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Climate and land use changes drive shifts in species distributions, causing variations in species richness. Yet the influence of shifts in species distributions on functional diversity at broad spatial scales remains uncertain. Here, we explored the potential effect of climate and land use changes on the functional diversity of European amphibian assemblages from the present to 2050, along with their effect on species richness. We performed species distribution modelling using a scenario of climate and land use change to estimate current and future potential distributions of 73 species. We estimated functional diversity using morphological and ecological functional traits. Our results highlight the intricate effects of climate and land use changes on taxonomic and functional diversity of amphibians. A climate-induced northward expansion of amphibians is anticipated, with temperature, precipitation, and forest cover prominently shaping future assemblages. Species expected to have shrinking ranges (n = 35) tend to mature sexually at a later age, produce fewer offspring per reproductive event, and live at higher maximum altitudes compared to species expected to expand (n = 38). Furthermore, trait composition changes are expected to exceed predictions based solely on species richness. These changes will vary geographically, with northern regions likely experiencing substantial increases in functional richness and functional redundancy, i.e., the coexistence of species with similar functional roles. Our findings underscore that functional diversity changes might serve as an early warning signal to assess human impacts on biodiversity. [ABSTRACT FROM AUTHOR]

Simple Summary: Functional redundancy, the coexistence of species with similar functional roles, is of critical importance for ecosystem function stability. However, drivers of functional redundancy remain relatively poorly understood. Here, we analyzed four traits of British butterflies and aimed to identify the biotic and abiotic factors that affect the spatial patterns of functional redundancy. The most important factor was taxonomic diversity, with species-rich communities having the highest level of functional redundancy. Temperature was associated with redundancy and with different facets of taxonomic and functional diversity. However, although warmer areas hosted species-rich communities, redundancy was greatest in areas of intermediate mean annual temperature and declined at higher temperatures. This might imply that despite the positive effect of increased temperature on butterfly diversity, warmer and species-rich areas are vulnerable, perhaps due to the land uses dominating in these regions. Landscape heterogeneity promoted species richness, functional redundancy and variation in species and functional composition of the butterfly assemblages, underscoring the importance of maintaining diverse landscapes. Biodiversity promotes the functioning of ecosystems, and functional redundancy safeguards this functioning against environmental changes. However, what drives functional redundancy remains unclear. We analyzed taxonomic diversity, functional diversity (richness and β-diversity) and functional redundancy patterns of British butterflies. We explored the effect of temperature and landscape-related variables on richness and redundancy using generalized additive models, and on β-diversity using generalized dissimilarity models. The species richness-functional richness relationship was saturating, indicating functional redundancy in species-rich communities. Assemblages did not deviate from random expectations regarding functional richness. Temperature exerted a significant effect on all diversity aspects and on redundancy, with the latter relationship being unimodal. Landscape-related variables played a role in driving observed patterns. Although taxonomic and functional β-diversity were highly congruent, the model of taxonomic β-diversity explained more deviance than the model of functional β-diversity did. Species-rich butterfly assemblages exhibited functional redundancy. Climate- and landscape-related variables emerged as significant drivers of diversity and redundancy. Τaxonomic β-diversity was more strongly associated with the environmental gradient, while functional β-diversity was driven more strongly by stochasticity. Temperature promoted species richness and β-diversity, but warmer areas exhibited lower levels of functional redundancy. This might be related to the land uses prevailing in warmer areas (e.g., agricultural intensification). [ABSTRACT FROM AUTHOR]

The challenge of predicting the distribution of alien species has long been a focus of invasion ecology. Herein, we assessed biotic and abiotic factors from the 1980s as potential predictors of alien bird species patterns 20 years later in the state of New York. To assess the ability of each factor to predict future alien species patterns, we analysed the influence of biotic (native taxonomic, functional and phylogenetic diversity, and human population density) and abiotic (climate and land use) factors from the 1980s on the observed alien species richness patterns in the 2000s and the temporal change in the composition of the alien communities between the 1980s and the 2000s using both single-predictor and multivariate models. Alien species richness from the 1980s was a reliable predictor of the alien species richness and temporal beta-diversity patterns in the 2000s. Among abiotic factors, maximum temperature and agricultural land-uses constituted sufficient predictors of future alien species richness and better predictors than the native biotic factors. The performance of single-predictor models was generally weaker in predicting temporal alien beta-diversity; however, past alien species richness and maximum temperature again outperformed the other factors. Predictions and management decisions should focus on warm and agricultural areas, as well as areas with an already high number of established alien species. [ABSTRACT FROM AUTHOR]

Assessing spatial and temporal patterns of biodiversity change is essential to understand how communities vary over time and confront to environmental changes for the resilience of ecosystem functioning. We use data from two bird atlases of Britain collected during the breeding periods 1988–1991 and 2008–2011 to measure temporal β‐diversity of taxonomic, functional and phylogenetic dimensions and examine the relationship and the level of congruence of the three dimensions of temporal β‐diversity and their respective partitioned components (turnover‐nestedness). Temporal β‐diversity, turnover and nestedness patterns were highly congruent for the taxonomic and phylogenetic dimension, although these dimensions were weakly associated with the functional dimension. We found higher levels of temporal changes for the taxonomic (mean Jaccard β‐diversity 0.27) and phylogenetic (mean Jaccard β‐diversity 0.21) dimensions than for the functional dimension (mean Jaccard β‐diversity 0.09), implying that despite the changes in species composition the functional composition of the communities remained less affected. For taxonomic and phylogenetic dimensions, turnover contributed more than nestedness to shaping β‐diversity, while for functional β‐diversity the two components contributed similarly. Communities at higher altitudes were also more functionally similar in 20 years but with more changes in taxonomic and phylogenetic diversity possibly due to environmental filtering. We hypothesize that the low congruence might be due to species with extreme trait values persisting throughout time and retaining the volume of functional space and thus contributing to the low temporal change of functional diversity despite the high levels of change in species composition, perhaps an indication of functional "stability." [ABSTRACT FROM AUTHOR]

Amphibians are among the most endangered group of vertebrates. To conserve their diversity we need to comprehend how functional diversity and species traits vary across environmental gradients. We investigate the distribution of functional diversity (functional richness–functional dispersion–functional evenness) and the environmental drivers (climate, energy availability, landscape and anthropogenic attributes) of these patterns for the 68 amphibian species of Europe using generalized least squares models and hierarchical partitioning. Based on eight functional traits, species were arranged in a multidimensional functional trait space and principal coordinates analysis (PCoA) was applied to investigate the occupancy of this space by amphibians. Functional richness mirrored species richness pattern and decreased towards higher latitudes; while, functional dispersion showed an even stronger negative correlation with latitude. Functional evenness did not display a clear latitudinal trend. Areas with higher functional richness and functional dispersion are associated with lower temperature seasonality and increased land cover diversity, in contrast areas with higher functional evenness are characterized by lower mean annual temperature. Climate seasonality mostly influenced the traits related to the first two PCoA axes (i.e., foraging location, mobility mode) which could have been considered as functional response traits and could be used as indicators to examine how communities respond to environmental change. Our work describes the macroecological patterns and discusses the relative importance of alternative underlying mechanisms driving functional diversity of this high‐risk taxonomical group and highlight that species richness presents only part of the biodiversity patterns, while other facets like functional evenness behave distinctively differently. [ABSTRACT FROM AUTHOR]

Trait‐based approaches and functional diversity have been previously used to enlighten our knowledge on the structure of community assemblages which are driven by species interactions or abiotic factors. We assess what amphibian functional diversity implies for the community assembly of amphibians of Europe and whether the use of different Functional Trait Groups (FTGs) affects the results. We used presence/absence atlas with 50 km × 50 km grain size and three functional diversity indices (FRic, RaoQ and FDiv) which reflect functional richness and divergence to estimate functional diversity patterns calculated for three FTGs: Morphological, Habitat‐related, Reproductive and the complete set of traits. To identify the two key processes (environmental filtering and limiting similarity) that may shape amphibian communities and how the relative importance of these processes could change using different FTGs, we used null models to test for non‐random patterns of functional diversity accounting or not for the difference in regional species pool. We show that for the same grid cell, for one FTG we might observe lower than randomly expected functional diversity (i.e., trait convergence or environmental filtering as the dominant community assembly process) while for another FTG or for the complete set of traits, higher than randomly expected functional diversity (i.e., trait divergence or limiting similarity as the dominant community assembly process). This highlights the role of trait selection on the inference drawn regarding community assembly. Furthermore, the number of traits (complete set vs. FTGs) used to quantify functional diversity also affects the conclusions regarding community assembly. We assess what amphibian functional diversity implies for the community assembly of amphibians of Europe and whether the use of different Functional Trait Groups (FTGs) affect the results. We show that for the same grid cell, for one FTG we might observe lower than randomly expected functional diversity (i.e. trait convergence or environmental filtering as the dominant community assembly process) while for another FTG or for the complete set of traits, higher than randomly expected functional diversity (i.e. trait divergence or limiting similarity as dominant community assembly process). [ABSTRACT FROM AUTHOR]

The species–area relationship (SAR) is one of the few generalizations in ecology. However, many different relationships are denoted as SARs. Here, we empirically evaluated the differences between SARs derived from nested-contiguous and non-contiguous sampling designs, using plants, birds and butterflies datasets from Great Britain, Greece, Massachusetts, New York and San Diego. The shape of SAR depends on the sampling scheme, but there is little empirical documentation on the magnitude of the deviation between different types of SARs and the factors affecting it. We implemented a strictly nested sampling design to construct nested-contiguous SAR (SA C R), and systematic nested but non-contiguous, and random designs to construct non-contiguous species richness curves (SA S Rs for systematic and SACs for random designs) per dataset. The SA C R lay below any SA S R and most of the SACs. The deviation between them was related to the exponent f of the power law relationship between sampled area and extent. The lower the exponent f , the higher was the deviation between the curves. We linked SA C R to SA S R and SAC through the concept of “effective” area ( A e ), i.e. the nested-contiguous area containing equal number of species with the accumulated sampled area ( A S ) of a non-contiguous sampling. The relationship between effective and sampled area was modeled as log( A e ) = k log( A S ). A Generalized Linear Model was used to estimate the values of k from sampling design and dataset properties. The parameter k increased with the average distance between samples and with beta diversity, while k decreased with f . For both systematic and random sampling, the model performed well in predicting effective area in both the training set and in the test set which was totally independent from the training one. Through effective area, we can link different types of species richness curves based on sampling design properties, sampling effort, spatial scale and beta diversity patterns. [ABSTRACT FROM AUTHOR]

Beta diversity provides a link between species diversity in a region to species diversity within sites. Many metrics have been proposed for its estimation each reflecting a different aspect of the phenomenon. Many of them are more informative of the variation in alpha diversity among samples and the sampling effort (number of sampling units) rather than of the species assemblage differentiation. Here, we propose an index based on the sampling effort needed to fulfil a certain criterion and accounts for the relationship between the initial slope of the species accumulation curve and mean alpha diversity., For defining the index, we consider a set of n samples with S( n) species among R( n) total occurrences. The shared species occurrences are I( n) = R( n) − S( n). The proposed new index ( N*) is defined as the point, in terms of n, where I( n) crosses S( n). Samples taken beyond that point ( N*) contribute, cumulatively, more to the shared occurrences rather than to new species. For the estimation of N*, we provide the R function 'Nstar' based on the specaccum function in the vegan package., We tested the properties of N* on simulated datasets with known community assembly patterns and on a dataset of plant diversity of Greek Natura 2000 protected areas., N* is not mathematically confounded with alpha or gamma diversity. It depends on the relationship between gamma and alpha (Whittaker's index) but, furthermore, it reflects the variation in species occupancies. Thus, if a number of random samples, sufficient for the reliable estimation of mean alpha diversity and the species accumulation curve, is collected, N* converges to a value that does not change by the inclusion of more samples from the same region. N* depends primarily on the proportion of new species expected in each next sample., N* declines with nestedness in community structure, while it increases with species turnover. This holds for plant diversity of Greek Natura 2000, where N* exhibited lower values in island compared to continental regions reflecting the increased nestedness of island communities. [ABSTRACT FROM AUTHOR]

Abstract: A critical issue in conservation biology is the establishment of a strong relationship between species richness and a surrogate index. Such a relationship could provide the basis for the establishment of cost effective and easy to monitor methods for measuring biodiversity, providing an alternative for the prioritization of sites for conservation. We found that richness of species of conservation interest could reliably be predicted from the richness of higher order taxa, such as genus and family, in amphibians, reptiles, birds and mammals. Furthermore, the networks of reserve sites selected based upon the richness of genera or families were as effective in including species diversity, as the ones selected based upon species richness. [Copyright &y& Elsevier]

The ongoing biodiversity crisis reinforces the urgent need to unravel diversity patterns and the underlying processes shaping them. Although taxonomic diversity has been extensively studied and is considered the common currency, simultaneously conserving other facets of diversity (e.g., functional diversity) is critical to ensure ecosystem functioning and the provision of ecosystem services. Here, we explored the effect of key climatic factors (temperature, precipitation, temperature seasonality, and precipitation seasonality) and factors reflecting human pressures (agricultural land, urban land, land-cover diversity, and human population density) on the functional diversity (functional richness and Rao's quadratic entropy) and species richness of amphibians (68 species), reptiles (107 species), and mammals (176 species) in Europe. We explored the relationship between different predictors and diversity metrics using generalized additive mixed model analysis, to capture non-linear relationships and to account for spatial autocorrelation. We found that at this broad continental spatial scale, climatic variables exerted a significant effect on the functional diversity and species richness of all taxa. On the other hand, variables reflecting human pressures contributed significantly in the models even though their explanatory power was lower compared to climatic variables. In most cases, functional richness and Rao's quadratic entropy responded similarly to climate and human pressures. In conclusion, climate is the most influential factor in shaping both the functional diversity and species richness patterns of amphibians, reptiles, and mammals in Europe. However, incorporating factors reflecting human pressures complementary to climate could be conducive to us understanding the drivers of functional diversity and richness patterns. [ABSTRACT FROM AUTHOR]

Human activities like urbanization and agriculture affect spatial biodiversity patterns. The presence and activities of humans richly benefit alien species, but native species usually decline in human-impacted areas. Considering that the richness of alien and native species are inter-related, we explored the effect of human population density, human-related land uses (agricultural and urban), and natural land area on avian (alien and native) species richness of Massachusetts for two time periods using Generalized Additive Models. Avian alien species richness increased with native species richness in both time periods. Despite the predominant role of native species richness as a major driver of alien species richness, human activities play an important additional role in shaping species richness patterns of established aliens. Human-related land uses (urban and agricultural) and human population favored alien species richness in both time periods. Counter to expectations, human activities were also positively associated to native avian species richness. Possible explanations of these patterns may include habitat heterogeneity, increased availability of resources, and reduced predation risk. [ABSTRACT FROM AUTHOR]

Elevational gradients provide a unique opportunity to explore species responses to changing environmental conditions. Here, we focus on an elevational gradient in Crete, a climate-vulnerable Mediterranean plant biodiversity hotspot and explore the diversity patterns and underlying mechanisms of different plant life forms. We found that the significant differences in life forms' elevational and environmental ranges are reflected in α- diversity (species richness at local scale), γ-diversity (species richness at regional scale) and β-diversity (variation in species composition). The α- and γ-diversity decreased with elevation, while β-diversity followed a hump-shaped relationship, with the peak varying between life forms. However, β-deviation (deviation from null expectations) varied significantly with elevation but was life formindependent. This suggests that species composition is shaped by the size of the available species pool which depends on life form, but also by other deterministic or stochastic processes that act in a similar way for different life forms. The strength of these processes varies with elevation, with hotter–drier conditions and increased human activities filtering species composition at lowlands and large-scale processes determining the species pool size overriding local ecological processes at higher elevations. [ABSTRACT FROM AUTHOR]

Understanding the patterns of species richness and their environmental drivers, remains a central theme in ecological research and especially in the continental scales where many conservation decisions are made. Here, we analyzed the patterns of species richness from amphibians, reptiles and mammals at the EU level. We used two different data sources for each taxon: expert-drawn species range maps, and presence/absence atlases. As environmental drivers, we considered climate and land cover. Land cover is increasingly the focus of research, but there still is no consensus on how to classify land cover to distinct habitat classes, so we analyzed the CORINE land cover data with three different levels of thematic resolution (resolution of classification scheme ˗ less to more detailed). We found that the two types of species richness data explored in this study yielded different richness maps. Although, we expected expert-drawn range based estimates of species richness to exceed those from atlas data (due to the assumption that species are present in all locations throughout their region), we found that in many cases the opposite is true (the extreme case is the reptiles where more than half of the atlas based estimates were greater than the expert-drawn range based estimates). Also, we detected contrasting information on the richness drivers of biodiversity patterns depending on the dataset used. For atlas based richness estimates, landscape attributes played more important role than climate while for expert-drawn range based richness estimates climatic variables were more important (for the ectothermic amphibians and reptiles). Finally we found that the thematic resolution of the land cover classification scheme, also played a role in quantifying the effect of land cover diversity, with more detailed thematic resolution increasing the relative contribution of landscape attributes in predicting species richness. [ABSTRACT FROM AUTHOR]