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Frequent fuel-reduction burning: The role of logs and associated leaf litter in the conservation of ant biodiversity
Abstract
Frequent low-intensity fires are used in management of Australian forests to reduce fuel loads and protect natural resources and human property. Low-intensity fires are typically patchy and unburned litter microhabitats are often associated with large objects such as logs, which may act as refuges both for vertebrate and for invertebrate fauna. The aim of this study was to determine whether ants were using unburned leaf litter microhabitats associated with logs as a refuge after fire. The study was carried out in Bulls Ground State Forest, New South Wales, Australia, where experimentally burned and unburned sites had previously been established. Species richness and abundance of ants in leaf litter did not differ between habitats adjacent to logs and away from logs, in burned and unburned sites. Fifteen of the 42 ant species were found in all four habitats, and contributed 94% of total ant abundance. Every habitat had a group of unique species, which together made up 30% of the total species richness. There was also a distinct group of species that was not found in the leaf litter associated with the burned/open habitat. However, as 45% of all species were found in low abundance (less than 10 individuals), care must be taken in inferring patterns for these groups. When functional groups were used to assess community structure, ‘cryptic’ species were found to be common in all habitats, whereas ‘subordinate Camponotini’ were found in burned habitats only. This study indicates that in an area where frequent burning is applied on a broad scale, preserving a range of microhabitats, including those associated with retained logs, may make a substantial contribution to conserving ant biodiversity.
... For ants, CWD is known to provide nesting habitat to species in the genera Camponotus, Formica, Pheidole and Aphaenogaster, among others [33][34][35], but the importance of wood presence to other ant taxa is unclear. Ant species richness has been shown to increase in the immediate vicinity of logs as compared to 3 m away [36], and the presence of both fire and CWD has been shown to benefit specific ant species [36]. CWD may offer wood-nesting ants protection from heat-and fire-inflicted mortality, as it does for termites [37]. ...
... For ants, CWD is known to provide nesting habitat to species in the genera Camponotus, Formica, Pheidole and Aphaenogaster, among others [33][34][35], but the importance of wood presence to other ant taxa is unclear. Ant species richness has been shown to increase in the immediate vicinity of logs as compared to 3 m away [36], and the presence of both fire and CWD has been shown to benefit specific ant species [36]. CWD may offer wood-nesting ants protection from heat-and fire-inflicted mortality, as it does for termites [37]. ...
... In our study, some seed removers such as P. bilimeki and O. brunneus were detected more often in plots with CWD, but species richness and the number of seeds removed did not vary with CWD presence. Unlike other studies where species nesting in wood was measured [32], or where specific measured distances from wood was a predictor variable for species richness [36], we did not check CWD for nests, and, while our seed trials were conducted at the center of each subplot, CWD occupied varying space and position within subplot parameters. While this study was unable to establish relationships between seed removers and CWD, future species-specific studies may reveal significant associations that necessitate more direct study. ...
Prescribed fire is used globally as a habitat restoration tool and is widely accepted as supporting biotic diversity. However, in fire-prone ecosystems, research has sometimes documented post-fire reduction in ant diversity and accompanying changes in seed removal behavior. This is concerning because ants provide important ecosystem services that can aid in restoration efforts, including seed dispersal. In this study, we examined the immediate impacts of fire in the well-studied ant community of longleaf pine forests (LLP) in the SE USA. We surveyed seed-removing ant species in a LLP sandhill ecosystem to investigate the effects of prescribed fire and coarse woody debris (CWD), a nesting and foraging resource, on ant community composition and ant–seed interactions. Seed-removing ants comprised a significant portion of detected ant species (20 of 45); eight of these species are documented removing seeds for the first time. Following an experimentally applied low-intensity summer burn, decreases in seed remover detection were observed, along with reductions in the number of seeds removed, across both burned and unburned areas; neither prescribed fire nor proximity to CWD significantly influenced these factors. Together, these results show that seed-removing ant species constitute a substantial proportion of the LLP sandhill ant community and are relatively robust to habitat changes mediated by low-intensity prescribed burning during the growing season. Considering ant community resiliency to fire, we can infer that using prescribed fire aligns with the goals of restoring and maintaining biotic diversity in this fire-prone ecosystem.
... Nearby areas which have remained unburnt for periods over 15 or 20 years support higher densities of some shrub and noneucalypt tree species, particularly those able to recruit between fires (Birk & Bridges 1989;Henderson & Keith 2002). Each regime provides habitat for an equally diverse, but substantially different, array of invertebrates and small mammals (Andrew et al. 2000;York 2000;Bickel & Tasker 2004;Tasker & Dickman 2004). ...
... York (2000) concluded that a variety of management strategies, from fire exclusion to frequent burning, would be needed in the forests of the region to maintain the full complement of ant species. Andrew et al. (2000) also studied ants, but two years after the study reported in York (2000) in the same study sites. Burnt plots were four years post-fire. ...
... Results from Stewart (1999), York (1999York ( , 2000a and Andrew et al. (2000) are particularly valuable in the current context, as this well-replicated experiment focuses directly on fire frequency without the complication of grazing which appears to have been unavoidable in a number of retrospective studies. Unusually, we know more about the effects of the two fairly extreme fire regime treatments on fauna, than we do about their effects on flora. ...
This literature review forms part of a suite of materials that Hotspots aims to produce in each Catchment Management Authority (CMA) region in which it works. While most Hotspots products are targeted to landholders, literature reviews are directed towards a professional audience. Their primary aim is to provide ecological background to underpin and inform the messages about fire that Hotspots and local NRM practitioners present. A secondary aim is to offer a platform for discussion and debate on the role of fire in regional vegetation types. In both cases we hope the outcome will be more informed fire management for biodiversity conservation.
This review considers literature relevant to a subset of vegetation classes in the Lachlan CMA region of New South Wales (NSW). It aims to help land and fire managers not only to understand the impacts of fire in the region, but also to place that understanding in a wider ecological context. Companion documents covering the Central West, Hunter, Namoi, Northern Rivers and Southern Rivers regions are also available (Watson 2006 a, b 2007; Watson and Tierney 2008, 2009).
Fire affects different plant and animal species differently, and fire regimes compatible with biodiversity conservation vary widely between ecosystems (Bond 1997; Watson 2001; Bradstock et al. 2002; Kenny et al. 2004). This document explores the role of fire in the vegetation formations of Keith (2004). All vegetation formations covered in this review also occur in the Namoi and Central West CMAs. However the literature is limited for some vegetation formations and this is reflected in this review. Fire is also of limited occurrence in most wetland types (though it can occur in Forested Wetlands), therefore wetlands are also not considered in this review. The broad vegetation formations of Keith (2004) can be further subdivided into classes (Table 1). Where literature permits, the fire ecology of classes that occur in the Lachlan CMA region are discussed (often there is no literature available at the class level or limited to only one study).
... Nearby areas which have remained unburnt for periods over 15 or 20 years support higher densities of some shrub and noneucalypt tree species, particularly those able to recruit between fires (Birk & Bridges 1989;Henderson & Keith 2002). Each regime provides habitat for an equally diverse, but substantially different, array of invertebrates and small mammals (Andrew et al. 2000;York 2000;Bickel & Tasker 2004;Tasker & Dickman 2004). ...
... York (2000) concluded that a variety of management strategies, from fire exclusion to frequent burning, would be needed in the forests of the region to maintain the full complement of ant species. Andrew et al. (2000) also studied ants, but two years after the study reported in York (2000) in the same study sites. Burnt plots were four years post-fire. ...
... Results from Stewart (1999), York (1999York ( , 2000a and Andrew et al. (2000) are particularly valuable in the current context, as this well-replicated experiment focuses directly on fire frequency without the complication of grazing which appears to have been unavoidable in a number of retrospective studies. Unusually, we know more about the effects of the two fairly extreme fire regime treatments on fauna, than we do about their effects on flora. ...
... Some studies of the effects of low intensity fire on ant populations indicate that burning does not affect ant richness or abundance, but it could change the types of ants that are present (Andrew et al. 2000) and affect the community organization (York 2000). ...
... Since complete suppression of fire is not ideal due to the risk of wildfire and the negative effects suppression can have on plant regeneration (Shang et al. 2007), we feel that including islands would provide a compromise treatment that would promote both insect and plant biodiversity. Similar studies that have looked at the influence of unburned refugia (islands) on insect diversity concur with our results in determining that the refugia was important for some insects to seek shelter during the fire (Andrew et al. 2000;Kalisz and Powell 2000;Gandhi et al. 2001;Panzer 2003;Knight and Holt 2005;Swengel and Swengel 2007). Pearce and Venier (2006) advocate that less intensively burned areas leave residual vegetation to aid in the re-colonization of open habitat, while Porter and Redak (1996) disagree, noting that small residual areas are still susceptible to high temperatures that can kill insect populations. ...
... hollows in large trees, Xanthorrhoea preissii, Brennan, Moir & Wittkuhn 2011). Each of these functions at a range of scales: for example, intrinsically flammable refuge habitats range from microhabitats associated with logs (Andrew, Rodgerson & York 2000) and unburned litter (Kiss & Magnin 2006) to larger patches of unburned vegetation (Swengel & Swengel 2007;Watson et al. 2012a). Biotic interactions also influence immediate survival, including competition for refuges just prior to and during the fire event, and predation during or shortly after the event (Whelan et al. 2002). ...
... In some instances, such as unburnt vegetation surrounded by severely burnt vegetation, patches are visibly distinct. In other situations, such as the persistence of small mammals or ants (Andrew, Rodgerson & York 2000) amongst logs and rocks in burnt vegetation, the difference between refuge and matrix may be subtle. Third, the postfire mosaic is temporally dynamic, changing in quality and contrast as vegetation recovery proceeds (e.g. ...
... Specific insect guilds are highly sensitive to habitat disturbance (Day et al. 1993;Samways 1994;Mendez et al. 1995). For example, carabids (Kromp 1990;Beaudry et al. 1997;Villa-Castillo & Wagner 2002), Lepidoptera (Holloway & Stork 1991;Kremen 1992), Odonata (Samways 1996), and Formicidae (Buffington 1967;Majer 1982;Andersen 1990Andersen , 1991Andersen , 1995Andersen , 1997aRoth et al. 1994;York 1994York , 1999York , 2000Brown 1997;King et al. 1998;Peck et al. 1998;Bromham et al. 1999;Andrew et al. 2000;Vanderwoude et al. 2000;Stephens & Wagner 2006), have all been used successfully as bioindicators (Peck et al. 1998). ...
... Peck et al. (1998) saw significant changes in ant communities based on vegetation community diversity and structure. Disturbance resulting from fire and timber management has been observed to affect ant communities (Neumann 1992;Andrew et al. 2000;York 2000). ...
Plantation forests are becoming an increasingly important component of the world’s forested ecosystem. However, relatively little is known about how forest plantation management, overstory tree species composition and diversity impact biodiversity of nontree components of the forest. We assessed changes in ant functional group composition as related to changes in overstory tree diversity (monocultures vs. polycultures), species composition (native African species vs. exotic teak), and time (one and two years after planting). A pitfall trapping scheme was implemented during the summer months of 2006 and 2007. A total of 7473 specimens were collected representing six subfamilies, 22 genera, and 65 species. We found no significant differences in traditional diversity measures or functional group composition between treatments one year after planting. Two years after planting, we found that species richness of ground foraging ants had significantly increased (F = 4.60, d.f. = 4, 15, p = 0.01). Several observed trends may have indicated that these ant communities were in transition and will likely become more distinct over time as the different plantation types recover from disturbance and diverge from each other in overstory structure.
... Vegetation structure is critical in providing suitable habitat for many vertebrates and invertebrates (Woinarski et al., 1997;Andrew et al., 2000;Majer et al., 2002;Spencer et al., 2005;Debus et al., 2006;Yarnell et al., 2008;Montague-Drake et al., 2009;Gregory et al., 2010;De Cáceres et al., 2013). Disturbances such as clearing, grazing and fire can result in altered vegetation complexity (Van Auken, 2000;Heisler et al., 2004;Schoennagel et al., 2004;Radloff et al., 2014;Brown et al., 2015;Sitters et al., 2015). ...
... Frequent low-intensity burning (i.e. hazard or prescribed burning) is carried out to reduce fuel in order to protect life and property while aiming to minimise the extent and severity of wildfires (Gill et al., 1987;Williams et al., 1994;Andrew et al., 2000;McCarthy et al., 2001;Whelan, 2002;Whelan, 2009;Clarke, 2008). Fuel consists of bark, elevated fuel (shrub, heath, suspended material) and surface fine fuel (litter bed, grass tussocks, low shrubs; McCarthy, 2002). ...
... Such accumulations of litter can be valuable habitats for some species. For example, Andrew et al. (2000) found that ant species richness was significantly higher in leaf litter adjacent to logs than in litter accumulations sampled away from logs. ...
... This can suppress the growth of plants such as grasses and benefit other plant taxa sensitive to competition from grasses (Kirkpatrick 1997). Conversely, large logs can act as micro firebreaks, not only because of their diameter and length but also because of the moisture they contain and moisture levels in the adjacent litter (Andrew et al. 2000). The moisture content of logs may explain why they are often not completely consumed in a single fire event. ...
A review is presented of the ecological values of logs in Australian eucalypt forests. Logs are a key component of stand structural complexity and have critical functional roles for forest biodiversity including:- (1) providing nesting and sheltering sites for biota, (2) providing for aging substrates for predators like snakes and predatory invertebrates such as velvet worms, (3) providing basking and hibernation sites for reptiles, (4) facilitating animal movement, (5) providing places for key social behaviours, (6) acting as plant germination sites, (7) providing substrates to promote the growth of fungi, (8) providing mesic refugia for organisms during drought and/or fire, and (9) contributing to heterogeneity in the litter layer and patterns of ground cover. Logs also play significant roles in nutrient cycling in forests. The role of logs is often ignored in forestry operations, including those where harvesting intensification will occur through the removal of dead and/or "defective" standing trees and logs under the guise of removing so-called waste or logging "residues". Recently proposed intensive large-scale forestry operations in the Australian native forest estate (e.g., biomass burning power plants and charcoal plants) have the potential to reduce stand structural complexity, after forest ecosystem function and negatively impact upon log-dependent species in those part of the landscape where harvesting takes place. The risks of such impacts have not been adequately measured in Australia, but they need to be addressed urgently. Prescriptions for the retention and future recruitment of logs must be developed to avert possible losses of biodiversity.
... L'ordre de similitud decreixent amb la zona control (Z4) és: Z3, Z2, Z1. El gràfic de similitud (Fig. 5) (Montblanc, 2005) o positiu (Rice, 1932;York, 1999;Andersen, 1988;Andersen & Müller, 2000) & Herbst 1973;Espadaler & Nieves, 1983;Franch & Espadaler, 1988;Andersen & Müller, 2000;Andrew et al. 2000;Armbrecht et al. 2004;Coelho & Ribeiro, 2006 després del foc (Rice, 1932;Andersen, 1988;York, 1999;Andersen & Müller, 2000) no ho hem detectat així en el cas estudiat, però això pot ser degut al lapse de temps que hi ha hagut entre el foc i el període de mostreig (Wilkinson et al. 2005). El nombre d'individus per trampa no sembla haver estat afectat negativament. ...
S’ha analitzat l’efecte del incendi forestal ocorregut a la franja oriental del Parc
Natural de Sant Llorenç del Munt l’Obac l’agost de 2003 i els posteriors tractaments
post-incendi sobre la vegetació i la fauna de la zona. Quatre anys després de
l’incendi s’observa una simplificació en l’estructura de la vegetació amb pèrdua dels
estrats arbori i arbustiu i augment de l’estrat herbaci. No s’han detectat efectes en la
vegetació degudes als tractaments post-incendi, tot i que la zona subsolada
presenta risc d’erosió especialment si es produeixen gran episodis de pluges. Quant
a la fauna, s’han censat 25523 animals de 70 grups taxonòmics diferents. S’han
determinat a nivell d’espècie els gasteròpodes, formigues de terra i de vegetació,
heteròpters de terra, coleòpters de vegetació, ortòpters, rèptils, aus, carnívors i
quiròpters. D’aquests grups s’han identificat 257 espècies, el 18% de les quals
només han estat localitzades en el bosc mentre que un altre 17% només s’han
localitzat en les zones cremades. Aquestes pèrdues i guanys de diversitat afecten a
tots els grups taxonòmics i indiquen que els paisatges heterogenis amb una barreja
d’espais oberts i bosc poden incrementar notablement la biodiversitat global. Els
grups taxonòmics responen de diferent manera als tractaments: l’extracció de fusta
afavoreix la riquesa d’espècies d’alguns grups i perjudica a la d’altres. Per aquesta
raó és aconsellable la creació de mosaics amb diferent gestió post-incendi que
afavoreixin una restauració més completa de les zones cremades. La recurrència
d’incendis juntament amb l’ús de les zones cremades per a la pastura han provocat
una reducció de biodiversitat probablement com a conseqüència de l’efecte
combinat dels dos factors.
... G4 species are rare in the Mediterranean forest, but they were especially abundant in the study riparian areas. These species are often associated with well-preserved woody areas because many of them need certain degree of moisture and/or because they are litter-twigs dwelling ants (Andrew et al. 2000;Ottonetti et al. 2006;Andersen et al. 2009;Kwon 2016). This fact emphasizes the role of riparian areas as refuges for interesting species, but at the same times their vulnerability to disturbances. ...
Biotic invasions have become major agents of human-driven global change. One of the most virulent species for trees is the Dutch elm disease (DED) (Ophiostoma novo-ulmi). However, few are the studies that investigate its indirect impact on the fauna. In a well-preserved area of Sierra Morena (Cordoba, Spain), we report the repercussion of tree cover loss due to DED on ants (Hymenoptera, Formicidae), a bioindicator group. For 10 years, before and after DED, we studied ant assemblages in different zones with a gradient of invasion. In the most affected ones, indicator species of well-preserved habitats decreased, while generalist and opportunist species increased. The forest management practices undertaken after the disease had an even more devastating effect, and thus the logging and removal of dead trees in the Bejarano stream caused that its ant assemblage became more similar to the one of a nearby meadow than to the ones of close riparian areas.
... Los incendios forestales han afectado de manera significativa a la biodiversidad de la flora y fauna. El siniestro parcial o total de la masa forestal trae como consecuencias la fragmentación de hábitats y en ocasiones la pérdida total del hábitats de diversidad faunística de los ecosistemas afectados, incluyendo zonas de anidación, reproducción, alimentación y descanso (Andrew, Rodgerson y York, 2000). ...
Los incendios forestales producen enormes daños ambientales por la afectación o destrucción de la cubierta vegetal, la muerte o huida de miles de animales, la pérdida del suelo fértil y el avance de la erosión. Además pueden suponer todos los años, la pérdida de vidas humanas y grandes daños en los bosques, cultivos y viviendas. Las pérdidas económicas y las fuertes inversiones necesarias para disminuir los efectos posteriores de los incendios, son otras de las consecuencias (Vellozas, Púa, D. Mello, & Cardozo, 2010) El fuego dañino se integra a un círculo en el que diversos fenómenos influyen como causa y efecto, unos de otros, entre ellos, podemos contar la pérdida de biodiversidad, la
... They are further significant to alter the physical and chemical environment and can cause the impact upon the plants, microorganisms and the other soil fauna (Folgarait, 1998). Ants perform a variety of roles such as herbivores, predators, scavengers, seed dispersers, plant and arthropod mutualists, and soil engineers (Andersen et al., 2002;Sanders et al., 2003;Maeto & Sato, 2004) and good indicators of ecological condition Andrew et al., 2000;Read & Andersen, 2000;Bestelmeyer & Wiens, 2001;Andersen et al., 2002;Andersen et al., 2003;Maeto & Sato, 2004) for many reasons such as they are a diverse group, sensitive to environmental change, easily collected and assist in important ecological functions (Alonso & Agosti, 2000). ...
Ant diversity was studied in Muhan Pokhari area of Shivapuri-Nagarjun National Park (SNNP) at 1,700 m to 1,900 m asl during winter and summer seasons of 2017. Ants were collected using pitfall traps, leaf litter sampling, bait and hand collection methods along a transect of 50 m in each of all 5 sites (1,700 m, 1,750 m, 1,800 m, 1,850 m and 1,900 m). Altogether 817 individual ants were collected representing 5 sub-families, 16 genera and 23 morpho species. Formicinae (57.67%) was the most abundant sub-family, followed by Myrmicinae (40.39%), Pseudomyrmicinae (0.8%), Ponerinae (0.73%) and Dolichoderinae (0.37%).Camponotus (437individuals) was the most abundant genus followed by Aphaenogaster (287). Species richness was higher in winter (17 morph species) than in spring (14 morph species). Shannon-Wiener diversity index (1.4618) and Evenness index (0.5539) were higher in spring season. Pitfall trap method was found most effective with highest number of individual ants (567) and of 21 species. The Shannon-Weiner diversity index was highest for pitfall method (1.3039) whereas evenness index was highest for the bait method (0.62615). Two genera Pachycondyla and Echinopla were were recorded for the first time in Nepal.
... A study by Threlfall, Williams [53] suggests that increasing the diversity and quantity of understorey, leaf litter and coarse woody debris in urban areas can benefit both bird and bat assemblages. The presence of leaf litter and debris also forms important habitat for many ant species [54]. Recommended methods to aid the recruitment of native plant species such as retaining fallen deadwood, leaf litter and mulch [55,56] could be considered dangerous in public open space in bushfire prone areas, although our findings suggests that there may be planting arrangements that can help reduce the associated fire risks. ...
Vegetation in urban areas provides many essential ecosystem services. These services may be indirect, such as carbon sequestration and biological diversity, or direct, including microclimate regulation and cultural values. As the global population is becoming ever more urbanized these services will be increasingly vital to the quality of life in urban areas. Due to the combined effects of shading and evapotranspiration, trees have the potential to cool urban microclimates and mitigate urban heat, reduce thermal discomfort and help to create comfortable outdoor spaces for people. Understory vegetation in the form of shrubs and grass layers are also increasingly recognized for the positive role they play in human aesthetics and supporting biodiversity. However, in fire-prone urban landscapes there are risks associated with having denser and more complex vegetation in public open spaces. We investigated the effects of plant selection and planting arrangement on fire risk and human thermal comfort using the Forest Flammability Model and Physiological Equivalent Temperature (PET), to identify how planting arrangement can help balance the trade-offs between these risks and benefits. Our research demonstrated the importance of vertical separation of height strata and suggests that Clumped and Continuous planting arrangements are the most effective way of keeping complex vegetation in public open space to deliver the greatest human thermal comfort benefit while minimizing potential fire behaviour. This study provides an example of how existing research tools in multiple ecological fields can be combined to inform positive outcomes for people and nature in urban landscapes.
... Exceptions are the studies made by Greenslade (1986) in South Australia and Andersen in the northern Territory, where species levels and functional groups were essential part of the data collected and analyzed (Andersen, 1991b). Also York (2000), Manwaring et al. (2014), Andrew et al. (2000), Gunawardene & Majer (2005), Parr & Andersen (2008) and few others included functional group analysis in their research. But it is still not an essential component of ant community composition researches. ...
Invertebrates are important indicators of ecosystem disturbances. Within this group ants have been studied
intensively. In this study ants were collected in a total of 75 sampling sites in the Wombat Forest in southeastern
Victoria, also known as the FESA study or Fire Effect Sample Areas. There 5 prescribed burning treatments are
being analyzed to measure the impact of each treatment on the environment. These treatments consist in different
frequency and seasonality of the fires. In 2012 litter sampling was made to collect invertebrates to analyze the taxa
and species composition, abundance and richness. This leaded to the identification of the impact of different prescribed
fire treatments on insect communities. Of these invertebrates, a total of 3515 ants have been sampled and
identified, representing 31 morphospecies, 22 genera and belonging to five subfamilies. The collected ants represent
7 functional groups. The most abundant was the Opportunist group, with 65 of the total, followed by the Dominant
Dolichoderinae group with 11.7. Rhytidonopera was the most abundant species, with 46.1 of all collected ants
and followed by Paraparatrechina with 18.7 of the total. This study analyses if there was an impact of ant species
composition after nearly 30 years of different fire treatments in the area. Parallel to the invertebrate sampling, 41
environmental variables were measured at the sample sites. These variables, related to geographic aspects, soil and
litter were analyzed in relation to the fire treatments and the ant species richness and composition. With the statistical
analysis it was determined that no significant impact of abundance or species richness was caused by the different
prescribed burning treatments. Neither a change in functional groups was found, but a shift of species within the
Opportunist functional group, caused by the seasonality of the fires.
... Likewise, species which require logs or deep litter layers may be excluded for decades after fire whilst these features develop (e.g. Andrew et al., 2000;Smith et al., 2013;Holland et al., 2017). In systems where standreplacing prescribed burns are conducted (e.g. ...
Prescribed (or “planned”) burning is used by land managers to reduce fuel-loads in order to mitigate the spread of wildfire, thereby protecting life and property, and to promote environmental heterogeneity to enhance biodiversity. Globally, many fire management agencies focus on increasing extent and frequency of prescribed burning. There is a need to assess how high levels of prescribed burning may affect the long-term, landscape-level persistence of ecological communities. We forward projected management scenarios over 21 years to explore how the operationally realistic implementation of four different prescribed burn targets, covering 5, 3, 1.5 and 0% of a large reserve per annum (p.a.) might affect provision and removal of fire-mediated habitat of 11 rare and threatened bird species. Sustained implementation of high targets (5 and 3% p.a.) homogenised the landscape toward young vegetation, substantially reducing highly suitable habitat for species requiring intermediate (20–60 years post-fire) and older (60+ years) age classes. In contrast, no prescribed burning generated insufficient habitat for species with early (<20 years) and intermediate seral requirements. Strategies reliant upon persistently high levels of prescribed burning are likely to have negative effects on a number of threatened species already considered vulnerable due to their low populations and restricted ranges. In contrast, management processes that allow for periodic evaluation and flexibility in how strategies are implemented would better enable practitioners to tailor fire management to individual ecosystems. Carefully targeting key areas for wildfire prevention, and promoting some successional changes through application of fire in other areas, will help to maintain and improve suitable habitat for species of conservation concern.
... York 1999;Pausas & Bradstock 2007;Bowman et al. 2014;Clarke et al. 2014). Fire frequency can sometimes be important to specific plant or animal species, which may rely on or benefit from frequent fire or long periods without fire (Andrew et al. 2000;Bradstock et al. 2005;Fisher et al. 2009;Duff et al. 2013;Bowman et al. 2014). For example caterpillars of an Australian butterfly, the Altona skipper (Hesperilla flavescens subsp. ...
Fire has a varied influence on plant and animal species through direct (e.g. fire‐induced mortality) and indirect (e.g. modification of habitat) effects. Our understanding of the influence of fire regime on invertebrates and their response to fire‐induced modifications to habitat is poor. We aimed to determine the response of a beetle family (Coleoptera: Cerambycidae) to varying fire treatments and hypothesised that the abundance of cerambycid beetles is influenced by fire frequency due to modifications in habitat associated with the fire treatments. Arthropods were sampled across 3 months in annually and triennially burnt areas (treatments starting in 1952 and 1973 respectively), an area unburnt since 1946, and a former unburnt treatment, burnt by wildfire in 2006. Eleven different cerambycid taxa were collected using flight intercept panel traps, dominated by three species (Ipomoria tillides, Adrium sp. and Bethelium signiferum) which made up 99% of individuals collected. Over the sampling period the long unburnt treatment had significantly lower species richness than the triennial and wildfire treatments. Cerambycid abundance was significantly higher in the triennially burnt treatment than in all other fire treatments. Ipomoria tillides was more abundant in both frequently burnt treatments, Adrium sp. was more common in triennially burnt areas, whereas B. signiferum, was more common in the wildfire affected treatment. Some, but not all, cerambycid beetles were more common in areas with a more open understorey (i.e. resulting from frequent burning), and lower tree basal area, as this likely influences their ability to fly easily between food sources. Cerambycid abundance was positively related to the volume of coarse woody debris and healthy tree crowns. Cerambycid beetles were clearly influenced by historic fire regime, suggesting that changes in fire regime can potentially have a profound influence on arthropod assemblages, and subsequent influences on ecosystem processes, which are currently poorly understood.
... The high pre-fire ant species richness seems coherent with the presence of variable sources of nourishment and niches. Thus, according to Andrew et al. (2000), the unburned litter microhabitats are often associated with different objects such as logs, acting as refuges both for vertebrate and for invertebrate fauna. The poorest post-fire communities can be explained by the modification of habitat complexity (Parr et al. 2004), affecting the species richness which might be more a surrogate of ant activities. ...
To maintain savanna vegetation,mid-seasonal fire has been applied since 1961 in the Lamto Savanna (Côte
d’Ivoire). However, this prescribed fire has not impeded tree encroachment during recent years, nor have its effects
on insect assemblages been documented. Also the impact of tree intrusion on insect assemblages is poorly studied in
savanna. To prevent tree density increasing, a change in fire regime might be a solution. In this study, we examined
the effect of different fire regimes (early, mid-seasonal and late fires) on leaf-litter ant assemblages in order to suggest
appropriate measures for preventing tree invasion without having an effect on insect communities. Sampling was
implemented by combining pitfall trapping and leaf-litter sampling before and after three different fire regimes, early,
mid-seasonal and late fires. While the ant species richness declined after the passage of early and mid-seasonal fires,
significantlymore specieswere found in the burnt savanna after the late fire. However, the losses or gains of species due
to different fire regimes did not cause severe changes in the ant species composition. Of the functional groups identified,
only the generalists and specialist predators were respectively strongly affected by the early and mid-seasonal fires,
certainly due to micro-habitat modification. Based on the trends observed in the present study, we suggest sampling
other invertebrate fauna in similar savanna plots to find out if other insect groups have similar reactions to the applied
fire regimes.
... The high pre-fire ant species richness seems coherent with the presence of variable sources of nourishment and niches. Thus, according to Andrew et al. (2000), the unburned litter microhabitats are often associated with different objects such as logs, acting as refuges both for vertebrate and for invertebrate fauna. The poorest post-fire communities can be explained by the modification of habitat complexity (Parr et al. 2004), affecting the species richness which might be more a surrogate of ant activities. ...
To maintain savanna vegetation, mid-seasonal fire has been applied since 1961 in the Lamto Savanna (Côte d'Ivoire). However, this prescribed fire has not impeded tree encroachment during recent years, nor have its effects on insect assemblages been documented. Also the impact of tree intrusion on insect assemblages is poorly studied in savanna. To prevent tree density increasing, a change in fire regime might be a solution. In this study, we examined the effect of different fire regimes (early, mid-seasonal and late fires) on leaf-litter ant assemblages in order to suggest appropriate measures for preventing tree invasion without having an effect on insect communities. Sampling was implemented by combining pitfall trapping and leaf-litter sampling before and after three different fire regimes, early, mid-seasonal and late fires. While the ant species richness declined after the passage of early and mid-seasonal fires, significantly more species were found in the burnt savanna after the late fire. However, the losses or gains of species due to different fire regimes did not cause severe changes in the ant species composition. Of the functional groups identified, only the generalists and specialist predators were respectively strongly affected by the early and mid-seasonal fires, certainly due to micro-habitat modification. Based on the trends observed in the present study, we suggest sampling other invertebrate fauna in similar savanna plots to find out if other insect groups have similar reactions to the applied fire regimes.
... A thick leaf litter layer has been shown to influence occurrence of A. flavipes (Stokes et al., 2004). Arthropods found in leaf litter are a necessary food component for carnivorous small mammals including Antechinus, and therefore this might be partially explained by the role of leaf litter for the abundance of invertebrate prey (Andrew et al., 2000, York, 1999. The lower amount of leaf litter at the burnt sites in November 2014 is likely explained by its removal through combustion in the October 2013 wildfire. ...
Since 2012, five new species of carnivorous marsupial Antechinus have been described. One of these, the threatened silver-headed antechinus (Antechinus argentus), has a highly restricted distribution and occurs in low abundance. When the present study commenced, almost nothing was known of the ecology of the species. Therefore, the aim of this research was to provide foundational knowledge by investigating three main components of the species' ecology: 1. diet, 2. life-history, and 3. habitat use. The aims were achieved and the research resulted in a threatened species listing. The present thesis provides necessary recommendations for ongoing conservation management of the species.
... At the broadest scales, salvage logging, wildfire due to forest mismanagement, and land conversion present significant threats to dead wood environments and all of the species they support (Andrew et al. 2000;Watt et al. 2002;Majer et al. 2007;Ulyshen and Hanula 2009;Lemperiere and Marage 2010;Lindenmayer et al. 2012;Luke et al. 2014;Boucher et al. 2015). These threats lend urgency to improving understanding of the species and their interactions in dead wood. ...
Although rarely considered as a saproxylic insect group, ants are an important, highly abundant insect taxon in dead wood environments worldwide. Ants directly impact the dead wood environment primarily through nesting in standing dead trees, logs, stumps, and coarse and fine woody materials, contributing to the physical breakdown of woody materials. Ants indirectly impact the dead wood environment through predation of a wide variety of arthropods, particularly termites, and by serving as a food source for other animals, particularly birds (woodpeckers) and bears that physically break down dead wood to prey upon ant colonies. The known impacts of ant nesting and predation in dead wood are reviewed with a case study that provides new information on the role of abiotic factors affecting nesting site location in dead wood in the eastern temperate US forests. Results showed horizontal and vertical nest stratification of ant nests that shifted with spatial scale. At broad scales, climate determines disparate ranges among species across a latitudinal gradient. At the scale of a forest floor, however, microsite temperature, moisture, and biotic interactions affect nesting locations in downed logs. Future research aimed at better understanding the interactions between ants and other organisms in dead wood environments is necessary to improve our understanding of the importance of ants in shaping dead wood communities and ecosystem processes like decomposition.
... En conjunto, en las zonas quemadas se han censado 25 especies de 12 géneros.May (1978) ySouthwood (1978) propusieron que los componentes estructurales en un hábitat pueden ser factores especialmente importantes que expliquen la composición y/o evolución de las comunidades de artrópodos que allí viven o usan recursos vegetales.Lawton (1983) sugiere que el número de artrópodos en hábitats terrestres viene parcialmente gobernado por la estructura de la vegetación. Aplicado a hormigas, este principio se concreta específicamente en que los microhábitats de nidificación de origen vegetal in situ o en el suelo (corteza, tocones, troncos, ramitas, bellotas, agallas y piñas) favorecen el establecimiento y el mantenimiento de la diversidad de hormigas(Pressic & Herbst, 1973;Andrew et al., 2000; Armbecht et al., 2004;Coelho & Ribeiro, 2006).247Según este principio y, de acuerdo con los tratamientos aplicados, por lo que respecta a la diversidad de especies de hormigas, seria de esperar encontrar una ordenación de las zonas estudiadas que siguiera este patrón: Z4, Z2, Z3, Z1; la zona 3, recordemos, sufrió un labrado adicional, que implica movimiento de piedras, afectando posibles lugares originales de nidificación. ...
... Coarse woody debris often supports high abundances of arthropod prey and thus provides food resources for predatory invertebrates, including carabids (Ulyshen and Hanula 2009a) and spiders (Varadi-Szabo and Buddle 2006). Despite apparent positive relationships between invertebrates and coarse woody debris, some studies reported no difference in invertebrate diversity between sites near and far from coarse woody debris (Marra and Edmonds 1998, Andrew et al. 2000, Buddle 2001). Differences among studies may be attributable to variation in responses by diverse invertebrate groups or variable sampling methods (Evans et al. 2003, Varadi-Szabo andBuddle 2006). ...
Increased market viability of harvest residues as forest bioenergy feedstock may escalate removal of coarse woody debris in managed forests. Meanwhile, many forest invertebrates use coarse woody debris for cover, food, and reproduction. Few studies have explicitly addressed effects of operational-scale woody biomass harvesting on invertebrates following clearcutting. Therefore, we measured invertebrate community response to large-scale harvest residue removal and micro-site manipulations of harvest residue availability in recently clearcut, intensively managed loblolly pine (Pinus taeda) forests in North Carolina (NC; n = 4) and Georgia (GA; n = 4), USA. We captured 39,794 surface-active invertebrates representing 171 taxonomic groups using pitfall traps situated among micro-site locations (i.e., purposefully retained piles of hardwood stems and piles of conifer stems and areas without coarse woody debris in NC; windrows and no windrows in GA). Micro-site locations were located within six, large-scale treatments (7.16 - 14.3 ha) in clearcuts. Large-scale treatments represented intensive harvest residue removal, 15% and 30% harvest residue retention, and no harvest residue removal. In NC, ground beetles (Coleoptera: Carabidae) and crickets (Orthoptera: Gryllidae) were three times more abundant in treatments with no harvest residue removal than those with the most intensive harvest residue removal and were reduced in treatments that retained 15% or 30% of harvest residues, although not significantly. Invertebrate taxa richness was greater at micro-site locations with retained hardwood and pine (Pinus spp.) harvest residues than those with minimal amounts of coarse woody debris. In both states, relative abundances of several invertebrate taxa, including cave crickets (Orthoptera: Rhaphidophoridae), fungus gnats (Diptera: Mycetophilidae and Sciaridae), millipedes (Diplopoda), and wood roaches (Blattodea: Ectobiidae), were greater at micro-site locations with retained harvest residues than those with minimal coarse woody debris. Intensified woody biomass harvesting without retention of >15% of harvest residue volume may reduce invertebrate taxa richness and abundances of some key invertebrate taxa in regenerating stands. Further, harvest residue management during and after woody biomass harvesting may be an important consideration for maintaining invertebrate diversity and conserving invertebrates that are influential in the maintenance of ecosystem function and integrity in young forests. This article is protected by copyright. All rights reserved.
... A thick leaf litter layer has been shown to influence occurrence of A. flavipes [57]. Arthropods found in leaf litter are a necessary food component for carnivorous small mammals including Antechinus, and therefore this might be partially explained by the role of leaf litter for the abundance of invertebrate prey [58,59]. The lower amount of leaf litter at the burnt sites in November 2014 is likely explained by its removal through combustion in the October 2013 wildfire. ...
Management of critical habitat for threatened species with small ranges requires location-specific, fine-scale survey data. The silver-headed antechinus (Antechinus argentus) is known from only two isolated, fire-prone locations. At least one of these populations, at Kroombit Tops National Park in central-eastern Queensland, Australia, possesses a very small range. Here, we present detailed vegetation species diversity and structure data from three sites comprising the known habitat of A. argentus at Kroombit Tops and relate it to capture data obtained over two years. We found differences in both vegetation and capture data between burnt and unburnt habitat. Leaf litter and grasstrees (Xanthorrhoea johnsonii) were the strongest vegetative predictors for A. argentus capture. The species declined considerably over the two years of the trapping study, and we raise concern for its survival at Kroombit Tops. We suggest that future work should focus on structural vegetative variables (specifically, the diameter and leaf density of grasstree crowns) and relate them to A. argentus occurrence. We also recommend a survey of invertebrate diversity in grasstrees and leaf litter with a comparison to A. argentus prey. The data presented here illustrates how critical detailed monitoring is for planning habitat management and fire regimes, and highlights the utility of a high-resolution approach to habitat mapping. While a traditional approach to fire management contends that pyrodiversity encourages biodiversity, the present study demonstrates that some species prefer long-unburnt habitat. Additionally, in predicting the distribution of rare species like A. argentus, data quality (i.e., spatial resolution) may prevail over data quantity (i.e., number of data).
... Other studies have also demonstrated positive effects of plant patches on faunal communities (e.g. Andrew et al. 2000;Oliver et al. 2006;Carpintero et al. 2011). Furthermore, different vegetation patches (and plant species) often support different species composition, including ground-active invertebrates (Oliver et al. 2006;Barton et al. 2010;Liu et al. 2012), mammals (Lumsden and Bennett 2005) and birds (Dean et al. 1999). ...
Vegetation can exert a strong influence on the distribution and activity of biotic communities across a broad range of spatial scales, especially in arid and semi-arid ecosystems. At fine spatial scales, patches created by individual plants can support different faunal and floral communities even at locations distant from the plant. These differences can have profound effects on a range of ecosystem processes, including seed dispersal, nutrient cycling and resource distribution. In semi-arid Australia, areas surrounding groves of western myall (Acacia papyrocarpa) trees are largely devoid of vegetation, being referred to as 'halos'. Here, we investigate the soil-dwelling Collembola in groves of western myall trees, the surrounding halos and nearby chenopod shrubland. We also investigated whether the abundance of Collembola was influenced by soil depth (0-5cm layer vs. 6-10cm layer) in groves. We found that collembolan density was approximately nine times lower and taxonomic richness half that in a halo compared with the grove and chenopod vegetation. Furthermore, analyses at finer taxonomic levels indicate that vegetation patches differed in species composition, with some species restricted to or preferring particular patches. In the grove, we found a higher abundance of Collembola in the 0-5cm soil layer compared with the 6-10 layer. Our results indicate vegetation patches strongly influence collembolan abundance and species composition in bare patches around western myall. As patches created by vegetation are a common feature of semi-arid and arid regions, we suspect that these effects are widespread although seldom reported. Furthermore, as Collembola are involved in the decomposition process, Acacia papyrocarpa patches will be influencing nutrient cycling through their effects on the soil biota. Our results also emphasize that comprehensive fauna survey and management of woodland ecosystems need to consider fine-scale processes.
... Distance from an unburnt habitat affects species directly by determining dispersal distances and indirectly, by determining the biotic milieuthe assemblage of prey, competitors and predators with which a species coexists (Andersen 1988;Higgs & Fox 1993;Sutherland & Dickman 1999). Abiotic factors, such as smallscale topographic features and biotic features such as logs are critical for survival during and after the fire (Andrew et al. 2000;Whelan et al. 2002;Robinson et al. 2013). Factors such as soil composition and microclimate play a role in population persistence and in filtering the biotic milieu following fire (Nakamura et al. 2008;Gongalsky & Persson 2013). ...
Climate change is likely to result in an increased frequency of extreme fire events, including more large-extent wildfires. The effects of fire extent on post-fire faunal recovery are poorly understood. Effects on invertebrate detritivores are of particular interest due to their functional importance in litter breakdown. We asked if distance from fire edge affected the composition and morphological traits of a key group of large invertebrate detritivores: cockroaches (Blattodea) 6 years after fire. We used six replicate transects in herb-rich foothill habitat in areas that were severely burnt during the 2009 Black Saturday fires, north-east of Melbourne, Australia. Transects extended from unburnt controls up to 5 km into large extent burns. Habitat variables were measured and cockroach abundances were recorded using artificial habitats comprised of stacked egg trays. Cockroach morphological traits were recorded in the laboratory. Multivariate generalized linear models revealed that habitats varied with transect, but not distance into the burn, suggesting recovery of habitat features relevant to cockroaches. Distance from burn did not affect the species richness or abundance of cockroaches, but both richness and abundance increased with bark and litter cover and decreased at lower temperatures. Cockroach assemblage composition responded significantly to distance into burn, transect and habitat variables, although only Platyzosteria similis was negatively associated with distance into the burn. Fourth corner models including traits did not provide greater predictive power than models including only species abundances and environmental variables. Wing presence, which was associated with smaller body size, did not affect site occupancy. Although species traits did not predict cockroach responses, our work shows that distance into a fire, a surrogate for fire extent, continued to be an important determinant of post-fire assemblages 6 years after fire. An increase in large-extent fires may reduce the recolonization potential of some cockroach species, potentially limiting their functional importance in litter breakdown.
... Favorable environmental conditions leading to high abundances of arthropod prey near downed wood also may lead to positive associations between predatory invertebrates, including carabids (Ulyshen and Hanula 2009a) and spiders (Varadi-Szabo and Buddle 2006), and CWD. Conversely, other studies found no difference in the diversity of invertebrate taxa between sites near and far from CWD (Marra and Edmonds 1998, Andrew et al. 2000, Buddle 2001). Differences among studies may be attributable to variation in responses by diverse invertebrate groups (Evans et al. 2003) or sampling methods (Varadi-Szabo and Buddle 2006). ...
... Outreach $9,000 Total Cost $300,000 6. MANAGEMENT OF NUYTS WILDERNESS 6.1 Fire As aestivation takes place in the leaf litter, the maintenance of an appropriate fuel load with wet winter burns is important as fire events can have detrimental effects on Western Swamp Tortoise populations (Burbidge et al. 2010). The management of fuel loads not only increases the likelihood of the survival of individuals (Agee and Skinner 2005), but when used in conjunction with naturally occurring low-intensity, controlled fires it can be a method of protection against larger, more destructive wildfires (Andrew et al. 2000). ...
Sample of report writing from undergraduate course work.
The Western Swamp Tortoise is the most endangered reptile in Australia. The survival of this species is dependent on the persistence of ephemeral swamps with clay or sand-over-clay bottoms, while its diet is supported by a community of living aquatic invertebrates. The species is currently found in four habitats on the Swan Coastal Plain, all of which will not be suitable in the forecasted future of climate. In light of the threat of climate change, this Recovery Plan proposes the assisted migration of the western swamp tortoises to a site within the Nuyts Wilderness, northwest of Walpole. The management actions and plans for reserve management are stipulated within the following plan, along with the justifications pertaining to the persistence of this species in the wild.
... The number of ants captured by trapping was transformed to √n + 0.5. This change was recommended to reduce the variability in data caused by social behaviors of ants (Andrew, Rodgerson, & York, 2000) that results in the grouped behavior of the samples (Longino, Coddington, & Colwell, 2002). With this change in the data, the quantity of ants in the traps was compared between the types of forests by traps using the non-parametric test of Kruskal-Wallis. ...
Ants have been considered as useful to bioindication due to their ecological characteristics. However, an important characteristic of a bioindicator group, there must be a consistent and repeatable response to an environmental disturbance. On this matter, divergent responses have been reported, even among closely related taxa. The aim of this work was to compare the diversity of ant communities from three temperate forests with different disturbance level and correlate their abundance, species richness and diversity with that found in other arthropod communities in the same forests. The results suggest that the site has an important influence on community ants and their values of richness, abundance and diversity are correlated to communities of spiders, beetles, grasshopers and true bugs, but not in all studied zones. The answers to environmental changes are not only by numerical ratios of abundance, richness or diversity, but also by indirect and causal ecological interactions. Finally the data seems to be indicating that the responds of ants to environmental disturbing are not necessarily reflected on other organism communities, in consequence the role of ants as bioindicator could be misleading
... If there were leaf litter-dependent invertebrates in the plots, these should have been detected in the Tullgren extraction collections (York 1999;Andrew et al. 2000). The Tullgren extractions could only be undertaken for woodchip and leaf litter plots. ...
Temperature (mean, standard error, range) at the soil surface under four experimental ground cover treatments in three seasons: winter (August 2009), spring (October 2009) and summer (January 2010). All measurements are in degrees Celsius. Superscript letters indicate where there is a significant difference in temperature between ground covers within the season, at P < 0.05.
... These functional groupings allow for broad-spectrum analysis of Australian ant species, as they are based on behavioural generalizations of each ant genus or species complex. This classification has been used in a variety of studies in Australia where specific behavioural data were lacking (Burbidge et al., 1992;King et al., 1998;Andrew et al., 2000). Table 1 describes the functional grouping scheme and lists some subfamilies or genera that are found in each group. ...
The invertebrates of the arid interior of Western Australia have been little studied. As part of a project investigating the effect of wild fire on vegetation in the Gibson Desert, ant species were also collected and analysed. A total of 71 ant species was identified from six replicated 250 m2 plots in an area within the Gibson Desert Nature Reserve. The six sites were established in recently burnt and long unburnt areas of three main vegetation types: Triodia basedowii grassland, Triodia shinzii grassland, and Acacia aneura woodland. Twenty-nine ant species occurred exclusively in recently burnt sites, 16 species were exclusive to the long unburnt sites and the remaining 26 occurred in both site types. Functional group analyses revealed a predominance of Subordinate Camponotini and Opportunists at the long unburnt sites whereas Dominant Dolichoderinae and Generalist Myrmicinae were more common in the recently burnt sites.
... Landscape burning at short intervals can have major effects on plant populations (Bradstock 1995;Bell 2001) and may drive the decline of plant populations (Keith, 1996). Consequently, frequent fire can have a significant effect on the composition of flora and fauna (Clark 1988;Andrew et al. 2000;York 2000;Moritz et al. 2004). The current study has identified varied fire responses of plants in four rare species within Gibraltar Range National Park. ...
... Many non-saproxylic ground-dwelling arthropods benefit from dead wood as well. For instance, a number of studies have shown litter-dwelling arthropods and other invertebrates to be more numerous immediately next to dead wood than short distances away from it [5][6][7][8][9][10][11][12][13][14][15][16][17]. These results can be attributed variously to dead wood providing a relatively stable source of moisture [18][19][20], shelter from predators or adverse weather conditions, and an abundance of prey or other food items. ...
Pitfall traps were used to sample beetles (Coleoptera) in plots with or without inputs of dead loblolly pine (Pinus taeda L.) wood at four locations (Louisiana, Mississippi, North Carolina and Texas) on the coastal plain of the southeastern United States. The plots were established in 1998 and sampling took place in 1998, 1999, and 2002 (only 1998 for North Carolina). Overall, beetles were more species rich, abundant and diverse in dead wood addition plots than in reference plots. While these differences were greatest in 1998 and lessened thereafter, they were not found to be significant in 1998 due largely to interactions between location and treatment. Specifically, the results from North Carolina were inconsistent with those from the other three locations. When these data were excluded from the analyses, the differences in overall beetle richness for 1998 became statistically significant. Beetle diversity was significantly higher in the dead wood plots in 1999 but by 2002 there were no differences between dead wood added and control plots. The positive influence of dead wood additions on the beetle community can be largely attributed to the saproxylic fauna (species dependent on dead wood), which, when analyzed separately, were significantly more species rich and diverse in dead wood plots in 1998 and 1999. Ground beetles (Carabidae) and other species, by contrast, were not significantly affected. These results suggest manipulations of dead wood in pine forests have variable effects on beetles according to life history characteristics.
As an ecological process fire plays a global role in structuring ecosystems and their constituent fauna and flora. Fire is also regularly applied as a landscape management tool and altered fire regimes affect global biodiversity. Fire can have a marked influence on vegetation composition and structure with resultant flow on impacts on faunal communities. However, faunal responses to fire are often quite varied and management recommendations of appropriate fire regimes therefore generally include utilising a fire mosaic approach to fire management. This thesis investigates the relationship between variable fire regimes, vegetation composition, condition and structure, and ground-dwelling vertebrate faunal communities.
The literature review (Chapter 1) revealed several gaps in current knowledge. This included a lack of detailed knowledge on the effects of variable fire regimes, including repeated management burns and fire mosaics, representative of multiple fire parameters (time since fire, number of fires, fire interval and fire type), on ecosystem biota. This was particularly evident for subtropical ecosystems. To analyse the effects of repeated burns, fire exclusion and wildfire, this study targeted one of the longest running fire experiments in Australia, at Bauple State Forest, where fire treatments have been applied annually since 1952 and triennially since 1973. Additional dry eucalypt forest sites at St Mary and Tiaro State Forests were included that represented variable fire management practices. Detailed fauna trapping surveys and vegetation assessments were completed on 35 plots across eight fire treatments at all three sites. Additionally, a broader scale GIS analysis of fire history was done across the three forests with surveys undertaken at an additional 74 sites allowing a comparison of reptile communities, forest condition and structure among variable fire regimes at multiple scales.
To quantify the structural and compositional influences that fire has on vegetation communities in subtropical systems, Chapter 3 involved a detailed analysis of the communities within the three dry eucalypt forests. Fire treatments significantly altered vegetation community diversity, structure and composition. Annual burning resulted in reduced floral diversity among all strata and reduced structural heterogeneity in the ground and shrub layers. Long unburned areas were more diverse but had lower canopy heterogeneity. Wildfires did not significantly impact the vegetation community.Consistent with previous research, this chapter found that frequent, repeated burning can reduce the diversity and structural complexity of forests.
The effects of disturbance (fire and logging) on forest condition and forest variables across the landscape were investigated in Chapter 4 using a biodiversity condition assessment toolkit among 63 plots. Forest variables and overall condition were correlated with historical disturbance patterns, derived from GIS, among Regional Ecosystems (RE), including time since fire, number of fires, fire interval, fire type and years since logging. The majority of forest variables were negatively affected by more frequent (61.5% of variables), or recent fire disturbances (76.9% of variables). The most pronounced negative impacts occurred for tree species richness, and two key habitat attributes for fauna including coarse woody debris and litter cover, which were maximised in long unburned areas highlighting the importance of maintaining long unburned refuges in the landscape.
Chapter 5 investigated the response of reptile and anuran communities, surveyed at 35 trapping plots, to different fire regimes and habitat characteristics quantified in Chapter 3. Reptiles were more vulnerable to fire impacts than anurans, particularly frequent fires (annual burning) which reduced the abundance of several species; however, species were generally not affected by wildfire. Species such as Lampropholis delicata and Eulamprus martini favoured long unburned areas, however, other species, i.e. Carlia p. pectoralis, preferred frequently and recently burned sites. Anurans, on the other hand appeared to be resilient to fires, corroborating previous studies on this taxon as they are able to retreat into moist microhabitats to survive. The ‘risk’ and ‘impact’ of fires to individual species was interpreted using a conceptual model that was able to categorise species as either tolerant or resilient to fire. These species-specific responses are important considerations when planning fire management guidelines that advocate frequent burning, as some species may be negatively affected.
In a parallel analysis, Chapter 6 assessed small mammal communities across the three sites and their response to variable fire regimes and habitat parameters. Mammals generally were not strongly influenced by fire but had highly variable responses which made it difficult to determine the factors influencing either species richness or abundance. It therefore appears likely that small mammal communities are not being negatively affected by repeated burning practices or infrequent wildfire. However, species were often correlated with habitat heterogeneity characteristics, highlighting the importance of maintaining a structurally diverse habitat that supports a variety of mammal species. As such, the indirect effects of fires may lead to a reduction in ideal habitat for certain mammals.
In Chapter 7, reptile communities were assessed across the landscape and correlated with various fire parameters and forest variables from Chapter 4. Number of fires, time since fire and fire type were key predictors for overall reptile abundance, as well as the abundance of four of the seven common study species. Overall abundance was negatively affected by number of fires and it also altered the overall reptile assemblage, while at a species level Carlia spp. were negatively associated with time since fire. Fire was generally a stronger predictor of reptile responses than habitat parameters with only shrub cover found to be negatively associated with Carlia spp. A reduction in total number of fires of some areas and increase in variability of burn intervals may support a greater diversity and abundance of reptiles in parts of the landscape where the total number of fires is high.
Fire heterogeneity was quantified within fire regimes across multiple scales in Chapter 8, using the variation in time since fire, number of fires, fire interval and unique (combination) fire mosaic regimes derived from GIS. Heterogeneity at the patch, local and site scales calculated from the Shannon-Wiener diversity index was weakly correlated with reptile communities and the heterogeneity measures appeared to be a poor surrogate of ‘fire diversity’. While this heterogeneity measure could not explain patterns in reptile communities, it is important to note that it captures only one element of landscape ‘pyrodiversity’. As other fire parameters including fire type revealed significant responses amongst reptiles, the specific nature of any biodiversity response to pyrodiversity appears linked to both scale and specific parameters used.
This thesis has demonstrated that aspects of the vegetation community as well as faunal species, favoured different fire regimes, where some species and structural characteristics preferred frequently burned areas while others (although more often than not) preferred infrequently burned or long unburned areas. Support is provided for the suggestion that a mix of frequently burned, infrequently burned and long unburned areas across the landscape will maximise floral and faunal communities, and help meet management goals of maintaining biodiversity. However, the scale of these unburned refuges is an important question that requires more research.
Ants are highly intelligent, social and ecologically important insects. They are known for their valuable contributions in ecosystems and found in all possible habitats. The present study deals with the checklist of ant species in and around Achalpur, Amravati district, Maharashtra, India. This work was carried out from June 2021 to December 2021 for total six months. Ants were sampled randomly by using different collection methods like all-out search method, hand collection method and species were identified with the help of standard taxonomic literature. During this study a total 09 species of ants were recorded under 07 genera belonging to 03 subfamilies. Myrmicinae (five species) was found to be a most abundant subfamily in terms of species followed by Formicinae (three species) and Dolichoderinae (one species).
Vegetation and mapping of Nocholeche Nature Reserve in far western New South Wales
Understanding the physiological tolerances of ectotherms, such as thermal limits, is important in predicting biotic responses to climate change. However, it is even more important to examine these impacts alongside those from other landscape changes: such as the reduction of native vegetation cover, landscape fragmentation and changes in land use intensity (LUI). Here, we integrate the observed thermal limits of the dominant and ubiquitous meat ant Iridomyrmex purpureus across climate (aridity), land cover and land use gradients spanning 270 km in length and 840 m in altitude across northern New South Wales, Australia. Meat ants were chosen for study as they are ecosystem engineers and changes in their populations may result in a cascade of changes in the populations of other species. When we assessed critical thermal maximum temperatures (CT max ) of meat ants in relation to the environmental gradients we found little influence of climate (aridity) but that CT max decreased as LUI increased. We found no overall correlation between CT max and CT min . We did however find that tolerance to warming was lower for ants sampled from more arid locations. Our findings suggest that as LUI and aridification increase, the physiological resilience of I. purpureus will decline. A reduction in physiological resilience may lead to a reduction in the ecosystem service provision that these populations provide throughout their distribution.
The complexities of forest insects and their needs present complicated scenarios for their effective conservation, whether efforts are directed to single species or wider communities. Forest management can hamper or support practical insect conservation in many ways, and some of the major themes and issues are outlined in this chapter, with examples of how they may contribute to wider perspectives.
Species-level conservation of insects is complex but that fine filter approach to conservation of such a diverse group cannot remain, or indeed become, the main plank in a modern conservation platform. The sheer numbers of individual needy species simply cannot be catered with current or foreseeable levels of funds, expertise and interest, and with the attention to fine detail needed perhaps not optimal for many of the co-occurring species. Whilst some insect species, notably amongst Lepidoptera (particularly butterflies) and Coleoptera have become invaluable flagships in both demonstrating how insect species conservation can be achieved and in education and disseminating awareness of insect variety and ecological complexity in conjunction with conservation need, wider approaches are the major path toward more comprehensive insect conservation. Assessing impacts of disturbances such as fire on assemblages, as well as on single species, is thus a key complementary need. Indeed, ‘Developing a predictive understanding of how species assemblages respond to fire is a key conservation goal’ (Langlands et al. 2011). Any such approach must flow from the best possible understanding of the ‘pattern’ of that assemblage, and its dynamics in space and season.
The Mindaribba Local Aboriginal Land Council (LALC) covers 1,672 km2 in the lower Hunter Valley of New South Wales, and falls within six local government areas (Newcastle, Port Stephens, Cessnock, Maitland, Dungog, Singleton). Approximately 796 km2, or 48 %, of the LALC comprises natural vegetation.
This Natural Resource Package outlines the environmental assets known within the Mindaribba LALC area, focusing particularly on plants and animals and their habitats. It identifies the known or potential occurrence of 18 threatened plants, 5 threatened frogs, 2 threatened reptiles, 18 threatened mammals, 41 threatened birds, 4 endangered populations, and 16 threatened ecological communities.
Issues and threats relating to the protection of biodiversity in the LALC include land clearing and development, under-scrubbing, rubbish dumping, car dumping, bushfire and arson, and weed invasion. Opportunities for preserving and managing these lands include Biobanking or the establishment of conservation agreements over private lands, collaboration with research institutions such as universities, or applying for funding from government and other organizations.
An extensive bibliography is included in the Package, which can be used to establish priorities for research and management of LALC lands, or to use as a guide to the environmental assets present on a property. Major government environmental planning initiatives have been discussed in the text to provide a background to regional planning.
There is a paucity of knowledge of whitegrub pest species in black wattle (Acacia mearnsii) plantations, which hampers the development of integrated pest management programmes. This study determined the composition and community structure of the various whitegrub morphospecies that attacked seedlings during their re-establishment on 10 previous wattle sites in KwaZulu-Natal, South Africa. Whitegrub specimens collected from these trials were examined in the laboratory to determine which morphospecies were present and their abundance. Morphospecies were separated on the basis of their species-specific raster patterns. Multivariate analyses were done using PRIMER (Plymouth Routines in Multivariate Ecological Research) as statistical package. The proportions of morphospecies at the different sites were evaluated by using the non-metric multi-dimensional scaling (MDS). Thirteen whitegrub pest morphospecies were found attacking A. mearnsii seedlings. About 98%of the total whitegrub abundance was represented by seven morphospecies and the remaining about 2%was represented by six whitegrub morphospecies. Three different whitegrub pest community structure patterns were found. The black wattle silvicultural weeding and plantation residue management practices of the South African forestry industry explained the resultant three whitegrub pest community assemblages. These practices were windrowed-burnt-weeded or with closer spacing, weeded fallow sites and windrowed-burnt-ripped or planted in an old arable land. The greatest species richness (13 morphospecies) and abundance (95 %) of whitegrubs was the community assemblage under the windrowed and burnt silvicultural practices. The whitegrub pest community was less abundant (3% and 2%) and diverse (six and five morphospecies) in sites that were left fallow before planting and where the silvicultural practices were windrowing, burning and ripping or planting in an old arable site, respectively.
The present study is aimed to evaluate forest health in a fragmented urban forest using characteristics of insect communities. Ants (Formicidae) and ground beetles (Carabidae) surveyed by pitfall trap method in the Hongneung forest located in the urban area of Seoul were compared with those in the Gwangneung forest. The Gwangneung forest is supposed to be health due to its high biodiversity and well-conserved nature. Ants of the Hongneung forest was much more abundant compared with those of the Gwangneung forest. However, ground beetles showed the opposite patterns; much more abundant in the Gwangneung forest than in the Hongneung forest. Species richness was higher in the Gwangneung forest than in the Hongneung forest, but species diversity was higher in the Hongneung forest. In the Hongneung forest, forest specialist species and generalist species were balanced, whereas few forest specialists dominated in the Gwangneung forest. This dominance decreased species diversity in those Gwangneung forest. Thus, characteristics of insect community in the Hongneung forest were greatly different with those in the Gwangneung forest.
Floristic analysis, vegetation mapping and community description for the Bush Heritage managed properties Naree and Yantabulla. Located in far north western plains of New South Wales on the Cuttaburra Creek and Yantabulla Swamp. Includes semi-arid landscapes, mulga, woodlands, wetlands and shrublands.
Vegetation and flora of the Five Corners Voluntary Conservation Agreement, Inverell, NSW, Australia
Floristic analysis, vegetation mapping and community description of Mawonga, Hillston, NSW, Australia
Vegetation mapping and community description for the Cooinda addition to Warrabah National Park, Northern Tablelands, NSW, Australia
Floristic analysis, vegetation mapping and community description for Mt Yarrowyck Nature Reserve, Northern Tablelands, NSW, Australia
Floristic analysis, vegetation mapping, community description of Avondale Nature Reserve, Northern Tablelands, NSW Australia
Floristic analysis, vegetation mapping and community description for Mt Duval Nature Reserve, Northern Tablelands, NSW, Australia
Floristic analysis, vegetation mapping and community descriptions for Booroolong Nature Reserve on the Northern Tablelands of NSW, Australia
Leaf litter invertebrates were sampled at eight sites, approximately 250 m apart in elevation, along an altitudinal transect extending from primary lowland rainforest to cloud forest in western Panama. The study focused on several diverse and numerically important litter invertebrate taxa (e.g., ants, spiders, and beetles) that were effectively sampled using a combination of litter sifting and test tube pitfall traps. The mean altitudinal range of species was around 500 m (standard deviation 370 m) and approximately 50% of the species characteristic of a given elevation dropped out after a 500 m change in elevation in either direction. There was no evidence for distinct altitudinal zonation in leaf litter assemblages. Both species richness and number of individuals of most taxa showed a pronounced decline in the vicinity of the upward transition to cloud forests. The data also suggest a broad mid-elevation peak in sample species richness for the litter invertebrate fauna. The implications of the results for biodiversity conservation are discussed.
Mean dry ant biomass (+SE) for mallee, woodland, shrubland and heath was 19.6 + 4.0, 6.9 + 1.1, 4.3 + 0.9 and 3.4 + 0.4 mg/m² respectively. Ants <2 mm, 4-7 mm, and >10 mm in length contributed little to biomass, irrespective of habitat. Ants 2-4 mm in length were most abundant in all habitats, accounting for 91% of biomass in mallee. Ants 7-10 mm were also important in woodland, shrubland and heath. Biomass also varied temporally, with marked winter minima and summer maxima, and correlated with soil temperature in habitats other than heath. Soil moisture had no apparent effect of ant biomass, irrespective of habitat. The differences between the four habitats (with respect to plant litter, canopy and vertical density of vegetation) were assessed for the six possible pairs of habitats. Woodland and mallee were most similar, with 7/14 variables showing significant differences. Shrubland/woodland and shrubland/heath were most dissimilar, with 12/14 variable showing differences. Ant biomass was positively associated with wood litter, broad-leaf litter and vegetation density at 2.5-3 m height, and negatively with grassy litter, vegetation density at 0-0.5 m height, and the coefficients of variation of litter and canopy cover. These associations probably reflect the importance of these aspects of the habitats in providing ants with diversity of food and shelter, and suitable microhabitats and microclimates. The ant fauna in these reserves may reflect past disturbances or management strategies such as fire exclusion for at least 45 yr, livestock grazing and selective logging. -from Author
The main problem in integrating wildlife conservation with commercial eucalypt production concerns the wildlife species which need old trees or mature forest as a habitat. This paper discusses possible strategies for resolving the problem.The three strategies of potential value are:1. to leave sufficiently large numbers of old trees on individual coupes2. to manage forests on long rotations, and3. to retain selected areas of old forest with minimal harvesting or for management on very long rotations, managing the remainder for high wood production.Existing evidence indicates that the third strategy would generally be most effective from the standpoint of both wildlife conservation and wood production, and it has a proven record in south-eastern Australia. Considerations such as size, shape and distribution of coupes may affect wildlife habitat but for given levels of production they have little bearing on the main problem.
Some 68 ant species in 22 genera were collected. There were no trends in species richness, diversity or evenness across vegetation transects although overall species composition differed between certain vegetation associations. These differences are discussed in terms of soil type and vegetation association.-from Authors
Environmental monitoring and conservation evaluation in terrestrial habitats may be enhanced by the use of invertebrate inventories, but taxonomic and logistic constraints frequently encountered during conventional taxonomic treatment have greatly restricted their use. To overcome this problem we suggest that nonspecialists may be used to classify invertebrates to morphospecies without compromising scientific accuracy. To test this proposition, large pitfall and litter samples of ants, beetles, and spiders from four forest types were sorted to morphospecies by a nonspecialist and to species by specialists. These data were used to generate morphospecies and species inventories and to estimate richness (alpha diversity), and turnover (beta diversity), information frequently used in the above activities. Our results show that the estimates of richness of ants and spiders varied little between morphospecies and species inventories. Differences between estimates of beetle richness were largely influenced by errors of identification in two families, Curculionidae and Staphylinidae. But morphospecies and species inventories yielded identical ranking of forest type using richness. Turnover was assessed by sample ordination which revealed similar clusters regardless of the type of inventory. Analysis of similarities of assemblages of ants and beetles showed significant differences between all forest types. Spider assemblages showed a lower level of discrimination. The assessment of turnover was consistent among inventories but different between the major taxa. Our findings suggest that morphospecies may be used as surrogates for species in some environmental monitoring and conservation, in particular when decisions are guided by estimates of richness and the assessment of turnover.
Inventories of vertebrate and flowering plants are frequently used as surrogates for estimates of total biodiversity. This is in part because the inclusion of invertebrates and nonflowering plants is perceived as being too time-consuming, costly, and difficult because of the shortage of specialists. Estimates of the species richness of field samples of spiders, ants, polychaetes, and mosses made by a biodiversity technician and by specialist taxonomists were compared. The biodiversity technician received a few hours training in the taxonomy of each group and separated specimens into recognizable taxonomic units (RTUs). The specialists sorted to species. For the three animal groups the biodiversity technician recorded 165 taxa and the specialists 147, with the error for the ants and spiders being 13% or less. A small amount of splitting and lumping of species was detected. The concordance of estimates remained very similar when small subsamples were used. The procedure was repeated by 13 undergraduates using a subsample of spiders. Their average error was 14.4%. The greatest similarity in estimates was for the mosses, but with high levels of splitting and lumping this result was entirely fortuitous. The results suggest that RTU estimates made by biodiversity technicians may be sufficiently close to formal taxonomic estimates of species richness to be useful for the rapid assessment of biodiversity. They also show, however, that the procedures outlined here should be used on invertebrate and nonflowering plant groups before they can be confidently included in biodiversity surveys.
Slight modifications of the ecosystem result in slight alterations in ant communities. Replacement of native vegetation by gardens or plantations results in a considerable reduction in species and generic richness, reduction in the number of functional groups and altered species composition. Particular species of Crematogaster, Tapinoma and Iridomyrmex are indicative of relatively undisturbed sites, while Melophorus and Tetramorium are indicative of highly disturbed environments. -from Authors
detritus
aridland forests
eucalypt forests
Fire and insects are natural disturbance agents in many forest ecosystems, often interacting to affect succession, nutrient cycling, and forest species composition. We review literature pertaining to effects of fire-insect interactions on ecological succession, use of prescribed fire for insect pest control, and effects of fire on insect diversity from northern and boreal forests in North America. Fire suppression policies implemented in the early 1900s have resulted in profound changes in forest species composition and structure. Associated with these changes was an increased vulnerability of forest stands to damage during outbreaks of defoliating insects. Information about the roles that both fire and insects play in many northern forests is needed to increase our understanding of the ecology of these systems and to develop sound management policies.
Summary Physical and chemical properties of litter and soil of two adjacent stands of high quality jarrah forest, one unburned since 1937, the other burned periodically during the past 40 years and last burned in Spring 1981, were compared in 1982 and 1983. Sampling of the larger elements of the invertebrate fauna was by litter and soil coring and pitfall-trapping three times during 1983. Most of the soil properties studied had higher values in the burned stand, suggesting that repeated low intensity fires do not deplete jarrah forest soils of nutrients. Periodic low intensity fires had little impact on the frequency of occurrence or capture of the invertebrate fauna studied.
The areas were harvested for sawlogs and pulpwood in 1976, and parts were burned to assist regeneration. Plots were assessed before harvesting and at intervals until 1980. Changes in total species composition were minimal. Total cover of understorey vegetation was reduced initially but recovered well. By 1980, cover at Maramingo was slightly greater than the low levels before harvesting. Some species there were favoured by burning while others were not. At Reedy Creek the original dense understorey had not regenerated fully by 1980. Snig tracks had revegetated to 60% of original average cover but log landings were slower to revegetate. Introduced species were initially a very minor component of the vegetation on both areas; they remained so at Reedy Creek (confined mainly to tracks) but at Maramingo 3 species proliferated along with other small herbaceous plants. -from Authors
The long-term impact of fire as an agent of habitat disturbance affecting ant communities was studied in a coastal forest environment (Australia, New South Wales, Myall Lakes National Park). A chronosequence approach utilising sites with understoreys aged between two and 14 years post-fire found that ant communities decreased in species richness with time since fire. Data from a control site monitored for seven years after fire showed similar trends. A substantial proportion of the forests' overall ant richness is, however, contributed by "rare' species, which are distributed across the full range of forest understorey age classes. Positive management through the prevention of frequent fires and the maintenance of habitat mosaics is required in this area to ensure the conservation of species. -Author
Sampling plots have been examined since 1971 in eucalypt and pine vegetation types near Canberra. No invertebrate order has an adaptive response solely to survive fire, but those orders least affected show high mobility or adaptations to conserve water and resist high ambient temperatures in seasonally dry habitats. The pattern and rate of recolonisation of burnt areas are influenced by the aerial movement of small litter insects. Post-burn recolonisation can be rapid, though community changes will be pronounced. The varying balance of invertebrate groups in pre-fire communities, the selective modification of this balance by fire, and the subsequent community structure and distribution are variables which make prediction of the effects of fire almost impossible. -P.J.Jarvis
Plant traits considered adaptive to fire may be distinguished by: their vegetative survival; enhanced reproduction through fire-stimulated disperal; or enhanced reproduction facilitated by in-soil storage with fire-stimulated germination. A single trait, eg. vegetative survival and resprouting, or hard-seededness, may be adaptive not only to fires but also to other variables. Different species in the same environment may have different adaptive traits but persist with equal success. Adaption must be considered in terms of the fire regime: type, season, frequency and intensity. Traits enabling survival and reproduction during a succession of fires must also enable survival and reproduction to take place during stresses imposed by other selective agents, eg. drought. -from Author
In rehabilitated mine sites in Western Australia, 42 species of ants were found, although many of the original forest species were not present. Ant species diversity and ant species richness were the most useful measures for relating to mined area parameters. Ant return was positively associated with plant species richness and diversity, time since rehabilitation, percentage plant cover and percentage litter cover. Presence of large logs was also important. Plant species richness, and diversity, rehabilitation age and percentage litter cover also influence the species composition of the ant community in rehabilitated areas. -from Author
The impacts of four different management systems on diversity of ground-foraging ants were examined to assess potential for conservation of biological diversity in human-influenced agricultural or agroforestry systems. Using a variety of indices, diversity was measured along a gradient of anthropogenically disturbed habitats. The gradient, in terms of increasing levels of disturbance, ranged from primary rain forest, abandoned cacao plantations, productive cacao plantations, to banana plantations. The primary forest and abandoned cacao plantations were situated in a reserve and the productive cacao plantations, and banana plantations were located on privately owned land within 35 km of the reserve in the Sarapiqui Valley of Costa Rica. To sample ground-foraging ants, we placed tuna baits along the ground in each habitat. Although tuna baits attract a generalist assemblage of ants that may be better able to adapt to more disturbed sites, diversity of this community was significantly reduced with increased disturbance. Ant diversity was not different for forest and abandoned cacao sites except in terms of evenness, with the forest having a more even distribution of species. Forest and abandoned cacao sites were significantly more diverse than both productive cacao and banana plantations. The latter two did not differ significantly from each other in terms of diversity, but there was considerable variability within each of these habitat types. The results of this study suggest that conservation of diversity may be possible in a @'mosaic@' of different land uses, but further studies, such as those addressing the importance of scale and nearby source populations, are necessary before management practices can be implemented.
Changes in wood density, nutrient content, and invertebrate populations throughout the decay of Cyrilla racemiflora (Cyrillaceaea) were compared with those observed in temperate woody tree species. Wood density tended to remain constant as decay advanced except in the late stages. Nutrients (N, P, Ca, Mg) were in highest concentrations in intact bark, surface wood, and wood in advanced decay Concentrations of N and P were highly correlated, as were concentrations of Ca and Mg. The C/N ratio was determined mainly by changes in N because C tended to remain constant as decay proceeded. The C/N ratio of wood in advanced decav was 79, one of the lowest reported, and the concentration of N was one of the highest reported (0.69%) in studies of wood decomposition. Nitrogen and P were in greater concentrations in the feces of the cerambycid Parandra cribata than in surrounding wood. A total of 138 invertebrate species was identified. The number of species increased as decay progressed. Termites (Parvitermes discolor and Glyptotermes pubescens) and ants (Pheidole moerens. Paratrechina spp. and Solenopsis spp.) were the most abundant invertebrates, with ants more abundant in snags than in logs. The scarcity of bark beetles and wood borers such as carpenter ants and bees in the wood of C. racemiflora contrasted with reports of their presence in dead wood from other tree species.
We assessed the colonisation of clearcut forests by ants by using pitfall-trap data collected from clearcut areas of different age in southern Finland. We compared mature forests (age over 120 yr) with areas cleared 0, 2 and 10 yr before trapping. We concluded that the old-forest wood-ant systems are destroyed by clear-cutting, and that this is probably based on the loss of food resources. In the colonisation stage the role of stochasticity is counter-balanced by a number of deterministic species-specific factors in the succession of ant assemblages. In the colonisation process pioneering species are capable of founding colonies independently by single queens, and they are followed by species known to found colonies by temporary parasitism. In later successional stages new colonies are established mainly by fission. In the succession, species richness was highest in the ten year-old clearcuts. Later, species richness decreased, probably because of increased shade of the canopy cover. The ant species we studied did not show clear seasonal segregation, probably because of the shortness of the northern summer. Ecologically similar species pairs tended to show exclusive spatial distributions that may reflect interspecific competition.
(1) An 8-ha area of southern English heath sampled in 1961 for species of ants and twelve habitat factors (four physical and eight vegetational) has been resurveyed after ten years by the same method. (2) Between surveys the bare areas decreased and the ericaceous shrubs (Calluna vulgaris, Erica cinerea and E. tetralix, particularly the first) increased. Ulex minor remained the same, but Molinia caerulea and Agrostis setacea (both grasses) and Pteridium aquilinum (bracken) decreased. (3) In 1971, 111 single and forty-six double records, a total of 203, were obtained at 157 stations. In 1961, by contrast 18/157 stations were without ants and none had more than one species present. Ant species were the same and all but one, Lasius alienus, were more abundant. (4) Mean values of the thirteen habitat variates (the height of Calluna was added to the twelve used in 1961) have been calculated for each ant species and a matrix of correlation coefficients obtained. From this principal components were extracted. (5) The first (accounting for 54% of the dispersion) represents a dry, sandy, bare, warm, soil with C. vulgaris and Ulex minor the principal plants (dry heath); it occurs at moderate heights. The second (with 26% dispersion) represents dry, sandy, well-covered, cool soil with Erica cinerea and Agrostis setacea the principal plants (dry grass heath); it occurs quite high up. The third, with 13% of dispersion, represents a moist, organic, moderately-covered, cold soil with gorse and bracken the main plants (scrub); it occurs low down. The fourth (with only 7%) represents a bracken-dominated area. The first component in 1971 is very similar to the first of 1961; others were less so. (6) The relative positions of the ants in the component space are very similar in 1961 and 1971. Lasius alienus and Tetramorium caespitum lie close in the first dimension (I) and far from Lasius niger and Myrmica scabrinodis. Component II brings M. sabuleti away from the rest and component III brings Formica fusca out. The fourth dimension is of some interest as it alone separates Tetramorium caespitum and Lasius alienus. Each type of habitat contains one representative of both the sub-families Myrmicinae and Formicinae. (7) About 60% of stations had the same species in 1961 as in 1971. Tetramorium caespitum and Formica fusca gained most, the former largely at the expense of Lasius alienus. However, the habitat it took from L. alienus was not different from the habitat that L. alienus held, and a possible ecodifferentiation between the two species in 1961 had vanished by 1971. The spread of vegetation probably tipped the competitive balance in favour of Tetramorium caespitum because it can build nest mounds in vegetation and live on seeds. Fire re-establishes a sparse plant cover more suitable for Lasius alienus, the two thus coexist through being adapted to opposite vegetational phases of the burn cycle.
In the wrapper approach to feature subset selection the learning algorithm itself is used in the selection process, thus making the process sensitive to the bias of the learning algorithm. The approach introduces a useful framework within which search algorithms and classifiers can be compared. To date, search algorithms used in conjunction with the wrapper method have focused on greedy search techniques, i.e. those which direct their search according to increased accuracy arising from the addition/removal of individual features. It is argued that since the error rate of the classifier is non-monotonic such searches may prune valid areas of the search space. In addition, the combinatorial nature of greedy searches makes their use infeasible for large (>20) feature sets. An alternative form of search, based upon the principles of genetic algorithms, is proposed and related work is discussed. Results indicate that improvements reported with the wrapper method are maintained whilst the robustness and applicability of the approach is increased. (8 pages)
The relative impacts of clearfelling followed by slash-burning, clearfelling, and no treatment were
monitored for 2 years in two major types of eucalypt forest in south-eastern Tasmania. Rates of change
in species cover were significantly greater in the burned area than in both the clearfell and control areas.
More than half the species for which suitable data were available increased most in the burned area and
least in the control. More higher plant taxa were present in the permanent burned plots 4 months after
the burn than before the burn. By the last 8 months of recording, new taxa were invading at a rate
of only 0.1 per month. Composites and shrubs constituted most of the late invaders. The behaviour
of diversity measures was largely a function of the behaviour of a few of the taxa. Fire intensity, as
measured by degree of soil baking, had a pronounced influence on species composition and cover. The
species composition of aerially sown seed had little influence on the species composition of the eucalypt
regeneration, with species not sown by the Forestry Commission recovering vegetatively, and much of
the sown seed not resulting in seedling establishment. The clearfelling and burning, and clearfelling
treatments did not result in the loss of any native species but there was substantial invasion by introduced
herbs. However, lack of substantial impact in the short term does not guarantee the same in the long
term.
In 379 logged areas comprising a total of 5606 ha, 930 individuals were found representing 7 species of glider and opossum. However, at 199 sites (52% of the forest area) no arboreal marsupials were found. About 63% of the individuals came from 9% of the area. From author's summary.
Publisher Summary
This chapter reviews the rates at which Coarse Woody Debris (CWD) is added and removed from ecosystems, the biomass found in streams and forests, and many functions that CWD serves. CWD is an important component of temperate stream and forest ecosystems and is added to the ecosystem by numerous mechanisms, including wind, fire, insect attack, pathogens, competition, and geomorphic processes. Many factors control the rate at which CWD decomposes, including temperature, moisture, the internal gas composition of CWD, substrate quality, the size of the CWD, and the types of organisms involved. The mass of CWD in an ecosystem ideally represents the balance between addition and loss. In reality, slow decomposition rates and erratic variations in input of CWD cause the CWD mass to deviate markedly from steady-state projections. Many differences correspond to forest type, with deciduous-dominated systems having generally lower biomass than conifer-dominated systems. Stream size also influences CWD mass in lotic ecosystems, while successional stage dramatically influences CWD mass in boat aquatic and terrestrial settings. This chapter reviews many of these functions and concludes that CWD is an important functional component of stream and forest ecosystems. Better scientific understanding of these functions and the natural factors influencing CWD dynamics should lead to more enlightened management practices.
Soil coring and pitfall trapping in high quality jarrah forest from December 1979 until November 1982 evaluated the effect of a moderate intensity fire on the abundance and activity of the larger invertebrates inhabiting soil and litter. A burnt plot subject to a moderate intensity fire (780 kW m-1) in January 1980 was compared with an adjacent unburned control plot. Differences between the plots in the invertebrate fauna collected on 17 sampling dates after the fire were assessed by the Wilcoxon non-parametric test. Ten taxa in the soil cores showed no significant difference in density between plots from February 1980 to November 1982: Megascolecidae (earthworms), Araneae (spiders), Isopoda (daters), Isoptera (termites), Dermaptera (earwigs), Orthoptera part (crickets), Coleoptera (beetle) larvae, Coleoptera adults, Diptera (fly) larvae and Formicidae (ants). Diplopoda (millipedes) occurred at significantly greater densities in the burnt plot, and Chilopoda (centipedes), Thysanura (silverfish) and Blattodea (cockroaches) at significantly lower densities in the burnt plot. The total number of taxa and the density and biomass of that part of the invertebrate fauna studied did not differ significantly between plots. Similar numbers of 12 taxa were captured in pitfall traps in both plots: earthworms, spiders, Pseudoscorpionida (pseudoscorpions), centipedes, termites, cockroaches, earwigs, adult beetles, fly larvae, Hemiptera (bugs), Lepidoptera larvae (caterpillars) and Orthoptera part (grasshoppers). Crickets, beetle larvae and ants were captured in greater numbers in the unburnt plot. Similar numbers of taxa and of individuals (of all taxa combined) were captured in the plots. Therefore, all but three taxa recovered in density within three years of a moderate intensity fire in the jarrah forest. The relative abundance and/or activity of three other taxa remained depressed on the burned plot during the same period.
Mesofauna was collected over a period of 10 months on plots which were not burned (control), burned periodically, and burned annually. The number of animals on the control and periodic burn plots was significantly greater than on the annual burn plots. Although more animals were recovered from the control plots than the periodic burn plots, the difference was not significant. The length of time for recovery of the mesofaunal population after a periodic burn was not determined but is less than 44 months. When mesofaunal populations were sampled immediately before and after burning on a plot burned annually, the number of animals was reduced drastically.
Forest fragmentation and the associated problem of population subdivision is a major factor threatening the long-term persistence of many forest-dependent taxa. VORTEX, a computer program for population viability analysis (PVA), was used to simulate the impacts of fragmentation and subdivision on the demography of populations of the mountain brushtail possum Trichosurus caninus Ogilby, which is a forest-dependent species of arboreal marsupial that inhabits wet sclerophyll forests and rainforests in eastern Australia. In this study, hypothetical populations of 100, 200 and 400 animals were partitioned into one to 10 subpopulations that were, in turn, linked by varying rates of inter-patch migration. These levels of population subdivision may be typical in extensive areas of wood production montane ash forest in central Victoria where there are limited and generally very small patches of old growth forest (< 10 ha) that will become increasingly important refugia for many species of hollow-dependent fauna such as T. caninus.
The effects of logging on three species of common skinks were estimated from censuses in four age classes of forest: unlogged, just logged, 1-year logged and 10–15 year regrowth. The effects of topography (ridge and gully) were examined in each age class. Afire in November 1980 occurred fust after the initial census was completed. Another census was taken in December 1980 to assess its immediate effects. Further censuses were carried out each December from 1981 to 1984. An intense drought overlapped from 1980 to 1983 with the census period. Lampropholis guichenoti occurred in about equal numbers in unlogged and recently logged forest, but its numbers were reduced in the 10–15 year regrowth forest. This was attributed to changes in the amount and pattern of sunlight reaching the ground. A similar pattern of response was found for Lampropholis delicata. The numbers of Eulamprus heatwolei, a gully species requiring partial shade, were lowest in the exposed, recently-logged forest, but had increased in the 10–15 year regrowth class to about equal their numbers in unlogged forest. Fire reduced the numbers ofL. guichenoti on ridges but had no immediate impact on numbers of tire other species, while drought markedly depressed numbers of all species. Lampropholis guichenoti recovered more quickly from the drought than did L. delicata, but the numbers of E. heatwolei were still declining 19 months after the drought broke. The drought also revealed a habitat (ridge/gully) difference between the two Lampropholis species. The management of these species in commercial forests requires that some areas, particularly gullies, be reserved and the logging sequence modified to prevent the creation of widespread stands of uniform regrowth.
The effects of prescribed low‐intensity burning during spring and autumn on invertebrates in litter/upper soil were assessed in dry sclerophyll mixed eucalypt forest near Daylesford, west–central Victoria. The 4‐year study was based on 68 848 arthropod specimens representing 29 ordinal or lower level taxa contained in 1980 pitfall trap samples, and on in situ counts of earthworms (Annelida) in 2220 litter/upper soils samples.
The spring bum caused short‐term reductions in activity among the common ‘major’ taxa Collembola (springtails) and Diptera (flies), and among the rarely trapped ‘minor’ taxa Opilionida (harvestmen), Lepidoptera (moths) and Apocrita (parasitic wasps) for up to one year. These reductions were associated with low fine fuel loads in the first year after the fire. Populations of earthworms also declined substantially, but recovered within 3 years of the burn. The autumn burn suppressed the Collembola and the ‘minor’ taxa Blattodea, Polydesmida, Thysanura and Tettigoniidae for up to 10 months. Earthworms were not affected. Very dry soil conditions were associated with depressed collembolan activity at study sites irrespective of burning.
Given the importance of Collembola, larval Diptera and earthworms among decomposers in forest litter, it appears that the spring burn, and to a lesser extent the autumn burn, may have temporarily reduced the decomposer cycle. Further research on individual species is required to substantiate this conclusion, and also on the effects of high frequency burning. In the interim, any broadscale fuel reduction burning in forest ecosystems similar to that studied here should be scheduled for autumn rather than spring to protect earthworms and no burning should be permitted during drought periods, to minimize adverse impacts on the overall invertebrate fauna inhabiting litter/upper soil.
Abstract The impact of silvicultural practices (clearfelling, slash burning and sowing) on carabid beetle communities in tall wet Eucalyptus obliqua forests in southern Tasmania was examined using traplines of pitfalls in a chronosequence of regenerating coupes. Total species richness (n= 18) was modest compared to other temperate forests and was not systematically changed by forest management, although it was considerably lower in 20 year old regrowth than in younger regrowth or old-growth controls, possibly due to habitat simplification. The Shannon-Weiner Index was at a minimum in intermediate aged regeneration. TWINSPAN analysis assisted recognition of beetle communities typical of broad stages in the forest succession, with a major dichotomy between most old-growth sites plus young sites and intermediate plus advanced regeneration sites. Vector fitting of environmental variables in an ordination of the sites by non-metric multidimensional scaling revealed a significant influence for the age of regeneration and litter depth, but not bare ground percentage or soil pH. Survival of carabids in the habitat mosaic created by commercial forestry activity is likely to depend on both reinvasion from edges and survival of individuals in the fire-protected refuges that exist within the coupes. Pioneer species were winged, small in size, and non-endemic whereas the opposite was true of the fauna in the older sites. Carabids in eucalypt forests have good potential as indicators but their seasonality in occurrence demands that sampling be extended over most of the year.
The effect of mild fires on the soil fauna was examined in a Pinus pinaster plantation and in Jarrah (Eucalyptus marginata) and Karri (E. diversicolor) forests. In the pine plantation, litter decomposition ceases until four years after burning. In both native forests, species diversity and density are reduced after burning and do not recover their pre-burning values during a normal prescribed burning rotation. Prescribed burning on a five to seven year rotation is likely to permanently simplify the litter fauna and flora, with far-reaching effects on forest and hygiene.
Low-intensity fire is extensively used in Australian dry eucalypt forests to reduce fuel levels. The long-term impact of this management practice on terrestrial invertebrates is, however, unknown and is of concern given their contribution to ecosystem function and forest biodiversity. This study found that areas subjected to frequent low-intensity fire had significantly lower numbers of spiders, ticks and mites, pseudoscorpions, woodlice, springtails, bugs, beetles, ants and insect larvae in the leaf litter compared with adjacent unburnt areas. Taxa numbers were between 41 and 82% lower and these reductions in abundance have led to an overall decline in taxon richness. This decrease was attributed to a reduction in the amount of litter and associated moisture levels, and a simplification of habitat structure. The extent of local and regional extinctions will depend upon the scale of this disturbance, with future studies investigating the impact on individual species within these communities. A comparison of two sampling techniques, pitfall-trapping and litter extraction, highlighted important considerations for spatial components of invertebrate sampling designs.
Digging-in effects were recorded while using pitfall traps in a study of ants in Southern Australia. These effects consist of high catches immediately after traps are established which subsequently decline. They are most pronounced among ants with nests close, or accessible to traps, but catches of ants from more distant traps may show delayed digging-in effects. It is suggested that the digging-in effect can be reduced by placing pitfalls, inverted, for one week prior to operating them as traps.Les effets d'enfouissement ont t observs en utilisant des piges au cours d'une tude des fourmis du Sud australien. Ces effets consistent en de nombreuses captures, aussitt aprs la mise en place des piges, suivis d'une rduction de ce nombre. Ils sont plus marqus chez les fourmis dont les nids sont proches ou accessibles par rapport aux piges, mais des captures de fourmis dans des piges plus loigns peuvent prsenter des effets retards. Il est suggr que l'effet d'enfouissement peut tre rduit en plaant les trappes renverses une semaine avant de les utiliser comme piges.
Ant distribution and behavioural dominance is examined at nine sites along an elevational gradient (1400–2600 m) in south eastern Arizona, in order to classify North American species according to a functional group scheme used extensively in Australia. The functional groups are then used as a basis for determining patterns of community structure along the environmental gradient, and for comparing community structure between Australia and North America. Quantitative information on species com- position was obtained from pitfall traps, and patterns of ant abundance at tuna baits were used to determine relative behavioural dominance among taxa. A total of eighty-three species from twenty-eight genera was recorded along the elevational gradient, with site species richness ranging from four (high elevation Douglas fir forest) to thirty-three (mid elevation oak–juniper woodland). There was a strong correlation between ant abundance and richness, which was not an artefact of sampling intensity. The most common ants were species of Forelius, Monomorium, Crematogaster and Pheidole at the three desert sites, species of Formica, Pheidole and Crematogaster at the three woodland sites, and species of Prenolepis and Formica at one forest site. No species were abundant at two other forest sites. The most common species in traps also tended to be the most common species at baits. In terms of behavioural dominance, highly competitive ants included species of Solenopsis, Forelius, Monomorium and Liometopum. Species of Pheidole and Crematogaster tended to be moderately competitive, whereas species of Dory- myrmex, Myrmica, Camponotus and Formica (fusca gp) had low competitive ability. On the basis of these results and on published records of other taxa, North American ants were assigned to functional groups as follows (major taxa only given here): Dominant Dolichoderinae—Forelius, Liome- topum; Subordinate Camponotini—Camponotus; Hot Climate Specialists—Pogonomyrmex, Myrmecocystus; Cold Climate Specialists—Formica (rufa, exsecta and microgyna groups), Leptothorax, Stenamma, Lasius, Prenolepis; Cryptic Species—Smithistruma, Solenopsis (subgenus Diplorhop- trum), Acanthomyops; Opportunists—Formica (fusca group), Myrmica, Paratrechina, Dorymyrmex; Generalized Myr- micinae—Pheidole, Crematogaster, Monomorium; Specialist Predators—no major taxa. Functional group composition varied systematically along the elevation gradient: Dominant Dolichoderinae, Generalized MyrÃmicinae and Hot Climate Specialists were predominant at desert sites; Generalized Myrmicinae and Opportunists were predominant at woodland sites; and Opportunists and Cold Climate Specialists were predominant at forest sites. These patterns are consistent with published studies from elsewhere in North America. Almost all North American taxa can be matched with what appear to be ecologically equivalent taxa in Australia, and biogeographic patterns of functional group composition are broadly similar across the two continents. The major differences are that Australian ant communities are far richer in species, and are almost always dominated by dolichoderines, particularly species of Iridomyrmex. Generalized myrmicines are subdominant to dolichoderines in Australia, but are the behaviourally dominant ants throughout the warmer parts of North America. In cool-temperate North America, species of Formica (especially rufa and exsecta groups) are behaviourally dominant, as they are throughout the Palearctic. Some major features of the North American fauna can be linked to its poor representation of Dominant Dolichoderinae, including (1) the relatively low degree of physiological, morphological and behavioural specialization of Hot Climate Specialists; (2) behavioural dominance by formicines in cool-temperate habitats; and (3) the susceptibility to invasion by behaviourally dominant species such as the imported fire ant Solenopsis invicta and the Argentine ant Linepithema humile.
A system is proposed whereby ant functional groups are used as structural attributes to classify ninety-four Australian ant communities in a manner analogous to the classification of vegetation according to predominant life-forms. In terms of their responses to stress and disturbance, Dominant Dolichoderinae (DD) are considered analogous to trees, functionally subdominant Generalized Myrmicinae (GM) to shrubs and ruderal Opportunists (OPP) to grasses. Community types DDO (twenty-two sites), DD1 (twenty-two sites), DD2 (eight sites), DD3 (thirty-nine sites) and DD4 (three sites), respectively, are defined as having the relative abundance of Dominant Dolichoderinae <10%, 10-19%, 20-29%, 30-70% and >90%. They are structurally analogous to treeless plant communities, open woodlands, woodlands, forests and plantations, respectively. DDO communities are classified as DD0GM (analogous to shrublands) when Generalized Myrmicinae predominate, DD0OPP (analogous to grasslands) when Opportunists predominate and DD0CS (analogous to cold-adapted heathlands) when neither functional group is abundant. Similarly, the relative abundances of Generalized Myrmicinae and Opportunists are used to classify DD1-3 communities in a manner analogous to the classification of woodlands and open forests according to understorey type. DD3OPP communities, for example, where the relative abundance of Dominant Dolichoderinae is 30-70% and Opportunists are predominant among remaining ants, are structurally analogous to grassy forests. The distribution of ant functional groups is considered in relation to stress and disturbance by adopting Grime's (1979) triangular ordination concepts and nomenclature, with ant community structural types being analysed in terms of the relative importance of competition, stress and disturbance as factors regulating community structure. DD0 and DD1 structural types are stress-tolerant, or ruderal, communities; DD2 and DD3 types are competitive communities when Generalized Myrmicinae are abundant, and competitive ruderal or competitive stress-tolerant ruderal when Opportunists are predominant among non-dolichoderines; and DD4 communities are competitive ruderal. In temperate regions, seasonal changes in ant community structure parallel those occurring along biogeographical gradients spanning comparable temperature regimes. A positive relationship was found between the abundance of functionally dominant ants (DD + GM) and species richness. Plant and ant communities often differ from each other in their responses to the same stress or disturbance, such that there is often a poor correspondence between ant and plant community structural type at any particular site.
Ants were sampled using pitfall traps in two replicate 1 ha plots of each of three experimental fire treatments (annually burned, biennially burned, and unburned for over 14 yr) in a eucalypt-dominated savanna in Kakadu National Park. The ant fauna was extremely diverse, with 81 specis from 24 genera. Species were classified into functional groups based on habitat requirements and competitive interactions, with the most important groups being dominant species of Iridomyrmex (11 species, 14-63% total ants in traps); generalized myrmicines (mostly species of Monomorium and Pheidole; total of 22 species, 11-61% total ants in traps); hot climate specialists (species of Melophorus, Monomorium ("Chelaner') and Meranoplus; 14 species, 1-16% total ants in traps); cryptic species (many genera; 13 species, 2-26% total ants in traps;) and opportunists (mostly species of Rhytidoponera and Tetramorium; 11 species, 3-12% total ants in traps). Ant communities in the annually burned plots were characterized by relatively high numbers of dominant Iridomyrmex, hot climate specialists and opportunistic Rhytidoponera aurata, and low numbers of generalized myrimicines and cryptic species. The reverse was true for unburned plots. Many species were common under one fire regime, but were rarely or never recorded under the other, differences attributed to structural changes in the habitat caused by fire, and in particular to the levels of litter accumulation and insolation on the ground. These changes influenced ants directly, but also had important indirect effects through their influence on the abundance of dominant Iridomyrmex, and therefore on competitive interactions. -from Author
Ecologists need to develop formal systems of assessing Australian ecosystems that can be used to evaluate land degradation and restoration processes. Ants are likely to be excellent bio-indicators in this context because they: 1) are ubiquitously diverse and abundant; 2) interact in many ways with other parts of ecosystems and are functionally important at all trophic levels, such that they integrate a wide variety of biotic and abiotic variables; 3) are readily sampled and processed; 4) are highly sensitive to environmental variables; and 5) respond rapidly to environmental change. Most Australian ants are poorly known at the species level, but provide interpretable results when classified into functional groups whose relative abundances vary predictably with climate, vegetation type, and level of disturbance. The relative abundance of these functional groups is not only sensitive to environmental change, but provides insights into the processes underlying such change. -from Author