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At the nearly pristine hydrothermal vents of the deep sea, highly endemic animals depend upon bacteria nourished by hydrothermal fluids that emerge as outflows from the seafloor. These animals are remarkable in tolerating extreme conditions, including high heat, toxic reduced sulfide, and low oxygen. Here, we test whether the extreme vent environment has selected for functionally similar species across the world's deep ocean, despite well-established global geographic patterns of high phylogenetic distinctness. High functional redundancy in species pools within regions suggests that the extreme environments select for species with specific traits. Yet, some regions emerge as functional hotspots where species pools with distinct functional trait compositions may represent geological idiosyncrasies of the habitats. Moreover, many species are functionally unique, an outcome of low species richness in a system where the species pool is small at all scales. Given the high proportion of functionally unique species, simulated species extinctions indicate that species losses would rapidly translate to the elimination of functionally irreplaceable species and could tip vent systems to functional collapse. Ocean changes and human-induced threats are expected to significantly impact many vent species as human activities expand in the remote deep sea. The opportunity exists now to take precautionary actions to limit the rates of extinction now ubiquitous in more accessible areas of Earth. [ABSTRACT FROM AUTHOR]

Elements are the basic substances that make up living organisms, and the element composition in plants quantitatively reflect the adaptation of plants to environment. However, the drivers that constitute the species‐specific plant elementome, as well as the bivariate bioelemental correlations in determining the stability of different bioelements are yet unclear. Based on 1058 leaf observations of 84 plant species from 232 wetlands across large environmental gradients, we found that bioelements with higher concentration were more stable and evolutionary constrained. We proposed a stability of well‐coordinated elements hypothesis, suggesting that bioelements that coordinate well in driving certain physiological functions constrain each other, thus maintaining relatively stable ratios in plants. In contrast, those functionally independent bioelements fluctuate greatly with environmental nutrient availability. Cold and saline stresses decreased plant stoichiometric network connectivity, complexity, and stability. Our research filled the gap in study of wetland plant elementome, and provided new evidences of plant–environment interactions in regions sensitive to climate change. [ABSTRACT FROM AUTHOR]

Aim: Dispersal and environmental filtering processes affect plant species colonisation success on islands and can be identified by functional traits. However, the lack of synthesis about the different methodological approaches in functional ecology hampers generalisation of filtering processes across island systems. Location: Seventy islands of the Houtman Abrolhos archipelago, Western Australia. Major Taxa Studied: Angiosperms. Methods: We (i) apply a simple, conceptual framework based on the mean and variability of individual functional traits in plant assemblages to identify species filters on islands, (ii) illustrate how trait distributions of island assemblages change in relation to island area and their source pool, (iii) compare distributions of individual traits to multivariate functional diversity indices and trait spaces and (iv) provide guidelines to detect a signal of trait filtering in island floras. Results: The island assemblages showed evidence for selective filters operating on seed mass and marginally on leaf area but not on plant height. Mean and variability of seed mass differed to those of the source pool indicating selective forces operating between source pool and island assemblages, especially on smaller islands. Multivariate functional diversity indices and trait spaces failed to reveal filtering processes acting on the island assemblages and insights into the putative processes. Main Conclusions: Using the mean and variability of individual traits in plant assemblages provides direct information on the trait composition of island floras and the processes involved beyond what can be inferred from multivariate functional diversity indices or trait spaces. We used islands as their distinct boundaries and relatively simple sets of species provide good research models, but joint analyses of trait means and variability should also be applicable to understand filtering processes in isolates and habitat fragments on mainlands. [ABSTRACT FROM AUTHOR]

The timing of flowering is an important driver of species distribution and community assembly patterns. However, we still have much to learn about the factors that shape flowering diversity (i.e., number of species flowering per period) in plant communities. One potential explanation of flowering diversity is the mid-domain effect, which states that geometric constraints on species ranges within a bounded domain (space or time) will yield a mid-domain peak in diversity regardless of ecological factors. Here, we determine whether the mid-domain effect explains peak flowering time (i.e., when most species of communities are flowering) across China. We used phenological data of 16,267 herbaceous and woody species from the provincial Flora in China and species distribution data from the Chinese Vascular Plant Distribution Database to determine relationships between the observed number of species flowering and the number of species flowering as predicted by the mid-domain effect model, as well as between three climatic variables (mean minimum monthly temperature, mean monthly precipitation, and mean monthly sunshine duration). We found that the mid-domain effect explained a significant proportion of the temporal variation in flowering diversity across all species in China. Further, the mid-domain effect explained a greater proportion of variance in flowering diversity at higher latitudes than at lower latitudes. The patterns of flowering diversity for both herbaceous and woody species were related to both the mid-domain effect and environmental variables. Our findings indicate that including geometric constraints in conjunction with abiotic and biotic predictors will improve predictions of flowering diversity patterns.

Silicon (Si) content in plant tissues is considered a functional trait that can provide multiple morpho‐physiological benefits to plant individuals. However, it is still unclear whether and how these individual benefits extend to plant community processes and ecosystem functioning. Here we investigated how plant Si content is associated with plant community properties and the ecosystem structure of herbaceous communities in Israel. We sampled 15 sites across the Mediterranean and desert ecosystems and built models to evaluate how plant silicon content (community‐weighted mean and standard variation) is associated with variables such as species richness, biomass production, plant cover, and functional diversity. Finally, we used model selection techniques to test whether models depicting plant Si content perform better than models using data on soil Si instead. Sites with lower susceptibility to drought had significantly more Si‐accumulating grass species and higher soils Si content. Models with plant Si content instead of soil Si, always performed better, although those considering Si content variation had overall stronger associations with community properties than only mean Si content. For instance, up to 51% of plant Si content variation was explained by climate, biomass production, and species richness, combined. Still, mean plant Si content and plant cover combined explained up to 42% of plant functional diversity. Our results suggest the that plant Si content serves as a proxy for understanding the ecological properties and functioning of arid and Mediterranean ecosystems. Nevertheless, the significance of Si has not been fully explored in other ecosystem types, where its influence may be less pronounced compared with the ecosystems examined in this study. In light of various global change scenarios, enhancing our understanding of Si as a plant functional trait could help bridge existing knowledge gaps and improve ecological modeling, thus enabling more accurate forecasts of changes in plant distributions. [ABSTRACT FROM AUTHOR]

Aim: The equilibrium theory of island biogeography predicts the positive species–area relationship and the negative species–isolation relationship, resulting in higher species richness on large and close islands. Unlike species richness, soundscape diversity integrates sound from various sources (e.g. biophony, geophony and anthrophony). However, how soundscape diversity varies with island area and isolation still needs to be tested. Here, we explored the island biogeography of bird soundscapes and the determinants of island attributes in shaping bird diversity and soundscape diversity. Location: Thousand Island Lake, Zhejiang, China. Taxon: Birds. Methods: We recorded avian soundscapes by audio recorders and censused bird diversity by line transects on 20 land‐bridge islands. We calculated four acoustic indices (acoustic complexity index, bioacoustic index, acoustic evenness index and acoustic entropy index) to assess acoustic richness, evenness and heterogeneity to explore the soundscape diversity of birds. We used multiple linear regressions, spatial autoregressions and piecewise structural equation models to examine the relationships between bird richness and acoustic diversity, and island attributes. Results: We found positive diversity–area relationships for avian soundscapes. Larger islands had more vocal species and higher habitat diversity, which led to an increment in the richness and unevenness of avian soundscapes on large islands. Acoustic evenness decreased with increasing isolation (distance to the mainland). Main Conclusions: Soundscapes on large islands are more diverse than those on small islands. Rich acoustic assemblages and heterogeneous habitats promote increased soundscape diversity on islands. Conversely, the lack of vocal contributors, resulting in a decrement in the communication of acoustic signals, can create a lower soundscape diversity on small and remote islands. Our study emphasizes the necessity of examining both species and habitat diversity in island biogeography for better understanding the underlying mechanisms determining biological soundscapes on islands. [ABSTRACT FROM AUTHOR]

Simplifying complex species interactions can facilitate tracking and predicting functional responses to ecological stressors. This is important for highly migratory pelagic predators, exploiting diverse prey fields as they respond to dynamic environments. We reconstructed the historical resource use of albacore tuna (Thunnus alalunga) globally from the 1900s to 2015 and confirmed highly biodiverse diets with 308 prey species, and an additional 238 taxa at coarser taxonomic resolution. We synthesised prey diversity into seven functional trait guilds using hierarchical divisive clustering algorithms as a function of four traits that describe habitat use and influence predator–prey encounter rates – prey habitat association vertically in the water column, horizontally along the coastal to pelagic gradient, seasonal and diel vertical migratory behaviour. We explored variability in historical composition of albacore diets across geographies based on species identity, individual trait information and functional trait guilds using a multi‐matrix modelling framework. Taxonomic information remains important for trophic ecology, however, species‐based diet composition in albacore tuna was highly variable across geographies and years sampled, making interpretation of these patterns difficult. By simplifying species identity into habitat‐based traits, we highlight changes in prey resources consumed, such as the historical importance of near‐surface epipelagic prey resources from coastal to oceanic habitats, and seasonally migrating continental shelf prey, with less frequent pulses of deeper water and demersal taxa. Trait information and trait guilds serve as useful classification frameworks for identifying functionally redundant food web linkages across biodiverse prey, and will prove useful in tracking predators' foraging responses to changing resource availability. [ABSTRACT FROM AUTHOR]

Aim: There is widespread support that species richness increases with the available energy of an ecosystem, but the mechanisms underlying this driver of biodiversity patterns remain elusive. We evaluated gradients of functional diversity to test whether the higher species richness of productive, structurally diverse environments is due to a greater range of niches being supported by the abiotic conditions present (environmental filtering), greater availability of biotic resource and habitat niches (more niches) or increasing functional similarity of species (niche packing). Location: Australia. Taxon: Birds and mammals. Methods: We used structural equation modelling to evaluate the relative contributions of climatic harshness (actual evapotranspiration, AET) and the availability of resource (gross primary productivity, GPP) and habitat (tree height) niches on taxonomic richness and functional richness, dispersion and evenness. We performed parallel analyses within 15 bioclimatic zones and continentally to evaluate the scaling of biodiversity gradients and the shifting balance between niche‐based mechanisms along environmental gradients. Results: All continental diversity gradients were primarily associated with energy variables, but while species richness of both taxa and all functional diversity measures of bird assemblages increased with AET, mammal functional diversity was more strongly associated with GPP gradients. Results were more variable at the regional scale, but species richness gradients along tree height (birds and mammals) and GPP (mammals) within bioclimatic zones tended not to be paralleled by increases in functional richness or dispersion. Main Conclusions: The niche‐based explanations of biodiversity gradients varied in importance with scale, position on environmental gradients and taxonomic group. At the continental extent, bird biodiversity gradients were structured by environmental filtering by climatic harshness, while mammal biodiversity was related to the increasing availability of resource niches with increasing productivity. Niche packing was more prominent at the regional scale, especially in bioclimatic zones where productivity and vegetation height were less limiting, and in mammal assemblages, suggesting that biodiversity patterns scale differently for birds and mammals. [ABSTRACT FROM AUTHOR]

Abstract Silicon (Si) content in plant tissues is considered a functional trait that can provide multiple morpho‐physiological benefits to plant individuals. However, it is still unclear whether and how these individual benefits extend to plant community processes and ecosystem functioning. Here we investigated how plant Si content is associated with plant community properties and the ecosystem structure of herbaceous communities in Israel. We sampled 15 sites across the Mediterranean and desert ecosystems and built models to evaluate how plant silicon content (community‐weighted mean and standard variation) is associated with variables such as species richness, biomass production, plant cover, and functional diversity. Finally, we used model selection techniques to test whether models depicting plant Si content perform better than models using data on soil Si instead. Sites with lower susceptibility to drought had significantly more Si‐accumulating grass species and higher soils Si content. Models with plant Si content instead of soil Si, always performed better, although those considering Si content variation had overall stronger associations with community properties than only mean Si content. For instance, up to 51% of plant Si content variation was explained by climate, biomass production, and species richness, combined. Still, mean plant Si content and plant cover combined explained up to 42% of plant functional diversity. Our results suggest the that plant Si content serves as a proxy for understanding the ecological properties and functioning of arid and Mediterranean ecosystems. Nevertheless, the significance of Si has not been fully explored in other ecosystem types, where its influence may be less pronounced compared with the ecosystems examined in this study. In light of various global change scenarios, enhancing our understanding of Si as a plant functional trait could help bridge existing knowledge gaps and improve ecological modeling, thus enabling more accurate forecasts of changes in plant distributions.

Aim: Geographic variation in metabolic resources necessary for functional trait expression can set limits on species distributions. For species that need to produce and maintain biomineralized traits for survival, spatial variation in mineral macronutrients may constrain species distributions by limiting the expression of biomineralized traits. Here, we examine whether Oreohelix land snails that express heavily biomineralized shell ornaments are restricted to CaCO3 rock regions, if they incorporate greater amounts of CaCO3 rock carbon in their shell than less biomineralized smooth forms, and if ornamentation increases shell strength. Location: Western United States. Taxon: Oreohelix land snails. Methods: We used random forest classification models at multiple spatial resolutions to evaluate the contribution of topographic, vegetation, climate, and geologic variables in predicting the presence of heavily biomineralized shell ornaments across the range of Oreohelix. We then measured and compared shell biometric variables, 14C/12C ratios, and peak force for fracture for ornamented and smooth forms from calcareous and non‐calcareous substrates. Results: Distance to CaCO3 rock was the most important variable in all models and closer proximity to CaCO3 rock was associated with greater probability of local ornamentation classification. Pairwise comparisons of 14C/12C ratios in closely occurring ornamented vs. smooth population pairs revealed ornamented forms incorporate greater CaCO3 rock carbon than smooth forms. Ornamented types measured in this study were generally heavier and required greater peak force for fracture than smooth forms, except when comparing ornamented forms to smooth forms sampled from CaCO3 rock. Main Conclusions: Biomineralization expression, species distribution, and trait function appear to be constrained by mineral supply in a highly diverse group of land snails. This trait‐environment relationship provides a basis for future investigations of CaCO3 macronutrient constraints on shell form and species distribution in other terrestrial molluscs and has a direct impact on the management of Oreohelix species. [ABSTRACT FROM AUTHOR]

Characterizing the spatial structure of taxonomic and functional diversity (FD) of marine organisms across regional and latitudinal scales is essential for improving our understanding of the processes driving species richness and those that may constrain or enhance the set of species traits that define the functional structure of communities. Here, we present the functional diversity of coastal invertebrate macrofaunal species along the south‐eastern Pacific from 7°N to 56°S, describe spatial variation of species traits, and examine the relationship with environmental variables. For that, we defined the functional traits and distribution ranges of 2350 marine macroinvertebrates calculated eight metrics of FD. Random forest regression was applied to identify significant relationships between FD and six environmental variables. Finally, functional β‐turnover was estimated to detect alongshore shifts in functional structure and their coincidence with biogeographical domains. Our results show, in contrast with taxonomic richness that measures of trait differences, functional space and functional specialisation increase with latitude, while functional evenness exhibits a non‐linear shape, peaking at mid latitudes. Functional redundancy decreased significantly poleward, while indicators of vulnerability increase. In contrast to taxonomic richness, FD was tightly connected to variables indicative of stress and productivity, such as dissolved oxygen and nutrients. Sea surface temperature and coastal area best explained the increased FD redundancy and richness towards the tropics. The high spatial correlation between taxonomic and functional turnover suggests environmental filters play an important role in the functional structure of the seascape. Our findings suggest that processes favouring taxonomic richness are latitudinally divergent from those favouring functional diversity. Correlations with environmental variables suggest that increased sea surface temperature and measures of stability increase redundancy, while variations in dissolved oxygen and nutrients positively affect functional diversification. Moreover, the functional diversity patterns suggest low resilience of high latitude coastal ecosystems, which are heavily exploited and threatened by climate change, hence highlighting the urgent need for effective conservation policies. [ABSTRACT FROM AUTHOR]

Aim: Understanding how combinations of ecological traits at the community‐level vary with environmental conditions is crucial to anticipate and respond to the biodiversity crisis. While this topic is popular, most attempts to analyse and predict multiple traits in space and time ignore the inherent correlations between these traits. In doing so, the predicted traits in unobserved environments are likely to be flawed (i.e. unrealistic trait combinations). Here, we propose a framework that addresses this methodological question in functional biogeography. Innovation: Our framework relies on joint trait distribution models to quantify how combinations of mean trait values at the community level co‐vary as a function of environmental conditions. Making use of joint probabilities and the constraints imposed by trait correlations, our framework not only predicts the most suitable combination of traits in a given environment but also the envelope of possible alternatives. This innovation allows visualizing how the correlation structure between traits imposes a strong constraint (or not) on the expected combination of traits in a given environment. The stronger trait correlations, the smaller the envelope of likely alternative states. We provide an R package implementing our framework. Main Conclusions: Applied to plant communities in the French Alps, our framework quantifies the variation of trait combinations at the community‐level along environmental gradients that, otherwise, could not be identified. Strong correlations in community mean leaf traits led to a low diversity of alternative combinations of community means, which can only vary along the acquisition‐conservation spectrum. Instead, height varied partly independently of leaf traits, leading to a higher diversity in the combinations of mean community traits. Our framework allows for a more integrated understanding and prediction of the distribution of traits, thus moving a descriptive functional biogeography to a more predictive science. [ABSTRACT FROM AUTHOR]

Background and Aims Studying trait variability and restricted gene flow between populations of species can reveal species dynamics. Peripheral populations commonly exhibit lower genetic diversity and trait variability due to isolation and ecological marginality, unlike central populations experiencing gene flow and optimal conditions. This study focused on Carex curvula , the dominant species in alpine acidic meadows of European mountain regions. The species is sparser in dry areas such as the Pyrenees and Balkans, compared to the Central–Eastern Alps and Carpathians. We hypothesized that distinct population groups could be identified based on their mean functional trait values and their correlation with the environment; we predicted that ecologically marginal populations would have stronger trait correlations, lower within-population trait variability (intraspecific trait variability, ITV) and lower genetic diversity than populations of optimal habitats. Methods Sampling was conducted in 34 populations that spanned the entire distribution range of C. curvula. We used hierarchical clustering to identify emergent functional groups of populations, defined by combinations of multiple traits associated with nutrient economy and drought tolerance (e.g. specific leaf area, anatomy). We contrasted the geographical distribution of these groups in relation to environment and genetic structure. We compared pairwise trait relationships, within-population trait variation (ITV) and neutral genetic diversity between groups. Key Results Our study identified emergent functional groups of populations. Those in the southernmost ranges, specifically the Pyrenees and Balkan region, showed drought-tolerant trait syndromes and correlated with indicators of limited water availability. While we noted a decline in population genetic diversity, we did not observe any significant changes in ITV in ecologically marginal (peripheral) populations. Conclusions Our research exemplifies the relationship between ecological marginality and geographical peripherality, which in this case study is linked to genetic depauperation but not to reduced ITV. Understanding these relationships is crucial for understanding the biogeographical factors shaping trait variation. [ABSTRACT FROM AUTHOR]

Water availability is an important driver of plant functional biogeography. Most studies focus on the effects of precipitation, and neglect the contribution of groundwater as a source when the water table depth (WTD) is accessible to roots. Previous studies suggested that shallow water tables select for acquisitive traits. These studies have mostly contrasted shallow vs. deep water tables, without considering a more fine-grained perspective within shallow water tables or the temporal WTD behavior. Here we tested whether the degree of variation in WTD translates into divergent modes of trait selection. We expect constantly shallow WTD leading to the selection of acquisitive traits, whilst high fluctuation of WTD would lead to tree communities with more conservative traits. We used community and trait data (wood density and leaf traits) from 25 1-ha forest monitoring plots spread over 600 km in central Amazonia, covering a gradient of shallow to intermediate (0–8 m deep) WTD along the Purus-Madeira interfluve. Wood density was measured directly in trunk cores (498 trees) and leaf traits (Specific Leaf Area, Leaf Dry Mass Content, Leaf Thickness) of >6,000 individuals were estimated with FT-NIR (Fourier-Transformed Near-Infrared Spectroscopy) spectral models calibrated with cross-Amazonian data. We observed a turnover of families, genera, and species along the gradient of temporal WTD fluctuation range. This taxonomic turnover was accompanied by a change in wood traits, with higher wood density associated to higher WTD fluctuation and higher climatic water deficit. Leaf traits, however, varied in the opposite direction than initially hypothesized, i.e., trees had more acquisitive traits toward intermediate WTD with higher fluctuation. Based on those results, we propose that the effect of WTD selection should be conceptualized in a quadratic form, going from water excess in very shallow WTD (5 m, limiting condition, with conservative traits again).

Functional diversity is widely used and widespread. However, the main packages used to compute functional diversity indices are not flexible and not adapted to the volume of data used in modern ecological analyses. We here present fundiversity, an R package that eases the computation of classical functional diversity indices. It leverages parallelization and memoization (caching results in memory) to maximize efficiency with data with thousands of columns and rows. We also did a performance comparison with packages that provide analog functions. In addition to being more flexible, fundiversity was always an order of magnitude quicker than alternatives. fundiversity aims to be a lightweight, efficient tool to compute functional diversity indices, which can be used in a variety of contexts. Because it has been designed following clear principles, it is easy to extend. We hope the wider community will adopt it and we welcome all contributions. [ABSTRACT FROM AUTHOR]

Bioregionalisation partitions diversity so that similarity of the selected biological and ecological variables is higher within regions than it is outside those regions. The classic approach partitions an area based on species composition, whereas more recent methods based on remotely sensed data classify biogeographic regions on biophysical and structural variables of vegetation. Another, yet to be explored opportunity, is offered by identifying distinct ecological strategies of plants inhabiting a given area, that is, a functional trait‐based bioregionalisation. Here, we propose such a bioregionalisation using trait hypervolumes. We also compare the proposed functional bioregionalisation with established classifications based on species composition or on remotely sensed data to identify spatial congruence among them, and suggest possible reasons behind observed patterns.Natural history collections represent an underexploited resource, despite holding both trait and locality information and being taxonomically comprehensive. We compile values of traits (leaf size, plant height, seed number per fruit, seed volume) derived from natural history collections for a random sample of African angiosperm species (~1% of the continental flora) to estimate a trait hypervolume. We use hierarchical clustering to divide the hypervolume into four segments (each representing a distinct ecological strategy), whose spatial intersections produced 12 putative biogeographic regions, each containing one or more of these strategies. We spatially map the hypervolume segments onto the entire African continent and calculate the spatial congruence of the putative functional biogeographic regions with previous bioregionalisations.We identify values and combinations of traits that can be indicative of biogeographic regions. This functional bioregionalisation shows greater spatial congruence with that derived from species composition than from remote sensing. However, spatial congruence is low at the continent scale (19%–37%), and varies greatly among regions and in pairwise comparisons between bioregionalisations.Synthesis. Plant traits from natural history collections offer an underused source of information for biogeographic analyses. We demonstrate potential applications of trait hypervolumes in functional biogeography, and outline strengths and drawbacks of the different bioregionalisation methods. Finally, we suggest that key ecological strategies could be used in future models as proxies to anticipate shifts of species assemblages and biogeographic regions. [ABSTRACT FROM AUTHOR]

Lineage‐specific traits determine how plants interact with their surrounding environment. Unrelated species may evolve similar phenotypic characteristics to tolerate, persist in, and invade environments with certain characteristics, resulting in some traits becoming relatively more common in certain types of habitats. Analyses of these general patterns of geographical trait distribution have led to the proposal of general principles to explain how plants diversify in space over time. Trait–environment correlation analyses quantify to what extent unrelated lineages have similar evolutionary responses to a given type of habitat. In this synthesis, I give a short historical overview on trait–environment correlation analyses, from some key observations from classic naturalists to modern approaches using trait evolution models, large phylogenies, and massive data sets of traits and distributions. I discuss some limitations of modern approaches, including the need for more realistic models, the lack of data from tropical areas, and the necessary focus on trait scoring that goes beyond macromorphology. Overcoming these limitations will allow the field to explore new questions related to trait lability and niche evolution and to better identify generalities and exceptions in how plants diversify in space over time. [ABSTRACT FROM AUTHOR]

BackgroundRefugia are island-like habitats that are linked to long-term environmental stability and, as a result, high endemism. Conservation of refugia and endemism hotspots should be based on a deep ecological and evolutionary understanding of their functioning, which remains limited. Although functional traits can provide such insights, a corresponding, coherent framework is lacking.Proposed frameworkPlant communities in refugia and endemism hotspots should, due to long-term environmental stability, display unique functional characteristics linked to distinct phylogenetic patterns. Therefore, such communities should be characterized by a functional signature that exhibits: (1) distinct values and combinations of traits, (2) higher functional diversity and (3) a prevalence of similar traits belonging to more distantly related lineages inside, compared to outside, of endemism hotspots and refugia. While the limited functional trait data available from refugia and endemism hotspots do not allow these predictions to be tested rigorously, three potential applications of the functional signature in biogeography and conservation planning are highlighted. Firstly, it allows the functional characteristics of endemism hotspots and refugia to be identified. Secondly, the strength of the functional signature can be compared among these entities, and with the surrounding landscape, to provide an estimate of the capacity of endemism hotspots and refugia to buffer environmental changes. Finally, the pattern of the functional signature can reveal ecological and evolutionary processes driving community assembly and functioning, which can assist in predicting the effect of environmental changes (e.g. climate, land-use) on communities in endemism hotspots and refugia.ConclusionThe proposed functional signature concept allows the systematic integration of plant functional traits and phylogeny into the study of endemism hotspots and refugia, but more data on functional traits in these entities are urgently needed. Overcoming this limitation would facilitate rigorous testing of the proposed predictions for the functional signature, advancing the eco-evolutionary understanding of endemism hotspots and refugia.

It has been argued that the mechanisms structuring ecological communities may be more generalizable when based on traits than on species identities. If so, patterns in the assembly of community‐level traits along environmental gradients should be similar in different places in the world. Alternatively, geographical change in the species pool and regional variation in climate might result in site‐specific relationships between community traits and local environments. These competing hypotheses are particularly untested for animal communities.Here we test the geographical constancy of trait‐based assembly patterns using a widespread multi‐trophic community: aquatic macroinvertebrates within bromeliads. We used data on 615 invertebrate taxa from 1,656 bromeliads in 26 field sites from Mexico to Argentina. We summarized invertebrate traits with four orthogonal axes, and used these trait axes to examine trait convergence and divergence assembly patterns along three environmental gradients: detrital biomass and water volume in bromeliads, and canopy cover over bromeliads.We found no overall signal of trait‐based assembly patterns along any of the environmental gradients. However, individual sites did show trait convergence along detrital and water gradients, and we built predictive models to explore these site differences.Sites that showed trait convergence along detrital gradients were all north of the Northern Andes. This geographical pattern may be related to phylogeographical differences in bromeliad morphology. Bromeliads with low detritus were dominated by detritivorous collectors and filter feeders, where those with high detritus had more sclerotized and predatory invertebrates.Sites that showed the strongest trait convergence along gradients in bromeliad water were in regions with seasonal precipitation. In such sites, bromeliads with low water were dominated by soft‐bodied, benthic invertebrates with simple life cycles. In less seasonal sites, traits associated with short‐term desiccation resistance, such as hard exoskeletons, were more important.In summary, we show that there are strong geographical effects on the trait‐based assembly patterns of this invertebrate community, driven by the biogeography of their foundational plant species as well as by regional climate. We suggest that inclusion of biogeography and climate in trait‐based community ecology could help make it a truly general theory. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The capacity to forecast the effects of climate change on biodiversity largely relies on identifying traits capturing mechanistic relationships with the environment through standardized field experiments distributed across relevant spatial scales. The effects of short‐term experimental manipulations on local communities may overlap with regional climate gradients that have been operating during longer time periods. However, to the best of our knowledge, there are no studies simultaneously assessing such long‐term macroecological drivers with local climate manipulations.We analysed this issue with springtails (Class Collembola), one of the dominant soil fauna groups, in a standardized climate manipulation experiment conducted across six European countries encompassing broad climate gradients. We combined community data (near 20K specimens classified into 102 species) with 22 eco‐morphological traits and reconstructed their phylogenetic relationships to track the evolution of adaptations to live at different soil depths, which is key to cope with desiccation. We then applied joint species distribution models to investigate the combined effect of the regional aridity gradient with the local experimental treatment (drought and warming) over the assembly of springtail communities and tested for significant trait–environment relationships mediating their community‐level responses.Our results show (1) a convergent evolution in all three major collembolan lineages of species adapted to inhabit at different soil strata; (2) a clear signature of aridity selecting traits of more epigeic species at a biogeographical scale and (3) the association of short‐term experimental drought with traits related to more euedaphic life‐forms.The hemiedaphic condition would be the plesiomorphic state for Collembola while the adaptations for an epigeic life would have been secondarily gained. Epigeic springtails are not only more resistant to drought, but also have a higher dispersal capacity that allows them to seek more favourable micro‐habitats after experiencing drier conditions. The observed relative edaphization of the springtail communities after short‐term experimental drought may thus be a transient community response.The disparity between macroecological trends and fast community‐level responses after climate manipulations highlights the need of simultaneously assessing long‐term and short‐term drivers at broad spatial scales to adequately interpret trait–environment relationships and better forecast biodiversity responses to climate change. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Summary: Many biomes still lack an overall view of their macro-functional structure (i.e., natural biogeographical regions and zones), including the Atlantic Forest biodiversity hotspot. The effective design of protected areas depends on the spatial identification of units with ecologically distinct content, whether it be floristic, phylogenetic or functional. This study used a regionalization approach to identify the potential functional regions of the Atlantic Forest by interpolating functional data from forest remnants into the entire original occurrence area of the biome, including deforested lands. Conservation status was then estimated. Analysis of seven traits of leaf, wood, seed and plant size revealed that the biome is structured over 14 functional regions and three zones (clusters of regions). Functional regions represented specific combinations of traits rather than being characterized by extremely high or low values of a single trait. They retained an average of 29.5% of forest remnants (range: 7.63–54.66%) and 10.82% of protected areas (range: 0.35–35.78%). By analysing the functional space occupied by all regions, captured by two principal component analysis axes using the pixel-level information contained in interpolated trait maps, we showed that large parts of this space were not covered by forest remnants or protected areas and that the most represented regions had serious deficits in protected areas. Although the Serra do Mar mountain range in the south and south-east Atlantic Forest is relevant as a centre of species endemism and richness and has received considerable attention for carrying out ecological studies and creating protection areas, this range does not fully encompass the functional biodiversity of such a rich biome. Our results demonstrate the potential for combining regionalization and conservation approaches to unravel the macro-structures of biomes. [ABSTRACT FROM AUTHOR]

Assessing the impacts of anthropogenic degradation and climate change on global carbon cycling is hindered by a lack of clear, flexible and easy‐to‐use productivity models along with scarce trait and productivity data for parameterizing and testing those models. We provide a simple solution: a mechanistic framework (RS‐CFM) that combines remotely‐sensed foliar‐trait and canopy‐structural data with trait‐based metabolic theory to efficiently map productivity at large spatial scales. We test this framework by quantifying net primary productivity (NPP) at high‐resolution (0.01‐ha) in hyper‐diverse Peruvian tropical forests (30040 hectares) along a 3322‐m elevation gradient. Our analysis captures hotspots and elevational shifts in productivity more accurately and in greater detail than alternative empirical‐ and process‐based models that use plant functional types. This result exposes how high‐resolution, location‐specific variation in traits and light competition drive variability in productivity, opening up possibilities to fully harness remote sensing data and reliably scale up from traits to map global productivity in a more direct, efficient and cost‐effective manner. [ABSTRACT FROM AUTHOR]

Understanding how environmental change alters the composition of plant assemblages, and how this in turn affects ecosystem functioning is a major challenge in the face of global climate change. Assuming that values of plant traits express species adaptations to the environment, the trait-based approach is a promising way to achieve this goal. Nevertheless, how functional traits are related to species' environmental tolerances and how trait spectra respond to broad-scale environmental gradients remains largely unexplored. Here, we identify the main trait spectra for US angiosperm trees by testing hypotheses for the relationships between functional traits and species' environmental tolerances to environmental stresses, as well as quantifying the environmental drivers of assemblage means and variances of these traits. We analyzed >74,000 community assemblages from the US Forest Inventory and Analysis using 12 functional traits, five traits expressing species' environmental tolerances and 10 environmental variables. Results indicated that leaf traits, dispersal traits, and traits related to stem hydraulics were related to cold or drought tolerance, and their assemblage means were best explained by minimum temperatures. Assemblage means of traits related to shade tolerance (tree growth rate, leaf phosphorus content, and bark thickness) were best explained by aridity index. Surprisingly, aridity index, rather than minimum temperature, was the best predictors of assemblage variances of most traits, although these relationships were variable and weak overall. We conclude that temperature is likely to be the most important driver of functional community structure of North American angiosperm trees by selecting for optimum strategies along the cold and drought stress trade-off. In turn, water availability primarily affects traits related to shade tolerance through its effect on forest canopy structure and vegetation openness.

Abstract Climate‐induced changes in the ocean and sea ice environment of the Arctic are beginning to generate major and rapid changes in Arctic ecosystems, but the effects of directional forcing on the persistence and distribution of species remain poorly understood. Here, we examine the reproductive traits and population dynamics of the bivalve Astarte crenata and sea star Ctenodiscus crispatus across a north–south transect that intersects the polar front in the Barents Sea. Both species present large oocytes indicative of short pelagic or direct development that do not differ in size–frequency between 74.5 and 81.3º latitude. However, despite gametogenic maturity, we found low frequencies of certain size classes within populations that may indicate periodic recruitment failure. We suggest that recruitment of A. crenata could occur periodically when conditions are favorable, while populations of C. crispatus are characterized by episodic recruitment failures. Pyloric caeca indices in C. crispatus show that food uptake is greatest at, and north of, the polar front, providing credence to the view that interannual variations in the quantity and quality of primary production and its flux to the seafloor, linked to the variable extent and thickness of sea ice, are likely to be strong determinants of physiological fitness. Our findings provide evidence that the distribution and long‐term survival of species is not only a simple function of adaptive capacity to specific environmental changes, but will also be contingent on the frequency and occurrence of years where environmental conditions support reproduction and settlement.

Aim: Climate shapes the composition and function of plant communities globally, but it remains unclear how this influence extends to floral traits. Flowering phenology, or the time period in which a species flowers, has well‐studied relationships with climatic signals at the species level but has rarely been explored at a cross‐community and continental scale. Here, we characterise the distribution of flowering periods (months of flowering) across continental plant communities encompassing six biomes, and determine the influence of climate on community flowering period lengths. Location: Australia. Taxon: Flowering plants. Methods: We combined plant composition and abundance data from 629 standardised floristic surveys (AusPlots) with data on flowering period from the AusTraits database and additional primary literature for 2983 species. We assessed abundance‐weighted community mean flowering periods across biomes and tested their relationship with climatic annual means and the predictability of climate conditions using regression models. Results: Combined, temperature and precipitation (annual mean and predictability) explain 29% of variation in continental community flowering period. Plant communities with higher mean temperatures and lower mean precipitation have longer mean flowering periods. Moreover, plant communities in climates with predictable temperatures and, to a lesser extent, predictable precipitation have shorter mean flowering periods. Flowering period varies by biome, being longest in deserts and shortest in alpine and montane communities. For instance, desert communities experience low and unpredictable precipitation and high, unpredictable temperatures and have longer mean flowering periods, with desert species typically flowering at any time of year in response to rain. Main conclusions: Current climate conditions shape flowering periods across biomes, with implications for phenology under climate change. Shifts in flowering periods across climatic gradients reflect changes in plant strategies, affecting patterns of plant growth and reproduction as well as the availability of floral resources for pollinators across the landscape. [ABSTRACT FROM AUTHOR]

Plant functional traits can greatly influence invasion success on islands. However, interrelationships between traits and invasion success are rarely integrated with the island biogeography theory. Here, we explored relations between functional traits and plant distributions to assess which traits are associated with invasion success (i.e. high island occupancy), test whether non-native richness and seed mass of species with distinct growth forms and dispersal modes vary differently with island characteristics (e.g. area, isolation, exposure to ocean-borne disturbances, distance from the nearest urban area, and whether islands were managed for conservation), and whether results differ from native species. We assembled a database of 264 northern New Zealand offshore islands, amalgamating species lists from field surveys and previously published data, and comprising 822 native and 855 non-native species. Non-native graminoids occurred on islands more frequently than forbs and woody species, and long-distance dispersal modes (wind, animal, unspecialized) more than species with short-distance dispersal modes. Most differences among trait categories of non-native species were associated with human-related variables (i.e. distance from the nearest urban area, and whether islands were conservation areas). Non-native plant species with high island occupancy were less commonly associated with human-related variables than non-native species with low island occupancy. Instead, they were more similar in their distributional patterns to native species within the same trait category, suggesting comparable processes regulate both sets of species. Our results illustrate that integrating trait-based approaches in the island biogeography framework can be a useful tool in understanding and predicting plant invasions. [ABSTRACT FROM AUTHOR]

Evolutionary history and environmental filtering shape the phylogenetic and functional structure of regional assemblages. However, detecting the footprint of such eco‐evolutionary drivers is challenging because these may often counter each other's signature. Here, we examined whether a biogeographic deconstruction approach of phylogenetic (PD) and functional diversity (FD) patterns may help in identifying eco‐evolutionary signals in extant regional assemblages. As model system, we used forest understorey angiosperms found in three regions of Italy (Alpine, Mediterranean, Continental). We quantified PD and FD of all species inhabiting the three regions (regional assemblages). Then, we computed PD and FD for the subsets of species restricted to each region (biogeographic elements), also examining diversity patterns of species found across the three regions (widespread element). We used aboveground and belowground traits capturing major plant functions to calculate FD. Additionally, we assessed FD patterns decoupled from phylogeny. We found that species restricted to climatically harsh regions (Alpine and Mediterranean elements) were phylogenetically and functionally clustered, whereas widespread species were characterised by overdispersion. Species confined to the climatically intermediate (Continental) region were randomly sorted. By including all species occurring within a region, the patterns found for the region‐restricted species blurred. Phylogenetically decoupled FD patterns were qualitatively similar to non‐decoupled ones with the exception of the Alpine element, where we detected a clear signature of functional differentiation between closely related species. This suggests that recent speciation events contributed to shaping the Alpine flora. Compared to the belowground compartment, aboveground traits showed a more coherent pattern with that of all‐trait FD – likely because most biomass is allocated aboveground in forest understoreys. This biogeographic deconstruction study illustrates which type of eco‐evolutionary insights can be gained by implementing multifaceted and integrated approaches at the macroecological scale. [ABSTRACT FROM AUTHOR]

Assemblage-level studies of mean trait variation are common in macroecology. However, how phylogenetic relationships among species affect trait-based macroecological patterns is still unresolved. I used an approach based on variation partitioning analysis using environmental and phylogenetic lineage variation as predictors to investigate whether variation in mean trait values among Neotropical sigmodontine rodent communities is best explained by macroecological adaptation, biogeographical history, or joint effects of both – the latter resulting in phylogenetic niche conservatism (PNC) at the metacommunity scale. Metacommunity PNC best explained mean variation in body size and skull/mandible shape across assemblages, and the pattern of metacommunity PNC suggests that influence of environmental factors on mean trait variation relies heavily on spatial biogeographical clade sorting. This suggests that biogeographical lineage distribution should be taken into account in analyses seeking to correlate environmental variables with mean trait variation.

Trait-based approaches are increasingly recognized as a tool for understanding ecosystem re-assembly and function under intensifying global change. Here we synthesize trait-based research globally (n = 865 studies) to examine the contexts in which traits may be used for global change prediction. We find that exponential growth in the field over the last decade remains dominated by descriptive studies of terrestrial plant morphology, highlighting significant opportunities to expand trait-based thinking across systems and taxa. Very few studies (less than 3%) focus on predicting ecological effects of global change, mostly in the past 5 years and via singular traits that mediate abiotic limits on species distribution. Beyond organism size (the most examined trait), we identify over 2500 other morphological, physiological, behavioural and life-history traits known to mediate environmental filters of species' range and abundance as candidates for future predictive global change work. Though uncommon, spatially explicit process models—which mechanistically link traits to changes in organism distributions and abundance—are among the most promising frameworks for holistic global change prediction at scales relevant for conservation decision-making. Further progress towards trait-based forecasting requires addressing persistent barriers including (1) matching scales of multivariate trait and environment data to focal processes disrupted by global change, and (2) propagating variation in trait and environmental parameters throughout process model functions using simulation. [ABSTRACT FROM AUTHOR]

Species interactions are influenced by the trait structure of local multi‐trophic communities. However, it remains unclear whether mutualistic interactions in particular can drive trait patterns at the global scale, where climatic constraints and biogeographic processes gain importance. Here we evaluate global relationships between traits of frugivorous birds and palms (Arecaceae), and how these relationships are affected, directly or indirectly, by assemblage richness, climate and biogeographic history. We leverage a new and expanded gape size dataset for nearly all avian frugivores, and find a positive relationship between gape size and fruit size, that is, trait matching, which is influenced indirectly by palm richness and climate. We also uncover a latitudinal gradient in trait matching strength, which increases towards the tropics and varies among zoogeographic realms. Taken together, our results suggest trophic interactions have consistent influences on trait structure, but that abiotic, biogeographic and richness effects also play important, though sometimes indirect, roles in shaping the functional biogeography of mutualisms. [ABSTRACT FROM AUTHOR]

Microbial biogeography has predominantly been studied through a taxonomic lens. However, functional properties of microbial communities are often decoupled from their taxonomic compositions, emphasizing the need to study the biogeography of microbial functional genes directly.Here, using the Pearl River Estuary (PRE) sediments as a study system, we characterized the biogeographical patterns of the diversities and abundances of key microbial nitrogen‐cycling genes using metagenomic techniques.We found that functional genes involved in denitrification and dissimilatory nitrate reduction to ammonium pathways were more diverse and abundant than genes involved in other processes (i.e. nitrogen fixation, nitrification, assimilatory nitrite reduction). The diversities and abundances of certain nitrogen‐cycling genes were, to some extent, spatially decoupled. Specifically, the diversities of narG, napA, nirK and nrfA were greater adjacent to the river outlet, whereas the abundances of narG, napA and norB were greater in the downstream of the PRE. These spatial variations were mainly driven by water depth, C/N and NH4+.Moreover, nitrogen‐cycling genes involved in the same pathways (e.g. denitrification) showed no consistent responses to environmental changes and the main taxa involved in different nitrogen‐cycling steps were diverse, providing important clues for explaining why the abundance of single functional gene often seems not to be a reliable proxy for the specific process rate. Overall, our results demonstrate that studying the biogeography of microbial functional genes can help expand our knowledge of the nitrogen cycle from a biogeographical perspective. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Leaf traits play key roles in plant resource acquisition and ecosystem processes; however, whether the effects of environment and phylogeny on leaf traits differ between herbaceous and woody species remains unclear. To address this, in this study, we collected data for five key leaf traits from 1,819 angiosperm species across 530 sites in China. The leaf traits included specific leaf area, leaf dry matter content, leaf area, leaf N concentration, and leaf P concentration, all of which are closely related to trade-offs between resource uptake and leaf construction. We quantified the relative contributions of environment variables and phylogeny to leaf trait variation for all species, as well as for herbaceous and woody species separately. We found that environmental factors explained most of the variation (44.4–65.5%) in leaf traits (compared with 3.9–23.3% for phylogeny). Climate variability and seasonality variables, in particular, mean temperature of the warmest and coldest seasons of a year (MTWM/MTWQ and MTCM/MTCQ) and mean precipitation in the wettest and driest seasons of a year (MPWM/MPWQ and MPDM/MPDQ), were more important drivers of leaf trait variation than mean annual temperature (MAT) and mean annual precipitation (MAP). Furthermore, the responses of leaf traits to environment variables and phylogeny differed between herbaceous and woody species. Our study demonstrated the different effects of environment variables and phylogeny on leaf traits among different plant growth forms, which is expected to advance the understanding of plant adaptive strategies and trait evolution under different environmental conditions. [ABSTRACT FROM AUTHOR]

Leaf traits play key roles in plant resource acquisition and ecosystem processes; however, whether the effects of environment and phylogeny on leaf traits differ between herbaceous and woody species remains unclear. To address this, in this study, we collected data for five key leaf traits from 1,819 angiosperm species across 530 sites in China. The leaf traits included specific leaf area, leaf dry matter content, leaf area, leaf N concentration, and leaf P concentration, all of which are closely related to trade-offs between resource uptake and leaf construction. We quantified the relative contributions of environment variables and phylogeny to leaf trait variation for all species, as well as for herbaceous and woody species separately. We found that environmental factors explained most of the variation (44.4–65.5%) in leaf traits (compared with 3.9–23.3% for phylogeny). Climate variability and seasonality variables, in particular, mean temperature of the warmest and coldest seasons of a year (MTWM/MTWQ and MTCM/MTCQ) and mean precipitation in the wettest and driest seasons of a year (MPWM/MPWQ and MPDM/MPDQ), were more important drivers of leaf trait variation than mean annual temperature (MAT) and mean annual precipitation (MAP). Furthermore, the responses of leaf traits to environment variables and phylogeny differed between herbaceous and woody species. Our study demonstrated the different effects of environment variables and phylogeny on leaf traits among different plant growth forms, which is expected to advance the understanding of plant adaptive strategies and trait evolution under different environmental conditions.

Forest understories play a vital role in ecosystem functioning and the provision of ecosystem services. However, the extent to which environmental conditions drive dominant ecological strategies in forest understories at the continental scale remains understudied. Here, we used ~29 500 forest vegetation plots sampled across Europe and classified into 25 forest types to explore the relative role of macroclimate, soil pH and tree canopy cover in driving abundance‐weighted patterns in the leaf economic spectrum (LES) and plant size spectrum (PSS) of forest understories (shrub and herb layers). We calculated LES using specific leaf area (SLA) and leaf dry matter content (LDMC) and PSS using plant height and seed mass of vascular plant species found in the understories. We found that forest understories had more conservative leaf economics in areas with more extreme mean annual temperatures (mainly Fennoscandia and the Mediterranean Basin), more extreme soil pH and under more open canopies. Warm and summer‐dry regions around the Mediterranean Basin and areas of Atlantic Europe also had taller understories with heavier seeds than continental temperate or boreal areas. Understories of broadleaved deciduous forests, such as Fagus forests on non‐acid soils, or ravine forests, more commonly hosted species with acquisitive leaf economics. In contrast, some coniferous forests, such as Pinus, Larix and Picea mire forests, or Pinus sylvestris light taiga and sclerophyllous forests, more commonly hosted species with conservative leaf economics. Our findings highlight the importance of macroclimate and soil factors in driving trait variation of understory communities at the continental scale and the mediator effect of canopy cover on these relationships. We also provide the first maps and analyses of LES and PSS of forest understories across Europe and give evidence that the understories of European forest types are differently positioned along major axes of trait variation. [ABSTRACT FROM AUTHOR]

Questions: Documenting the patterns and drivers of functional trait distributions at large spatial scales is key to our fundamental understanding of the composition of plant assemblages. However, phylogeographic patterns of fruit development time (FDT, the difference between flowering and fruiting dates) have remained unstudied. Here we compiled reproductive phenology (flowering and fruiting time) and species distribution data for 6838 angiosperm species in China to explore whether FDT is more phylogenetically conserved as latitude and elevation increase, whether the phylogenetic signal of FDT correlates with phylogenetic structure and potential climatic drivers across China, and whether the environmental determinants of phylogenetic signal of FDT differ between herbaceous and woody species. Location: China Methods: We divided China into 268 200 × 200 km grid cells and calculated the phylogenetic signals of FDT in each grid cell using pagel’s λ. We then regressed the phylogenetic signals of FDT as a function of either latitude or elevation, individually. We examined the relationship between phylogenetic signals of FDT and climate variables using both ordinary and spatial linear regressions. We also examined the relationship between the phylogenetic signal of FDT and either net relatedness index (NRI) or clade age of each grid-cell. Results: We found that phylogenetic signals in FDT increased as elevation and latitude increased. The Pagel’s λ of FDT was negatively correlated with clade age but positively correlated with NRI. Precipitation in the wettest quarter was the primary variable affecting the phylogenetic signal for herbaceous species, while minimum temperature of the coldest month and temperature seasonality were the two most important climatic factors for woody species. Conclusions: Strength of phylogenetic conservatism of FDT is greater at higher latitudes and elevations. The latitudinal and elevational patterns, where mean clade age of species lowers as temperature decreases, and angiosperm assemblages tend to be more phylogenetically clustered at higher elevations and higher latitudes, could be explained by the Tropical Niche Conservatism hypothesis. The phylogenetic signals of herbs and of woody plants are triggered by different climatic drivers. Our findings have important implications for the study of large-scale geographical gradients in plant species richness, phylogenetic diversity and community assembly.

Questions: How is community functional composition associated with environmental and historical factors and how is this relationship mediated by spatial and phylogenetic autocorrelation? Location: Atlantic Forest of South America. Methods: We compiled abundance data of 2,122 species (most trees) distributed across 281 communities, seven functional traits, and 29 environmental and historical predictors. We mapped traits using community-weighted means, and related traits to predictors by combining the fourth-corner and the extended RLQ approaches. Results: We found that decreases in rainfall, soil nutrition, biome stability in the last 120 kyr, and the increase in thermal variability were associated with high specific leaf area (SLA) and leaf N content, and reduced leaf thickness. In addition, increased temperature and soil sand content, and low biome stability in the last 21 kyr were associated with high wood density and leaf dry matter content, and reduced maximum plant height. Tree communities rich in taxa with N-rich thin leaves and high SLA were mostly located in semideciduous and deciduous forests (e.g., Fabaceae), while communities rich in taxa with N-poor thick leaves and low SLA were mostly found in rain forests (e.g., Myrtaceae and Lauraceae). Species with short stature, high wood density and heavy leaves were particularly abundant in the northern part of the Atlantic Forest (e.g., Myrtaceae), whereas tall species with light wood and leaves were abundant in the south (e.g., Lauraceae). There was not a particular direction in which seed dry mass increased most in response to predictors. Conclusions: Our study reinforces the view that the multifaceted nature of community assembly needs analytical approaches that integrate abundance, functional, phylogenetic, and spatial data to properly understand how environmental and historical factors determine the dominance of functional traits. The observed patterns suggest that different regions of a given biome function in different ways, and probably provide different ecosystem services. [ABSTRACT FROM AUTHOR]

Aim: Species with widespread distributions offer excellent opportunities for investigating recent biogeographical patterns across broad scales. Here, we tested the hypothesis that, due to its intermediate geographical location, NW Africa is pivotal in explaining the phylogeographical patterns of taxa with Mediterranean–Macaronesian distributions using a legume species with short generation times. Location: Mediterranean, with a focus on NW Africa and the Canary Islands. Taxon: Pitch trefoil (Bituminaria bituminosa). Methods: We generated genetic data and performed phylogeographical and demographic analyses at two geographical scales: Mediterranean Basin (MB), using plastid sequences (115 individuals), and Macaronesia, using plastid sequences (182 individuals) and 10 nuclear microsatellite loci (220 individuals). We also performed a literature survey focusing on phylogeographical studies of other circum‐Mediterranean taxa. Results: Northwest Africa was identified as a centre of genetic diversity (19 out of 38 haplotypes) and demographic expansion of B. bituminosa in the MB during the Pleistocene. Our literature review revealed two main phylogeographical patterns in widespread species: pre‐Mediterranean evergreen sclerophylls versus Pleistocene facultative‐deciduous (including Bituminaria) taxa, but on average, both functional groups show a similar, large genetic diversity (~40% of haplotypes) in NW Africa. At the Macaronesian scale, we found that Canarian Bituminaria is composed of two genetic sublineages that coexist and hybridize on the central islands and in the mainland Macaronesian enclave (Anti‐Atlas region). Demographic analyses rejected the progression rule as the model of island colonization but strongly suggested that Anti‐Atlas populations are the result of back‐colonization from the easternmost islands before the Last Glacial Maximum (LGM). Conclusions: Bituminaria displays a pattern of Quaternary eastward expansion in the MB that appears to be paralleled by several members of its functional plant group. Thus, our study reveals a previously undescribed dual role of NW Africa in plant biogeography, acting both as a source of species expansion to the rest of the MB and a LGM refugium of plant populations with a Macaronesian island origin. [ABSTRACT FROM AUTHOR]

Climate‐induced changes in the ocean and sea ice environment of the Arctic are beginning to generate major and rapid changes in Arctic ecosystems, but the effects of directional forcing on the persistence and distribution of species remain poorly understood. Here, we examine the reproductive traits and population dynamics of the bivalve Astarte crenata and sea star Ctenodiscus crispatus across a north–south transect that intersects the polar front in the Barents Sea. Both species present large oocytes indicative of short pelagic or direct development that do not differ in size–frequency between 74.5 and 81.3º latitude. However, despite gametogenic maturity, we found low frequencies of certain size classes within populations that may indicate periodic recruitment failure. We suggest that recruitment of A. crenata could occur periodically when conditions are favorable, while populations of C. crispatus are characterized by episodic recruitment failures. Pyloric caeca indices in C. crispatus show that food uptake is greatest at, and north of, the polar front, providing credence to the view that interannual variations in the quantity and quality of primary production and its flux to the seafloor, linked to the variable extent and thickness of sea ice, are likely to be strong determinants of physiological fitness. Our findings provide evidence that the distribution and long‐term survival of species is not only a simple function of adaptive capacity to specific environmental changes, but will also be contingent on the frequency and occurrence of years where environmental conditions support reproduction and settlement. [ABSTRACT FROM AUTHOR]

Southwestern Australia (SWA) is a global biodiversity hotspot characterized by a mediterranean climate and is among the world's oldest and resource-poorest landscapes. Within this region, granite outcrops provide habitat complexity, and contribute to high levels of species diversity and endemism. Granite outcrop plant species are characterized by distinct anatomical, morphological and eco-physiological traits. So far, functional studies of SWA granite outcrop plants examined trait patterns along the stark aridity gradient that occurs in the region. Despite precipitation seasonality being an important climatic driver of plant species richness and distribution in mediterranean-type ecosystems, relationships between plant traits and precipitation seasonality remain understudied. Here, we investigated granite outcrop species' responses to changes in precipitation seasonality in terms of average and variability values of leaf traits related to water use efficiency. We found that plants displayed more acquisitive and variable trait values with increasing precipitation seasonality. These patterns are likely associated with the long-term effect of the stable and predictable precipitation regime in the old SWA that may have fine-tuned plant water use strategies to maximize water acquisition during the most favourable season. [ABSTRACT FROM AUTHOR]

Patterns of plant trait variation across spatial scales are important for understanding ecosystem functioning and services. However, habitat-related drivers of these patterns are poorly understood. In a conceptual model, we ask whether and how the patterns of within- and among-site plant trait variation are driven by habitat type (terrestrial vs. wetland) across large climatic gradients. We tested these through spatial-hierarchical-sampling of leaves in herbaceous-dominated terrestrial and wetland communities within each of 26 sites across China. For all 13 plant traits, within-site variation was larger than among-site variation in both terrestrial and wetland habitats. Within-site variation was similar in most leaf traits related to carbon and nutrient economics but larger in specific leaf area and size-related traits (plant height, leaf area and thickness) in wetland compared to terrestrial habitats. Among-site variation was larger in terrestrial than wetland habitats for 10 leaf traits but smaller for plant height, leaf area and leaf nitrogen. Our results indicate the important role of local ecological processes in driving plant trait variation among coexisting species and the dependence of functional variation across habitats on traits considered. These findings will help to understand and predict the effects of climatic or land-use changes on ecosystem functioning and services. [ABSTRACT FROM AUTHOR]

The timing of flowering is an important driver of species distribution and community assembly patterns. However, we still have much to learn about the factors that shape flowering diversity (i.e., number of species flowering per period) in plant communities. One potential explanation of flowering diversity is the mid-domain effect, which states that geometric constraints on species ranges within a bounded domain (space or time) will yield a mid-domain peak in diversity regardless of ecological factors. Here, we determine whether the mid-domain effect explains peak flowering time (i.e., when most species of communities are flowering) across China. We used phenological data of 16,267 herbaceous and woody species from the provincial Flora in China and species distribution data from the Chinese Vascular Plant Distribution Database to determine relationships between the observed number of species flowering and the number of species flowering as predicted by the mid-domain effect model, as well as between three climatic variables (mean minimum monthly temperature, mean monthly precipitation, and mean monthly sunshine duration). We found that the mid-domain effect explained a significant proportion of the temporal variation in flowering diversity across all species in China. Further, the mid-domain effect explained a greater proportion of variance in flowering diversity at higher latitudes than at lower latitudes. The patterns of flowering diversity for both herbaceous and woody species were related to both the mid-domain effect and environmental variables. Our findings indicate that including geometric constraints in conjunction with abiotic and biotic predictors will improve predictions of flowering diversity patterns., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.)

Motivation: Trait data are fundamental to the quantitative description of plant form and function. Although root traits capture key dimensions related to plant responses to changing environmental conditions and effects on ecosystem processes, they have rarely been included in large‐scale comparative studies and global models. For instance, root traits remain absent from nearly all studies that define the global spectrum of plant form and function. Thus, to overcome conceptual and methodological roadblocks preventing a widespread integration of root trait data into large‐scale analyses we created the Global Root Trait (GRooT) Database. GRooT provides ready‐to‐use data by combining the expertise of root ecologists with data mobilization and curation. Specifically, we (a) determined a set of core root traits relevant to the description of plant form and function based on an assessment by experts, (b) maximized species coverage through data standardization within and among traits, and (c) implemented data quality checks. Main types of variables contained: GRooT contains 114,222 trait records on 38 continuous root traits. Spatial location and grain: Global coverage with data from arid, continental, polar, temperate and tropical biomes. Data on root traits were derived from experimental studies and field studies. Time period and grain: Data were recorded between 1911 and 2019. Major taxa and level of measurement: GRooT includes root trait data for which taxonomic information is available. Trait records vary in their taxonomic resolution, with subspecies or varieties being the highest and genera the lowest taxonomic resolution available. It contains information for 184 subspecies or varieties, 6,214 species, 1,967 genera and 254 families. Owing to variation in data sources, trait records in the database include both individual observations and mean values. Software format: GRooT includes two csv files. A GitHub repository contains the csv files and a script in R to query the database. [ABSTRACT FROM AUTHOR]

Aim: One of the main goals of functional biogeography is to examine distribution patterns of trait diversity, and islands provide excellent study cases for this emerging field. We tested the hypothesis that multiple dispersals from a common mainland pool would promote functional similarity among island systems when environmental conditions are similar, but also novel phenotypic traits related to colonization history and exploitation of new habitats. Location: Mediterranean Basin and Macaronesian islands. Taxon: Wolfbane (Periploca laevigata) Methods: We used the well‐known biogeographical history of a woody plant complex (P. laevigata s.l.) to examine trait variation and how it relates to climatic conditions of mainland and subtropical island settings. In a common garden experiment, we measured a suite of leaf physiological and anatomical traits tightly related to plant performance in 320 seedlings representing 21 populations of five sublineages—the oldest (2.6 my) island colonization (western Canary Islands) as a reference, three sublineages stemming from independent events of island colonization in the last 0.5 my from NW Africa (Cape Verde, Fuerteventura, Lanzarote) and their widespread Mediterranean mainland counterpart. Results: We observed strong phenotypic divergence between island and mainland sublineages linked to contrasting climatic conditions. Mediterranean mainland populations displayed a very specialized leaf phenotype characteristic of arid plants (i.e. small leaves, amphistomaty, isobilateral mesophyll, high photosynthetic rates). In turn, low seasonality on islands was linked to the recurrent expression of a phenotype characterized by larger leaves and lower photosynthetic rates. Our analyses showed that the high investment in secondary compounds (i.e. tannins) on islands decouples photosynthesis from growth rates. Despite this pattern of parallel differentiation, each island sublineage displayed a distinctive phenotype, with some traits related to colonization time, which resulted in a mosaic of functional variation across island systems. Main conclusions: Our data suggest that the studied subtropical islands promote expression of traits specific to certain sublineages and other common traits that are no longer adaptive in the original mainland pool due to Pleistocene climatic shifts. These findings ultimately extend the role of islands as biodiversity refugia and hotspots of plant functional diversity. [ABSTRACT FROM AUTHOR]

Aim: The timing of reproduction is a major determinant of the geographical distribution of plant species and resulting patterns of community assembly, yet few studies have assessed how the reproductive phenology of plant assemblages varies across large geographical and environmental gradients. In addition, it remains poorly known to what extent phenological trends and their drivers differ between flowering and fruiting phases or among different growth forms. To address these knowledge gaps, we examined the reproductive phenology and potential climatic drivers in herbaceous and woody species in ecosystems across China that varied in climate (temperate to tropical) seasonality and elevation. Location: China. Methods: We used data from the Flora Republicae Popularis Sinicae to estimate angiosperm flowering (n = 16,717 species) and fruiting (n = 11,605) phenology for 100 x 100 km grid cells (n = 943) throughout China. We assessed large‐scale geographical trends in mean flowering and fruiting date and the time needed for fruit development. The relationships of these phenological variables with seven climate variables were examined using both ordinary and spatial linear regression. Results: Higher latitudes and elevations had considerably reduced length of the reproductive season, with later flowering and earlier fruiting than lower latitudes and elevations. Woody plant assemblages flowered markedly earlier and needed three times longer for fruit development, and tended to show steeper geographical trends in reproductive phenology than herbaceous assemblages. Herbs and woody species differed strongly in their climatic triggers of flowering but largely shared the same cues for fruiting. Main conclusions: Woody species compensate for longer seed development times by an earlier onset of flowering, yet reproduction in both life‐forms has stronger climatic constraints. Distinct climatic drivers suggest that herbaceous and woody species assemblages will respond differently to climate change. Overall, our findings underpin the role of reproductive phenology as a key biological mechanism through which climate shapes large‐scale geographical trends in species richness, phylogenetic diversity and community assembly. [ABSTRACT FROM AUTHOR]

Arctic marine ecosystems are undergoing rapid correction in response to multiple expressions of climate change, but the consequences of altered biodiversity for the sequestration, transformation and storage of nutrients are poorly constrained. Here, we determine the bioturbation activity of sediment-dwelling invertebrate communities over two consecutive summers that contrasted in sea-ice extent along a transect intersecting the polar front. We find a clear separation in community composition at the polar front that marks a transition in the type and amount of bioturbation activity, and associated nutrient concentrations, sufficient to distinguish a southern high from a northern low. While patterns in community structure reflect proximity to arctic versus boreal conditions, our observations strongly suggest that faunal activity is moderated by seasonal variations in sea ice extent that influence food supply to the benthos. Our observations help visualize how a climate-driven reorganization of the Barents Sea benthic ecosystem may be expressed, and emphasize the rapidity with which an entire region could experience a functional transformation. As strong benthic-pelagic coupling is typical across most parts of the Arctic shelf, the response of these ecosystems to a changing climate will have important ramifications for ecosystem functioning and the trophic structure of the entire food web. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'. [ABSTRACT FROM AUTHOR]

Aim: Macroecological studies have commonly used study‐specific subsets of taxa to calculate metrics of functional diversity (FD) and explore their spatial patterns. However, FD metrics can be biased if the functional space (FS) does not cover an extensive, common and representative range of trait variation. Here, we propose an overarching FS covering the widest range of European freshwater taxa and trait variation compiled to date for a better evaluation of macroecological FD patterns. Location: Six regions distributed from Morocco to Scandinavia. Time period: 2008. Major taxa studied: Major orders of European freshwater macroinvertebrates (541 taxa). Methods: FD metrics (functional richness, dispersion and evenness) were estimated on FSs covering three decreasing grain sizes of trait variation: an overarching European scale (541 taxa), a continental context‐dependent scale that covers six regions (180 taxa) and six regional scale FSs (63–108 taxa). Taxonomic richness and FD metrics were modelled over the latitudinal gradient. Null models were performed to assess if FD patterns were independent of taxonomic richness variation and to identify community assembly mechanisms (filtering or overdispersion) along the latitudinal gradient. Results: The scale at which FSs were calculated influenced the shape and strength of the latitudinal FD patterns. Continental or regional scale FSs captured different axes of trait variation associated with scale‐specific taxa composition. These FS axes and resulting FD metrics moderately or poorly represent those based on the overarching FS. Null model analysis revealed distinct latitudinal patterns for each FS and FD metric, which led to contrasting assembly mechanisms along latitude. Main conclusions: An overarching FS (a) captures a wide, common and more representative range of trait variation, (b) offers a more generalizable framework to explore large‐scale functional patterns and community assembly mechanisms, and (c) enhances the comparison of FD metrics across studies to obtain more reliable macroecological patterns. [ABSTRACT FROM AUTHOR]

Aims: Taller forest canopies may harbour higher biodiversity by providing more and varied resources. No previous studies have assessed whether forest canopy height shapes the taxonomic and functional diversity of terrestrial vertebrates at global and regional scales. Here, we examine the roles of forest canopy height and other environmental variables in shaping global and regional patterns of species richness and functional diversity of mammals and birds. Location: Global. Time period: Present day. Major taxa studied: Terrestrial mammals and birds. Methods: Global forest canopy height data at 1 km spatial resolution were used to measure forest vertical structure. Species richness, functional richness and functional dispersion of mammals and birds were calculated using range maps and trait data. Spatial simultaneous autoregressive error models were used to evaluate associations between species richness and functional diversity and their predictors, including mean canopy height, standard deviation of canopy height, net primary productivity, current climate and historical climate stability, topography and human activities. Results: Mean canopy height emerged as one of two predictors most associated with species richness of mammals and birds as well as mammal functional richness. However, mean canopy height had little explanatory power for functional dispersion. Mean annual temperature and net primary productivity contributed most to explain global‐scale mammal and bird functional dispersion. At the regional scale, mean canopy height, net primary productivity and mean annual temperature were the variables most associated with the species richness and functional diversity of mammals and birds. Main conclusions: Forest canopy height is an important predictor of species richness and functional diversity of terrestrial vertebrates at both global and regional scales, at a similar overall level to productivity and temperature. Our study highlights the crucial role of the complex vertical structure in shaping the global and regional patterns of vertebrate diversity. [ABSTRACT FROM AUTHOR]

Aim: The Hutchinsonian niche is a foundational concept in ecology and evolutionary biology that describes fundamental characteristics of any species: the global maximum population growth rate (rmax); the niche optimum (the environment for which rmax is reached); and the niche width (the environmental range for which intrinsic population growth rates are positive). We examine whether these characteristics are related to inter‐ and intraspecific variation in functional traits. Location: Cape Floristic Region, South Africa. Time period: Present day. Major taxa studied: Twenty‐six plant species (Proteaceae). Methods: We measured leaf, plant‐architectural and seed traits across species geographical ranges. We then examined how species‐mean traits are related to demographically derived niche characteristics of rmax, in addition to niche optima and widths in five environmental dimensions, and how intraspecific trait variation is related to niche widths. Results: Interspecific trait variation generally exceeded range‐wide intraspecific trait variation. Species‐mean trait values were associated with variation in rmax (R2 = 0.27) but were more strongly related to niche optima (mean R2 = 0.56). These relationships generally matched trait–environment associations described in the literature. Both species‐mean traits and intraspecific trait variability were strongly related to niche widths (R2 = 0.66 and 0.59, respectively). Moreover, niche widths increased with intraspecific trait variability. Overall, the different niche characteristics were associated with few, largely non‐overlapping sets of traits. Main conclusions: Our study relating functional traits to Hutchinsonian niches demonstrates that key demographic properties of species relate to few traits with relatively strong effects. Our results further support the hypothesis that intraspecific trait variation increases species niche widths. Given that niche characteristics were related to distinct sets of traits, different aspects of environmental change might affect axes of trait variation independently. Trait‐based studies of Hutchinsonian niches thus yield important insights into the mechanisms shaping functional biodiversity, which should reinforce the role of traits in functional biogeography. [ABSTRACT FROM AUTHOR]

Interpreting the biogeographic distribution and underlying mechanisms of functional traits not only contributes to revealing the spatiotemporal dynamics of species biodiversity but also helps to maintain ecological stability during environmental variations. However, little is known about the functional profiles of diatom communities over large river systems. Herein, we provided the first blueprints about the spatiotemporal distributions and driving forces of functional traits for both planktonic and sedimentary diatoms over the 6030 km continuum of the Yangtze River, with the help of the high-throughput sequencing and functional identification. By investigating the 28 functional traits affiliated into five categories, we found that planktonic diatom functions showed clearer landform-heterogeneity patterns (ANOSIM R = 0.336) than sedimentary functions (ANOSIM R = 0.172) along the river, represented by life-forms and ecological-guilds prominent in water-plateau as well as cell-sizes and life-forms particularly in sediment-plateau. Planktonic diatom functions also displayed higher richness and network complexity in plateau (richness: 58.70 ± 9.30, network edges: 65) than in non-plateau regions (23.82 ± 13.16, 16), promoting the stability and robustness of diatom functions against the high-radiation and low-temperature plateau environment. Environmental selection (mainly exerted by PAR, UV, and Tw) played crucial roles in determining the functional variations of planktonic diatoms (explaining 80.5%) rather than sedimentary diatoms (14.5%) between plateau and non-plateau regions. Meanwhile, planktonic diatom traits within life-forms were identified to be well responsive to the ecological environment quality (r = 0.56–0.60, P < 0.001) in the Yangtze. This study provided comprehensive insights into the multifunctionality of diatoms and their responses to environmental disturbance and environment quality, which helps to develop effective strategies for maintaining ecological stability in changing river environments. [Display omitted] • Diatoms exhibited strong relationships between taxonomy and function. • Planktonic diatom functions showed clearer landform-heterogeneity patterns. • Planktonic diatom functions displayed higher richness and complexity in plateau. • Planktonic diatom functions were more related to environmental selection. • Planktonic diatom functions well responded to the ecological environment quality. [ABSTRACT FROM AUTHOR]