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Aim: Variation in community composition along environmental gradients provides crucial information for identifying zones where species turnover is rapid and to ascertain whether compositional changes occur gradually or rather abruptly. We examined changes in bird community composition along three bioclimatic transects in Australia to test whether drivers of species turnover are consistent, rather than spatially contingent, across biologically contrasting ecosystems. We also detected potential transition zones associated with environmental thresholds and determined whether certain abiotic conditions promote a higher rate of community compositional turnover. Location: Mainland Australia. Taxon: Terrestrial birds. Methods: We applied multivariate community analysis, generalised dissimilarity modelling (GDM) and threshold indicator taxa analysis (TITAN). Results: We observed that environmental variables are better predictors of community composition than spatial distance, which indicates that species sorting, rather than dispersal, plays a key role in structuring Australian avian communities. Annual precipitation constitutes a key driver of species turnover regardless of the analysed transect. The most humid landscapes and those with a higher tree canopy show lower spatial heterogeneity in community composition compared to those with less benign environmental conditions (e.g., dryer environments). TITAN detected significant transition points and supported the results obtained using GDM, which suggests that bird composition change along the gradients is not monotonic. Main Conclusions: Our results suggest that avian beta diversity increases with increasing environmental harshness, presumably through changes in the relative importance of stochastic versus deterministic processes. The obtained findings show that open forests and woodlands are extremely important ecosystems on this continent and deserve special attention in terms of conservation due to their vulnerability to global change. Lastly, this study exemplifies the value of combining community‐ and taxon‐based analyses to identify and interpret community thresholds, which can serve to pinpoint targets for preserving biodiversity. [ABSTRACT FROM AUTHOR]

Identifying drivers that shape biodiversity across biogeographical regions is important to predict ecosystem responses to environmental changes. While β‐diversity has been widely used to describe biodiversity patterns across space, the dynamic assembly of species over time has been comparatively overlooked. Insights from terrestrial and marine studies on temporal β‐diversity has mostly considered environmental drivers, while the role of biotic mechanisms has been largely ignored. Here, we investigated patterns of temporal variation in β‐diversity of seagrass‐associated amphipods. We conducted a study in three biogeographical regions across a temperate to subtropical latitudinal gradient (approximately 2000 km, 13° of latitude in total). In each region, we randomly selected three Cymodocea nodosa meadows, totaling nine meadows sampled seasonally (i.e., four times per year) from 2016 to 2018. We partitioned temporal β‐diversity into its turnover (i.e., species replacement) and nestedness (i.e., differences in species composition caused by species losses) components and addressed the relative influence of both temporal variation in habitat structure (i.e., biotic driver) and environmental conditions on the observed β‐diversity patterns. Our study revealed high temporal β‐diversity of amphipod assemblages across the three biogeographical regions, denoting significant fluctuations in species composition over time. We identified species turnover as the primary driver of temporal β‐diversity, strongly linked to temporal variability in local habitat structure rather than to regional climatic drivers. Subtropical Atlantic meadows with high structural stability over time exhibited the largest turnover rates compared with temperate Mediterranean meadows, under lower structural stability, where nestedness was a more relevant component of temporal β‐diversity. Our results highlight the crucial role of habitat stability in modulating temporal β‐diversity patterns on animals associated with seagrasses, stressing the importance of monitoring variations in habitat structure over time for developing management plans and restoration actions in the context of diversity loss and fragmentation of ecosystems. [ABSTRACT FROM AUTHOR]

Habitat loss can lead to biotic homogenization (decrease in β diversity) or differentiation (increase in β diversity) of biological communities. However, it is unclear which of these ecological processes predominates in human‐modified landscapes. We used data on vertebrates, invertebrates, and plants to quantify β diversity based on species occurrence and abundance among communities in 1367 landscapes with varying amounts of habitat (<30%, 30−60%, or >60% of forest cover) throughout the Brazilian Atlantic Forest. Decreases in habitat amount below 30% led to increased compositional similarity of vertebrate and invertebrate communities, which may indicate a process of biotic homogenization throughout the Brazilian Atlantic Forest. No pattern was detected in plant communities. We found that habitat loss was associated with a deterministic increase in faunal community similarity, which is consistent with a selected subset of species being capable of thriving in human‐modified landscapes. The lack of pattern found in plants was consistent with known variation between taxa in community responses to habitat amount. Brazilian legislation requiring the preservation of 20% of Atlantic Forest native vegetation may be insufficient to prevent the biotic homogenization of faunal communities. Our results highlight the importance of preserving large amounts of habitat, providing source areas for the recolonization of deforested landscapes, and avoiding large‐scale impacts of homogenization of the Brazilian Atlantic Forest. [ABSTRACT FROM AUTHOR]

There have been few advances in understanding the organization and dynamics of ants in tropical dry forests. The latter are a seriously threatened ecosystem, and ants are important indicators of diversity, disturbance, and restoration in forest ecosystems. Using diversity data and morphofunctional traits, we evaluated the spatial and temporal variation of taxonomic and functional ant groups; in addition, we explored the variation in functional traits and diversity among communities. Ants were sampled during the dry and rainy seasons using mini-Winkler bags. A total of 9 subfamilies, 57 genera, and 146 species were collected. Ant species composition and richness varied both spatially (75 to 119 species) and temporally (121 and 127 species). The fragments from N2 and N3 showed higher diversity than those from N1. The dissimilarity among all areas was moderate (50–60%), mainly attributable to species turnover processes (77%). Twenty functional groups were identified. The N3 fragments had the highest functional diversity, with lower resistance to species loss, while the N1 and N2 fragments reduced functional diversity and increased similarity among species. Our results highlight the importance of integrating a functional analysis with the taxonomic assessment of ants as an important contribution to understanding the organization and dynamics of this community of insects that inhabit the tropical dry forest. [ABSTRACT FROM AUTHOR]

One of the most noticeable environmental discontinuities in mountains is the transition that exists in vegetation below and above the treeline. In the North Patagonian Andean lakes (between 900 and 1950 m a.s.l.), we analyzed the bacterial community composition of lakes in relation to surrounding vegetation (erected trees, krummholz belt, and bare rocks), dissolved organic carbon (DOC), and total dissolved nutrients (nitrogen, TDN and phosphorus, TDP). We observed a decrease in DOC, TDP, and TDN concentrations with altitude, reflecting shifts in the source inputs entering the lakes by runoff. Cluster analysis based on bacterial community composition showed a segregation of the lakes below treeline, from those located above. This first cluster was characterized by the cyanobacteria Cyanobium PCC-6307, while in the krummholz belt and bare rocks, bacterial communities were dominated by Actinobacteria hgcl-clade and Proteobacteria (Sandarakinorhabdus and Rhodovarius), with the presence of pigments such as actinorhodopsin, carotenoids, and bacteriochlorophyll a. The net relatedness index (NRI), which considers the community phylogenetic dispersion, showed that lakes located on bare rocks were structured by environmental filtering, while communities of lakes below treeline were structured by species interactions such as competition. Beta-diversity was higher among lakes below than among lakes located above the treeline. The contribution of species turnover was more important than nestedness. Our study brings light on how bacterial communities may respond to changes in the surrounding vegetation, highlighting the importance of evaluating different aspects of community structure to understand metacommunity organization. [ABSTRACT FROM AUTHOR]

The services provided by the world's coral reefs are threatened by increasingly frequent and severe marine heatwaves. Heatwave-induced degradation of reefs has often been inferred from the extent of the decline in total coral cover, which overlooks extreme variation among coral taxa in their susceptibility and responses to thermal stress. Here, we provide a continental-scale assessment of coral cover changes at 262 shallow tropical reef sites around Australia, using ecological survey data on 404 coral taxa before and after the 2016 mass bleaching event. A strong spatial structure in coral community composition along large-scale environmental gradients largely dictated how coral communities responded to heat stress. While heat stress variables were the best predictors of change in total coral cover, the pre-heatwave community composition best predicted the temporal beta-diversity index (an indicator of change in community composition over time). Indicator taxa in each coral community differed before and after the heatwave, highlighting potential winners and losers of climate-driven coral bleaching. Our results demonstrate how assessment of change in total cover alone may conceal very different responses in community structure, some of which showed strong regional consistency, and may provide a telling outlook of how coral reefs may reorganize in a warmer future. [ABSTRACT FROM AUTHOR]

Conducting research on β-diversity (beta diversity) and its components, which reflect spatial or temporal variations in species composition among communities, helps to improve the understanding and knowledge of community structure and its maintenance mechanisms. The herbaceous layer of forest is an important part of forest community and forest ecosystem. Although some studies have been conducted on β-diversity of the understory herbaceous plant communities, there is still a lack of consensus on the proportion of β-diversity components such as turnover and nestedness components, as well as the influencing factors and the extent of their impact on β-diversity. This study was based on the survey data of herbaceous layer plant communities from 168 natural forest plots in Henan Province. It analyzed the β-diversity patterns of herbaceous layer in natural forests in Henan Province using Jaccard dissimilarity index, variance partitioning and other methods, and quantified the relative contributions of influencing factors such as spatial distance, environmental factor, and species richness to its β-diversity. The results were as follows: (1) The total β-diversity (as measured by the Jaccard dissimilarity index) of the herbaceous layer plant communities in natural forests was 0.94, which was mainly derived from the species turnover component (accounting for 96.8% of the total β-diversity) . (2) The total β-diversity and its species turnover component of plant communities in the herbaceous layer of natural forests showed a significant increasing trend with increasing spatial distance, while the nestedness component showed a significant decreasing trend with increasing spatial distance. (3) Mantel test showed that spatial distance, environmental factor, and species richness had significant effects on the total β-diversity of plant communities in the herbaceous layer of natural forests, with environmental factor, spatial distance, and species richness having the greatest, second, and least effect, respectively; variance partitioning results further showed that spatial distance, environmental factor, and species richness accounting for 27.14% and 20.35% of the variation in total β-diversity and its turnover component, respectively, with environmental factor alone accounting for the most variation (10.62% of total β-diversity and 9.35% of turnover component) . This study helps to enhance the understanding of the variation rules of plant composition in the herbaceous layers of natural forests and its influencing factors, thereby providing a solid scientific basis for the protection and management of forest vegetation and ecological restoration. [ABSTRACT FROM AUTHOR]

Aim: Beta‐diversity quantifies the change in taxonomic and phylogenetic composition between areas, and is a scalar between local (α) and regional (γ) diversity. Geographic distance, which reflects dispersal limitation, and climatic distance, which reflects environmental filtering, are major drivers of β‐diversity. Here, we analyse a comprehensive data set of angiosperms in regional floras across Africa to assess the relationships of β‐diversity, and its components, to three major types of environmental variables (current climate, Quaternary climate change and topographic heterogeneity) thought to drive β‐diversity. Location: Africa. Taxon: Angiosperms. Methods: Africa was divided into 27 regions. Species lists of angiosperms for each region were collated. The relationships of both taxonomic and phylogenetic β‐diversity, and their respective turnover and nestedness components, with geographic and environmental distances were assessed. Results: This study showed that (1) regions of the lowest β‐diversity are located in moist tropical climates, (2) the turnover and nestedness components of β‐diversity are negatively correlated with each other, (3) taxonomic β‐diversity is higher than phylogenetic β‐diversity across Africa, (4) variation in β‐diversity of angiosperms is more strongly associated with current climate than with Quaternary climate change and topographic heterogeneity and (5) the variation in taxonomic β‐diversity and its turnover component that is independently explained by geographic distance is much larger than that is independently explained by climatic distance for angiosperms in Africa. Main Conclusions: The finding that geographic distance explained more variation than climatic distance suggests that dispersal limitation plays a greater role than environmental filtering in shaping angiosperm β‐diversity in Africa. Of climatic factors, current climate plays a more important role than Quaternary climate change in shaping angiosperm β‐diversity in Africa. [ABSTRACT FROM AUTHOR]

Simple Summary: The use of inadequate cattle ranching practices (e.g., fire, agrochemical applications, long term extensive grazing, lack of paddock rotation in pastures) could have negative consequences on biodiversity and ecological functions. In this study, the influence of cattle ranching duration on the diversity of dung beetles and seed removal was evaluated in pastures having different times of establishment in a tropical dry forest landscape. Dung beetle species richness was similar along the gradient of grazing ages, but the diversity of common and dominant species declined with increasing grazing age. Seed removal was mainly carried out by an exotic species. Although native dung beetles persisted at low abundances along this gradient, the consequences of land use changes and inadequate practices in similar landscapes could lead to their disappearance. Cattle ranching is an economic activity responsible for the loss of large extensions of tropical dry forest around the world. Several studies have demonstrated that the use of inadequate practices of this activity in tropical forests (e.g., fire, agrochemicals, and lack of rotational grazing systems of cattle in pastures) have negative consequences on dung beetle diversity and their ecological functions. In the present study, the influence of the cattle ranching duration gradient on the diversity of dung beetles and seed removal was evaluated. This study was carried out in pastures with different times of establishment of cattle ranching (between 4 and 40 years) in a tropical dry forest of Mexico. Overall, the species richness of dung beetles was similar along the gradient of grazing ages. However, the diversity of common (q1) and dominant (q2) species decreased and was associated with an increasing abundance of exotic species and a decreasing abundance of native species. Seed removal was mainly carried out by four beetle species, among which the exotic species Digitonthophagus gazella was the most important. The results establish that the duration of cattle ranching primarily influences the composition of dung beetle communities, as reflected in changes in the structure and function of their assemblages in the pastures. Although native dung beetles persist at low abundances along this gradient, the consequences of land use changes are undeniable in other similar ecosystems where these species could definitively disappear. [ABSTRACT FROM AUTHOR]

Reptiles are one of the most diverse groups of vertebrates in the world that are distributed in almost all ecosystems. Many of these studies have focused on exploring their diversity patterns across different environments; and recent studies on reptile alpha and beta diversity have incorporated a multifaceted approach into their analysis to have more comprehensive evaluations. This study presents an assessment of the taxonomic diversity of reptile patterns using methods that incorporate the assessment of higher taxa. Likewise, the taxonomic dissimilarities between reptile communities in the physiographic regions of the state of Jalisco were analyzed. Evaluations for the groups of snakes and lizards independently are presented. We use the taxonomic distinctiveness index that assesses the complexity of the taxonomic structure of communities through hierarchical classification above the species level to measure the relationships between taxa. The dissimilarity of the taxonomic structure in each community was also analyzed. Beta diversity partitions were performed to identify the contribution of turnover and the differences in richness. We determined that alpha diversity of species and higher taxa maintain different patterns, indicating that Jalisco presents regions with overrepresentation of reptile families and genera, as well as regions with an opposite trend. The representation of higher taxa is higher in the lizard group, although in terms of species richness snakes are the most prominent group. The turnover is the most important component at species and higher taxa, with similar values for lizards and snakes. The findings presented show that incorporating phylogenetic information about species through taxonomic relationships provides complementary information that species diversity per se, especially at the level of alpha diversity. [ABSTRACT FROM AUTHOR]

The Gobi Desert ecosystem is currently experiencing the impacts of persistent climate warming and extreme weather. However, the relative influences of factors such as soil, climate, and spatial variables on the β-diversity of desert plants and their key components have not been systematically studied. In this research, the Dunhuang North Mountain and Mazong Mountain areas were selected as study areas, with a total of 79 plant community plots systematically established. The aim was to explore intercommunity β-diversity and its components and to analyze the interrelationships with climate factors, soil factors, and geographic distance. The results indicate that (1) there is a geographic decay pattern and significant differences among plant communities in the Dunhuang North Mountain and Mazong Mountain areas, with β-diversity primarily driven by replacement components. (2) Climate, soil, and geographic distance significantly influence β-diversity and its replacement components, with climate factors exerting the greatest influence and geographic distance the least. (3) Multiple regression analysis (MRM) reveals differential effects of climate factors, soil factors, and geographic distance on β-diversity and its replacement components, with climate and soil factors exerting a much greater influence than geographic distance. In summary, the β-diversity of plant communities and their replacement components in the Dunhuang North Mountain and Mazong Mountain areas result from the combined effects of habitat filtering and dispersal limitation, with habitat filtering having a greater impact, while environmental heterogeneity is an important factor influencing species differences in this region. [ABSTRACT FROM AUTHOR]

Research on Mesophotic Coral Ecosystems (MCEs; 30–150 m) has grown exponentially in the last few decades, highlighting their rich diversity and extensive distribution. However, they are still largely underexplored compared to shallow-water coral reefs and frequently remain under-protected and under-represented in marine spatial planning. One reason for the imbalance between the high ecological value of MCEs and the limited levels of protection may be that baseline data on MCEs are largely missing to date, yet are crucial to provide evidence-based information for management actions. Here, we present data on the alpha and beta diversity of the benthic communities within MCEs in the Chagos Archipelago, Indian Ocean. Using imagery collected from Remotely Operated Vehicle surveys, benthic invertebrate megafauna were surveyed along the entire depth gradient from shallow to lower mesophotic depths (15–160 m). The diversity of the benthic communities decreased with increasing depth, from shallow water to the lower mesophotic zone. Nevertheless, the deepest parts of MCEs in the Archipelago displayed higher species richness values than several other shallow subtropical regions. In addition, the benthic communities showed high dissimilarity along the depth gradient, indicating that the key driver of community composition change with depth is species turnover (species replacement), revealing the uniqueness of MCEs. This study presents novel findings on MCEs in the central Indian Ocean, demonstrating that they host a high and unique benthic diversity, and highlighting the need to protect these ecosystems to preserve the overall biodiversity of coral reefs. [ABSTRACT FROM AUTHOR]

There is evidence to suggest that vascular epiphytes experience low competition for resources (light, water, and nutrients) compared to terrestrial plants. We tested the hypothesis that low resource competition may lead to higher nestedness among vascular epiphyte assemblages compared to trees. We studied the species composition and biomass of epiphytes and trees along an elevation gradient in a tropical dry forest in SW Ecuador. Both life-forms were inventoried on 25 plots of 400 m2 across five elevation levels (550–1250 m). Tree species density and total species richness increased with elevation, whereas basal area and biomass did not show significant trends. Epiphyte species density and richness both increased strongly with elevation, in parallel to biomass. Plot-level compositional changes were similarly strong for both life-forms. We attribute elevational increases in the species richness of trees and epiphytes to increasing humidity, i.e., more mesic growth conditions. We attribute the more pronounced elevational increase in epiphyte biomass, species density, and richness—the latter coupled with a higher degree of nestedness—to the greater moisture dependency of epiphytes and relatively low direct competition for resources. Our study provides a first comparison of elevational trends in epiphyte and tree diversity and biomass for a tropical dry forest. [ABSTRACT FROM AUTHOR]

Aims: Knowledge about species niches along environmental gradients is needed to understand community assembly and spatial variation in floristic composition and species richness. In Amazonian rainforests, such knowledge is largely lacking, although ferns have been used to infer overall floristic and edaphic patterns. Here we explore fern species distributions along an important edaphic gradient, how narrow their realised niches are and how sensitive inferences are to species commonness, data quality and the region being sampled. Location: Amazonia. Methods: We used a large data set (1,215 transects across lowland Amazonia) to explore the realised niches of 54 species of two fern genera (Adiantum and Lindsaea) along a soil base cation concentration gradient. We used weighted averaging to estimate species optima and niche widths, and Huisman–Olff–Fresco modelling to assess species response shapes. Results: Overall, species optima were rather evenly spread along the soil base cation concentration gradient, but Lindsaea optima were limited to the lower half of the gradient, whereas Adiantum optima were more often in the upper half. Most species had unimodal response curves. Mean niche width was ca. 25% of the observed gradient length for Adiantum and 17% for Lindsaea and was only weakly or not at all related to different aspects of species commonness. Species optima were robust to different modelling approaches and consistent across regional subsets. However, the central Amazonian data contained no transects with high soil base cation concentration, so species with high optima were either absent or obtained a lower optimum than in the NW and SW regions. Conclusions: Our results support niche‐related species sorting as an important process that defines species co‐occurrence, turnover and richness patterns within Amazonian rainforests. All Adiantum and Lindsaea species, including the most abundant ones, had narrow enough realised niches to be considered useful indicators of edaphic and floristic variation within the rainforest. [ABSTRACT FROM AUTHOR]

Nitrogen enrichment impacts ecosystems productivity by altering different hierarchical community processes, ranging from responses of individual species traits to species reordering and ultimately species turnover. Most previous studies have focussed on examining the responses of these processes separately, but little has been done to examine how hierarchical community responses are linked and contribute to the changes in productivity.To fill this knowledge gap, we conducted a 4‐year nitrogen addition field experiment to investigate the hierarchical community responses of above‐ground net primary productivity (ANPP) in an alpine meadow ecosystem.We found that the individual species response contributed more to ANPP changes under nitrogen addition, while species reordering and species turnover contributed little over the 4‐year experiment. In particular, plant height was a key trait to ultimately explain and bridge nitrogen addition effects on ANPP across different community levels. Nitrogen addition promoted plant height and growth of individual species, and reordered functional groups by increasing taller grasses and sedges and decreasing shorter forbs and legumes. Species turnover had a weak effect on ANPP changes due to low biomass of both lost and gained species. Finally, taller persistent plants promoted ANPP more with nitrogen addition.Synthesis. This study provides a new perspective on how ecosystem productivity responds to nitrogen enrichment in a hierarchical manner linked to plant height, which is helpful for elucidating complex community processes and establishing direct links between plant traits and ecosystem function. [ABSTRACT FROM AUTHOR]

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This study focused on the Yellow River Wetland Nature Reserve of Henan Province, China. We calculated species and functional α diversity indices and decomposed β diversity into turnover and nestedness components to examine the species and functional diversity of bird communities across different seasons (breeding and wintering) and their ecological assembly processes. The results revealed: (1) The breeding season demonstrated higher species richness, whereas the wintering season exhibited significantly higher numbers of protected bird species compared to the breeding season. (2) The β diversity of species was predominantly driven by turnover components in both seasons, while functional β diversity was primarily influenced by nestedness components. The inconsistency between species and functional β diversity components suggested the presence of functional trait redundancy. (3) During the breeding season, a high proportion of birds that prey on insects contribute to the provision of potential ecosystem services. In conclusion, the reserve could develop seasonal conservation strategies tailored to the characteristics of bird communities in various seasons, with a specific emphasis on protecting key ecological niche bird species, particularly those exhibiting unique traits and birds that consume insects.

ABSTRACT Identifying drivers that shape biodiversity across biogeographical regions is important to predict ecosystem responses to environmental changes. While β‐diversity has been widely used to describe biodiversity patterns across space, the dynamic assembly of species over time has been comparatively overlooked. Insights from terrestrial and marine studies on temporal β‐diversity has mostly considered environmental drivers, while the role of biotic mechanisms has been largely ignored. Here, we investigated patterns of temporal variation in β‐diversity of seagrass‐associated amphipods. We conducted a study in three biogeographical regions across a temperate to subtropical latitudinal gradient (approximately 2000 km, 13° of latitude in total). In each region, we randomly selected three Cymodocea nodosa meadows, totaling nine meadows sampled seasonally (i.e., four times per year) from 2016 to 2018. We partitioned temporal β‐diversity into its turnover (i.e., species replacement) and nestedness (i.e., differences in species composition caused by species losses) components and addressed the relative influence of both temporal variation in habitat structure (i.e., biotic driver) and environmental conditions on the observed β‐diversity patterns. Our study revealed high temporal β‐diversity of amphipod assemblages across the three biogeographical regions, denoting significant fluctuations in species composition over time. We identified species turnover as the primary driver of temporal β‐diversity, strongly linked to temporal variability in local habitat structure rather than to regional climatic drivers. Subtropical Atlantic meadows with high structural stability over time exhibited the largest turnover rates compared with temperate Mediterranean meadows, under lower structural stability, where nestedness was a more relevant component of temporal β‐diversity. Our results highlight the crucial role of habitat stability in modulating temporal β‐diversity patterns on animals associated with seagrasses, stressing the importance of monitoring variations in habitat structure over time for developing management plans and restoration actions in the context of diversity loss and fragmentation of ecosystems.

Understanding environmental patterns of species diversity is essential for nature reserve planning and biodiversity conservation. In this study, we explored the birds’ alpha and beta diversity along the elevational gradients in Haba Snow Mountain Nature Reserve (hereafter, HBSM), a global biodiversity hotspot, and studied which environmental factor is the main driver in explaining alpha and beta diversity patterns. Our results indicated that taxonomic, functional, and phylogenetic alpha diversity consistently exhibited hump-shaped patterns with similar peaks. After controlling for species richness, both functional and phylogenetic alpha diversity increased with elevation, and the peaks at 3400–3700 m. Mean pairwise functional distance remained nearly constant along the elevation band, whereas mean pairwise phylogenetic distance shown hump-shaped pattern, and the predicted MPD peaked at the fifth band (3100–3400 m a.s.l). The functional and phylogenetic structure of bird communities in HBSM were more clustered along the elevation gradients, suggesting environmental filtering likely drove the assembly processes. Additionally, primary productivity (NDVI and/or habitat heterogeneity) and/or precipitation were robust predictors of variation in most diversity metrics. For multiple-site beta diversity, we observed that high turnover component in taxonomic, functional, and phylogenetic dimensions, indicating distinct bird assemblages across various elevational bands. In pairwise beta diversity, the spatial turnover of taxonomic and phylogenetic aspects was higher than nestedness, revealing species replacement occurs relatively frequently between evolutionarily related species with similar niche and functional traits. Overall, our findings highlight the importance of considering both different dimensions and multifaceted diversity when assessing elevational patterns of bird diversity. This study also provides valuable insights into the structuring mechanisms of bird communities and informs conservation planning along elevational gradients in HBSM, and offers a comprehensive case on species richness along elevational gradients.

Wetland ecosystems in the Qinghai-Tibet Plateau (QTP), the region with the richest biodiversity and the most important ecological barrier function at high altitudes, are highly sensitive to global change, and wetland plants, which are important indicators of wetland ecosystem structure and function, are also threatened by wetland degradation. Therefore, a comprehensive study of changes in the geographical distribution pattern of plant diversity, as well as species loss and turnover of wetlands in the QTP in the context of global climate change is of great importance for the conservation and restoration of wetland ecosystems in the QTP. In this study, species turnover and loss of 395 endemic wetland plants of the QTP were predicted based on the SSP2-4.5 climate change scenarios. The results showed that there were interspecific differences in the effects of climate change on the potential distribution of species, and that most endemic wetland plants would experience range contraction. Under the climate change scenarios, the loss of suitable wetland plant habitat is expected to occur mainly in parts of the southern, north-central and north-western parts of the plateau, while the gain is mainly concentrated in parts of the western Sichuan Plateau, the Qilian Mountains, the Three Rivers Source Region and the northern Tibetan Plateau. Overlaying the analysis of priority protected areas with the established protected areas in the QTP has resulted in the following conservation gaps: the eastern Himalayan region, midstream of the Yarlung Zangbo River, the transition zone between the northern Tibetan Plateau and the Hengduan Mountains, Minshan-Qionglai mountain, Anyemaqen Mountains (southeast) to Bayankala (southeast) mountains, the southern foothills of the Qilian Mountains and the northern Tibetan Plateau region. In the future, the study of wetland plant diversity in the QTP and the optimisation of protected areas should focus on the conservation gaps. This study is of great importance for the study and conservation of wetland plant diversity in the QTP, and also provides a scientific basis for predicting the response of wetland plants to climate change in the QTP. [ABSTRACT FROM AUTHOR]

Neotropical seasonal dry forest (NSDF) is one of the most threatened ecosystems according to global climate change predictions. Nonetheless, few studies have evaluated the global climate change impacts on diversity patterns of NSDF plants. The lack of whole biome‐scale approaches restricts our understanding of global climate change consequences in the high beta‐diverse NSDF. We analysed the impact of global climate change on species distribution ranges, species richness, and assemblage composition (beta diversity) for 1,178 NSDF species. We used five representative plant families (in terms of abundance, dominance, and endemism) within the NSDF: Cactaceae, Capparaceae, Fabaceae, Malvaceae, and Zygophyllaceae. We reconstructed potential species distributions in the present and future (2040–2080), considering an intermediate Shared Socioeconomic Pathway and two dispersal ability assumptions on the taxa. Using a resource use scores index, we related climate‐induced range contractions with species' water stress tolerance. Even under a favourable dispersal scenario, species distribution and richness showed future significant declines across those sites where mean temperature and precipitation seasonality are expected to increase. Further, changes in species range distribution in the future correlated positively with potential use of resources in Fabaceae. Results suggest that biotic heterogenization will likely be the short‐term outcome at biome scale under dispersal limitations. Nonetheless, by 2080, the prevailing effect under both dispersal assumptions will be homogenization, even within floristic nuclei. This information is critical for further defining new areas worth protecting and future planning of mitigation actions for both species and the whole biome. [ABSTRACT FROM AUTHOR]

Fire and herbivory have profound effects on vegetation in savanna ecosystems, but little is known about how different herbivore groups influence vegetation dynamics after fire. We assessed the separate and combined effects of herbivory by cattle and wild meso‐ and megaherbivores on postfire herbaceous vegetation cover, species richness, and species turnover in a savanna ecosystem in central Kenya. We measured these vegetation attributes for five sampling periods (from 2013 to 2017) in prescribed burns and unburned areas located within a series of replicated long‐term herbivore exclosures that allow six different combinations of cattle and wild meso‐ and megaherbivores (elephants and giraffes). Vegetation cover (grasses, mainly) and species richness were initially reduced by burning but recovered by 15–27 months after fire, suggesting strong resilience to infrequent fire. However, the rates of recovery differed in plots accessible by different wild and domestic herbivore guilds. Wildlife (but not cattle) delayed postfire recovery of grasses, and the absence of wildlife (with or without cattle) delayed recovery of forbs. Herbivory by only cattle increased grass species richness in burned relative to unburned areas. Herbivory by cattle (with or without wildlife), however, reduced forb species richness in burned relative to unburned areas. Herbivory by wild ungulates (but not cattle) increased herbaceous species turnover in burned relative to unburned areas. Megaherbivores had negligible modifying effects on these results. This study demonstrates that savanna ecosystems are remarkably resilient to infrequent fires, but postfire grazing by cattle and wild mesoherbivores exerts different effects on recovery trajectories of herbaceous vegetation. [ABSTRACT FROM AUTHOR]

Spatially driven turnover in species composition and relative abundance drives gamma diversity in all ecosystems. Assemblages of nocturnal Lepidoptera in rainforests are powerful tools for estimating and understanding this heterogeneity. There are three fundamental theoretical tools for explaining this place-to-place change: neutral stochasticity, niche-driven opportunity and historical contingency. We sampled moth and woody plant assemblages across the oceanic island landscape of La Réunion to tease apart how these factors shape diversity. We collected a total of ~ 13000 individuals of about 229 species and analyzed how distance and forest habitats shape moth assemblage turnover. We subdivided moth species into endemics and non-endemics. Our results show the local occurrence of the generally more diet-restricted endemic moths is more likely to be niche-driven due to host-plant preferences while occurrence of the generally more polyphagous non-endemic species is most parsimoniously explained by stochastic neutral mechanisms. Spatial patterns in the native flora may also be neutrally assembled sets across the rainforest region (with implications for native moth species) whereas introduced species reflect human-driven historical contingency. [ABSTRACT FROM AUTHOR]

We investigated the distance-decay pattern (an increase in dissimilarity with increasing geographic distance) in regional assemblages of fleas and their small mammalian hosts, as well as their interaction networks, in four biogeographic realms. Dissimilarity of assemblages (βtotal) was partitioned into species richness differences (βrich) and species replacement (βrepl) components. Dissimilarity of networks was assessed using two metrics: (a) whole network dissimilarity (βWN) partitioned into species replacement (βST) and interaction rewiring (βOS) components and (b) D statistics, measuring dissimilarity in the pure structure of the networks, without using information on species identities and calculated for hosts-shared-by-fleas networks (Dh) and fleas-shared-by-hosts networks (Df). We asked whether the distance-decay pattern (a) occurs among interactor assemblages or their interaction networks; (b) depends on the network dissimilarity metric used; and (c) differs between realms. The βtotal and βrepl of flea and host assemblages increased with distance in all realms except for host assemblages in the Afrotropics. βrich for flea and host assemblages increased with distance in the Nearctic only. In networks, βWN and βST demonstrated a distance-decay pattern, whereas βOS was mainly spatially invariant except in the Neotropics. Correlations of Dh or Df and geographic distance were mostly non-significant. We conclude that investigations of dissimilarity in interaction networks should include both types of dissimilarity metrics (those that consider partner identities and those that consider the pure structure of networks). This will allow elucidating the predictability of some facets of network dissimilarity and the unpredictability of other facets. [ABSTRACT FROM AUTHOR]

Summary: Anthropogenetic climate change has caused range shifts among many species. Species distribution models (SDMs) are used to predict how species ranges may change in the future. However, most SDMs rarely consider how climate‐sensitive traits, such as phenology, which affect individuals' demography and fitness, may influence species' ranges.Using > 120 000 herbarium specimens representing 360 plant species distributed across the eastern United States, we developed a novel 'phenology‐informed' SDM that integrates phenological responses to changing climates. We compared the ranges of each species forecast by the phenology‐informed SDM with those from conventional SDMs. We further validated the modeling approach using hindcasting.When examining the range changes of all species, our phenology‐informed SDMs forecast less species loss and turnover under climate change than conventional SDMs. These results suggest that dynamic phenological responses of species may help them adjust their ecological niches and persist in their habitats as the climate changes.Plant phenology can modulate species' responses to climate change, mitigating its negative effects on species persistence. Further application of our framework will contribute to a generalized understanding of how traits affect species distributions along environmental gradients and facilitate the use of trait‐based SDMs across spatial and taxonomic scales. [ABSTRACT FROM AUTHOR]

Aim: Ecoregions and the distance decay in community similarity are fundamental concepts in biogeography and conservation biology that are well supported across plants and animals, but not fungi. Here we test the relevance of these concepts for ectomycorrhizal (ECM) fungi in temperate and boreal regions. Location: Europe. Time Period: 2008–2015. Major Taxa Studied: Ectomycorrhizal fungi. Methods: We used a large dataset of ~24,000 ectomycorrhizas, assigned to 1350 operational taxonomic units, collected from 129 forest plots via a standardized protocol. We investigated the relevance of ecoregion delimitations for ECM fungi through complementary methodological approaches based on distance decay models, multivariate analyses and indicator species analyses. We then evaluated the effects of host tree and climate on the observed biogeographical distributions. Results: Ecoregions predict large‐scale ECM fungal biodiversity patterns. This is partly explained by climate differences between ecoregions but independent from host tree distribution. Basidiomycetes in the orders Russulales and Atheliales and producing epigeous fruiting bodies, with potentially short‐distance dispersal, show the best agreement with ecoregion boundaries. Host tree distribution and fungal abundance (as opposed to presence/absence only) are important to uncover biogeographical patterns in mycorrhizas. Main Conclusions: Ecoregions are useful units to investigate eco‐evolutionary processes in mycorrhizal fungal communities and for conservation decision‐making that includes fungi. [ABSTRACT FROM AUTHOR]

Conservation of lichens is impeded by knowledge gaps on their distribution and habitat requirements. This is a significant issue in vast, isolated and harsh environment regions such as subarctic regions, where lichen communities remain under documented. Lichen biodiversity assessments provide useful insights to better understand the functions supported by these ecologically important and sensitive species. This study aims i) to describe the conservation status of lichen communities and their α- and β-diversity components across a subarctic region in Northern Quebec (190 km2), ii) to describe their functional traits across the habitat types found in this region, and iii) to identify habitat types constituting lichen biodiversity hotspots. Lichens were sampled in 45 plots in habitats ranging from coniferous and deciduous forests to bogs, fens and rocky outcrops. A total of 115 species of largely macrolichens, calicioid lichens and allied fungi were identified, of which 18% currently have ranks of conservation concern at the provincial level, and 38% are newly reported for the region (∼124,000 km2 around our study area). Richness across plots averaged 36 ± 9 species and plots richer in microhabitats often harbored more species (R2 = 0.22). Differences in species composition were identified among plots and habitat types through NMDS and perMANOVA analyses (R2 = 0.35; p < 0.001), both being supported by differences in microhabitat composition (Mantel r = 0.22 and perMANOVA R2 = 0.29, respectively; p < 0.001). Thirty-five species showed significant preferences for a habitat based on the Pearson's phi coefficient of association. Our analysis on functional traits revealed significant patterns of association with habitat types, including i) saxicolous species with rocky outcrops, ii) epiphytic/epixylic species and vegetative reproduction traits (soredia, isidia) with coniferous stands, and iii) species belonging to the Parmeliaceae family with fens. Rocky outcrops represented the main lichen biodiversity hotspots in the region, while other habitat types were also important for maintaining total and complementary biodiversity. We are confident that our methodological approach including systematic sampling, full habitat variability representation, and the evaluation of complementary biodiversity components, can be effectively applied to fill gaps on lichen biodiversity in other underexplored regions across the globe. [ABSTRACT FROM AUTHOR]

As the globe gets more urbanised, the question about how natural biodiversity is structured in cities becomes increasingly pertinent. To contribute to an answer, we studied species richness and spatio-temporal structure of bees in a North European metropolitan area. A gradient of 13 sites in the city of Aarhus, Denmark, was censused from April to September 2016. Forty species, i.e. 29 solitary species (40 % of all individuals), ten Bombus species (28 %), and Apis mellifera (32 %), were sampled monthly in pan traps. (i) Information about species traits was extracted from the literature, and trait values were correlated and used to characterize the fauna. Most were soil-nesters, pollen generalists, and common. (ii) Habitat diversity within five concentric circles with trap at the centre and radii from 50 m to 1000 m was related to bee α diversity. The relationship was significant only within 1,000 m for all bees and for bumblebees. Solitary bee diversity was uncorrelated with habitat diversity at all spatial levels. (iii) Spatio-temporal structure was analysed as two networks, one for bees linked to sites, and one for bees linked to months. Link patterns were analysed for levels of nestedness, modularity, and spatio-temporal β diversity. The two networks were weakly and non-significantly nested, but strongly modular, being composed of five and four modules of co-occurring bees, respectively. (iv) Finally, we studied total β diversity, β TOTAL , being the sum of species turnover, β TURN , and species loss/gain or nestedness, β NEST. For both site and season, β TURN was higher than β NEST , and site β TOTAL was higher than season β TOTAL. One reason for this metacommunity structure may be a high spatio-temporal habitat patchiness, sustaining a rich biodiversity. Thus, a few large areas may not compensate for the loss of several small patches. Consequently, establishment of many green, even small habitats is recommended. [ABSTRACT FROM AUTHOR]

Evaluating the impacts of farming systems on biodiversity is increasingly important given the need to stem biodiversity loss, decrease fossil fuel dependency, and maintain ecosystem services benefiting farmers. We recorded woody and herbaceous plant species diversity, composition, and abundance in 43 wetland‐adjacent prairie remnants beside crop fields managed using conventional, minimum tillage, organic, or perennial cover (wildlife‐friendly) land management in the Prairie Pothole Region. We used a hierarchical framework to estimate diversity at regional and local scales (gamma, alpha), and how these are related through species turnover (beta diversity). We tested the expectation that gamma richness/evenness and beta diversity of all plants would be higher in remnants adjacent to perennial cover and organic fields than in conventional and minimum tillage fields. We expected the same findings for plants providing ecosystem services (bee‐pollinated species) and disservices (introduced species). We predicted similar relative effects of land management on alpha diversity, but with the expectation that the benefits of organic farming would decrease with increasing grassland in surrounding landscapes. Gamma richness and evenness of all plants were highest for perennial cover, followed by minimum tillage, organic, and conventional sites. Bee‐pollinated species followed a similar pattern for richness, but for evenness organic farming came second, after perennial cover sites, followed by minimum tillage and conventional. For introduced species, organic sites had the highest gamma richness and evenness. Grassland amount moderated the effect of land management type on all plants and bee‐pollinated plant richness, but not as expected. The richness of organic sites increased with the amount of grassland in the surrounding landscape. Conversely, for conventional sites, richness increased as the amount of grassland in the landscape declined. Our results are consistent with the expectation that adopting wildlife‐friendly land management practices can benefit biodiversity at regional and local scales, in particular the use of perennial cover to benefit plant diversity at regional scales. At more local extents, organic farming increased plant richness, but only when sufficient grassland was available in the surrounding landscape; organic farms also had the highest beta diversity for all plants and bee‐pollinated plants. Maintaining native cover in agroecosystems, in addition to low‐intensity farming practices, could sustain plant biodiversity and facilitate important ecosystem services. [ABSTRACT FROM AUTHOR]

Community weighted mean trait, i.e., functional composition, has been extensively used for upscaling of individual traits to the community functional attributes and ecosystem functioning in recent years. Yet, the importance of intraspecific trait variation relative to species turnover in determining changes in CWM still remains unclear, especially under nutrient enrichment scenarios. In this study, we conducted a global data synthesis analysis and three nutrient addition experiments in two sites of alpine grassland to reveal the extent to which species turnover and ITV contribute to shift in CWM in response to nutrient enrichment. The results consistently show that the importance of ITV relative to species turnover in regulating CWM in response to nutrient enrichment strongly depends on trait attributes rather than on environmental factors (fertilization type, climatic factors, soil properties, and light transmittance). For whole plant traits (height) and leaf morphological traits, species turnover is generally more important than ITV in determining CWM following most treatments of nutrient addition. However, for leaf nutrient traits, ITV outweighed species turnover in determining shifts in CWM in response to almost all treatments of nutrient addition, regardless of types and gradients of the nutrient addition. Thus, our study not only provides robust evidence for trait-dependent importance of ITV in mediating community functional composition, but also highlights the need to consider the nature of functional traits in linking ITV to community assembly and ecosystem functioning under global nutrient enrichment scenarios. [ABSTRACT FROM AUTHOR]

Examining beta diversity of animal assemblages in fragmented habitats, which measures variation in species composition among different fragments, is important for understanding the impact of habitat fragmentation on biodiversity. However, relying solely on taxonomic composition may not provide a comprehensive understanding. Incorporating measures of functional and phylogenetic diversities is essential for elucidating the ecological mechanisms underlying changes in community composition. In addition, prevailing studies often prioritize the evaluation of landscape characteristics within fragments as determinants of beta diversity, neglecting differences in habitat type and plant community composition. In this study, we surveyed birds in 26 remnant woodlot patches (ranging from 0.3 to 290.4 ha) in an urban landscape, southwest China, during the breeding season from 2017 to 2022. We recorded 70 bird species (excluding those recorded only once and high‐flying birds, including raptors, swallows, and swifts), with the number of species per patch varying from 14 to 56. The overall bird taxonomic and phylogenetic beta diversities were primarily contributed by the turnover component, while functional beta diversity was dominated by the nestedness‐resultant component. Patch area and perimeter area ratio significantly influenced the taxonomic, functional, and phylogenetic beta diversities, primarily mediated through the nestedness‐resultant component, while inter‐patch distance had a significant effect via the turnover component. In addition, there was a considerable correlation of bird taxonomic, functional, and phylogenetic beta diversities with habitat type and woody plant beta diversities, including their respective partitioned turnover and nestedness‐resultant components. Our results suggest that bird assemblages in these patches may be regulated by selective extinction, interspecific competition, and environmental filtering. The findings have significant implications for sustainable landscape planning and habitat restoration. Conserving habitat patches of different sizes and maintaining or enhancing habitat heterogeneity between patches can facilitate the persistence of metacommunities. [ABSTRACT FROM AUTHOR]

An understanding of how biodiversity is distributed across the broad spatial scales can resolve pure questions about ecological and historical processes and solve applied problems in conservation planning. Invertebrates such as insects make up much of biodiversity yet are rarely a focus in studies of regional‐scale diversity patterns, partly due to data deficiency.We took advantage of historical field notebooks to investigate the richness and compositional pattern of grasshoppers across a vast area of Australia (Western Australia, 2.6 million km2). We extracted grasshopper occurrence records from historical surveys of 1328 locations spanning 1947 to 1985. We developed generalised dissimilarity models to identify species compositional turnover across families and modelled species richness with regression analyses.Species composition was most distinct in mesic south‐west, north and north‐west regions and was most uniform through the arid interior region with the exception of the topographically complex Pilbara region. Species richness was highest in the arid interior and north and lowest in the cool and wet south‐west.The patterns of grasshopper species diversity and endemism were like patterns previously reported for lizards and this may reflect their common independence from water and their phylogenetic bias towards warm environments.Although high species richness was predicted in the Pilbara region, the area remains underrepresented in the national reserve system, with <10% of its area protected. High levels of short‐range endemism were found in general, with only ~1/4 of short‐range endemics being located in the national reserve system.Our analyses demonstrate that field notebooks can be a valuable resource for biogeographic analyses and for planning invertebrate conservation. [ABSTRACT FROM AUTHOR]

A long‐standing debate exists among ecologists as to how diversity regulates infectious diseases (i.e., the nature of diversity‐disease relationships); a dilution effect refers to when increasing host diversity inhibits infectious diseases (i.e., negative diversity‐disease relationships). However, the generality, strength, and potential mechanisms underlying negative diversity‐disease relationships in natural ecosystems remain unclear. To this end, we conducted a large‐scale survey of 63 grassland sites across China to explore diversity‐disease relationships. We found widespread negative diversity‐disease relationships that were temperature‐dependent; non‐random diversity loss played a fundamental role in driving these patterns. Our study provides field evidence for the generality and temperature dependence of negative diversity‐disease relationships in grasslands, becoming stronger in colder regions, while also highlighting the role of non‐random diversity loss as a mechanism. These findings have important implications for community ecology, disease ecology, and epidemic control. [ABSTRACT FROM AUTHOR]

Reptiles are one of the most diverse groups of vertebrates in the world that are distributed in almost all ecosystems. Many of these studies have focused on exploring their diversity patterns across different environments; and recent studies on reptile alpha and beta diversity have incorporated a multifaceted approach into their analysis to have more comprehensive evaluations. This study presents an assessment of the taxonomic diversity of reptile patterns using methods that incorporate the assessment of higher taxa. Likewise, the taxonomic dissimilarities between reptile communities in the physiographic regions of the state of Jalisco were analyzed. Evaluations for the groups of snakes and lizards independently are presented. We use the taxonomic distinctiveness index that assesses the complexity of the taxonomic structure of communities through hierarchical classification above the species level to measure the relationships between taxa. The dissimilarity of the taxonomic structure in each community was also analyzed. Beta diversity partitions were performed to identify the contribution of turnover and the differences in richness. We determined that alpha diversity of species and higher taxa maintain different patterns, indicating that Jalisco presents regions with overrepresentation of reptile families and genera, as well as regions with an opposite trend. The representation of higher taxa is higher in the lizard group, although in terms of species richness snakes are the most prominent group. The turnover is the most important component at species and higher taxa, with similar values for lizards and snakes. The findings presented show that incorporating phylogenetic information about species through taxonomic relationships provides complementary information that species diversity per se, especially at the level of alpha diversity.

There have been few advances in understanding the organization and dynamics of ants in tropical dry forests. The latter are a seriously threatened ecosystem, and ants are important indicators of diversity, disturbance, and restoration in forest ecosystems. Using diversity data and morphofunctional traits, we evaluated the spatial and temporal variation of taxonomic and functional ant groups; in addition, we explored the variation in functional traits and diversity among communities. Ants were sampled during the dry and rainy seasons using mini-Winkler bags. A total of 9 subfamilies, 57 genera, and 146 species were collected. Ant species composition and richness varied both spatially (75 to 119 species) and temporally (121 and 127 species). The fragments from N2 and N3 showed higher diversity than those from N1. The dissimilarity among all areas was moderate (50–60%), mainly attributable to species turnover processes (77%). Twenty functional groups were identified. The N3 fragments had the highest functional diversity, with lower resistance to species loss, while the N1 and N2 fragments reduced functional diversity and increased similarity among species. Our results highlight the importance of integrating a functional analysis with the taxonomic assessment of ants as an important contribution to understanding the organization and dynamics of this community of insects that inhabit the tropical dry forest.

Despite the importance of biodiversity-ecosystem functioning (BEF) relationships in ecology and conservation, relatively little is known about how BEF relationships change across spatial scales. Theory predicts that change in BEF relationships with increasing spatial scale will depend on variation in species composition across space (β-diversity), but empirical evidence for this is limited. Moreover, studies have not quantified the direct and indirect role the environment plays in costructuring ecosystem functioning across spatial scales. We used 14 temperate-forest plots 1.4 ha in size containing 18,323 trees to quantify scale-dependence between aboveground tree biomass and three components of tree-species diversity-α-diversity (average local diversity), γ-diversity (total diversity), and β-diversity. Using structural-equation models, we quantified the direct effects of each diversity component and the environment (soil nutrients and topography), as well as indirect effects of the environment, on tree biomass across 11 spatial extents ranging from 400 to 14,400 m2 . Our results show that the relationship between β-diversity and tree biomass strengthened with increasing spatial extent. Moreover, β-diversity appeared to be a stronger predictor of biomass than α-diversity and γ-diversity at intermediate to large spatial extents. The environment had strong direct and indirect effects on biomass, but, in contrast to diversity, these effects did not strengthen with increasing spatial extent. This study provides some of the first empirical evidence that β-diversity underpins the scaling of BEF relationships in naturally complex ecosystems.

Ungulate grazing involves multiple components, including defoliation, dung and urine return, and trampling, which supply offsetting or synergistic effects on plant community composition and productivity (ANPP), but these effects have not been fully studied. Plant functional traits may reflect the response of plants to disturbance and their impact on ecosystem functions. Species turnover and intraspecific trait variation (ITV) are important drivers of community trait composition. We conducted a simulated grazing experiment in a steppe grassland in northern China to examine the effects of defoliation, dung and urine return, and trampling on community-weighted mean (CWM), functional diversity (FD) and ANPP, and to disentangle the roles of species turnover and ITV in driving these changes. We found that defoliation had a dominant effect on CWMs and FDs of all four traits through species turnover and ITV, respectively, resulting in a convergence of traits towards as more resource-acquisitive strategy. Dung-urine return resulted in more resource-acquisitive community traits mainly through ITV, whereas there were no significant effects on FDs except for leaf C/N. Trampling increased CWM of leaf dry matter content primarily driven by ITV, and had no significant effect on FDs. Furthermore, our simulated grazing positively affected ANPP, primarily due to nutrient additions from dung and urine, and ITV largely explained the variation in ANPP. These findings highlight the multifaceted effects of grazing components on community structure and ANPP, and the significance of ITV in shaping grassland plant communities and productivity. [ABSTRACT FROM AUTHOR]

Evaluating the diversity of multiple taxa is fundamental to understand community assembly and to assess the integrity and functionality of tropical secondary forests. In this study, we analyzed the natural regeneration of tropical dry forests (TDFs) in three regions of Brazil using Hill–Simpson diversity, abundance and β‐diversity of trees and five groups of insects (herbivores, fruit‐feeding butterflies, ants, culicid mosquitoes and dung beetles). Sampling was conducted in 39 0.1 ha plots using a chronosequence approach (13 plots in early, intermediate and old‐growth forests). We evaluated the contribution of three different levels to γ‐diversity: α (within plots), β1 (among plots) and β2 (among successional stages), and further determined the relative importance of turnover (species replacement) and nestedness (differences in species number among sites) to β2. Our results showed that, unexpectedly, the Hill–Simpson diversity was consistently higher in early than old‐growth stages for all regions, but varied more widely in the intermediate stages. For each group separately, the same trend was observed for butterflies, ants, dung beetles and herbivores and did not differ among stages for mosquitoes. Successional differences in abundance were only detected for trees (increasing along the gradient) and for mosquitoes (decreasing). According to our expectations, the additive partitioning analysis showed that β2‐diversity contributed more to γ‐diversity than β1‐diversity, when all taxa were considered together and for most of them separately (except for butterflies and dung beetles). Most of the β2‐diversity was due to species turnover, but this contribution varied among groups and regions, with the highest turnover for herbivores and the lowest for dung beetles. Our results suggest that the Hill–Simpson diversity and changes in species composition (as given by β2‐diversity) are better indicators of forest natural regeneration than raw species richness, corroborating previous studies with plants and animals. [ABSTRACT FROM AUTHOR]

A robust understanding of the interactions between global and local anthropogenic stressors is crucial for ecosystem management in the Anthropocene. Manipulative experiments in the laboratory or in the field can be used to build knowledge about the physiological and ecological effects of stressors, but predicting the combined landscape‐scale effects of global stressors such as climate change, and local stressors such as land‐use change requires a different approach.Here we used water quality and hydrology process‐based models of entire river catchments in combination with a large biomonitoring dataset to predict the responses of macroinvertebrate communities under different climate change and land‐use change scenarios. Using the River Thames in the U.K. as a model system, we predicted changes in water quality (temperature, flow, phosphorus [P], nitrogen, dissolved oxygen [DO]) and subsequent changes in macroinvertebrate communities for two climate change scenarios, individually and in combination with intensified agriculture and reduced P pollution (representing improved wastewater treatment).Our models predicted that water‐quality changes associated with climate change may not influence total species richness, but that community composition will shift towards more pollution‐tolerant and common taxa based on responses of community indices and taxon‐specific responses. We also found that the negative impacts of climate change on water quality (e.g., increased P concentration, decreased DO concentration) accumulate through the catchment, but that local land‐use practices influencing P dynamics can modify this trend. Furthermore, although the intensified agriculture scenario was predicted to have minimal impacts on macroinvertebrate communities (a result potentially related to shifting baselines as the Thames is already heavily polluted), we found that reduced P pollution resulting from improved wastewater treatment was able to mostly offset the negative impacts of climate change on macroinvertebrate communities.Our results demonstrate that using process‐based models to study networks of interacting stressors at a landscape scale can provide useful insights into the ecological impacts of anthropogenic global change, and adds support to the idea that management of local stressors has the potential to mitigate some of the impacts of climate change on ecosystems. [ABSTRACT FROM AUTHOR]

Long-term data sets documenting temporal changes in vegetation communities are uncommon, yet imperative for understanding trends and triggering potential conservation management interventions. For example, decreasing species diversity and increasing non-native species abundance may be indicative of decreasing community stability. We explored long-term plant community change over a 40-year period through the contribution of data collected in 2019 to two historical datasets collected in 1979 and 1999 to evaluate decadal changes in plant community biodiversity in a tidal freshwater marsh in the Fraser River Estuary in British Columbia, Canada. We found that plant assemblages were characterized by similar indicator species, but most other indicator species changed, and that overall α-diversity decreased while β-diversity increased. Further, we found evidence for plant assemblage homogenization through the increased abundance of invasive species such as yellow flag iris (Iris pseudacorus), and reed canary grass (Phalaris arundinacea). These observations may inform concepts of habitat stability in the absence of direct anthropogenic disturbance, and corroborate globally observed trends of native species loss and non-native species encroachment. Our results indicate that within the Fraser River Estuary, active threat management may be necessary in areas of conservation concern in order to prevent further native species biodiversity loss. [ABSTRACT FROM AUTHOR]

Introduction: Biodiversity maintenance and its underlying mechanisms are central issues of ecology. However, predicting the composition turnovers of microbial communities at multiple spatial scales remains greatly challenging because they are obscured by the inconsistent impacts of climatic and local edaphic conditions on the assembly process. Methods: Based on the Illumina MiSeq 16S/18S rRNA sequencing technology, we investigated soil bacterial and eukaryotic communities in biocrusts with different successional levels at a subcontinental scale of Northern China. Results: Results showed that irrespective of spatial scale, bacterial a diversity increased but eukaryotic diversity decreased with the primary succession, whereas both ß diversities decreased at the subcontinental scale compared with smaller scales, indicating that the biogeographic pattern of soil microorganisms was balanced by successional convergence and distance decay effect. We found that the convergence of bacterial and eukaryotic communities was attributed to the turnovers of generalist and specialist species, respectively. In this process, edaphic and climatic factors showed unique roles in the changes of diversity at local/subcontinental scales. Moreover, the taxonomic diversity tended to be more susceptible to climatic and edaphic conditions, while biotic factors (photosynthesis and pigments) were more important to phylogenetic diversity. Conclusion: Taken together, our study provided comprehensive insights into understanding the pattern of microbial diversity at multiple spatial scales of drylands. [ABSTRACT FROM AUTHOR]

Small wetlands provide crucial ecosystem services but are facing widespread loss and degradation. At present, small wetland complexes provide an alternative avenue for conservation; we used a dataset to illustrate how zeta diversity can be assessed in a small wetland complex. The small wetland complex studied consisted of nine hydrologically connected ponds, and all the ponds were connected by narrow ditches. Data collected included the composition of both zooplankton and phytoplankton communities, water physicochemical parameters, and hydrological connectivity. Two ways in which connectivity affects biodiversity, dispersal filtration (path distance-controlled biological diffusion) and environmental filtration (environment-selected species), were quantified. As a result, (1) 46 zooplankton and 119 phytoplankton species were identified, with species richness distribution significantly affected by water properties (explained variances of 68% and 39%, respectively), reflecting significant environmental filtration, and (2) both zooplankton and phytoplankton showed zeta diversity distance decay (p < 0.001), reflecting significant dispersal filtration, and (3) relatively rare species dominated community turnover, in which environmental filtration was far stronger than dispersal filtration. Overall, the small wetland complex in this study was characterized by hydrological connectivity, which not only allowed moderate biological connectivity but also promoted the coexistence of diverse habitats and communities. We emphasize the applicability of zeta diversity for assessing small wetland complexes, further demonstrating the value of small wetland complexes in promoting biodiversity such as species richness and species turnover. [ABSTRACT FROM AUTHOR]

Karst peak-cluster depressions in tropical China are characterized by high habitat heterogeneity, supporting complex seasonal rainforest communities, and harboring a rich abundance of endemic and endangered plants. However, for these rainforests, species and phylogenetic beta diversity and their limiting factors are poorly understood. In this study, the relationships between the beta diversity of three vertical layers (herb, shrub, and tree), environmental factors, and physical distance in China's tropical karst seasonal rainforest were studied. The results showed that each layer exhibited high species and beta diversity, with species turnover being the dominant contributing factor. Environmental filtering and dispersal limitations were significant drivers of community assembly. Environmental filtering exerted a strong influence, with slope position, soil availability of phosphorus and potassium, pH, and organic matter being the key factors. These findings elucidate seasonal rainforest species and beta diversity spatial patterns within karst peak-cluster depressions, providing a foundation for developing karst ecosystem forest management and vegetation restoration measures. [ABSTRACT FROM AUTHOR]

Abstract Examining beta diversity of animal assemblages in fragmented habitats, which measures variation in species composition among different fragments, is important for understanding the impact of habitat fragmentation on biodiversity. However, relying solely on taxonomic composition may not provide a comprehensive understanding. Incorporating measures of functional and phylogenetic diversities is essential for elucidating the ecological mechanisms underlying changes in community composition. In addition, prevailing studies often prioritize the evaluation of landscape characteristics within fragments as determinants of beta diversity, neglecting differences in habitat type and plant community composition. In this study, we surveyed birds in 26 remnant woodlot patches (ranging from 0.3 to 290.4 ha) in an urban landscape, southwest China, during the breeding season from 2017 to 2022. We recorded 70 bird species (excluding those recorded only once and high‐flying birds, including raptors, swallows, and swifts), with the number of species per patch varying from 14 to 56. The overall bird taxonomic and phylogenetic beta diversities were primarily contributed by the turnover component, while functional beta diversity was dominated by the nestedness‐resultant component. Patch area and perimeter area ratio significantly influenced the taxonomic, functional, and phylogenetic beta diversities, primarily mediated through the nestedness‐resultant component, while inter‐patch distance had a significant effect via the turnover component. In addition, there was a considerable correlation of bird taxonomic, functional, and phylogenetic beta diversities with habitat type and woody plant beta diversities, including their respective partitioned turnover and nestedness‐resultant components. Our results suggest that bird assemblages in these patches may be regulated by selective extinction, interspecific competition, and environmental filtering. The findings have significant implications for sustainable landscape planning and habitat restoration. Conserving habitat patches of different sizes and maintaining or enhancing habitat heterogeneity between patches can facilitate the persistence of metacommunities.

Beta-diversity reflects the spatial changes in community species composition which helps to understand how communities are assembled and biodiversity is formed and maintained. Larch (Larix) forests, which are coniferous forests widely distributed in the mountainous and plateau areas in North and Southwest China, are critical for maintaining the environmental conditions and species diversity. Few studies of larch forests have examined the beta-diversity and its constituent components (species turnover and nestedness-resultant components). Here, we used 483 larch forest plots to determine the total beta-diversity and its components in different life forms (i.e., tree, shrub, and herb) of larch forests in China and to evaluate the main drivers that underlie this beta-diversity. We found that total beta-diversity of larch forests was mainly dependent on the species turnover component. In all life forms, total beta-diversity and the species turnover component increased with increasing geographic, elevational, current climatic, and paleoclimatic distances. In contrast, the nestedness-resultant component decreased across these same distances. Geographic and environmental factors explained 20%–25% of total beta-diversity, 18%–27% of species turnover component, and 4%–16% of nestedness-resultant component. Larch forest types significantly affected total beta-diversity and species turnover component. Taken together, our results indicate that life forms affect beta-diversity patterns of larch forests in China, and that beta-diversity is driven by both niche differentiation and dispersal limitation. Our findings help to greatly understand the mechanisms of community assemblies of larch forests in China.

The Gobi Desert ecosystem is currently experiencing the impacts of persistent climate warming and extreme weather. However, the relative influences of factors such as soil, climate, and spatial variables on the β-diversity of desert plants and their key components have not been systematically studied. In this research, the Dunhuang North Mountain and Mazong Mountain areas were selected as study areas, with a total of 79 plant community plots systematically established. The aim was to explore intercommunity β-diversity and its components and to analyze the interrelationships with climate factors, soil factors, and geographic distance. The results indicate that (1) there is a geographic decay pattern and significant differences among plant communities in the Dunhuang North Mountain and Mazong Mountain areas, with β-diversity primarily driven by replacement components. (2) Climate, soil, and geographic distance significantly influence β-diversity and its replacement components, with climate factors exerting the greatest influence and geographic distance the least. (3) Multiple regression analysis (MRM) reveals differential effects of climate factors, soil factors, and geographic distance on β-diversity and its replacement components, with climate and soil factors exerting a much greater influence than geographic distance. In summary, the β-diversity of plant communities and their replacement components in the Dunhuang North Mountain and Mazong Mountain areas result from the combined effects of habitat filtering and dispersal limitation, with habitat filtering having a greater impact, while environmental heterogeneity is an important factor influencing species differences in this region.

Cattle ranching is an economic activity responsible for the loss of large extensions of tropical dry forest around the world. Several studies have demonstrated that the use of inadequate practices of this activity in tropical forests (e.g., fire, agrochemicals, and lack of rotational grazing systems of cattle in pastures) have negative consequences on dung beetle diversity and their ecological functions. In the present study, the influence of the cattle ranching duration gradient on the diversity of dung beetles and seed removal was evaluated. This study was carried out in pastures with different times of establishment of cattle ranching (between 4 and 40 years) in a tropical dry forest of Mexico. Overall, the species richness of dung beetles was similar along the gradient of grazing ages. However, the diversity of common (q1) and dominant (q2) species decreased and was associated with an increasing abundance of exotic species and a decreasing abundance of native species. Seed removal was mainly carried out by four beetle species, among which the exotic species Digitonthophagus gazella was the most important. The results establish that the duration of cattle ranching primarily influences the composition of dung beetle communities, as reflected in changes in the structure and function of their assemblages in the pastures. Although native dung beetles persist at low abundances along this gradient, the consequences of land use changes are undeniable in other similar ecosystems where these species could definitively disappear.

Interaction β‐diversity is a measure essential for understanding and conserving species interactions and ecosystem functioning. Interaction β‐diversity explains the variation in species interactions across spatial and temporal gradients, resulting from species turnover or interaction rewiring. Each component of interaction β‐diversity has different ecological implications and practical consequences. While interaction β‐diversity due to species turnover is related to assembly processes and fragmentation, rewiring can support high biodiversity and confer resilience to ecological networks. However, it is unclear whether both components respond to the same or different ecological drivers. Here, we assessed the ecological drivers of plant–pollinator interaction β‐diversity and its components across 24 sites in 9 longleaf pine (LLP) savannas in north and central Florida. We evaluated the effects of flowering plant composition and flower abundance, vegetation, fire regime, soil moisture, terrain characteristics, climate, spatial context and geographic location. We used path analysis to evaluate the drivers of spatial interaction β‐diversity and its main components. We then used generalized linear mixed models to assess the temporal patterns of spatial β‐diversity among sites within preserves. We found that plant–pollinator networks in LLP savannas are highly variable across space and time, mainly due to species turnover and possibly in response to abiotic gradients and dispersal boundaries. Flower abundance and flowering plant composition, geographic location, fire seasonality, soil moisture, and landscape context were the main drivers of plant–pollinator β‐diversity, highlighting the role of fire management and habitat connectivity in preserving plant–pollinator networks. [ABSTRACT FROM AUTHOR]