) can represent a reliable ‘first cut’ indicator of river health.
1. Freshwater ecosystems are amongst the most threatened and poorly protected globally. They continue to be degraded through habitat loss, pollution and invading species and conservation measures are urgently needed to halt declining trends in their biodiversity and integrity.
2. During the past decade a suite of decision support tools and computational approaches have been developed for efficient and targeted conservation action in terrestrial or marine ecosystems. These methods may be poorly suited for planning in freshwater systems because connectivity in terrestrial and marine systems is typically modelled in a way unsuitable for rivers, where connectivity has a strong directional component.
3. We modify the conservation prioritization method and software, zonation , to account for connectivity in a manner better suited to freshwater ecosystems. Prioritization was performed using subcatchment/catchment‐based planning units and connectivity was modified to have directional upstream and downstream components consistent with the ecology of our target species.
4. We demonstrate this modified method for rivers and streams in the southern North Island of New Zealand. Data included predicted occupancy from boosted regression tree models of species distributions for 18 fish species. The study area covered 2.1 million hectares and included 394 first‐ to fourth order catchment or subcatchment planning units.
5. Realistic modelling of connectivity had a major influence on the areas proposed for conservation. If connectivity was ignored, recommended conservation areas were very fragmented. By contrast, when connectivity was modelled, high priority conservation targets consisted of entire river basins or headwater subcatchments.
6. The proposed method serves as a starting point for the implementation of reserve selection methods in river ecosystems.
1. The Upper Yangtze River drains a catchment of c. 1 million km2 from its headwaters on the Tibetan Plateau to the city of Yichang below the Three Gorges Dam. The Upper Yangtze River Basin supports a diverse aquatic fauna, including 118 endemic fish species. The river basin has a long history of human use and environmental alteration and is further threatened by the demands of a large population and rapid economic development.
2. We identified a set of areas that, with adequate protection and/or management, might maintain the aquatic biodiversity and ecological processes representative of the basin. Methods were developed to address the scope and scale of conservation planning across the entire Upper Yangtze Basin in a short time-frame using available data. The analytical framework is a watershed hierarchy of five catchment size classes derived from a globally available hydrography dataset called HydroSHEDs. Catchments were assigned to ecosystem types according to catchment area and patterns of climate, catchment morphology, geology and sources of water. Catchments were also ranked by ecological condition using an index of cumulative anthropogenic impacts.
3. We defined conservation priorities as a combination of expert-designated focal areas that support endemic fish assemblages and habitat in good condition; sites selected with the conservation planning software MARXAN to meet representation targets for ecosystems and optimise ecological condition and longitudinal connectivity; and a set of rivers selected to provide refugia for fishes affected by a hydropower and flood control infrastructure development project.
4. Areas selected as conservation priorities include 3200 km (27% of total length) of large rivers, 9900 km (39% of total length) of small rivers and 30% of small stream catchments in the basin. To evaluate the degree to which the set of conservation priority areas supports threatened and endemic fishes, we conducted a gap analysis using survey records and historic range maps of 131 threatened and/or endemic fish species. The conservation priority areas contain survey records or portions of the known historic range of 116 (88%) of the 131 species we evaluated, with an average of 49% of the survey records and/or 26% of the known historic ranges of each species.
Predicting the distribution of endangered species from habitat data is frequently perceived to be a useful technique. Models that predict the presence or absence of a species are normally judged by the number of prediction errors. These may be of two types: false positives and false negatives. Many of the prediction errors can be traced to ecological processes such as unsaturated habitat and species interactions. Consequently, if prediction errors are not placed in an ecological context the results of the model may be misleading. The simplest, and most widely used, measure of prediction accuracy is the number of correctly classified cases. There are other measures of prediction success that may be more appropriate. Strategies for assessing the causes and costs of these errors are discussed. A range of techniques for measuring error in presence/absence models, including some that are seldom used by ecologists (e.g. ROC plots and cost matrices), are described. A new approach to estimating prediction error, which is based on the spatial characteristics of the errors, is proposed. Thirteen recommendations are made to enable the objective selection of an error assessment technique for ecological presence/absence models.
Declining trends in the integrity of freshwater systems demand exploration of all possible conservation solutions. Freshwater protected areas have received little attention, despite the prominence of protected areas as conservation interventions for terrestrial and more recently marine features. We argue that a dialogue on freshwater protected areas has been neglected both because few models of good protected area design exist, and because traditional notions of protected areas translate imperfectly to the freshwater realm. Partly as a result of this conceptual disconnect, freshwaters have been largely ignored in protected area accounting schemes, even though a number of existing freshwater conservation strategies could qualify according to general protected area definitions. Rather than impose terrestrially-motivated ideas about protected areas onto freshwaters, we propose new vocabulary – freshwater focal area, critical management zone, and catchment management zone – that can be used in conjunction with IUCN protected area categories and that recognize the special ecological dynamics of freshwaters, and in particular the critical role of fluvial processes. These terms, which attempt to diffuse concerns about locking away essential ecosystem goods and services, move us toward consideration of protected areas for freshwaters. This conceptual shift, which acknowledges that freshwater conservation may occur remotely from freshwater features, opens the door for improved integration of freshwater, terrestrial, and marine concerns in protected area design and management.
A method for assessing anthropogenic river disturbance is described. The grid-based spatial modeling procedure computes indices of disturbance for individual stream sections. These indices rank streams along a continuum from near-pristine to severely disturbed. The method couples geographical data, recording the extent and intensity of human activities known to impact on river condition, with a Digital Elevation Model (DEM) used for drainage analysis. It was developed to produce the first nation-wide assessment of river disturbance from which Australia’s least disturbed or ‘wild’ rivers were identified. A national summary of the extent and the potential impact of human activities is presented, calculated from the disturbance index values computed for more than 1.5×106 stream sections with a total length of over 3×106 km. Index values close to the undisturbed end of the continuum are rare, especially among large rivers. Most of the least disturbed streams are predicted to lie within the monsoonal tropical north or the arid/semi-arid center of the continent.The disturbance indices generated provide a comprehensive and consistent characterization of river and catchment disturbance that has applications beyond the identification of wild rivers. These include identification of priorities for rehabilitation and restoration; development of systematic survey strategies for aquatic, riparian and estuarine biota and identification of reserve networks for river systems. However, these applications depend on validating the correlation between river disturbance indices and intensively sampled physical and biological indicators of river condition.
The European Union Water Framework Directive recognises the need for and value of biological monitoring. This paper reviews the modelling approach known as River Invertebrate Prediction and Classification System (RIVPACS) for assessing the ecological quality of river sites using macroinvertebrate sampling. The RIVPACS philosophy is to develop statistical relationships between the fauna and the environmental characteristics of a large set of high quality reference sites which can be used to predict the macroinvertebrate fauna to be expected at any site in the absence of pollution or other environmental stress. The observed fauna at new test sites can then be compared with their site-specific expected fauna to derive indices of ecological quality. All methodological decisions in any such model development have implications for the reliability, precision and robustness of any resulting indices for assessing the ecological quality and ecological grade (‘status’) of individual river stretches. The choice of reference sites and environmental predictor variables, the site classification and discrimination methods, the estimation of the expected fauna, and indices for comparing the agreement, or lack of it, between the observed and expected fauna, are all discussed. The indices are assessed on the reference sites and on a separate test set of 340 sites, which are subject to a wide range of types and degrees of impairment.
Past work ascribing priorities for the selection of nature reserves has weighted attributes and applied formulae in a single stage process. This single application of a formula means that areas of differing priority may contain similar mixes of species, communities or habitats, and may thus lead to imbalance in representation when preservation takes place, with some previously unpreserved or poorly preserved species, communities or habitats being found in several of the new reserves, and others being absent. An iterative method that has been applied to assess priorities for the preservation of threatened species in the central east coast of Tasmania overcomes this difficulty. The area with the highest score in the initial stages of analysis is assumed to be preserved and the weightings of attributes are altered accordingly. These new weightings are applied to locate the area of next highest priority, and the process continues until predetermined preservation goals are met.
Modelling techniques used in binary classification problems often result in a predicted probability surface, which is then translated into a presence–absence classification map. However, this translation requires a (possibly subjective) choice of threshold above which the variable of interest is predicted to be present. The selection of this threshold value can have dramatic effects on model accuracy as well as the predicted prevalence for the variable (the overall proportion of locations where the variable is predicted to be present). The traditional default is to simply use a threshold of 0.5 as the cut-off, but this does not necessarily preserve the observed prevalence or result in the highest prediction accuracy, especially for data sets with very high or very low observed prevalence. Alternatively, the thresholds can be chosen to optimize map accuracy, as judged by various criteria. Here we examine the effect of 11 of these potential criteria on predicted prevalence, prediction accuracy, and the resulting map output. Comparisons are made using output from presence–absence models developed for 13 tree species in the northern mountains of Utah. We found that species with poor model quality or low prevalence were most sensitive to the choice of threshold. For these species, a 0.5 cut-off was unreliable, sometimes resulting in substantially lower kappa and underestimated prevalence, with possible detrimental effects on a management decision. If a management objective requires a map to portray unbiased estimates of species prevalence, then the best results were obtained from thresholds deliberately chosen so that the predicted prevalence equaled the observed prevalence, followed closely by thresholds chosen to maximize kappa. These were also the two criteria with the highest mean kappa from our independent test data. For particular management applications the special cases of user specified required accuracy may be most appropriate. Ultimately, maps will typically have multiple and somewhat conflicting management applications. Therefore, providing users with a continuous probability surface may be the most versatile and powerful method, allowing threshold choice to be matched with each maps intended use.
To study the Earth system and to better understand the implications of global environmental change, there is a growing need for large‐scale hydrographic data sets that serve as prerequisites in a variety of analyses and applications, ranging from regional watershed and freshwater conservation planning to global hydrological, climate, biogeochemical, and land surface modeling. Yet while countless hydrographic maps exist for well‐known river basins and individual nations, there is a lack of seamless high‐quality data on large scales such as continents or the entire globe. Data for many large international basins are patchy, and remote areas are often poorly mapped.
In response to these limitations, a team of scientists has developed data and created maps of the world's rivers that provide the research community with more reliable information about where streams and watersheds occur on the Earth's surface and how water drains the landscape. The new product, known as HydroSHEDS (Hydrological Data and Maps Based on Shuttle Elevation Derivatives at Multiple Scales), provides this information at a resolution and quality unachieved by previous global data sets, such as HYDRO1k [ U.S. Geological Survey (USGS) , 2000].
The Cape Floristic Region of South Africa is a global biodiversity hotspot. In 1998, a process of conservation planning began in the region that required quantitative targets for biodiversity. We combined new information and previously available data sets on biodiversity pattern and process to formulate targets for five groups of features: 102 broad habitat units (land types); locality records for 364 plant species in the family Proteaceae; locality records for 345 species of reptiles, amphibians and freshwater fish; estimated distributions and densities of 41 species of large and medium-sized mammals; and six types of spatial surrogates for ecological and evolutionary processes. We discuss our approach to formulating quantitative targets in the context of the general role of targets in conservation planning, the inadequacy of commonly used standard targets such as 10% of features or whole regions, and the uncertainties around setting targets for land types. We then describe our reasoning and methods for analysing data and identifying targets for each group of features. Our targets are not theoretical-they have been used to develop a regional conservation plan for which implementation is underway. Our targets are, however, provisional. Like any other conservation targets, they are estimates of the requirements for persistence of a region's biodiversity made within the constraints of limited information. We expect them to be improved in future reviews of appropriate targets for the Cape Floristic Region and elsewhere. Crown Copyright (C) 2003 Published by Elsevier Science Ltd. All rights reserved.
Realistic time frames in which management decisions are made often preclude the completion of the detailed analyses necessary for conservation planning. Under these circumstances, efficient alternatives may assist in approximating the results of more thorough studies that require extensive resources and time. We outline a set of concepts and formulas that may be used in lieu of detailed population viability analyses and habitat modeling exercises to estimate the protected areas required to provide desirable conservation outcomes for a suite of threatened plant species. We used expert judgment of parameters and assessment of a population size that results in a specified quasiextinction risk based on simple dynamic models The area required to support a population of this size is adjusted to take into account deterministic and stochastic human influences, including small-scale disturbance deterministic trends such as habitat loss, and changes in population density through processes such as predation and competition. We set targets for different disturbance regimes and geographic regions. We applied our methods to Banksia cuneata, Boronia keysii, and Parsonsia dorrigoensis, resulting in target areas for conservation of 1102, 733, and 1084 ha, respectively. These results provide guidance on target areas and priorities for conservation strategies.
Conservation planning is the process of locating and designing conservation areas to promote the persistence of biodiversity in situ. To do this, conservation areas must be able to mitigate at least some of the proximate threats to biodiversity. Information on threatening processes and the relative vulnerability of areas and natural features to these processes is therefore crucial for effective conservation planning. However, measuring and incorporating vulnerability into conservation planning have been problematic. We develop a conceptual framework of the role of vulnerability assessments in conservation planning and propose a definition of vulnerability that incorporates three dimensions: exposure, intensity, and impact. We review and categorize methods for assessing the vulnerability of areas and the features they contain and identify the relative strengths and weaknesses of each broad approach. Our review highlights the need for further development and evaluation of approaches to assess vulnerability and for comparisons of their relative effectiveness.
National Surface Water Information
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Geoscience Australia (2011) National Surface Water Information. Canberra.
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