The ecozones of the world. The ecological division of the geosphere
Abstract
Recent studies have greatly contributed to a better understanding of the earth's ecosystem. This abundantly illustrated book provides a fundamental introduction to the ecological zones of the geosphere. Nine terrestrial ecozones have been distinguished and described in individual chapters with respect to: distribution, climate, relief/hydrology, soil vegetation/animal lifeand land use. The first chapter provides the reader with a general introduction to each subject area. The second edition is a competely revised and updated version. A large number of new Anglo-American ecological studies are included. The book also includes more than 70 new figures and tables and detailed maps on global agricultural regions and soil classification. Another new feature is the discussion of the correlation between northern ecosystems and the carbon dioxide balance in the global atmosphere.
Chapters (15)
The Ecozones of the World, Second EditionThe Ecological Divisions of the Geosphere
10.1007/3-540-28527-X_4
JürgenSchultz
4.Soils
The Ecozones of the World, Second EditionThe Ecological Divisions of the Geosphere
10.1007/3-540-28527-X_5
JürgenSchultz
5.Vegetation and animals
The Ecozones of the World, Second EditionThe Ecological Divisions of the Geosphere
10.1007/3-540-28527-X_8
JürgenSchultz
8.Boreal zone
The Ecozones of the World, Second EditionThe Ecological Divisions of the Geosphere
10.1007/3-540-28527-X_11
JürgenSchultz
11.Subtropics with winter rain
The Ecozones of the World, Second EditionThe Ecological Divisions of the Geosphere
10.1007/3-540-28527-X_12
JürgenSchultz
12.Subtropics with year-round rain
... Numerous direct and indirect effects of wind speed on terrestrial ecosystems exist, including gas and heat exchange, dispersal of pollen, seeds, pests or pollutants, and wind throw (Nobel, 1981). The impacts of wind exposure on microclimate and vegetation patterns are particularly evident, for example, in the polar and subpolar zones (Schultz, 2005). We estimated monthly averages of sfcWind at 30 arcsec resolution by downscaling and bias-correcting the ERA5 time series (sfcW E ) using an aggregation of the Global Wind Atlas product (wind G 10 ; see subsection "Input data"). ...
... Snow cover days are the number of days per year on which the ground is covered with snow. Snow cover affects local climate, hydrology, and ecosystems in complex ways (Callaghan et al., 2011;Schultz, 2005) by insulating the soil from temperature minima during winter months (Zhang, 2005), determining Arctic vegetation patterns (Evans et al., 1989), or providing hiding opportunities from predators for small mammals (Callaghan et al., 2011). We used a B-spline interpolation S (tas, t) to get from monthly to daily estimates of tas, with t being a vector of Julian days marking the middle of each month, i.e., [349,15,45,74,105,135,166,196,227,258,288,319,349,15], and tas being the mean of near-surface 2 m air temperature for the respective month. ...
... rsds describes the amount of solar energy available. It can critically affect local climate and vegetation patterns in high-latitude environments (Andrade et al., 2018;Schultz, 2005). In the tropics with yearround rain, where temperature and precipitation are not limiting, it can constrain primary productivity (Nemani et al., 2003). ...
A multitude of physical and biological processes on which ecosystems and human societies depend are governed by the climate, and
understanding how these processes are altered by climate change is central
to mitigation efforts. We developed a set of climate-related variables at
as yet unprecedented spatiotemporal detail as a basis for environmental and ecological analyses. We downscaled time series of near-surface relative
humidity (hurs) and cloud area fraction (clt) under the consideration of orography and wind as well as near-surface wind speed (sfcWind) using the delta-change
method. Combining these grids with mechanistically downscaled information on
temperature, precipitation, and solar radiation, we then calculated vapor pressure deficit (vpd), surface downwelling shortwave radiation (rsds), potential
evapotranspiration (pet), the climate moisture index (cmi), and site water balance (swb) at a monthly temporal and 30 arcsec spatial resolution globally from 1980 until 2018 (time-series variables). At the same spatial resolution, we
further estimated climatological normals of frost change frequency (fcf), snow
cover days (scd), potential net primary productivity (npp), growing degree days
(gdd), and growing season characteristics for the periods 1981–2010, 2011–2040,
2041–2070, and 2071–2100, considering three shared socioeconomic pathways
(SSP126, SSP370, SSP585) and five Earth system models (projected variables).
Time-series variables showed high accuracy when validated against
observations from meteorological stations and when compared to alternative products. Projected variables were also highly correlated with observations,
although some variables showed notable biases, e.g., snow cover days.
Together, the CHELSA-BIOCLIM+ dataset presented here (https://doi.org/10.16904/envidat.332, Brun et al., 2022) allows improvement to
our understanding of patterns and processes that are governed by climate,
including the impact of recent and future climate changes on the world's ecosystems and the associated services on societies.
... Numerous direct and indirect effects of wind speed on terrestrial ecosystems exist, including gas and heat exchange, dispersal of pollen, seeds, pests or pollutants, and wind throw (Nobel, 1981). The impact of wind exposure on microclimate and vegetation patterns are particularly evident, for example, in the polar and subpolar zones (Schultz, 2005). We estimated monthly averages of near-surface (10 m) wind speed (sfcWind) at 30 arcsec resolution by downscaling and bias-correcting the ERA5 time-series (sfcWE), using an aggregation of the Global Wind Atlas product ( 10 ; see subsection Input data). ...
... Snow cover days (scd) are the number of days per year on which the ground is covered with snow. Snow cover affects local climate, hydrology, and ecosystems in complex ways (Callaghan et al. 2011, Schultz 2005, by insulating the soil from 265 temperature minima during winter months (Zhang, 2005), by determining Arctic vegetation patterns (Evans et al., 1989), or by providing hiding opportunities form predators for small mammals (Callaghan et al., 2011). We used a B-spline interpolation S(tas, t) to get from monthly to daily estimates of tas, with t being a vector of Julian days marking the middle of each month, i.e., [349,15,45,74,105,135,166,196,227,258,288,319,349,15] , and tas being the mean of near-surface 2 m air temperature for the respective month. ...
... rsds describes the amount of solar energy available. It can critically affect local climate and vegetation patterns in high-latitude environments (Andrade et al., 2018;Schultz, 2005). In the tropics with year-round rain, where temperature 335 and precipitation are not limiting, it can constrain primary productivity (Nemani et al., 2003). ...
A multitude of physical and biological processes on which ecosystems and human societies depend are governed by climatic conditions. Understanding how these processes are altered by climate change is central to mitigation efforts. Based on mechanistically downscaled climate data, we developed a set of climate-related variables at yet unprecedented spatiotemporal detail as a basis for environmental and ecological analyses. We created gridded data for near-surface relative humidity (hurs), cloud area fraction (clt), near-surface wind speed (sfcWind), vapour pressure deficit (vpd), surface 15 downwelling shortwave radiation (rsds), potential evapotranspiration (pet), climate moisture index (cmi), and site water balance (swb), at a monthly temporal and 30 arcsec spatial resolution globally, from 1980 until 2018 (time-series variables). At the same spatial resolution, we further estimated climatological normals of frost change frequency (fcf), snow cover days (scd), potential net primary productivity (npp), growing degree days (gdd), and growing season characteristics for the periods three shared socioeconomic pathways (SSP126, SSP370, 20 SSP585) and five Earth system models (projected variables). Time-series variables showed high accuracy when validated against observations from meteorological stations. Projected variables were also highly correlated to observations, although some variables showed notable biases, e.g., snow cover days (scd). Together, the CHELSA-BIOCLIM+ data set presented here (https://doi.org/10.16904/envidat.332, Brun et al., 2022) allows improving our understanding of patterns and processes that are governed by climate, including the impact of recent and future climate changes on the world's ecosystems and 25 associated services to societies.
... Forest-steppe ecosystems are complex systems, composed by a mosaic of forest and grasslands taxa (Breshears, 2006;Innes et al., 2013;Prevedello et al., 2018). The largest forest-steppes are located in Eurasia and are of major ecological importance (Erdős et al., 2018) due to their very high net primary productivity (Schultz, 2005;Pfadenhauer and Klötzli, 2014), their considerable biomass and their potential as a carbon sink (Schultz, 2005). In Mongolia, they are also of economic interest, because nomadic and semi-nomadic populations have used these regions for mobile pastoralism since the Bronze Age, around 5000 yr BP (3000 BCE), although the exact period of appearance of these practices remains debated (Anthony and Brown, 1991;Dulamsuren et al., 2005;Hanks, 2010;Fernández-Giménez et al., 2017;Słowiński et al., 2022). ...
... Forest-steppe ecosystems are complex systems, composed by a mosaic of forest and grasslands taxa (Breshears, 2006;Innes et al., 2013;Prevedello et al., 2018). The largest forest-steppes are located in Eurasia and are of major ecological importance (Erdős et al., 2018) due to their very high net primary productivity (Schultz, 2005;Pfadenhauer and Klötzli, 2014), their considerable biomass and their potential as a carbon sink (Schultz, 2005). In Mongolia, they are also of economic interest, because nomadic and semi-nomadic populations have used these regions for mobile pastoralism since the Bronze Age, around 5000 yr BP (3000 BCE), although the exact period of appearance of these practices remains debated (Anthony and Brown, 1991;Dulamsuren et al., 2005;Hanks, 2010;Fernández-Giménez et al., 2017;Słowiński et al., 2022). ...
... Own compilation according to various approaches (Hagedorn & Poser 1974, Hövermann 1987, Höverman 1985, Lehmkuhl et al. 2003. The type of vegetation and geomorphological processes are assigned to the different ecozones (Schultz 2016, Schultz 2005. ...
... While climate controls the broad categories of vegetation cover and density as well as soils, the detailed type of vegetation, its distribution and composition depend strongly on local factors. These include micro-climatic conditions, rela-tive relief and slope gradient, lithology, weathering processes and soil development, drainage conditions and the manner in which a particular constellation of processes is interacting (Huddart & Stott 2020, Riebe et al. 2004, Schultz 2005. The relationship between these factors is crucial with respect to soil dynamics and the balance between weathering and soil development rates and the rates of denudation and erosion processes. ...
Global approaches in geomorphology, encompassing morphotectonic and climatic geomorphological features have a long tradition. This paper evaluates the concepts of geomorphologists on climatic geomorphology especially from Göttingen University (Germany) in and discusses their present value and possible applications. A major focus of this paper is the discussion of the concept of a global map of different processes and process combinations from Hagedorn and Poser (1974) and of the climatic geomorphological approach to landforms of Hövermann (1985: system of climatic geomorphology on a landscape basis). These concepts are critically discussed in the light of new research and with respect to the limits of the climatic geomorphological approaches. Based on previous research it appeared necessary to modify the global map of Hagedorn and Poser by supplementing especially the arid landform regions of Hövermann. The geomorphological processes and landform assemblages encompass on a global scale from pole to the equator twelve regions. These are discussed with respect to the recent and past process constellations and their composite landforms. The results show, that the climatic geomorphological approach seems to match quite well with the results of more recent research on the development of composite meso-scale landscapes in the polar, hyperarid to semi-arid climatic zones, and with some constrains, with the temperate climatic zone. Consideration of the effects of climate on past and present landforming processes may support the development of a more comprehensive landscape models and the processual approach provides a link to both analysis of ecozonal systems and of human interferences.
... We differentiate between the temperate and Mediterranean biome according to Schultz (2005) in the domain extending from 10°W to 45°E and 35°N to 60°N, excluding all boreal forests (Fig. 1a). ...
... P ′ 90d and T 2m ′ 90d , however, do not necessarily represent the actual site-level temperature and precipitation values and their interpretation requires care . This 515 specifically applies when comparing the meteorological storyline of the temperate with the Mediterranean biome, respectively, as the latter climatologically receives little precipitation during summer (Schultz, 2005). The use of basic meteorological variables instead of a more complex drought index is motivated by the overarching research question of this study, which is to characterize the meteorological storyline of these events. ...
Recent forest decline in Europe is strongly influenced by meteorological conditions imposed by seasonal variations of temperature, T2m, and precipitation, P, and can be monitored with forest greenness. This study quantitatively investigates anomalous characteristics of the three-year meteorological storyline preceding events of reduced forest greenness in Europe's temperate and Mediterranean biome in the phase space of seasonal-mean anomalies of (T2m, P). A specific focus is on the amplitude, persistence, and co-variability of these anomalies. A pragmatic approach based on remote sensing observations of normalized difference vegetation index NDVI serves to identify low forest NDVI events at the 50 km scale in Europe in June to August 2000–2020. An independent forest disturbance data set is used to qualitatively validate the identified more than 1'500 low NDVI events. These events occur in summers with particularly dry and hot conditions but their meteorological storylines feature significant anomalies during multiple seasons preceding the events, with clear differences between the two biomes. In the Mediterranean biome, the anomalously dry conditions persist over more than 1.5 y prior to the events, whereas T2m is anomalously warm only during the last 0.4 y. In contrast, in the temperate biome, T2m is anomalously large during most of the 2.5 y prior to the events and, most interestingly, the autumn/winter preceding the events is characterized by anomalously wet and warm conditions. These anomalies potentially induce a negative legacy on the following summer drought. The seasonal-mean anomalies of P are strongly determined by synoptic-scale weather systems, such that long dry periods are characterized by a deficit of cyclones and an excess of anticyclones. A final analysis investigates the peculiarities of low NDVI events that occur in two consecutive summers and the potential role of drought legacy effects. In the temperate biome, the second event summer of an event sequence has less hot and less dry anomalies than the first one and than during a single event. In summary, detailed investigations of the multi-annual meteorological storyline of low forest NDVI events provided clear evidence that anomalies of surface weather and synoptic-scale weather systems over time periods of up to 2.5 y can negatively impact European forest activity, with important differences between the temperate and Mediterranean biomes.
... Here, we address this question, using the same data. For this purpose, we selected three different typologies that are widely used and carry different but complementary information: (a) biomes (reflecting the climax vegetation according to the macroclimate; Schultz 2005;Hunter et al. 2021), (b) ecological-physiognomic vegetation types (at two levels of resolution) and (c) phytosociological classes (reflecting the actual species composition; see Dengler et al. 2008;Mucina et al. 2016). Based on the findings regarding environmental predictors ) and our hypotheses on causal pathways ( Figure 1), we have the following a priori expectations: 1. ...
... We tested how the modelled z-values depended on biome and vegetation types of three different typologies. First, as a biome typology, we used the ecozones of Schultz (2005) with additional separation of an Alpine biome (Körner et al. 2017) -as implemented by Bruelheide et al. (2019). Further, we used the coarse and fine vegetation typology of GrassPlot (Biurrun et al. 2019), which is mainly based on ecological and physiognomic criteria (for details see Suppl. ...
Aims : To quantify how fine-grain (within-plot) beta diversity differs among biomes and vegetation types. Study area : Palaearctic biogeographic realm. Methods : We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database spanning broad geographic and ecological gradients. Next, we calculated the slope parameter ( z -value) of the power-law species–area relationship (SAR) to use as a measure of multiplicative beta diversity. We did this separately for vascular plants, bryophytes and lichens and for the three groups combined (complete vegetation). We then tested whether z -values differed between biomes, ecological-physiognomic vegetation types at coarse and fine levels and phytosociological classes. Results : We found that z -values varied significantly among biomes and vegetation types. The explanatory power of area for species richness was highest for vascular plants, followed by complete vegetation, bryophytes and lichens. Within each species group, the explained variance increased with typological resolution. In vascular plants, adjusted R ² was 0.14 for biomes, but reached 0.50 for phytosociological classes. Among the biomes, mean z -values were particularly high in the Subtropics with winter rain (Mediterranean biome) and the Dry tropics and subtropics. Natural grasslands had higher z -values than secondary grasslands. Alpine and Mediterranean vegetation types had particularly high z -values whereas managed grasslands with benign soil and climate conditions and saline communities were characterised by particularly low z -values. Conclusions : In this study relating fine-grain beta diversity to typological units, we found distinct patterns. As we explain in a conceptual figure, these can be related to ultimate drivers, such as productivity, stress and disturbance, which can influence z -values via multiple pathways. The provided means, medians and quantiles of z -values for a wide range of typological entities provide benchmarks for local to continental studies, while calling for additional data from under-represented units.
Syntaxonomic references : Mucina et al. (2016) for classes occurring in Europe; Ermakov (2012) for classes restricted to Asia.
Abbreviations : ANOVA = analysis of variance; EDGG = Eurasian Dry Grassland Group; SAR = species-area relationship.
... Here, we address this question, using the same data. For this purpose, we selected three different typologies that are widely used and carry different but complementary information: (a) biomes (reflecting the climax vegetation according to the macroclimate; Schultz 2005;Hunter et al. 2021), (b) ecological-physiognomic vegetation types (at two levels of resolution) and (c) phytosociological classes (reflecting the actual species composition; see Dengler et al. 2008;Mucina et al. 2016). Based on the findings regarding environmental predictors ) and our hypotheses on causal pathways ( Figure 1), we have the following a priori expectations: 1. ...
... We tested how the modelled z-values depended on biome and vegetation types of three different typologies. First, as a biome typology, we used the ecozones of Schultz (2005) with additional separation of an Alpine biome (Körner et al. 2017) -as implemented by Bruelheide et al. (2019). Further, we used the coarse and fine vegetation typology of GrassPlot (Biurrun et al. 2019), which is mainly based on ecological and physiognomic criteria (for details see Suppl. ...
Aims : To quantify how fine-grain (within-plot) beta diversity differs among biomes and vegetation types. Study area : Palaearctic biogeographic realm. Methods : We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database spanning broad geographic and ecological gradients. Next, we calculated the slope parameter ( z -value) of the power-law species–area relationship (SAR) to use as a measure of multiplicative beta diversity. We did this separately for vascular plants, bryophytes and lichens and for the three groups combined (complete vegetation). We then tested whether z -values differed between biomes, ecological-physiognomic vegetation types at coarse and fine levels and phytosociological classes. Results : We found that z -values varied significantly among biomes and vegetation types. The explanatory power of area for species richness was highest for vascular plants, followed by complete vegetation, bryophytes and lichens. Within each species group, the explained variance increased with typological resolution. In vascular plants, adjusted R ² was 0.14 for biomes, but reached 0.50 for phytosociological classes. Among the biomes, mean z -values were particularly high in the Subtropics with winter rain (Mediterranean biome) and the Dry tropics and subtropics. Natural grasslands had higher z -values than secondary grasslands. Alpine and Mediterranean vegetation types had particularly high z -values whereas managed grasslands with benign soil and climate conditions and saline communities were characterised by particularly low z -values. Conclusions : In this study relating fine-grain beta diversity to typological units, we found distinct patterns. As we explain in a conceptual figure, these can be related to ultimate drivers, such as productivity, stress and disturbance, which can influence z -values via multiple pathways. The provided means, medians and quantiles of z -values for a wide range of typological entities provide benchmarks for local to continental studies, while calling for additional data from under-represented units.
Syntaxonomic references : Mucina et al. (2016) for classes occurring in Europe; Ermakov (2012) for classes restricted to Asia.
Abbreviations : ANOVA = analysis of variance; EDGG = Eurasian Dry Grassland Group; SAR = species-area relationship.
... Geiger, 1961;в работе Udvardy, 1975 дается более широкое определение и используется больше физиографических характеристик, что представляет основу классификации, используемой в отношении объектов всемирного наследия ЮНЕСКО (см. также работы: Рачковская, 2003;Schröder, 1998;Schultz, 2005;Shmida et al., 1985;Walter, 1968). ...
The World Heritage thematic study for Central Asia has been produced as a contribution to supporting the implementation of the World Heritage Convention in Central Asia. It provides a response to a Decision of the World Heritage Committee in order to identify outstanding areas with potential for future nomination to the World Heritage List with primary focus on criteria (ix) and (x) at the regional scale. The approach applied in this study, focusing on criteria (ix) and (x), follows that from the 2013 study on terrestrial biodiversity and the World Heritage List. Criteria (ix) and (x) are clearly the primary ones for recognition of extant biodiversity values, and they have been applied to a wide range of biodiversity features, including ecosystems, species, and ecological and/or biological processes. Although this study is an initial assessment, most areas and sites recommended here have appeared repeatedly as being of particular interest for biodiversity conservation during the work process, whether through literature analysis or in discussions with experts and specialists. The recommendations reflect the current level of knowledge that should be strengthened in the future, to ensure that the identified areas and sites are well supported with the necessary data and empirical evidence to address the requirements of the Operational Guidelines.
... Thus, 2,372 plots deviating less than 10% from standard grain sizes (0.0009, 0.09, 9, 10.89, 900 and 1,024 m 2 ) were also selected and used for the benchmarks of the respective grain size. The final data set contained 126,524 plots (Table 1) Biomes were assigned using the biome classification provided in Bruelheide et al. (2019), which is based on the nine ecozones of Schultz (2005) plus an additional alpine biome based on Körner et al. (2017). Plots were also assigned to ten geographic regions following Dengler et al. (2020a). ...
Aims
Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups).
Location
Palaearctic biogeographic realm.
Methods
We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001 m², 0.001 m², 0.01 m², 0.1 m², 1 m², 10 m², 100 m² and 1000 m² and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class.
Results
Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats.
Conclusions
The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, , biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology.
... Cold winter deserts (also referred to as temperate/nemoral deserts) are geographically defined in different ways. The most prominent definition is likely the climate classification after Köppen & Geiger, 1961;Udvardy, 1975 gives a broader definition, including more physiographic features, which is the reference for the classification of UNESCO WH Sites (see also Rachkovskaya, 2003;Schröder, 1998;Schultz, 2005;Shmida et al., 1985;Walter, 1968). ...
... However, to provide a comprehensive overview and for consistency reasons, in this synthesis we also cover intensified as well as arctic-alpine grasslands. Fig. 1 Delimitation of the Palaearctic biogeographic realm according to Olson et al. (2001) combined with the biome classification of Bruelheide et al. (2019), largely based on Schultz (2005) (map kindly provided by C. Marcenò). Note that according to other concepts, the "Subtropics with year-round rain" do not reach as far north and, for example, most of Japan would belong to the Temperate midlatitudes. ...
Grasslands are spontaneously occurring herbaceous vegetation types that are mostly dominated by grasses or other graminoids and have usually more than 10% herb-layer cover, while woody species area absent or have a significantly lower abundance than the herbs. In Palaearctic biogeographic realm natural and secondary grasslands (76% and 24% of all grasslands, respectively) cover about 9.3 million km², i.e. 17% of its territory, which constitute 38% of global grasslands –more than any other biogeographic realm. In the “Encyclopedia”, the Palaearctic grasslands are placed in the section “Grasslands and Shrublands”, where we defined 10 regions, which are treated in individual chapters: Western Europe, Northern Europe and Baltic States, Eastern Europe, Mediterranean Basin, Middle East and Caucasus, Russia, Kazakhstan and Middle Asia, Mongolia, China, and Japan. These regions covered the huge majority of the realm and about 98% of its grasslands. Each chapter described the extent, physiogeography, origin, biodiversity and typology of the grasslands in the region, the threats for grassland diversity and extent, as well as grassland management and conservation. Grasslands are important habitats for many groups of taxa. Dry calcareous grasslands and steppes constitute habitat of most of Europe’s butterfly and Orthoptera species, and they host significant number of European endemic plants. In small spatial scales (i.e. below 100 m2) Palaeartic grasslands, especially meso-xeric ones, can hold even higher species diversity of plants than tropical rainforest. However, Palaearctic grasslands are also among the most intensively and negatively human-impacted habitats. Changes in grassland management, like overgrazing or other types of intensification as well as abandonment were assessed as the most important recent and future threats. Other important reasons of decline in grassland diversity are habitat loss and altered site conditions. The negative impact of climate change and invasive species is predicted to be stronger in the future. In the last years, various conservation efforts to monitor, maintain and promote grassland extent and diversity were made. However, to counteract the negative trends these efforts urgently need to be intensified and their efficiency needs to be improved.
... As sampling methodology has been repeatedly suggested to influence the shape of SARs (Dengler, 2008;Williamson, 2003), we tested for an effect of some key sampling method aspects using Table S1.1 and Figure S1.4). Furthermore, we tested whether the performance of the functions depended on (d) taxonomic group (vascular plants, bryophytes, lichens), (e) biome (Bruelheide et al., 2019; based on Schultz, 2005), (f) vegetation type or (g) richness in the largest plot of the series (see Figure S1.1, Tables S1.2 and S1.3). ...
Aim: Species-area relationships (SARs) are fundamental scaling laws in ecology although their shape is still disputed. At larger areas power laws best represent SARs. Yet, it remains unclear whether SARs follow other shapes at finer spatial grains in continuous vegetation. We asked which function describes SARs best at small grains and explored how sampling methodology or the environment influence SAR shape.
Location: Palaearctic grasslands and other non-forested habitats.
Taxa: Vascular plants, bryophytes and lichens.
Methods: We used the GrassPlot database, containing standardised vegetation-plot data from vascular plants, bryophytes, and lichens spanning a wide range of grassland types throughout the Palaearctic and including 2057 nested-plot series with at least seven grain sizes ranging from 1 cm2 to 1024 m². Using non-linear regression, we assessed the appropriateness of different SAR functions (power, power quadratic, power breakpoint, logarithmic, Michaelis-Menten). Based on AICc, we tested whether the ranking of functions differed among taxa, methodological settings, biomes or vegetation types.
Results: The power function was the most suitable function across the studied taxonomic groups. The superiority of this function increased from lichens to bryophytes to vascular plants to all three taxonomic groups together. The sampling method was highly influential as rooted-presence sampling decreased the performance of the power function. By contrast, biome and vegetation type had practically no influence on the superiority of the power law.
Main conclusions: We conclude that SARs of sessile organisms at smaller spatial grains are best approximated by a power function. This coincides with several other comprehensive studies of SARs at different grain sizes and for different taxa, thus supporting the general appropriateness of the power function for modelling species diversity over a wide range of grain sizes. The poor performance of the Michaelis-Menten function demonstrates that richness within plant communities generally does not approach any saturation, thus calling into question the concept of minimal area.
... The WWF approach is based on a bottom-up expert system using various regional biodiversity sources to define ecoregions, which in turn are grouped into realms and biomes (Olson et al., 2001). In addition, we created a shapefile for the ecozones defined by Schultz (2005) to represent major biomes in response to global climatic variation. Since these zones are climatically heterogeneous in mountain regions, we differentiated an additional "alpine" biome for mountain areas above the lower mountain thermal belt, as defined in the classification of world mountain regions by Körner et al. (2017). ...
Aims: Vegetation-plot records provide information on the presence and cover or abundance of plants co-occurring in the same community. Vegetation-plot data are spread across research groups, environmental agencies and biodiversity research centers and, thus, are rarely accessible at continental or global scales. Here we present the sPlot database, which collates vegetation plots worldwide to allow for the exploration of global patterns in taxonomic, functional and phylogenetic diversity at the plant community level.
Results: sPlot version 2.1 contains records from 1,121,244 vegetation plots, which comprise 23,586,216 records of plant species and their elative cover or abundance in plots collected worldwide between 1885 аnd 2015. We complemented the information for each plot by retrieving climate and soil conditions and the biogeographic context (e.g., biomes) from external sources, and by calculating community-weighted means and variances of traits using gap-filled data from the global plant trait database TRY. Moreover, we created a phylogenetic tree for 50,167 out of the 54,519 species identified in the plots. We present the first maps of global patterns of community richness and community-weighted means of key traits.
Conclusions: The availability of vegetation plot data in sPlot offers new avenues for vegetation analysis at the global scale.
... The WWF approach is based on a bottom-up expert system using various regional biodiversity sources to define ecoregions, which in turn are grouped into realms and biomes (Olson et al., 2001). In addition, we created a shapefile for the ecozones defined by Schultz (2005) to represent major biomes in response to global climatic variation. Since these zones are climatically heterogeneous in mountain regions, we differentiated an additional "alpine" biome for mountain areas above the lower mountain thermal belt, as defined in the classification of world mountain regions by Körner et al. (2017). ...
Questions: Vegetation-plot records provide information on presence and cover or abundance of plants co-occurring in the same community. Vegetation-plot data are spread across research groups, environmental agencies and biodiversity research centers, and thus, are rarely accessible at continental or global scales. Here we present the sPlot database, which collates vegetation plots worldwide to allow for the exploration of global patterns in taxonomic, functional and phylogenetic diversity at the plant community level. - Location: sPlot version 2.1 contains records from 1,121,244 vegetation plots, which comprise 23,586,216 records of plant species and their relative cover or abundance in plots collected between 1885 and 2015. - Methods: We complemented the information for each plot by retrieving environmental conditions (i.e. climate and soil) and the biogeographic context (i.e. biomes) from external sources, and by calculating community-weighted means and variances of traits using gap-filled data from the global plant trait database TRY. Moreover, we created a phylogenetic tree for 50,167 out of the 54,519 species identified in the plots. - Results: We present the first maps of global patterns of community richness and community-weighted means of key traits. -
Conclusions: The availability of vegetation plot data in sPlot offers new avenues for vegetation analysis at the global scale.
... What is more, in soils contaminated with excessive metal content (particularly cadmium or lead) high cation exchange capacity prevents leaching and transfer of metals to the food chain [6]. The cation exchange capacity in the created soil mixtures is very high compared to soils characteristic of Poland, and may be only compared with fertile chernozem soils [15]. The soil mixtures are characterised by high values for the sum of the total exchangeable bases (S). ...
Land redevelopment is necessary due to the amount of a degraded area. Depositing waste on the small area of landfills is harmful for the environment. New methods of managing and utilizing waste are being sought in order to minimize the deposition of waste. In small amounts, many types of waste can be treated as a substrate or material improving physicochemical properties of soils, and hence can be used in reclamation of degraded lands. The study analysed the effect of different doses of sewage sludge (35%, 17.5%) with addition (2.5% and 5%) of drilling waste on the properties of degraded soils. The results show that created mixtures improve the sorption properties of soil. The mixtures contain the optimal the ratio of nutrient elements for growth of plants is N:P:K.
The Arctic ecosystems and their species are exposed to amplified climate warming and, in some regions, to rapidly developing economic activities. This study assesses, models, and maps the geographic patterns of community‐level plant species richness in the Western Siberian Arctic and estimates the relative impact of environmental and anthropogenic factors driving these patterns. With our study, we aim at contributing toward conservation efforts for Arctic plant diversity in the Western Siberian Arctic. Western Siberian Arctic, Russia. We investigated the relative importance of environmental and anthropogenic predictors of community‐level plant species richness in the Western Siberian Arctic using macroecological models trained with an extensive geobotanical dataset. We included vascular plants, mosses and lichens in our analysis, as non‐vascular plants substantially contribute to species richness and ecosystem functions in the Arctic. We found that the mean community‐level plant species richness in this vast Arctic region does not decrease with increasing latitude. Instead, we identified an increase in species richness from South‐West to North‐East, which can be well explained by environmental factors. We found that paleoclimatic factors exhibit higher explained deviance compared to contemporary climate predictors, potentially indicating a lasting impact of ancient climate on tundra plant species richness. We also show that the existing protected areas cover only a small fraction of the regions with highest species richness. Our results reveal complex spatial patterns of community‐level species richness in the Western Siberian Arctic. We show that climatic factors such as temperature (including paleotemperature) and precipitation are the main drivers of plant species richness in this area, and the role of relief is clearly secondary. We suggest that while community‐level plant species richness is mostly driven by environmental factors, an improved spatial sampling will be needed to robustly and more precisely assess the impact of human activities on community‐level species richness patterns. Our approach and results can be used to design conservation strategies and to investigate drivers of plant species richness in other arctic regions.
Forecasting the risks of climate change for species and ecosystems is necessary for developing targeted conservation strategies. Previous risk assessments mapped the exposure of the global land surface to changes in climate. However, this procedure is unlikely to robustly identify priority areas for conservation actions because nonlinear physiological responses and colimitation processes ensure that ecological changes will not map perfectly to the forecast climatic changes. Here, we combine ecophysiological growth models of 135,153 vascular plant species and plant growth-form information to transform ambient and future climatologies into phytoclimates, which describe the ability of climates to support the plant growth forms that characterize terrestrial ecosystems. We forecast that 33% to 68% of the global land surface will experience a significant change in phytoclimate by 2070 under representative concentration pathways RCP 2.6 and RCP 8.5, respectively. Phytoclimates without present-day analogue are forecast to emerge on 0.3–2.2% of the land surface and 0.1–1.3% of currently realized phytoclimates are forecast to disappear. Notably, the geographic pattern of change, disappearance and novelty of phytoclimates differs markedly from the pattern of analogous trends in climates detected by previous studies, thereby defining new priorities for conservation actions and highlighting the limits of using untransformed climate change exposure indices in ecological risk assessments. Our findings suggest that a profound transformation of the biosphere is underway and emphasize the need for a timely adaptation of biodiversity management practices.
The first comprehensive phytosociological classification of all vegetation types in Europe (EuroVegChecklist; Applied Vegetation Science, 2016, 19, 3-264) contained brief descriptions of each type. However, these descriptions were not standardized and mentioned only the most distinct features of each vegetation type. The practical application of the vegetation classification system could be enhanced if users had the option to select sets of vegetation types based on various combinations of structural, ecological, and biogeographical attributes. Based on a literature review and expert knowledge, we created a new database that assigns standardized categorical attributes of 12 variables to each of the 1106 alliances dominated by vascular plants defined in EuroVegChecklist. These variables include dominant life form, phenological This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Eurasian forest-steppes form a 9000-km-long transitional zone between temperate forests and steppes, featuring a complex mosaic of herbaceous and woody habitats. Due to its heterogeneity regarding climate, topography and vegetation, the forest-steppe zone has been divided into several regions. However, a continental-scale empirical delineation of the zone and its regions was missing until recently. Finally, a map has been proposed by Erdős et al. based on floristic composition, physiognomy, relief, and climate. By conducting predictive distribution modeling and hierarchical clustering, here we compared this expert delineation with the solely macroclimate-based predictions and clusters. By assessing the discrepancies, we located the areas where refinement of the delineation or the inclusion of non-macroclimatic predictors should be considered. Also, we identified the most important variables for predicting the existence of the Eurasian forest-steppe zone and its regions. The predicted probability of forest-steppe occurrence showed a very high agreement with the expert delineation. The previous delineation of the West Siberia region was confirmed by our results, while that of the Inner Asia region was the one least confirmed by the macroclimate-based model predictions. The appropriate delineation of the Southeast Europe region from the East Europe region should be refined by further research, and splitting the Far East region into a southern and northern subregion should also be considered. The main macroclimatic predictors of the potential distribution of the zone and its regions were potential evapotranspiration (zone and regions), annual mean temperature (regions), precipitation of driest quarter (regions) and precipitation of warmest quarter (zone), but the importance of climatic variables for prediction showed great variability among the fitted predictive distribution models.
Anthracological analyses of charcoal samples retrieved from Pit 16 of Perdigões (Reguengos de Monsaraz, Portugal), a secondary deposition of cremated human remains dated back to the middle of the 3rd millennium BC, enabled the identification of 7 different taxa: Olea europaea, Quercus spp. (evergreen), Pinus pinaster, Fraxinus cf. angustifolia, Arbutus unedo, Cistus sp. and Fabaceae. All taxa are characteristic of both deciduous and evergreen Mediterranean vegetation, and this data might indicate that the gathering of woods employed for the human cremation/s occurred either on site, or in its vicinity. However, considering both the large distribution of the identified taxa and data about human mobility, it is not possible to conclusively determine the origin of the wood used in the cremation(s). Chemometric analysis were carried out to estimate the absolute burning temperature of woods employed for the human cremation/s. An in-lab charcoal reference collection was created by burning sound wood samples of the three main taxa identified from Pit 16, Olea europaea var. sylvestris, Quercus suber (evergreen type) and Pinus pinaster, at temperatures between 350 and 600 °C. The archaeological charcoal samples and the charcoal reference collection were chemically characterized by using mid-infrared (MIR) spectroscopy in the 1800-400 cm-1 range, and Partial Least Squares (PLS) regression method was used to build calibration models to predict the absolute combustion temperature of the archaeological woods. Results showed successful PLS forecasting of burn temperature for each taxon (significant (P <0.05) cross validation coefficients). The anthracological and chemometric analysis evidenced differences between the taxa coming from the two stratigraphic units within the Pit, SUs 72 and 74, suggesting that they may come from two different pyres or two different depositional moments.
Biomes are large-scale biotic communities (ecosystems) distinguished by specific ecological functionality and evolutionary origins. They can be studied and delimited using functional variables but also using physiognomic and vegetation-textural surrogates. Biomes are spatially explicit units, and as such, they can be seen as complexes of biotic communities at various hierarchical levels, including zonobiomes, global biomes, continental biomes, and regional biomes. Each of these categories has its characteristic own set of ecological drivers. Walter's zonobiome system is possibly the most common biome system coined to explain the diversity of large-scale biotic communities on Earth. It is a bioclimatic approach, recognising the role of climatic factors driving the zonal biome patterns at large scales. It also provides for biomes driven by other factors, such as soils and hydrology, called azonal biomes. This chapter aims to revisit the usefulness of the zonal/azonal conceptual framework in the ocean-dominated Southern Hemisphere. It puts significant emphasis (at the large-scale biome levels) on the climato-genetic drivers, modern tools of bioclimatology, and sources of bioclimatic data. By doing so, this chapter is also a prelude to the formulation of a new zonobiome system, serving as a basis for a Global Hierarchical Biome System.KeywordsAzonalityContinental biomeEcotoneGlobal biomeGlobal hierarchical biome systemRegional biomeSouthern hemisphereSpatial climatic diagramZonalityZonobiome
Trees are major components of the biosphere and their wood is one of the most important renewable resources. Wood as it exists is the result of an evolutionary process to perfectly meet the three main functions: water transport, mechanical support, and storage of reserve material. Detailed information is provided on the photosynthesis and its basic biochemistry as the process by which trees use light energy to synthesize carbohydrates. Wood formation is presented on the cellular level with the cambium as the responsible tissue. Cell divisions, differentiation steps as well as seasonal rhythms are described. Principles of wood tissue variations as well as heartwood formation are shown. A detailed insight into structure and formation of reaction wood is given and the cellular processes of wound reactions are reflected. Felling, storage, drying, and steaming of wood cause a variety of discolorations, which reduce wood quality. Their underlying physiological processes are explained. Anatomical and also selected chemical characteristics of plantation wood are exemplarily provided for teak, black locust, and Douglas fir. The chapter also comes up with state of the art knowledge on international laws and regulations against trading of illegally logged timber and its products. CITES-protection is another field which requires efficient control mechanisms like wood identification on the basis of anatomical features. Recently, wood identification in pulp, paperwood, and fiberboards received increasing importance. Finally, a brief overview is given on structure and utilization of bamboo, rattan, and three selected palms as monocotyledons which develop wood-like tissue.KeywordsWood biologyPhotosynthesisWood formationCambiumWood anatomyReaction woodPlantation woodTimber trade regulationsBambooRattan
Forest dieback in Europe has recently intensified and has become more extensive. This dieback is strongly influenced by meteorological variations of temperature, T 2m, and precipitation, P, and can be monitored with forest greenness. This study quantitatively investigates the 3-year meteorological history preceding events of reduced forest greenness in Europe’s temperate and Mediterranean biome with a systematic approach. A specific focus lies in the timing of unusually persistent and unusually strong anomalies of T 2m and P, as well as their relation to synoptic weather systems. A pragmatic approach based on remote sensing observations of the normalized difference vegetation index (NDVI) serves to identify low-forest-NDVI events at the 50 km scale in Europe in June to August 2002–2022. We quantify the impact of the hottest summer on record in Europe in 2022, which, according to our criteria, negatively affected 37% of temperate and Mediterranean forest regions, and thereby reduced forest greenness more extensively than any other summer in 2002–2022.
The low-NDVI events occurred in particularly dry and hot summers, but their meteorological histories also featured significant anomalies further in the past, with clear differences between the temperate and Mediterranean biome. A key feature is the anomalous accumulation of dry periods (i.e., periods with a P deficit) over the preceding 26 and 34 months in the temperate and Mediterranean biome, respectively. In the temperate biome only, T 2m was anomalously persistent during almost the same 26-month period and featured distinctive peaks late in the past three growing seasons. While anomalously strong hot–dry conditions were characteristic of temperate low-NDVI events already in the previous summer, we find hardly any other systematic meteorological precursor in the Mediterranean prior to the event year. The identified dry periods went along with reduced cyclone activity in the Mediterranean and positive anticyclone frequency in the temperate biome. The occurrence of these two weather systems is locally more nuanced, showing, e.g., consistently increased and decreased cyclone frequency over western and northern Europe, respectively, in all event summers. Finally, the systematic meteorological histories are useful to test whether locally observed meteorological impacts, e.g., structural overshoot, systematically influenced the investigated events. In summary, systematic investigations of the multi-annual meteorological history provided clear evidence of how surface weather and synoptic-scale weather systems over up to 3 years can negatively impact European forest greenness. The observation of the recordextensive low-NDVI event in the summer of 2022 underlines that understanding the forest–meteorology interaction is of particular relevance for forest dieback in a changing climate.
The worldwide dromedary milk production has increased sharply since the beginning of this century due to prolonged shelf life, improved food-safety and perceived health benefits. Scientific confirmation of health claims will expand the market of dromedary milk further. As a result, more and more dromedaries will be bred for one purpose only: the highest possible milk production. However, intensive dromedary farming systems have consequences for animal welfare and may lead to genetic changes. Tighter regulations will be implemented to restrict commercialization of raw milk. Protocols controlling welfare of dromedaries and gene databases of milk-dromedaries will prevent negative consequences of intensive farming. In countries where dromedaries have only recently been introduced as production animal, legislators have limited expertise on this species. This is exemplified by an assessment on behalf of the Dutch government, recommending prohibiting keeping this species from 2024 onwards because the dromedary was deemed to be insufficiently domesticated. Implementation of this recommendation in Dutch law would have devastating effects on existing dromedary farms and could also pave the way for adopting similar measures in other European countries. In this paper it is shown that the Dutch assessment lacks scientific rigor. Awareness of breeders and legislators for the increasing knowledge about dromedaries and their products would strengthen the position of dromedaries as one of the most adapted and sustainable animals.
Two main leaf types are recognized among vascular plant species: compound and simple. Compound leaves are believed to be photosynthetically more productive than simple ones, by diluting mass tissue in more projected area. Conversely, simple leaves are believed to be more stress-tolerant by packing mass tissue in less projected area during stress like drought. Nevertheless, convective cooling is more efficient in compound than simple leaves, a process that could alleviate water loss in drought periods. In Central Chile, woody species with simple and compound leaves coexist. This zone is facing a mega-drought event, causing browning and tree mortality. However, how severe droughts affect photosynthetic traits on both leaf-type species have not been addressed so far. We measured photosynthetic traits in well-watered and drought conditions in three compound and three simple leaf species, and drought response ratios were obtained. We hypothesized that with no water limitation compound leaf species will show higher net photosynthesis (AN) than simple leaf species associated with a higher mesophyll conductance (gm). Opposite results are expected for simple leaf species due to their stress-tolerant physiology, showing fewer changes in their photosynthetic traits. We found that gm and AN were larger in compound leaf species in well-watered conditions. With drought, both leaf-type species were negatively affected despite foliar temperature in compound leaf species was 4 °C lower. Our result suggests that regardless of leaf shape the matorral species in Central Chile will be seriously affected in their AN due to the megadrought currently affecting this zone.
Cities are making infrastructure investments to make travel by bicycle safer and more attractive. A challenge for promoting bicycling is effectively using data to support decision making and ensuring that data represent all communities. However, ecologists have been addressing a similar type of question for decades and have developed an approach to stratifying landscapes based on eco-zones or areas with homogenous ecology. Our goal is to classify street and path segments and map streetscape categories by applying ecological classification methods to diverse spatial data on the built environment, communities, and bicycling. Piloted in Ottawa, Canada, we use GIS data on the built environment, socioeconomics and demographics of neighborhoods, and bicycling infrastructure, behavior, and safety, and apply a k-means clustering algorithm. Each street or path, an intuitive spatial unit that reflects lived experience in cities, is assigned a streetscape category: bicycling destination; wealthy neighborhoods; urbanized; lower income neighborhoods; and central residential streets. We demonstrate how streetscape categories can be used to prioritize monitoring (counts), safety, and infrastructure interventions. With growing availability of continuous spatial data on urban settings, it is an opportune time to consider how street and path classification approaches can help guide our data collection, analysis, and monitoring. While there is no one right answer to clustering, care must be taken when selecting appropriate input variables, the number of categories, and the correct spatial unit for output. The approach used here is designed for bicycling application, yet the methods are applicable to other forms of active transportation and micromobility. ARTICLE HISTORY
Sapwood area is an important parameter for estimating canopy transpiration in the forest water cycle. However, sapwood area highly varies across species and forest ecosystems and is difficult to measure directly. Therefore, species- and site-specific allometric equations are needed to estimate the sapwood area of all trees in a forest. Here, we conducted a comprehensive campaign to measure sapwood thickness and to estimate the sapwood area of 14 common tree species in a successional forest in Thailand. These data represent the first comprehensive measurements of sapwood area in south-east Asian successional forests growing under diverse environmental conditions in terms of soil moisture and canopy density. The results show that a power function can significantly explain the relationship between sapwood area and stem size, represented by diameter at breast height (DBH), in all species in both primary and secondary forests. Interestingly, a single equation could describe the sapwood area~DBH relationship in all species and forest stages, except for Dipterocarpus gracilis, an emergent, dominant species in the primary forest. The latter showed slower growth in sapwood area once the trees reached a DBH of ~30 cm. Overall, our results can benefit future studies that estimate canopy transpiration of tropical forests with similar conditions as in our study sites.
Global patterns of regional (gamma) plant diversity are relatively well known, but whether these patterns hold for local communities, and the dependence on spatial grain, remain controversial. Using data on 170,272 georeferenced local plant assemblages, we created global maps of alpha diversity (local species richness) for vascular plants at three different spatial grains, for forests and non-forests. We show that alpha diversity is consistently high across grains in some regions (for example, Andean-Amazonian foothills), but regional 'scaling anomalies' (deviations from the positive correlation) exist elsewhere, particularly in Eurasian temperate forests with disproportionally higher fine-grained richness and many African tropical forests with disproportionally higher coarse-grained richness. The influence of different climatic, topo-graphic and biogeographical variables on alpha diversity also varies across grains. Our multi-grain maps return a nuanced understanding of vascular plant biodiversity patterns that complements classic maps of biodiversity hotspots and will improve predictions of global change effects on biodiversity.
Recent advances in ecology and biogeography demonstrate the importance of fire and large herbivores – and challenge the primacy of climate – to our understanding of the distribution, stability, and antiquity of forests and grasslands. Among grassland ecologists, particularly those working in savannas of the seasonally dry tropics, an emerging fire–herbivore paradigm is generally accepted to explain grass dominance in climates and on soils that would otherwise permit development of closed‐canopy forests. By contrast, adherents of the climate–soil paradigm, particularly foresters working in the humid tropics or temperate latitudes, tend to view fire and herbivores as disturbances, often human‐caused, which damage forests and reset succession. Towards integration of these two paradigms, we developed a series of conceptual models to explain the existence of an extensive temperate forest–grassland mosaic that occurs within a 4.7 million km2 belt spanning from central Europe through eastern Asia. The Eurasian forest‐steppe is reminiscent of many regions globally where forests and grasslands occur side‐by‐side with stark boundaries. Our conceptual models illustrate that if mean climate was the only factor, forests should dominate in humid continental regions and grasslands should prevail in semi‐arid regions, but that extensive mosaics would not occur. By contrast, conceptual models that also integrate climate variability, soils, topography, herbivores, and fire depict how these factors collectively expand suitable conditions for forests and grasslands, such that grasslands may occur in more humid regions and forests in more arid regions than predicted by mean climate alone. Furthermore, boundaries between forests and grasslands are reinforced by vegetation–fire, vegetation–herbivore, and vegetation–microclimate feedbacks, which limit tree establishment in grasslands and promote tree survival in forests. Such feedbacks suggest that forests and grasslands of the Eurasian forest‐steppe are governed by ecological dynamics that are similar to those hypothesised to maintain boundaries between tropical forests and savannas. Unfortunately, the grasslands of the Eurasian forest‐steppe are sometimes misinterpreted as deforested or otherwise degraded vegetation. In fact, the grasslands of this region provide valuable ecosystem services, support a high diversity of plants and animals, and offer critical habitat for endangered large herbivores. We suggest that a better understanding of the fundamental ecological controls that permit forest–grassland coexistence could help us prioritise conservation and restoration of the Eurasian forest‐steppe for biodiversity, climate adaptation, and pastoral livelihoods. Currently, these goals are being undermined by tree‐planting campaigns that view the open grasslands as opportunities for afforestation. Improved understanding of the interactive roles of climate variability, soils, topography, fire, and herbivores will help scientists and policymakers recognise the antiquity of the grasslands of the Eurasian forest‐steppe.
Water yield (WY) is an important provisioning ecosystem service that maintains the sustainable water resources supply and ecosystem water cycle. As a case study, the Tumen River Basin (TRB), located at the junction of China, North Korea, and Russia, was chosen as the study area considering that it belongs to a prioritized protection area for wild aquatic animals and a water shortage area where WY ecosystem service is critical for local ecological security and water resources management. Nevertheless, the spatiotemporal dynamics and driving mechanism of WY ecosystem service in TRB have so far remained poorly understood. In this study, the WY model based on the InVEST model is adopted to reveal the interannual change in WY and its driving factors in TRB from 1990 to 2019. The final results showed that (1) the annual average WY reached 227.40 mm and increased at a rate of 0.72 mm/year in TRB in the last 30 years. Specifically, WY and evapotranspiration were approximately equal to 35% and 65% of the precipitation in this study, respectively; (2) correlation analysis shows that precipitation and actual evapotranspiration are the dominant natural factors affecting watershed WY, with correlation coefficients of 0.65 (p < 0.01) and − 0.56 (p < 0.01), respectively, and that the trade-off between them jointly dominates the change in watershed WY; (3) in the seven cities of the study area, Helong City, Yanji City, and Hunchun City were highly important water resource–protect areas (WY > 300 mm) and should be regarded as the key protection areas. Overall, WY was increasing in TRB over the past three decades, but its trend was not significant, which implied a potential water shortage crisis in some years with extremely low precipitation. Therefore, artificial water-saving measures must be implemented immediately to cope with potential water crisis in the future.
Background
Several migratory ungulates, including caribou, are dramatically declining. Caribou of the Barren-ground ecotype, which forms its own subspecies, are known to be mainly migratory. By contrast, within the Woodland subspecies, animals of the Boreal ecotype are known to be mainly sedentary, while those within the Northern and Central Mountain ecotypes to be partially migratory, with only some individuals migrating. Promotion of conservation actions (e.g., habitat protection) that are specific to both residents and migrants, as well as to the areas they frequent seasonally (which may be separate for migrants), requires distinguishing migration from other movement behaviours, which might be a challenge.
Methods
We aimed at assessing seasonal movement behaviours, including migratory, resident, dispersing, and nomadic, for caribou belonging to the Barren-ground and Woodland subspecies and ecotypes. We examined seasonal displacement, both planar and altitudinal, and seasonal ranges overlap for 366 individuals that were GPS-collared in Northern and Western Canada. Lastly, we assessed the ability of caribou individuals to switch between migratory and non-migratory movement behaviours between years.
Results
We detected migratory behaviour within each of the studied subspecies and ecotypes. However, seasonal ranges overlap (an index of sedentary behaviour) varied, with proportions of clear migrants (0 overlap) of 40.94% for Barren-ground caribou and 23.34% for Woodland caribou, and of 32.95%, 54.87%, and 8.86% for its Northern Mountain, Central Mountain, and Boreal ecotype, respectively. Plastic switches of individuals were also detected between migratory, resident, dispersing, and nomadic seasonal movements performed across years.
Conclusions
Our unexpected findings of marked seasonal movement plasticity in caribou indicate that this phenomenon should be better studied to understand the resilience of this endangered species to habitat and climatic changes. Our results that a substantial proportion of individuals engaged in seasonal migration in all studied ecotypes indicate that caribou conservation plans should account for critical habitat in both summer and winter ranges. Accordingly, conservation strategies are being devised for the Woodland subspecies and its ecotypes, which were found to be at least partially migratory in this study. Our findings that migration is detectable with both planar and altitudinal analyses of seasonal displacement provide a tool to better define seasonal ranges, also in mountainous and hilly environments, and protect habitat there.
Cycles of freeze–thaw (FT) are among the key landscape processes in cold regions. Under current global warming, understanding the alterations in FT characteristics is of a great importance for advising land management strategies in northern latitudes. Using a generic statistical approach, we address the impacts of compound changes in air temperature and snow depth on FT responses across Québec, a Canadian province ~ 2.5 times larger than France. Our findings show significant and complex responses of landscape FT to compound changes in temperature and snow depth. We note a vivid spatial divide between northern and southern regions and point to the asymmetric and nonlinear nature of the FT response. In general, the response of FT characteristics is amplified under compound warming compared to cooling conditions. In addition, FT responses include nonlinearity, meaning that compounding changes in temperature and snow depth have more severe impacts compared to the cumulative response of each individually. These asymmetric and nonlinear responses have important implications for the future environment and socio-economic management in a thawing Québec and highlight the complexity of landscape responses to climatic changes in cold regions.
Assessing biodiversity status and trends in plant communities is critical for understanding, quantifying and predicting the effects of global change on ecosystems. Vegetation plots record the occurrence or abundance of all plant species co‐occurring within delimited local areas. This allows species absences to be inferred, information seldom provided by existing global plant datasets. Although many vegetation plots have been recorded, most are not available to the global research community. A recent initiative, called ‘sPlot’, compiled the first global vegetation plot database, and continues to grow and curate it. The sPlot database, however, is extremely unbalanced spatially and environmentally, and is not open‐access. Here, we address both these issues by (a) resampling the vegetation plots using several environmental variables as sampling strata and (b) securing permission from data holders of 105 local‐to‐regional datasets to openly release data. We thus present sPlotOpen, the largest open‐access dataset of vegetation plots ever released. sPlotOpen can be used to explore global diversity at the plant community level, as ground truth data in remote sensing applications, or as a baseline for biodiversity monitoring. Vegetation plots (n = 95,104) recording cover or abundance of naturally co‐occurring vascular plant species within delimited areas. sPlotOpen contains three partially overlapping resampled datasets (c. 50,000 plots each), to be used as replicates in global analyses. Besides geographical location, date, plot size, biome, elevation, slope, aspect, vegetation type, naturalness, coverage of various vegetation layers, and source dataset, plot‐level data also include community‐weighted means and variances of 18 plant functional traits from the TRY Plant Trait Database. Global, 0.01–40,000 m². 1888–2015, recording dates. 42,677 vascular plant taxa, plot‐level records. Three main matrices (.csv), relationally linked.
Previous studies found that pedunculate oak, one of the most widespread and abundant species in European deciduous forests, regenerates in open habitats and forest edges, but not in closed forest interiors. However, these observations usually come from the core areas of the biome, and much less is known about such processes at its arid boundary, where limiting factors may be different. In a full factorial field experiment, we tested the effects of different habitats (grassland, forest edge, forest interior) and increased growing season precipitation on the early regeneration of pedunculate oak in a forest-steppe ecosystem in Central Hungary, at the arid boundary of temperate deciduous forests. In the grassland habitat, seedling emergence was very low, and no seedlings survived by the fourth year. In contrast, seedling emergence was high and similar at forest edges and forest interiors, and was not affected by water addition. Most seedlings survived until the fourth year, with no difference between forest edge and forest interior habitats in numbers, and only minor or transient differences in size. The lack of oak regeneration in the grassland differs from previous reports on successful oak regeneration in open habitats, and may be related to a shift from light limitation to other limiting factors, such as moisture or microclimatic extremes, when moving away from the core of the deciduous forest biome towards its arid boundary. The similar number and performance of seedlings in forest edges and forest interiors may also be related to the decreasing importance of light limitation.
The Falconidae family is a well-supported monophyletic group that radiated during the early Miocene (Sect. 1.1). This family is divided into three subfamilies (Herpetotherinae, Polyborinae, and Falconinae). Falconinae started to diversify between 12.6 and 19.3 Mya, and the divergence of the genus Falco was favoured by the spread of savannahs during the late Miocene (Sect. 1.1). Overall, this genus shows very low genetic divergence in spite of geographical segregation and current systematic and includes 12 resident and breeding species of the Western Palearctic ecozone (Sect. 1.1.1). In fact despite considerable morphological variation in plumage and meristic characteristics, no sufficient evolutionary time passed to accumulate the genetic variation needed to reach a full subspecies level (Sect. 1.1.2). All endemic resident falcons of the Western Palearctic are related to small islands; almost all of them entirely belong to the common kestrel. Plumage polymorphisms (Sect. 1.2.2), the reversed size dimorphism (Sect. 1.3), wing and tail aerodynamics (Sect. 1.4), and vision (Sect. 1.5) are the main morphological traits greatly involved in breeding biology, dispersal, and predatory performances of this group.
The cool-temperate (nemoral) zone is currently the most densely populated zone on Earth; its vegetation has therefore been altered considerably over the past centuries. Particularly in Europe and East Asia, anthropogenic land use (forest plantations, agricultural and settlement areas, including many neobiota) has replaced the summergreen broad-leaved forest, which mostly constitutes the natural zonal vegetation. Furthermore, under extremely oceanic conditions, there are evergreen laurel and Nothofagus forests on the western side of the Andes and the Southern Alps of New Zealand, and tall nemoral coniferous forests on the Pacific side of North America. A distinctive feature of the summergreen broad-leaved forests is the seasonal rhythm of the vegetation of the tree and field layers, from leaf development in spring to leaf shedding in fall, with abundant geophytes in spring.
The introductory chapter provides the basic knowledge needed in order to understand the conditions under which the present zonal, azonal and anthropogenic vegetation on Earth has developed. This includes, among other things, an introduction to the evolution of vascular plants, their geographical distribution on the continents (“phytoregions”) and the main features of phytodiversity. In addition, the components of the macroclimate that are decisive for zonal vegetation types, their graphic representation (“climate diagrams”), the terminology and ecological properties of zonal and azonal soils, and the ecozones fundamental to the book are explained. A considerable part of the chapter is devoted to the derivation and definition of the plant formations of the world on the basis of physiognomic plant functional types (pPFTs). Finally, the principles according to which the vegetation of the high mountains of the Earth is subdivided as well as the properties of azonal and anthropogenic vegetation are presented. The boxes accompanying the text contain additional information on various topics, e.g. the origin of grasslands, phylogenetic evolution and quantum evolution, the origin and geographical distribution of the genus Nothofagus, and leaf functional traits and their ecological significance.
This chapter describes the vegetation of the largest ecozone on Earth, which covers 21% of the entire land surface. It includes xerophytic dry forests and shrublands as well as succulent, dwarf shrub, halophyte and grass semi-deserts; furthermore, hot deserts with a plant cover only in ephemeral riverbeds and in areas with fog precipitation are discussed in this chapter. The diversity of the vegetation is attributable to the temporal variability of precipitation, which is characteristic of the transitional area between the tropics and subtropics. Both individually and in combination, the flora exhibits a wealth of strategies to ensure survival under hot and dry site conditions; these are reflected in the growth and life-forms of the species, i.e. stem and leaf succulents, phreatophytes, xerophytes, halophytes, ephemerals, fog-harvesting plants, and others.
The largest contiguous forest areas on Earth are located in the boreal zone which occurs exclusively in the Northern Hemisphere. They largely consist of evergreen coniferous forests of spruce, Scots pine and fir. The summergreen larch is a stand-forming tree only in Central and Eastern Siberia, where the climate is extremely cold and precipitation is low. The boreal forests are highly affected by fire and windthrow. At a mean interval of about 200 years between fire events, regeneration phases of different ages exist next to each other in a mosaic-like manner. Forests of summergreen broad-leaved trees (birch, poplar) only occur as pioneer phases and (zonally) in extremely oceanic regions of Eurasia.
Background
The Sunda-Sahul Convergence Zone, defined here as the area comprising Australia, New Guinea, and Southeast Asia (Indonesia to Myanmar), straddles the Sunda and Sahul continental shelves and is one of the most biogeographically famous and important regions in the world. Floristically, it is thought to harbour a large amount of the world’s diversity. Despite the importance of the area, a checklist of the flora has never before been published. Here we present the first working checklist of vascular plants for the Sunda-Sahul Convergence Zone. The list was compiled from 24 flora volumes, online databases and unpublished plot data. Taxonomic nomenclature was updated, and each species was coded into nested biogeographic regions. The list includes 60,415 species in 5,135 genera and 363 families of vascular plants.
New information
This is the first species-level checklist of the region and presents an updated census of the region’s floristic biodiversity. The checklist confirms that species richness of the SSCZ is comparable to that of the Neotropics, and highlights areas in need of further documentation and taxonomic work. This checklist provides a novel dataset for studying floristic ecology and evolution in this biogeographically important region of very high global biodiversity.
Biomes are constructs for organising knowledge on the structure and functioning of the world’s ecosystems, and serve as useful units for monitoring how the biosphere responds to anthropogenic drivers, including climate change. The current practice of delimiting biomes relies on expert knowledge. Recent studies have questioned the value of such biome maps for comparative ecology and global‐change research, partly due to their subjective origin. Here we propose a flexible method for developing biome maps objectively. The method uses range modelling of several thousands of plant species to reveal spatial attractors for different growth‐form assemblages that define biomes. The workflow is illustrated using distribution data from 23 500 African plant species. In an example application, we create a biome map for Africa and use the fitted species models to project biome shifts. In a second example, we map gradients of growth‐form suitability that can be used to identify sites for comparative ecology. This method provides a flexible framework that (1) allows a range of biome types to be defined according to user needs and (2) enables projections of biome changes that emerge purely from the individualistic responses of plant species to environmental changes.
Featuring a transitional zone between closed forests and treeless steppes, forest-steppes cover vast areas, and have outstanding conservation importance. The components of this mosaic ecosystem can conveniently be classified into two basic types, forests and grasslands. However, this dichotomic classification may not fit reality as habitat organization can be much more complex. In this study, our aim was to find out if the main habitat types can be grouped into two distinct habitat categories (which would support the dichotomic description), or a different paradigm better fits this complex ecosystem. We selected six main habitats of sandy forest-steppes, and, using 176 relevés, we compared their vegetation based on species composition (NMDS ordination, number of common species of the studied habitats), relative ecological indicator values (mean indicators for temperature, soil moisture, and light availability), and functional species groups (life-form categories, geoelement types, and phytosociological preference groups). According to the species composition, we found a well-defined gradient, with the following habitat order: large forest patches, medium forest patches, small forest patches, north-facing edges, south-facing edges, and grasslands. A considerable number of species were shared among all habitats, while the number of species restricted to certain habitat types was also numerous, especially for north-facing edges. The total (i.e., pooled) number of species peaked near the middle of the gradient, in north-facing edges. The relative ecological indicator values and functional species groups showed mostly gradual changes from the large forest patches to the grasslands. Our results indicate that the widely used dichotomic categorization of forest-steppe habitats into forest and grassland patches is too simplistic, potentially resulting in a considerable loss of information. We suggest that forest-steppe vegetation better fits the gradient-based paradigm of landscape structure, which is able to reflect continuous variations.
GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phytocoenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems.
Crop biodiversity is one of the major inventions of humanity through the process of domestication. It is also an essential resource for crop improvement to adapt agriculture to ever-changing conditions like global climate change and consumer preferences. Domestication and the subsequent evolution under cultivation have profoundly shaped the genetic architecture of this biodiversity. In this review, we highlight recent advances in our understanding of crop biodiversity. Topics include the reduction of genetic diversity during domestication and counteracting factors, a discussion of the relationship between parallel phenotypic and genotypic evolution, the role of plasticity in genotype × environment interactions, and the important role subsistence farmers play in actively maintaining crop biodiversity and in participatory breeding. Linking genotype and phenotype remains the holy grail of crop biodiversity studies.
We are pleased to present you the first issue of Palaearctic Grasslands in 2019, the fourth one after the relaunch of the EDGG Bulletin last year. The successful collaboration of our enlarged Editorial Board has made it possible to continuously improve the quality of the journal. This improvement is visible on our impressive cover page, where we present as usual the winner of the Photo Competition. This issue comes with two important announcements. First is the call for nominations for election to the EDGG Executive Committee 2019-2021, with the deadline on 25th February. Second, we are happy to announce that thanks to the hard work of Didem Ambarlı, Tobias Gehrold and the webpage Editorial Team, the new EDGG homepage is now online. You can find more details about contents and organization on pages 6–8. The second call for the EGC 2019 in Graz (Austria) and Slovenia is published on pages 11-21. Registration is now open on the EGC website (https://edgg.org/egc2019). Important dates are 1st March for early bird registration and travel grant application, and 22nd March for late registration and abstract submission. This year the conference includes an optional three-day postconference excursion in Slovenia. It is important to note that the number of participants in this promising excursion is restricted to 40 people and so the local organizers will apply the principle of “first come, first served”. This issue also includes two scientific papers. We would like to highlight the Forum article by Erdős et al. on Eurasian forest-steppes, where they have complemented the key findings reported by the same authors in a synthesis paper published last year in Applied Vegetation Science which was highlighted by this journal for the Editor’s Award for 2018. We hope that you enjoy reading this issue, and would like to thank you for your participation in EDGG activities. We would also encourage more people to become active, especially any contributions to the journal, both in the photo section and as scientific articles.
A biome is a key community ecological and biogeographical concept and, as such, has profited from the overall progress of community ecology, punctuated by two major innovations: shifting the focus from pure pattern description to understanding functionality, and changing the approach from observational to explanatory and, most importantly, from descriptive to predictive. The functional focus enabled development of mechanistic and function‐focused predictive and retrodictive modelling; it also shaped the current understanding of the concept of a biome as a dynamic biological entity having many aspects, with deep roots in the evolutionary past, and which is undergoing change. The evolution of the biome concept was punctuated by three synthetic steps: the first synthesis formulated a solid body of theory explaining the ecological and biogeographical meaning of zonality and collated our knowledge on drivers of vegetation patterns at large spatial scales; the second translated this knowledge into effective mechanistic modelling tools, developing further the link between ecosystem functionality and biogeography; and the third (still in progress) is seeking common ground between large‐scale ecological and biogeographic phenomena, using macroecology and macroevolutionary research tools.
In ‘zonal’ vegetation, climatic factors are the main influence on growth and performance and the climate determines the vegetation type completely, which makes this vegetation dominant in the landscape. If vegetation is ‘azonal’ however, local stresses are assumed to have an overwhelming influence on plant performance and climatic influences will be minimal; typically, this vegetation occurs only in small patches in the landscape. In this study I ask whether wetland plant communities, as they are described for South Africa, are evenly distributed among different terrestrial vegetation types, to test whether they are zonal or azonal. Three contingency tables were construed based on the counts of wetland vegetation records, defined on three hierarchical levels (Main Clusters, Community Groups and Community) and their occurrence in the country (at the level of Biome, Bioregion and terrestrial vegetation type). An ‘azonality index’ was calculated as the sum of all Chi‐square values for each wetland vegetation type divided by the total number of records. The overall correlation between hydroperiod and the azonality index was very weak. At the finest level, terrestrial vegetation types were clustered on the basis of having similar combinations of wetland community types. Eighteen different ‘wetland ecoregions’ have been defined, on the basis of wetland vegetation types occurring within them. Instead of regarding wetland vegetation as azonal, it should rather be regarded as ‘intrazonal’, meaning that climate does have an impact but many vegetation types are widespread across climatic regions. The reason why community types in wetlands are widespread is due to the monodominance of a single widespread, often clonal, species. The different wetland ecoregions do not correspond to terrestrial biomes, so it is expected that wetland vegetation responds differently to climate than terrestrial vegetation.
Aims
Eurasian forest‐steppes are among the most complex non‐tropical terrestrial ecosystems. Despite their considerable scientific, ecological, and economic importance, knowledge of forest‐steppes is limited, particularly at the continental scale. Here we provide an overview of Eurasian forest‐steppes across the entire zone: (i) we propose an up‐to‐date definition of forest‐steppes, (ii) give a short physiogeographic outline, (iii) delineate and briefly characterize the main forest‐steppe regions, (iv) explore forest‐steppe biodiversity and conservation status, (v) and outline forest‐steppe prospects under predicted climate change.
Location
Eurasia (29°‐56° N, 16°‐139° E).
Results and Conclusions
Forest‐steppes are natural or near‐natural vegetation complexes of arboreal and herbaceous components (typically distributed in a mosaic pattern) in the temperate zone, where the coexistence of forest and grassland is enabled primarily by the semihumid to semiarid climate, complemented by complex interactions of biotic and abiotic factors operating at multiple scales. This new definition includes lowland forest‐grassland macromosaics (e.g. in Eastern Europe), exposure‐related mountain forest‐steppes (e.g. in Inner Asia), fine‐scale forest‐grassland mosaics (e.g. in the Carpathian Basin), and open woodlands (e.g. in the Middle East). Using criteria of flora, physiognomy, relief, and climate, nine main forest‐steppe regions are identified and characterized. Forest‐steppes are not simple two‐phase systems, as they show a high level of habitat diversity, with forest and grassland patches of varying types and sizes, connected by a network of differently oriented edges. Species diversity and functional diversity may also be exceptionally high in forest‐steppes. Regarding conservation, we conclude that major knowledge gaps exist in determining priorities at the continental, regional, national, and local levels, and in identifying clear target states and optimal management strategies. When combined with other threats, climate change may be particularly dangerous to forest‐steppe survival, possibly resulting in compositional changes, rearrangement of the landscape mosaic, or even the latitudinal or altitudinal shift of forest‐steppes.
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Based on a symposium held at Aarhus University, Denmark in August 1988, the 30 contributions are arranged in sections which examine dynamics, speciation and diversity (all contributions being abstracted separately), together with a section on past, present and future work on tropical forests. -P.J.Jarvis
During the summer of 1987, 500-1000 caribou became stranded on Rideout Island in Bathurst Inlet, Northwest Territories. The 40 km2 island did not have sufficient forage to support the animals until freeze-up, and the caribou eventually died from malnutrition after severely overgrazing the vegetation. In late July 1988, we found that most of the vascular vegetation on Rideout Island had recovered considerably. Vascular species composition and cover in the two major plant communities were comparable to those in similar communities on the adjacent, moderately grazed mainland. The willows (Salix spp.) and graminoid species were vigorous, and no differences were found in biomass allocation patterns of Salix lunata plants between the island and the mainland. However, essentially all of the macrolichen biomass was eliminated on the island, and full recovery could take more than 20 years.
Soil carbon data were collected from published sources for 50 measurement sites spanning the globe's major climate and vegetation types. For each site, climate, vegetation, and land-use variables were determined and entered into a multiple curvilinear regression program to predict soil carbon. The best model incorporates an estimate of site disturbance, annual actual evapotranspiration, and annual soil moisture deficit, and yields an R = 0-803. The curvilinear regression equation was coupled with a large climatic database and computer cartography programs to produce first-generation maps of estimated soil carbon. These maps correctly portray soil carbon as high in boreal and cool temperate zones and low in deserts and tropical zones.
Computer planimetry of maps of soil carbon for an ‘undisturbed’ world and for a ‘disturbed’ world resulted in estimates of 1457 × 109 mtC and 504 × 109 mtC respectively. These estimates compare favourably with recent estimates using other approaches. Clearly, the disturbance factor is critical to future refinements in estimates, suggesting the need for detailed studies of the relationship between land-use history and the creation and destruction of this important carbon pool.
Diverse populations of ephemeral herbs form the dominant element of community biomass in the first year of growth following a fall burn in chamise chaparral. Ephemeral herbs constituted 337 kg ha-1 of above-ground biomass after the first season of post-fire growth. This was 64% of the total, with the majority of the remaining biomass being in resprouts of Adenostoma fasciculatum. Ephemeral herb biomass following fire in other stands was as high as 1117 kg ha-1. Nutrient contents of ephemeral herbs were 6.68 kg N ha-1, 0.71 kg P ha-1, 10.05 kg K ha-1, 4.75 kg Ca ha-1 and 0.91 kg Mg ha-1. These were 55, 54, 81, 71 and 70% respectively of the above-ground totals. In the second year following fire, the total herb biomass was 40% higher, but the nutrient pool in above-ground biomass of these herbs was only 30–60% of what it had been the first year. Resprouts of A. fasciculatum and short-lived wood shrubs constituted more than 90% of above-ground biomass at this stage of postfire succession.
This paper examines the potential impact on the terrestrial C cycle if global agriculture were to increase to the limits permitted by future GHG-induced climates. Climatic limits to global agricultural zones were determined, the new climatic limits to agricultural zones projected, and the amount of C the terrestrial biosphere would store under the new climate and agricultural conditions was calculated. Following a warming loss of C from agriculture could be an important as gain of C by climate effects. As much or less C would be stored by a terrestrial biosphere in which agriculture reached its new climatic limits as is stored by the current biosphere in which agriculture reaches its climatic limits. We project that agriculture alone could produce a C source of 0.3 to 1.7 Pg yr-1 if doubling of GHGs required 50 to 100 yr. The gains in agriculture would occur almost entirely in the developed countries of high latitudes, and the losses, in the less developed countries of the lower latitudes. -from Authors
The exact knowledge of structure and function of the natural ecosystems and those influenced by men is necessary for a successful management of the biosphere. Project studies represent a new and effective method to solve current environmental problems. They should be also an important part in the education and training in environmental science for students and postgraduates.
Rational use of forest resources should be based upon accurate knowledge of land and soil properties. Selected characteristics of 149 soil profiles of the humid tropics are analyzed. General environmental characteristics, physical, chemical and mineralogical soil data have been derived from ISIS, the ISRIC Soil Information System. The humid zone includes 6 major soil groupings: Acrisols, Arenosols, Cambisols, Ferralsols, Luvisols and Podzols. For these soils the arithmetic mean and standard deviation of selected key analytical characteristics, relevant for agronomic and ecological research, are presented for a standardized topsoil and subsoil. In addition, their major agronomic constraints were assessed. About 64 % of the humid tropics is covered by Acrisols, Arenosols, Ferralsols and Podzols of low fertility, all presenting various degrees of limitations when forests are cleared for (low input) arable farming. A low plant nutrient content, a low nutrient retention capacity and a high toxic exchangeable aluminium content are major constraints. The overall data presented in this paper show that Ferralsols and Acrisols, covering 57 % of the humid tropics, have rather similar key characteristics. The taxonomic separation is principally based on a relatively small increase in clay content, which will not determine the major vegetation type or crop productivity level. When considering conservation of the natural vegetative cover and its biodiversity, several special properties of the soils have to be taken into account, such as depth of the litter layer, rootable depth and the mineral composition of the deeper subsoil and the substratum, as well as the geomorphologic-pedologic history of the terrain units and the degree of short-distance variation in soil conditions. It is concluded that land assessment studies and soil-vegetation/bio diversity research should not rely on a soil taxonomic approach alone, but should also be based on measured key pedological characteristics. The study illustrates the usefulness of the ISIS database to correlate soil characteristics and to determine agronomic-ecological constraints of major soil groupings.
The forests of lower elevations (700 to 1000 m) in the Coweeta Basin are similar to those studied elsewhere in the southern Appalachians (Whittaker 1966; Mowbray and Oosting 1968). Several species of oaks dominate these forests today; however, chestnut was the leading dominant prior to invasion by the chestnut blight. Spatial distribution of species on the slopes seems to follow topographic moisture gradients. A group of mesic species (tulip poplar, yellow birch, hemlock, witch hazel, dogwood, and rhododendron) are positively correlated with distance from the water divide and aspect, and are negatively correlated with distance from the stream channel and elevation. A group of xeric species (chestnut oak, scarlet oak, pignut hickory, mountain laurel, sourwood, red maple, and black gum) are positively correlated with distance from the stream channel and elevation, and are negatively correlated with distance from the water divide (Day and Monk 1974; Monk and Day 1984). A more detailed population and community description is summarized by Day et al. (Chapter 10).
The chaparral is but one of a number of plant communities found in the mediterranean-climate region of North America. It is, however, one of the best studied and hence will serve as the focal point for this chapter.
By far the most outstanding topographical feature influencing the climate of Scandinavia is the mountain range running close to the west coast of Norway along the entire Scandinavian Peninsula. Hardangervidda (Norway) is a mountain plateau within this mountain range, while Abisko (Sweden) and Kevo (Finland) are located at the eastern side of it (Sonesson et al., 1975). Polar days last for about 7 weeks at the Swedish (Abisko) and Finnish (Kevo) IBP tundra study areas. The Norwegian IBP tundra study area, Hardangervidda, is located about 6° south of the Polar Circle, which results in marked differences in average sunshine duration between Hardangervidda and Abisko (Fig. 1). Kevo is considered to have a sunshine duration fairly close to, or somewhat lower than that of Abisko.
One of the requirements for progress in climatic geomorphology is a more specific yet standardized and widely applicable identification of morphoclimatic conditions. An approach to this goal is seen in the systematic application of magnitude-frequency analysis to rainfall and other morphoclimatic phenomena; the magnitudes of relevant meteorological events are subjected to regression analysis as functions of the decadic logarithm of their recurrence interval, expressed in years. -from Author
A classification of climates of the earth is presented on the base of eco-physiological characteristics of the real vegetation. It considers the regional differentiation of the heat and water budget as well as the interaction of the system 'climate-soil-plant' in the sense of an ecological 'circuit'. The delimitation of climatic zones is based on the spatial variation of solar radiation. The limits of the four principal zones (tropics, subtropics, mid-latitudes and polar regions) are quantitatively marked by day-length variation of irradiation. Within the solar radiation zones, climatic types are defined on the base of parameters of the heat and water budget. These climatic types form spatial units (climatic regions) by the interference of the isolines indicating the duration of the thermic (Isothermomenes) and hygric (Isohygromenes) vegetation period. The climatic map, developed with the aid of the hygrothermic parameter, shows the present state of the climatic configuration of the Earth's surface, including its actual cover of plant. The methodical way opens up the possibility to record quantitatively every climatic variation caused by a change of vegetation cover with the help of available data.
For communities of Leucospermum parile and Thamnochortus punctatus annual litter production was 84 and 72 g m-2 during 1981-82 and 1982-83 respectively with summer-autumn the main period of litterfall; the major litter came from the ericoid elements. Mean annual litter production under canopies of L. parile was 357 and 429 g m-2 during 1981-82 and 1982-83, respectively with 51-58% being leaf litter. Female plants of T. punctatus had an annual litter production of 23 g m-2 compared with 12 g m-2 for males. The main litter category from both sexes was inflorescence parts. Turnover times of dry mass were 14.5 and 11.4 yr for leaf litter of L. parile and sterile culms of T. punctatus, respectively; male flowerheads of T. punctatus showed no significant decay. -from Authors
The volume comprises 25 chapters and is divided into the following 7 parts: Introduction * Stand Structure and Dynamics * Light Harvesting and Gas Exchange * Nutrient Cycling at the Stand Level * Hydrology and Biogeochemistry of Catchments * Responses to Disturbances * Animals in the Forest: Ecology of Two Main GroupsThe complete Table of Contents can be found on the internet.
The micrometeorology and the primary production of a lowland tropical rain forest at Pasoh, West Malaysia were studied.About 50% of incoming solar radiation was diminished by the upper 5m layer of canopy and only 3% reached the ground surface. The diurnal range of air temperature was small and humidity was higher than 90% throughout the day near ground. The upward water vapour transfer from the canopy to the atmosphere was observed even at night. This seemed to be related to the formation of night fog. Because the leaf area density of the forest was small, the gradients of air temperature, water vapour pressure, and carbon dioxide concentration in the forest were also small.The net canopy photosynthesis was about 43mgCO2⋅100cm-2·hr-1 when incoming solar radiation was 1.3cal·cm-2·min-1. The annual gross production of the forest was estimated at 81 ton D.W.·ha-1·year-1 and the efficiency of solar energy conversion for it was 3.0%.
The microclimates of the arctic tundra at Barrow, Alaska, are described
for the near-surface terrestrial layers in which most biological
activities take place. Temperature profiles are constructed from
detailed measurements in the air, vegetation and soil, from 16 m above
to 6 m below the tundra surface. Wind and radiation measurements
supplement these data. Considering the tundra as a two-dimensional heat
exchange surface, daily components of the heat balance are computed and
summarized for a number of periods throughout the year, which are
characterized by changes of the physical nature of the tundra surface
such as appearance and disappearance of snow, meltwater and
precipitation, and growth and decay of vegetation. Through changes in
surface terrain parameters such as albedo and roughness length, and
availability of water for phase changes, the thermal and moisture
regimes of the near-surface layer change markedly during these periods
as reflected by the heat balance.
Although it is natural to consider the development of the comparative approach known as Foreign Policy Analysis (FPA) as the most obvious source of theories of foreign policy behaviour, it is important to remember that all perspectives on the subject of international relations contain statements about foreign policy. Historically this has been the case because virtually all approaches to the study of international relations took the state to be the central actor. Thus, approaches as diverse as those concentrating on political economy, international society and Marxism have all included a notion of what the state is and how its foreign policy results, regardless of the way in which policy might be defined. Theories of foreign policy are therefore intrinsic to theories of international relations, even for those who deny the centrality of the state as an actor in international society.
The continuous permafrost zone of the former Soviet Union (FSU) occupies 5% of the land surface area of the earth and stores a significant amount of carbon. To assess the future carbon cycle within the permafrost zone under a climate-warming scenario, it is necessary to quantify present carbon pools and fluxes. The present carbon cycle was assessed on the basis of an ecosystem/ecoregion approach. Under the present climate, the phytomass carbon pool was estimated at 17.0 Gt (109 t). The mortmass (coarse woody debris) carbon pool was estimated at 16.1 Gt. The soil carbon pool, including peatlands, was 139.4 Gt. The present rate of carbon turnover was 1.6 Gt/yr. Under a warming climate 0.46-0.72 Gt C/yr may be gradually released to the atmosphere, mainly due to the increase in mortmass and litter decomposition. The increased efflux may be concurrently balanced by carbon uptake by vegetation as a result of enhanced productivity and forest migration to the north. However, the possibility exists that a lag between increased carbon efflux and uptake by vegetation may occur. Degradation of permafrost may not have a substantial influence on future carbon emissions. -from Authors
Seasonal change in the energy balance on the arctic tundra is presented. The thermal stability of a dry snow cover is investigated
in detail. In addition to high reflection by the snow cover, a significant absorption of solar radiation on the very surface
of the snow cover was found responsible for the thermal stability. The efficient absorption of solar radiation by the surface
rather than the interior of the snow cover and the almost immediate removal of the absorbed energy through radiative emission
and turbulent heat fluxes keep the temperature of the snow cover low.
The energy balances for the melt and postmelt period for various arctic surfaces are compared. The most important difference
of the energy balance between the tundra and tther low attitude arctic surface, such as the sea and ablation areas of glaciers,
is not the net radiation but the latent heat of fusion. Extremely small heat cosuumption through the melt on the tundra is
the basis for higher temperature, characteristics to the tundra climate in the Arctic.
The Boreal Forest Transect Case Study (BFTCS) is a multi-disciplinary ecological study organised around a 1000 km transect located in central Canada. The transect is oriented along an ecoclimatic gradient in a region likely to undergo significant environmental change within the next few decades, and crosses the climate-sensitive boreal forest biome, including the transitions north and south into tundra and grassland respectively. Originally conceived as an extension to the BOReal Ecosystem Atmosphere Study (BOREAS), the 10-year BFTCS project projects the intensive canopy-scale measurements and modelling advances obtained from BOREAS to a wider range of sites with a longer-term perspective. In addition to considering ecophysiological processes with time-frames of the order of one year or shorter, BFTCS addresses the effects of larger scale, longer term processes including vegetation succession and ecosystem disturbances. The BFTCS currently provides practical linkages among ecosystem monitoring, field experiments and regional scale modelling. It will ultimately provide a knowledge-base of key processes and their environmental sensitivities, and assessments of possible climate feedbacks, which can be used to assess the possible consequences of global change both regionally and globally.
The pattern of decomposition of branch-wood greater than 2 cm diameter is described for a one hectare site at Meathop Wood, Cumbria, based on studies carried out as part of the IBP between 1967 and 1972. Three phases of decomposition are recognised. Following the death of branches in the canopy and their colonisation by fungi, decomposition proceeded at an average annual loss rate of about 8.4%. Wood at branch-fall had on average lost about 40% of its original dry weight. On the forest floor the average annual rate of weight lost to decomposition was 17.1%. This could be divided into two phases; fungi were predominant initially but shortly after branch-fall invasion by wood-boring animals occurred. The average annual branch-fall between 1967 and 1971 was 31.5 gm-2. The standing crop of dead branch-wood on the forest floor was estimated in 1971 to be 203.3 gm-2. Assuming steady state this implies an annual turnover of 15.5% of the standing crop which is in good agreement with the observed decomposition rate.Considerable differences in the rates of decay were observed between individual branches. No significant differences were found between branches of the four main species of tree investigated (Quercus robur pluspetraea, Fraxinus excelsior, Betula pendula pluspubescens, Corylus avellana).
Annual grass production in ungrazed plots was 2,731 kg ha-1, litter production was 1,619 kg ha-1 and decomposition was 1,789 kg ha-1. In grazed plots the corresponding figures were 3,157 kg ha-1, 1,440 kg ha-1, and 1,475 kg ha-1 respectively; cattle consumed 1,405 kg ha-1. Litter disappearance was greatest in the dry season: 1,226 kg ha-1 (69% of the annual total) disappearing in the 4 months of December to March in the ungrazed plots, largely due to consumption (790 kg ha-1 in December to March) by fungus-growing termites (Macrotermitinae). A positive linear relationship was found between maximum grass biomass and annual rainfall in West Africa.
The book brings together information from scattered sources with the purpose of providing a comprehensive background to the various soils and biota of arid regions. The 9 chapters in part 1 of the volume provide descriptions of arid soil distribution, soil genesis and classification, and of its chemical and physical properties. There are also contributions on arid soil flora, fauna and microbiology, and the effects that these components have on nutrient cycling. Part II begins with a treatise on the causes of desertification, followed by ten discussions of current aspects of arid soil management: the use of controlled grazing and reduced tillage, the application of succession theory in revegetation, the utilization of nitrogen-fixing plant associations, and the importance of mycorrhizae and cyanobacteria and of algal cultivation for food and fodder. Also included are chapters on the importance of desert crust maintenance and development, application of organic matter, and inorganic fertilization. Lastly, a discussion on water management is included. Twenty of the chapters are abstracted separately in Geographical Abstracts: Physical Geography, International Development Abstracts and/or Ecological Abstracts. -after Editor