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Summary: Relationships between crop genetic and functional diversity are key to addressing contemporary agricultural challenges. Yet, there are few approaches for quantifying the relationship between genetic diversity and crop functional trait expression. Here, we introduce 'functional space accumulation curves' to analyze how trait space increases with the number of crop genotypes within a species.We explore the potential for functional space accumulating curves to quantify genotype–trait space relationships in four common annual crop species: barley (Hordeum vulgare), rice (Oryza sativa), soybean (Glycine max), and durum wheat (Triticum durum). We also employ these curves to describe genotype–trait space relationships in the wild annual Arabidopsis thaliana, which has not been subjected to artificial selection.All five species exhibited asymptotic functional space accumulation curves, suggesting a limit to intraspecific functional crop diversity, likely due to: dominant phenotypes represented by several genotypes; or functional redundancy that might exist among genotypes. Our findings indicate that there is a diminishing return of functional diversity with increasing number of genotypes.Our analysis demonstrates the efficacy of functional space accumulation curves in quantifying trait space occupancy of crops, with implications for managing crop diversity in agroecosystems, and genetic diversity in crop breeding programs. [ABSTRACT FROM AUTHOR]

Background: Leaf nitrogen (N) and phosphorus (P) resorption is a fundamental adaptation strategy for plant nutrient conservation. However, the relative roles that environmental factors and plant functional traits play in regulating N and P resorption remain largely unclear, and little is known about the underlying mechanism of plant functional traits affecting nutrient resorption. Here, we measured leaf N and P resorption and 13 plant functional traits of leaf, petiole, and twig for 101 representative broad-leaved tree species in our target subtropical transitional forests. We integrated these multiple functional traits into the plant economics spectrum (PES). We further explored whether and how elevation-related environmental factors and these functional traits collectively control leaf N and P resorption. Results: We found that deciduous and evergreen trees exhibited highly diversified PES strategies, tending to be acquisitive and conservative, respectively. The effects of PES, rather than of environmental factors, dominated leaf N and P resorption patterns along the elevational gradient. Specifically, the photosynthesis and nutrient recourse utilization axis positively affected N and P resorption for both deciduous and evergreen trees, whereas the structural and functional investment axis positively affected leaf N and P resorption for evergreen species only. Specific leaf area and green leaf nutrient concentrations were the most influential traits driving leaf N and P resorption. Conclusions: Our study simultaneously elucidated the relative contributions of environmental factors and plant functional traits to leaf N and P resorption by including more representative tree species than previous studies, expanding our understanding beyond the relatively well-studied tropical and temperate forests. We highlight that prioritizing the fundamental role of traits related to leaf resource capture and defense contributes to the monitoring and modeling of leaf nutrient resorption. Therefore, we need to integrate PES effects on leaf nutrient resorption into the current nutrient cycling model framework to better advance our general understanding of the consequences of shifting tree species composition for nutrient cycles across diverse forests. [ABSTRACT FROM AUTHOR]

Ecological processes such as environmental filtering and biotic interactions that shape species' traits and community diversity often vary with geographic distance, potentially generating spatial structures in trait variation, covariation and biodiversity data. Understanding spatial structures of trait, environment and biodiversity, or the spatial link between those factors, is fundamental to identifying spatially explicit assembly processes or biodiversity distributions in spatially heterogeneous landscapes but remains unclear.To address the issue, we gathered individual‐level leaf and diameter traits data paired with environmental data from a 4.8 ha subtropical Chinese forest and divided the forest into 25, 100, 400 and 1936 m2 grids representing contrasting spatial grains. Using Moran's correlograms, we quantified the spatial structures of trait variation and covariation, environmental conditions and biodiversity. We assessed the links between those variables using path analyses.Most variables were spatially positively autocorrelated. However, trait mean was more autocorrelated than trait variation or covariation, and intraspecific trait variation was more autocorrelated than interspecific variation. Autocorrelations in those community properties were generally weak at the large grain.Path analyses indicated positive associations between interspecific trait variation and species diversity at a very small to medium scale and a positive association between intraspecific variation and small‐scale functional diversity. Trait covariation constrained biodiversity, and multi‐trait means were negatively linked to very small‐ to medium‐scale species diversity but positively to medium‐ and large‐scale functional diversity. Patterns regarding multi‐trait community structure–environment–biodiversity associations were generally held for individual traits. However, depending on the trait, spatial scale and plant ontogenic stage, the pattern's strength changed, or occasionally, their sign reversed.We attribute spatial patterns in multi‐trait mean and covariation to scale‐dependent variation in environmental heterogeneity and trait variation to scale‐dependent competition.Synthesis. Our study provides novel insights into spatial and scale‐dependent variability in functional community structure, environment and biodiversity, and their relationships. Our results demonstrate the usefulness of spatial trait analyses in identifying scale‐dependent assembly processes or finding the importance of processes to biodiversity distributions in spatially heterogeneous landscapes. A spatially explicit perspective is thus helpful for the progress of trait ecology. [ABSTRACT FROM AUTHOR]

Aims: The Raunkiær's system classifies vascular plants into life forms based on the position of renewal buds during periods unfavourable for plant growth. Despite the importance of Raunkiær's system for ecological research, a study exploring the diversity and distribution of life forms on a continental scale is missing. We aim to (i) map the diversity and distribution of life forms in European vegetation and (ii) test for effects of bioclimatic variables while controlling for habitat‐specific responses. Location: Europe. Methods: We used data on life forms of 8883 species recorded in 546,501 vegetation plots of different habitats (forest, grassland, scrub and wetland). For each plot, we calculated: (i) the proportion of species of each life form and (ii) the richness and evenness of life forms. We mapped these plot‐level metrics averaged across 50 km × 50 km grid cells and modelled their response to bioclimatic variables. Results: Hemicryptophytes were the most widespread life form, especially in the temperate zone of Central Europe. Conversely, therophyte and chamaephyte species were more common in the Mediterranean as well as in the dry temperate regions. Moreover, chamaephytes were also more common in the boreal and arctic zones. Higher proportions of phanerophytes were found in the Mediterranean. Overall, a higher richness of life forms was found at lower latitudes while evenness showed more spatially heterogeneous patterns. Habitat type was the main discriminator for most of the responses analysed, but several moisture‐related predictors still showed a marked effect on the diversity of therophytes and chamaephytes. Conclusions: Our maps can be used as a tool for future biogeographic and macro‐ecological research at a continental scale. Habitat type and bioclimatic conditions are key for regulating the diversity and distribution of plant life forms, with concomitant consequences for the response of functional diversity in European vegetation to global environmental changes. [ABSTRACT FROM AUTHOR]

Summary: The exploration of phenotypic spaces of large sets of plant species has considerably increased our understanding of diversification processes in the plant kingdom. Nevertheless, such advances have predominantly relied on interspecific comparisons that hold several limitations.Here, we grew in the field a unique set of 179 inbred lines of durum wheat, Triticum turgidum spp. durum, characterized by variable degrees of artificial selection. We measured aboveground and belowground traits as well as agronomic traits to explore the functional and agronomic trait spaces and to investigate trait‐to‐agronomic performance relationships.We showed that the wheat functional trait space shared commonalities with global cross‐species spaces previously described, with two main axes of variation: a root foraging axis and a slow–fast trade‐off axis. Moreover, we detected a clear signature of artificial selection on the variation of agronomic traits, unlike functional traits. Interestingly, we identified alternative phenotypic combinations that can optimize crop performance.Our work brings insightful knowledge about the structure of phenotypic spaces of domesticated plants and the maintenance of phenotypic trade‐offs in response to artificial selection, with implications for trade‐off‐free and multi‐criteria selection in plant breeding. [ABSTRACT FROM AUTHOR]

Summary: Knowledge about changes in plant functional traits is valuable for the mechanistic understanding of warming effects on ecosystem functions. However, observations have tended to focus on aboveground plant traits, and there is little information about changes in belowground plant traits or the coordination of above‐ and belowground traits under climate warming, particularly in permafrost ecosystems.Based on a 7‐yr field warming experiment, we measured 26 above‐ and belowground plant traits of four dominant species, and explored community functional composition and trait networks in response to experimental warming in a permafrost ecosystem on the Tibetan Plateau.Experimental warming shifted community‐level functional traits toward more acquisitive values, with earlier green‐up, greater plant height, larger leaves, higher photosynthetic resource‐use efficiency, thinner roots, and greater specific root length and root nutrient concentrations. However, warming had a negligible effect in terms of functional diversity. In addition, warming shifted hub traits which have the highest centrality in the network from specific root area to leaf area.These results demonstrate that above‐ and belowground traits exhibit consistent adaptive strategies, with more acquisitive traits in warmer environments. Such changes could provide an adaptive advantage for plants in response to environmental change. See also the Commentary on this article by Spitzer & Blume-Werry, 240: 1712–1713. [ABSTRACT FROM AUTHOR]

Aim: Globally distributed plant trait data are increasingly used to understand relationships between biodiversity and ecosystem processes. However, global trait databases are sparse because they are compiled from many, mostly small databases. This sparsity in both trait space completeness and geographical distribution limits the potential for both multivariate and global analyses. Thus, 'gap‐filling' approaches are often used to impute missing trait data. Recent methods, like Bayesian hierarchical probabilistic matrix factorization (BHPMF), can impute large and sparse data sets using side information. We investigate whether BHPMF imputation leads to biases in trait space and identify aspects influencing bias to provide guidance for its usage. Innovation: We use a fully observed trait data set from which entries are randomly removed, along with extensive but sparse additional data. We use BHPMF for imputation and evaluate bias by: (1) accuracy (residuals, RMSE, trait means), (2) correlations (bi‐ and multivariate) and (3) taxonomic and functional clustering (valuewise, uni‐ and multivariate). BHPMF preserves general patterns of trait distributions but induces taxonomic clustering. Data set–external trait data had little effect on induced taxonomic clustering and stabilized trait–trait correlations. Main Conclusions: Our study extends the criteria for the evaluation of gap‐filling beyond RMSE, providing insight into statistical data structure and allowing better informed use of imputed trait data, with improved practice for imputation. We expect our findings to be valuable beyond applications in plant ecology, for any study using hierarchical side information for imputation. [ABSTRACT FROM AUTHOR]

Background and Aims Plants can respond to drought by changing their relative investments in the biomass and morphology of each organ. The aims of this study were to quantify the relative contribution of changes in morphology vs. allocation and determine how they affect each other. These results should help us understand the mechanisms that plants use to respond to drought events. Methods In a glasshouse experiment, we applied a drought treatment (well-watered vs. drought) at early and late stages of plant growth, leading to four treatment combinations (well-watered in both early and late periods, WW; drought in the early period and well-watered in the late period, DW; well-watered in the early period and drought in the late period, WD; drought in both early and late periods, DD). We used the variance partitioning method to compare the contribution of organ (leaf and root) biomass allocation and morphology to the leaf area ratio, root length ratio and root area ratio, for the rhizomatous grass Leymus chinensis (Trin.) Tzvelev. Key Results Compared with the continuously well-watered treatment, the leaf area ratio, root length ratio and root area ratio showed increasing trends under various drought treatments. The contribution of leaf mass allocation to leaf area ratio differed among the drought treatments and was 2.1- to 5.3-fold greater than leaf morphology, and the contribution of root mass allocation to root length ratio was ~2-fold greater than that of root morphology. In contrast, root morphology contributed more to the root area ratio than biomass allocation under drought in both the early and late periods. There was a negative correlation between the ratio of leaf mass fraction to root mass fraction and the ratio of specific leaf area to specific root length (or specific root area). Conclusions This study suggested that organ biomass allocation drove a larger proportion of variation than morphological traits for the absorption of resources in this rhizomatous grass. These findings should help us understand the adaptive mechanisms of plants when they are confronted with drought stress. [ABSTRACT FROM AUTHOR]

Plant ecologists and molecular biologists have long considered the hypothesis of a trade-off between plant growth and defence separately. In particular, how genes thought to control the growth–defence trade-off at the molecular level relate to trait-based frameworks in functional ecology, such as the slow–fast plant economics spectrum, is unknown. We grew 49 phenotypically diverse rice genotypes in pots under optimal conditions and measured growth-related functional traits and the constitutive expression of 11 genes involved in plant defence. We also quantified the concentration of silicon (Si) in leaves to estimate silica-based defences. Rice genotypes were aligned along a slow–fast continuum, with slow-growing, late-flowering genotypes versus fast-growing, early-flowering genotypes. Leaf dry matter content and leaf Si concentrations were not aligned with this axis and negatively correlated with each other. Live-fast genotypes exhibited greater expression of OsNPR1 , a regulator of the salicylic acid pathway that promotes plant defence while suppressing plant growth. These genotypes also exhibited greater expression of SPL7 and GH3.2 , which are also involved in both stress resistance and growth. Our results do not support the hypothesis of a growth–defence trade-off when leaf Si and leaf dry matter content are considered, but they do when hormonal pathway genes are considered. We demonstrate the benefits of combining ecological and molecular approaches to elucidate the growth–defence trade-off, opening new avenues for plant breeding and crop science. [ABSTRACT FROM AUTHOR]

The Cretaceous–Palaeogene (K-Pg) extinction of the non-avian dinosaurs (66 Ma) led to a 25 million year gap of megaherbivores (>1000 kg) before the evolution of megaherbivorous mammals in the Late Eocene (40 Ma). The botanical consequences of this 'Palaeocene megaherbivore gap' (PMHG) remain poorly explored. We hypothesize that the absence of megaherbivores should result in changes in the diversification and trait evolution of associated plant lineages. We used phylogenetic time- and trait-dependent diversification models with palms (Arecaceae) and show that the PMHG was characterized by speciation slowdowns, decreased evolution of armature and increased evolution of megafaunal (≥4 cm) fruits. This suggests that the absence of browsing by megaherbivores during the PMHG may have led to a loss of defence traits, but the absence of megaherbivorous seed dispersers did not lead to a loss of megafaunal fruits. Instead, increases in PMHG fruit sizes may be explained by simultaneously rising temperatures, rainforest expansion, and the subsequent radiation of seed-dispersing birds and mammals. We show that the profound impact of the PMHG on plant diversification can be detected even with the overwriting of adaptations by the subsequent Late Eocene opening up of megaherbivore-associated ecological opportunities. Our study provides a quantitative, comparative framework to assess diversification and adaptation during one of the most enigmatic periods in angiosperm history. [ABSTRACT FROM AUTHOR]

Land‐use intensification is the main factor for the catastrophic decline of insect pollinators. However, land‐use intensification includes multiple processes that act across various scales and should affect pollinator guilds differently depending on their ecology. We aimed to reveal how two main pollinator guilds, wild bees and hoverflies, respond to different land‐use intensification measures, that is, arable field cover (AFC), landscape heterogeneity (LH), and functional flower composition of local plant communities as a measure of habitat quality. We sampled wild bees and hoverflies on 22 dry grassland sites within a highly intensified landscape (NE Germany) within three campaigns using pan traps. We estimated AFC and LH on consecutive radii (60–3000 m) around the dry grassland sites and estimated the local functional flower composition. Wild bee species richness and abundance was positively affected by LH and negatively by AFC at small scales (140–400 m). In contrast, hoverflies were positively affected by AFC and negatively by LH at larger scales (500–3000 m), where both landscape parameters were negatively correlated to each other. At small spatial scales, though, LH had a positive effect on hoverfly abundance. Functional flower diversity had no positive effect on pollinators, but conspicuous flowers seem to attract abundance of hoverflies. In conclusion, landscape parameters contrarily affect two pollinator guilds at different scales. The correlation of landscape parameters may influence the observed relationships between landscape parameters and pollinators. Hence, effects of land‐use intensification seem to be highly landscape‐specific. [ABSTRACT FROM AUTHOR]

Identifying patterns and drivers of plant community assembly has long been a central issue in ecology. Many studies have explored the above questions using a trait‐based approach; however, there are still unknowns around how patterns of plant functional traits vary with environmental gradients. In this study, the responses of individual and multivariate trait dispersions of 134 species to soil resource availability were examined based on correlational analysis and torus‐translation tests across four spatial scales in a subtropical forest, China. Results indicated that different degrees of soil resource availability had different effects on trait dispersions. Specifically, limited resource (available phosphorus) showed negative relationships with trait dispersions, non‐limited resource (available potassium) showed positive relationships with trait dispersions, and saturated resource (available nitrogen) had no effect on trait dispersions. Moreover, compared with the stem (wood density) and architectural trait (maximum height), we found that leaf functional traits can well reflect the response of plants to nutrient gradients. Lastly, the spatial scale only affected the magnitude but not the direction of the correlations between trait dispersions and environmental gradients. Overall, the results highlight the importance of soil resource availability and spatial scale in understanding how plant functional traits respond to environmental gradients. [ABSTRACT FROM AUTHOR]

Plant functional traits shape many ecosystem processes, including carbon sequestration in vegetation and soil. The shifts of trait-based indices can reflect changes in plant resource-use strategies during successional processes. The aim of this study was to determine how plant functional diversity affects carbon sequestration during secondary succession in semi-arid grassland, and how the limiting environmental factor (that is, soil water) affects these processes. We investigated 16 plots at three sites with different stand ages and climate conditions in the semi-arid area of the Loess Plateau, China. We measured the key plant functional traits: plant height; leaf dry matter content (LDMC); specific leaf area (SLA); leaf carbon (LC), nitrogen (LN), and phosphorus contents (LP); and ecosystem carbon components: aboveground biomass (AGB); root biomass (RB); and soil organic carbon stock (SOC). The community weighted mean (CWM) of LDMC increased and SLA and LN decreased with stand age at a wetter site, indicating that plants' resource-use strategy might shift from acquisition to conservation during succession. The exception of the shifting of CWM_SLA deviated from the general trend during succession can be attributed to the appearance of slow-growing species in the early successional stage at a drier site. The structural equation models (SEM) showed that stand age, soil water content (SWC) and functional diversity indices accounted for 55.7%, 53.2%, and 56.5% of variations in AGB, RB, and SOC during succession, respectively. The interplays of stand age and SWC were regulated by functional diversity indices, especially the CWMs of plant height and SLA, functional variance (FDvar) of plant height and functional evenness (FEve). Carbon stocks accumulated faster at wetter sites. Our results indicate that the mass ratio and niche complementary hypotheses are not contradictory in explaining relationships between community functional diversity and ecosystem carbon stocks during the restoration of semi-arid grasslands, and that SWC affects the progress of succession and carbon sequestration. [ABSTRACT FROM AUTHOR]

Background and aims: Plant growth strategies represent a gradient from slow to fast economic strategies. Rhizosphere microbiomes have a continual and profound impact on plant growth. However, our understanding of differences in plant economic spectrum among various crop varieties and their associations with rhizosphere microbiome remains limited.Here, pepper (Capsicum spp.) was employed as a model plant to examine the differentiation of 73 varieties in plant economic strategies. Meanwhile, this study explored the associations of economic strategy differentiation with rhizosphere microbiomes.The 73 varieties displayed significant differentiation in both above- and below-ground growth traits, enabling their growth classification into fast economic strategy (FES), medium economic strategy (MES), and slow economic strategy (SES). A significantly consistent distribution was observed among plant functional traits and rhizosphere microbial communities (bacteria and protists) of SES varieties, which was not discovered in FES varieties. Compared with FES varieties, the SES varieties exhibited a lower microbial diversity and community complexity. Pepper varieties with SES were more strongly correlated with their rhizosphere microbiomes compared to FES varieties. Rhizosphere microbial and community complexity indirectly regulated above-ground growth of SES varieties by affecting the root growth and nutrient uptake.Overall, these findings enhance our understanding of the connections between plant economic strategies and rhizosphere microbiomes, offering valuable insights into selection and popularization of exceptional Capsicum varieties.Methods: Plant growth strategies represent a gradient from slow to fast economic strategies. Rhizosphere microbiomes have a continual and profound impact on plant growth. However, our understanding of differences in plant economic spectrum among various crop varieties and their associations with rhizosphere microbiome remains limited.Here, pepper (Capsicum spp.) was employed as a model plant to examine the differentiation of 73 varieties in plant economic strategies. Meanwhile, this study explored the associations of economic strategy differentiation with rhizosphere microbiomes.The 73 varieties displayed significant differentiation in both above- and below-ground growth traits, enabling their growth classification into fast economic strategy (FES), medium economic strategy (MES), and slow economic strategy (SES). A significantly consistent distribution was observed among plant functional traits and rhizosphere microbial communities (bacteria and protists) of SES varieties, which was not discovered in FES varieties. Compared with FES varieties, the SES varieties exhibited a lower microbial diversity and community complexity. Pepper varieties with SES were more strongly correlated with their rhizosphere microbiomes compared to FES varieties. Rhizosphere microbial and community complexity indirectly regulated above-ground growth of SES varieties by affecting the root growth and nutrient uptake.Overall, these findings enhance our understanding of the connections between plant economic strategies and rhizosphere microbiomes, offering valuable insights into selection and popularization of exceptional Capsicum varieties.Results: Plant growth strategies represent a gradient from slow to fast economic strategies. Rhizosphere microbiomes have a continual and profound impact on plant growth. However, our understanding of differences in plant economic spectrum among various crop varieties and their associations with rhizosphere microbiome remains limited.Here, pepper (Capsicum spp.) was employed as a model plant to examine the differentiation of 73 varieties in plant economic strategies. Meanwhile, this study explored the associations of economic strategy differentiation with rhizosphere microbiomes.The 73 varieties displayed significant differentiation in both above- and below-ground growth traits, enabling their growth classification into fast economic strategy (FES), medium economic strategy (MES), and slow economic strategy (SES). A significantly consistent distribution was observed among plant functional traits and rhizosphere microbial communities (bacteria and protists) of SES varieties, which was not discovered in FES varieties. Compared with FES varieties, the SES varieties exhibited a lower microbial diversity and community complexity. Pepper varieties with SES were more strongly correlated with their rhizosphere microbiomes compared to FES varieties. Rhizosphere microbial and community complexity indirectly regulated above-ground growth of SES varieties by affecting the root growth and nutrient uptake.Overall, these findings enhance our understanding of the connections between plant economic strategies and rhizosphere microbiomes, offering valuable insights into selection and popularization of exceptional Capsicum varieties.Conclusions: Plant growth strategies represent a gradient from slow to fast economic strategies. Rhizosphere microbiomes have a continual and profound impact on plant growth. However, our understanding of differences in plant economic spectrum among various crop varieties and their associations with rhizosphere microbiome remains limited.Here, pepper (Capsicum spp.) was employed as a model plant to examine the differentiation of 73 varieties in plant economic strategies. Meanwhile, this study explored the associations of economic strategy differentiation with rhizosphere microbiomes.The 73 varieties displayed significant differentiation in both above- and below-ground growth traits, enabling their growth classification into fast economic strategy (FES), medium economic strategy (MES), and slow economic strategy (SES). A significantly consistent distribution was observed among plant functional traits and rhizosphere microbial communities (bacteria and protists) of SES varieties, which was not discovered in FES varieties. Compared with FES varieties, the SES varieties exhibited a lower microbial diversity and community complexity. Pepper varieties with SES were more strongly correlated with their rhizosphere microbiomes compared to FES varieties. Rhizosphere microbial and community complexity indirectly regulated above-ground growth of SES varieties by affecting the root growth and nutrient uptake.Overall, these findings enhance our understanding of the connections between plant economic strategies and rhizosphere microbiomes, offering valuable insights into selection and popularization of exceptional Capsicum varieties. [ABSTRACT FROM AUTHOR]

One of the few laws in ecology is that communities consist of few common and many rare taxa. Functional traits may help to identify the underlying mechanisms of this community pattern, since they correlate with different niche dimensions. However, comprehensive studies are missing that investigate the effects of species mean traits (niche position) and intraspecific trait variability (ITV, niche width) on species abundance. In this study, we investigated fragmented dry grasslands to reveal trait‐occurrence relationships in plants at local and regional scales. We predicted that (a) at the local scale, species occurrence is highest for species with intermediate traits, (b) at the regional scale, habitat specialists have a lower species occurrence than generalists, and thus, traits associated with stress‐tolerance have a negative effect on species occurrence, and (c) ITV increases species occurrence irrespective of the scale. We measured three plant functional traits (SLA = specific leaf area, LDMC = leaf dry matter content, plant height) at 21 local dry grassland communities (10 m × 10 m) and analyzed the effect of these traits and their variation on species occurrence. At the local scale, mean LDMC had a positive effect on species occurrence, indicating that stress‐tolerant species are the most abundant rather than species with intermediate traits (hypothesis 1). We found limited support for lower specialist occurrence at the regional scale (hypothesis 2). Further, ITV of LDMC and plant height had a positive effect on local occurrence supporting hypothesis 3. In contrast, at the regional scale, plants with a higher ITV of plant height were less frequent. We found no evidence that the consideration of phylogenetic relationships in our analyses influenced our findings. In conclusion, both species mean traits (in particular LDMC) and ITV were differently related to species occurrence with respect to spatial scale. Therefore, our study underlines the strong scale‐dependency of trait‐abundance relationships. [ABSTRACT FROM AUTHOR]

Understanding how plant individuals perform in non‐local sites is key in the context of contemporary range shifts along elevation. Transplant experiments conducted in mountain ecosystems are rising as key tools to measure the intraspecific response of individuals transplanted across contrasting elevations. However, a synthesis quantifying patterns of plant performance in response to changes in abiotic factors across different species and mountain ranges is still lacking.We conducted a meta‐analysis to quantitatively summarize patterns of plant species' performance variation in response to changes in temperature and precipitation within their elevation range across multiple transplant experiment studies. We compiled a dataset obtained from 38 studies and 49 vascular plant species in total addressing intraspecific performance variation in terms of survival, germination, biomass, height, number of vegetative organs, number of reproductive units, SLA and leaf size. We both compared pairs of transplanted individuals to those growing at their site of origin ('away vs. home') and to the local individuals found at the site of transplant ('foreign vs. local').Overall, individuals transplanted downward showed larger biomass and height compared to their site of origin but failed to adjust these traits and survival to that of local individuals. Individuals transplanted upward adjusted their traits by decreasing plant growth and number of reproductive units to that of local individuals but showed lower survival. Importantly, changes in survival, biomass, height, leaf size, number of vegetative organs and reproductive units increased linearly with the difference in mean annual temperature between site of transplant and site of origin in the 'away vs. home' comparison. Conversely, changes in biomass, leaf size, number of vegetative organs and reproductive units increased with mean annual precipitation difference between sites in the 'foreign vs. local' comparison.Synthesis. We detected common trends in survival and intraspecific trait variation across different species and transplant experiments conducted along elevational gradients. Because plasticity and adaptation play a crucial role in plant shift, establishment and persistence under non‐local environmental conditions, our meta‐analysis contributes to better understand how rapid plant shifts are constrained by climatic conditions within species' elevational range. [ABSTRACT FROM AUTHOR]

Aim: Ecological specialization is defined by the variety of environments species occupy. Identifying the mechanisms that influence specialization is critical to understand patterns of species coexistence and biodiversity. However, the functional attributes that result in specialization are still unknown. Similarly, there is contrasting evidence between the degree of specialization and the local abundance of species. We investigated whether specialist and generalist plant species (a) are associated with distinct functional profiles, using core plant functional traits and strategies, (b) show similar functional variation and (c) perform at the local scale. Location: France. Taxon: Herbaceous plants. Methods: We analysed the structure of a bipartite network that includes the occurrences of ~2,900 plant species at ~90,000 sites to identify ecologically consistent sets of species and sites (i.e. 'modules'). This innovative approach then enabled us to define a metric of specialization, by quantifying occurrences of species at sites that belong to one or several modules. We used functional traits related to resource acquisition, competition for light and dispersal ability, as well as indices of competitive, stress tolerance and ruderal strategies. Results: We identified five major modules in the bipartite network related to different environments and composed of species with differing functional attributes. Specialist species were less competitive and shorter, and had higher stress tolerance and stronger resource conservation, while generalist species were taller. Generalists were also more similar to each other than specialists. In addition, specialists had higher local abundances and occurred in communities with plants of similar height. Main conclusions: We found distinctive functional signatures of specialist and generalist species in grassland communities across diverse environments at regional and community scales. By testing classic macro‐ecological hypotheses, network metrics can benefit community ecology by identifying distinct ecological units at a large scale and quantifying the links developed by species. [ABSTRACT FROM AUTHOR]

Aims: Uncovering the importance of soil and plant characteristics in driving the legacy effects of nitrogen (N) deposition on plant community nutrient stoichiometry would improve our understanding of plant-soil interaction during restoration of historically N-enriched ecosystems. Methods: Based on a field experiment with the cessation of six-year N addition in a temperate steppe of northern China, we measured concentrations and stoichiometry of N and phosphorus (P) in soils and different plant functional groups, under both mown and unmown conditions. Results: Historical N addition did not affect soil total and available N and P concentrations and stoichiometry, but significantly altered plant community composition. Plant nutrient concentrations and N:P ratios significantly differed among four plant functional groups. The concentrations and stoichiometric ratios of N and P between soils and plants were generally not correlated. The positive legacy effects of N addition on community N:P stoichiometry were caused by the biomass enhancement of tall bunchgrass, the functional group with the highest N:P ratios. Conclusions: Changes in plant community composition instead of soil nutrient status were the main driver for the positive legacy effects of N enrichment on plant community stoichiometry. Given that the recovery of community composition after the cessation of N deposition is generally slow, our findings indicate that the legacy effects of N deposition on soil nutrient cycling would persist in long-term due to the importance of plant-mediated pathway. [ABSTRACT FROM AUTHOR]

Semi‐natural mountain grasslands are increasingly exposed to environmental stress under climate change. However, which are the environmental factors that limit plants in these grasslands? Also, is the present management effective against these changes? Fitness‐related functional traits may offer a way to detect changes in performance and provide new insights into their vulnerability to climate change. We investigated changes in performance and variability of functional traits of the mountain grassland target species Arnica montana along a climate gradient in Central German low mountain ranges. This gradient represents at its lower end climate conditions that are expected at its upper end under future climate change. We measured vegetative, generative, and physiological traits to account for multiple ways of plant responses to the environment. Using mixed effects and multivariate models, we evaluated changes in trait values among individuals as well as the variability of their populations in order to assess performance under changing summer aridity and different management regimes. Fitness‐related performance of most traits showed strongly positive associations with reduced summer aridity at higher elevations, while only specific leaf area and leaf dry matter content showed no association. This suggests a higher performance level at less arid montane sites and that the physiological traits are less sensitive to this climate change factor. The coefficient of variation of almost all traits declined steadily with decreasing site aridity. We suggest that this reduced variability indicates a lower environmental stress level for A. montana toward its environmental optimum at montane elevations, especially because the trait performance increased simultaneously. Surprisingly, management factors and habitat characteristics had only low influence on both trait performance and variability. In summary, summer aridity had a stronger effect to shape the trait performance and variability of A. montana under increased environmental stress than management and other habitat characteristics. [ABSTRACT FROM AUTHOR]

Plant germination ecology involves continuous interactions between changing environmental conditions and the sensitivity of seed populations to respond to those conditions at a given time. Ecologically meaningful parameters characterizing germination capacity (or dormancy) are needed to advance our understanding of the evolution of germination strategies within plant communities. The germination traits commonly examined (e.g., maximum germination percentage under optimal conditions) may not adequately reflect the critical ecological differences in germination behavior across species, communities, and seasons. In particular, most seeds exhibit primary dormancy at dispersal that is alleviated by exposure to dry after‐ripening or to hydrated chilling to enable germination in a subsequent favorable season. Population‐based threshold (PBT) models of seed germination enable quantification of patterns of germination timing using parameters based on mechanistic assumptions about the underlying germination physiology. We applied the hydrothermal time (HTT) model, a type of PBT model that integrates environmental temperature and water availability, to study germination physiology in a guild of coexisting desert annual species whose seeds were after‐ripened by dry storage under different conditions. We show that HTT assumptions are valid for describing germination physiology in these species, including loss of dormancy during after‐ripening. Key HTT parameters, the hydrothermal time constant (θHT) and base water potential distribution among seeds (Ψb(g)), were effective in describing changes in dormancy states and in clustering species exhibiting similar germination syndromes. θHT is an inherent species‐specific trait relating to timing of germination that correlates well with long‐term field germination fraction, while Ψb(g) shifts with depth of dormancy in response to after‐ripening and seasonal environmental variation. Predictions based on variation among coexisting species in θHT and Ψb(g) in laboratory germination tests matched well with 25‐yr observations of germination dates and fractions for the same species in natural field conditions. Seed dormancy and germination strategies, which are significant contributors to long‐term species demographics under natural conditions, can be represented by readily measurable functional traits underlying variation in germination phenologies. [ABSTRACT FROM AUTHOR]

Phylogenetic analyses are essential for disentangling how environmental filtering and competition determine species coexistence across spatial scales. Inner Mongolia steppe has strong environmental gradients, but how the phylogenetic relatedness of co-occurring species and phylogenetic signals of functional traits change across spatial scales remains unclear. We investigated the phylogenetic structure of grass assemblages along environmental gradients from regional to local scales, and measured functional traits within assemblages. We compared phylogenetic signals of plant traits between the same numbers of species randomly selected from the regional pool and species observed at the local scale, did phylogenetic principal component analysis to infer the main factors driving species coexistence, and examined the key plant trait–environment relationships across the phylogeny to reveal ecological adaptation mechanisms. Regionally, grass species were phylogenetically clustered with contrasting climate preferences. With decreasing spatial scales, species richness declined, changing from phylogenetically clustered to overdispersed, and phylogenetic signals of plant traits became weaker. At the local scale, grass assemblages were structured by soil water content and neighbor density, and the trait–environment relationships were less clear than those at the regional scale. This study demonstrated that at smaller scales, co-occurring grass species in the steppe tended to be more phylogenetically overdispersed, and that phylogenetic signals of plant functional traits became weaker with increasing abiotic and biotic interactions. Our findings contributed evidence for understanding species coexistence and maintenance at scales spanning regional to local communities in the East Asia steppe biome. [ABSTRACT FROM AUTHOR]

Between‐species variation in nutrient resorption is one of the mechanisms explaining the positive relationship between biodiversity and primary productivity. Yet, the role of within‐species variations in nutrient resorption in mediating the relationship between biodiversity and productivity remains unclear.We examined how within‐species nutrient resorption, and ultimately productivity, respond to changes in species richness by using four traits related to nitrogen and phosphorus use in four dominant species from different plant functional groups in a biodiversity removal experiment in the temperate steppe.Nitrogen and phosphorus concentrations in both green and senesced leaves in all species significantly decreased with increasing plant species richness, suggesting that plants used those limiting nutrients more efficiently with increasing biodiversity. Plants in higher diversity communities resorbed more nutrients during senescence, which may facilitate reproduction and vegetative regrowth in the next year.Synthesis. Our results highlight the importance of considering within‐species variation in nutrient resorption as an important underlying mechanism explaining the positive effects of biodiversity on primary productivity and ecosystem carbon accumulation. [ABSTRACT FROM AUTHOR]

1. Considering intraspecific trait variability (ITV) in ecological studies has improved our understanding of species persistence and coexistence. These advances are based on the growing number of leaf ITV studies over local gradients, but logistical constraints have prevented a solid examination of ITV in root traits or at scales reflecting species’ geographic ranges. 2. We compared the magnitude of ITV in above‐ and below‐ground plant organs across three spatial scales (biophysical region, locality and plot). We focused on six understorey species (four herbs and two shrubs) that occur both in disturbed and undisturbed habitats across boreal and temperate Canadian forests. We aimed to document ITV structure over broad ecological and geographical scales by asking: (a) What is the breadth of ITV across species range‐scale? (b) What proportion of ITV is captured at different spatial scales, particularly when local scale disturbances are considered? and (c) Is the variance structure consistent between analogous leaf and root traits, and between morphological and chemical traits? 3. Following standardized methods, we sampled 818 populations across 79 forest plots simultaneously, including disturbed and undisturbed stands, spanning four biophysical regions (~5,200 km). Traits measured included specific leaf area (SLA), specific root length (SRL) and leaf and root nutrient concentrations (N, P, K, Mg, Ca). We used variance decomposition techniques to characterize ITV structure across scales. 4. Our results show that an important proportion of ITV occurred at the local scale when sampling included contrasting environmental conditions resulting from local disturbance. A certain proportion of the variability in both leaf and root traits remained unaccounted for by the three sampling scales included in the design (36% on average), with the largest amount for SRL (54%). Substantial differences in magnitude of ITV were found among the six species, and between analogous traits, suggesting that trait distribution was influenced by species strategy and reflects the extent of understorey environment heterogeneity. 5. Even for species with broad geographical distributions, a large proportion of within‐species trait variability can be captured by sampling locally across ecological gradients. This has practical implications for sampling design and trait selection for both local studies and continental‐scale modelling. [ABSTRACT FROM AUTHOR]

Summary: In the rapidly warming tundra biome, plant traits provide an essential link between ongoing vegetation change and feedbacks to key ecosystem functions. However, only recently have comprehensive trait data been compiled for tundra species and sites, allowing us to assess key elements of functional responses to global change. In this review, we summarize trait‐based research in tundra ecosystems, with a focus on three components: plant trait variation and how it compares with global patterns; shifts in community‐level traits in response to environmental change; and the use of traits to understand and predict ecosystem function. Quantifying patterns and trends in plant traits will allow us to better project the consequences of environmental change for the ecology and functioning of tundra ecosystems. [ABSTRACT FROM AUTHOR]

Abstract Tree growth rate can complicate our understandings of plant belowground responses to elevated CO 2 (eCO 2) in tropical ecosystems. We studied the effects of eCO 2 on plant growth parameters, and rhizospheric soil properties including soil organic carbon (SOC), glomalin related soil protein (GRSP), microbial biomass C (C mic), CO 2 efflux (C efflux), and microbial extracellular enzyme activities under two tropical tree saplings of fast-growing Tectona grandis (Teak) and slow-growing Butea monosperma (Butea). We exposed these saplings to eCO 2 (∼550 ppm) and ambient CO 2 (aCO 2 ; ∼395 ppm) in the Indo-Gangetic plain region, and further (after 10 and 46 months) measured the changes in their rhizospheric soil properties. With respect to aCO 2 treatment, eCO 2 significantly increased plant height, stem and shoot weight, and total plant biomass of Teak. However, these plant traits did not considerably differed between eCO 2 and aCO 2 treatments of Butea. The eCO 2 induced greater extent of increase in rhizospheric soil properties including SOC fractions (particulate OC, non-particulate OC and total OC), GRSP fractions (easily extractable- GRSP, difficulty extractable- GRSP and total- GRSP), C mic , C efflux and extracellular enzyme activities (phosphatase, dehydrogenase, β-glucosidase and fluorescein diacetate) were observed under Teak compared with Butea. Compared with aCO 2 treatment, eCO 2 slightly reduced soil available N and P under the Teak, but no changes were apparent between eCO 2 and aCO 2 treatments of the Butea. The greater extent of responses from soil variables observed after longer period (46 months) of CO 2 exposure. The multivariate analysis confirmed that eCO 2 treatment with Teak is more responsive compared with other treatments of Teak and Butea. This contrasting rhizospheric soil feedback to eCO 2 between two tropical trees, suggesting fast-growing species will be more responsive to future climate. Such species will have a competitive advantage over coexisting less responsive species (e.g. Butea) under future eCO 2 climate. Graphical abstract Image 1 Highlights • Two tropical species having contrasting growth rate are exposed to eCO 2. • Tectona grandis accumulated more biomass than slow-growing Butea monosperma. • Rhizospheric soil properties are also more responsive to eCO 2 under T. grandis. • Future climate are likely provide competitive advantage to fast-growing species. [ABSTRACT FROM AUTHOR]

Highlights • Mortality of coastal plants are driven by different growth stress under increasing salinity. • Deciduous baldcypress is more affected by nutrient stress than water stress. • Evergreen and N 2 -fixing waxmyrtle is more affected by water stress than nutrient stress. Abstract With rising sea levels, mortality of glycophytes can be caused by water and nutrient stress under increasing salinity. However, the relative effects of these two stressors may vary by species-specific functional traits. For example, deciduous species, with leaves typically emerging during low salinity periods of the year, may suffer less from water stress than evergreen species. We sampled two woody species with contrasting functional traits: the evergreen and N 2 -fixing waxmyrtle ( Morella cerifera ), and the deciduous and non-N 2 fixing baldcypress ( Taxodium distichum ) along a coastal river (South Carolina, USA) showing an increasing pattern of plant mortality along a salinity gradient. We first analyzed oxygen and hydrogen isotope ratios of plant stem water and river water to determine changes in plant source water at different sites. Then we analyzed foliar carbon and nitrogen isotope ratios (δ13C and δ15N) along with nitrogen and phosphorus content (%N and %P) as proxies for the water and nutrient stress. Results showed that: (1) the two species had different water sources at the higher salinity sites; (2) foliar δ15N values of baldcypress decreased with higher salinity while retaining a constant δ13C value, and both of these isotope values were positively related with foliar %P, suggesting greater nutrient stress but minor water stress under high salinity; and (3) foliar δ13C values of waxmyrtle increased with higher salinity while retaining a constant foliar δ15N value, and neither of the values was significantly related to foliar nutrients, suggesting greater water stress but minor nutrient stress under high salinity. The different responses of the two species to high salinity may be related to their differences in leaf phenology and N 2 -fixation. Our results suggest that nutrient stress, particularly of P, can contribute to stress and eventual high mortality of baldcypress exposed to salt water intrusion. [ABSTRACT FROM AUTHOR]

Abstract Collembola is an abundant group of soil organisms playing a major role on litter decomposition process and nutrient cycling in forest ecosystems. Habitat structure strongly influences Collembola assemblages as plant litter physical characteristics and quantity provide structural niches and determine the outcome of their interactions with predators. Collembola are also extremely sensitive to environmental conditions such as soil temperature that control their demographic parameters and activity. In this context, increasing temperature with the ongoing climate change can have strong impact on Collembola assemblages and their responses to predation either directly by altering their behaviour or indirectly by altering their habitat structure. We therefore examined how the increase of temperature combined to the decrease of specific leaf area (SLA, a major functional plant trait) of the European common oak (Quercus robur L.) and the presence of a centipede predator (Chilopoda: Lithobiidae) will affect the abundance of Folsomia candida (Collembola: Isotomidae) in a 5-week microcosm experiment. Increasing temperature, decreasing SLA and presence of centipede altered F. candida abundance. We observed a significant temperature × predation interaction suggesting differential effects of increasing temperature on F. candida abundance with and without predator. We also observed a significant SLA × predation interaction highlighting that lower SLA decreases F. candida abundance only in predator presence. Finally, our findings evidenced that increasing temperature and decreasing SLA amplify the negative effect of centipede predation on F. candida abundance, suggesting that both direct and indirect effects of climate change would conjointly strengthen the top-down control of predators on preys. Highlights • Temperature, SLA and centipede predation alter Collembola abundance. • +5 °C stimulates Collembola abundance only in centipede absence. • +10 °C strongly decreases Collembola abundance with and without centipede. • Lower SLA decreases Collembola abundance only in centipede presence. • Increasing temperature and decreasing SLA amplify centipede predation. [ABSTRACT FROM AUTHOR]

Abstract: Plants adopt a variety of life history strategies to succeed in the Earth's diverse environments. Using functional traits which are defined as “morphological, biochemical, physiological, or phonological” characteristics measurable at the individual level, plants are classified according to their species’ adaptative strategies, more than their taxonomy, from fast growing plant species to slower‐growing conservative species. These different strategies probably influence the input and output of carbon (C)‐resources, from the assimilation of carbon by photosynthesis to its release in the rhizosphere soil via root exudation. However, while root exudation was known to mediate plant‐microbe interactions in the rhizosphere, it was not used as functional trait until recently. Here, we assess whether root exudate levels are useful plant functional traits in the classification of plant nutrient‐use strategies and classical trait syndromes? For this purpose, we conducted an experiment with six grass species representing along a gradient of plant resource‐use strategies, from conservative species, characterized by low biomass nitrogen (N) concentrations and a long lifespans, to exploitative species, characterized by high rates of photosynthesis and rapid rates of N acquisition. Leaf and root traits were measured for each grass and root exudate rate for each planted soil sample. Classical trait syndromes in plant ecology were found for leaf and root traits, with negative relationships observed between specific leaf area and leaf dry matter content or between specific root length and root dry matter content. However, a new root trait syndrome was also found with root exudation levels correlating with plant resource‐use strategy patterns, specifically, between root exudation rate and root dry matter content. We therefore propose root exudation rate can be used as a key functional trait in plant ecology studies and plant strategy classification. [ABSTRACT FROM AUTHOR]

Aims: We aimed to know how plant species colonize landslides under a semi-arid climate.Methods: We selected 30 landslides triggered by the continuous rainstorms in the hilly-gullied region of the Chinese Loess Plateau in July 2013. We quantified post-landslide changes in a core list of soil properties, vegetation properties and plant functional traits and also analyzed their relationships.Results: After landslides, there were no large changes in the soil properties except slope angle. Correspondingly, there were no large changes in plant species richness, species composition and the functional traits. The vegetation cover of scars (the newly exposed soil surfaces because of landslides) was significantly lower than those of deposits (the deposition zones of landslides) and undisturbed vegetated areas surrounding the landslides (control areas), but the vegetation recovery of scars should be only a matter of time.Conclusions: Under the semi-arid climate of the area, landslides do not have profound effects on soil properties and plant species richness and composition, telling a different story from those landslides under other climate regimes and implying great potential for the restoration of landslides. [ABSTRACT FROM AUTHOR]

Abstract: Questions: How do plant functional trait abundance and diversity in urban remnants of a rapidly urbanizing city change with fragmentation? Is there a delayed functional response to fragmentation? Location: Thirty remnant Banksia woodlands, Perth, Australia. Methods: We used GLMM to examine the effects of remnant age and area, and their interaction, on the relative abundance and functional diversity (FD) of five plant functional traits: growth form, pollination, seed dispersal, nutrient acquisition and regeneration strategies. We then used fourth‐corner analysis to examine the influence of a wider set of fragmentation‐related factors on trait abundances. Results: The functional composition and diversity of Banksia woodlands changed with remnant age, particularly in the smaller remnants. Plants more prone to decline with remnant age were the growth form shrubs, root‐clustered trees, herbaceous obligate seeders and understorey species that are insect‐pollinated, have seeds dispersal internally by animals and have arbuscular or ericoid mycorrhizas. In contrast, plants more prone to persist were growth forms trees, sedges and rushes, ectomycorrhizal trees, herbaceous resprouters, wind‐pollinated and root‐clustered understorey species. FD increased with remnant age in the growth forms and overstorey, but declined among the herbaceous and shrub pollination and nutrient acquisition traits. Conclusions: Functional traits that consistently signalled the plant community response to fragmentation were growth form, pollination and dispersal. This functional response was largely delayed, suggesting a ″functional extinction debt″, which will lead to a further decline of plants with vulnerable trait states in the future, especially in the small‐ and medium‐sized remnants. Our study illustrates the vulnerability of small remnants to changes in community assembly and ecosystem function due to fragmentation. Furthermore, it exemplifies how a functional trait approach is valuable to understand the impacts of urbanization on remnant plant communities, before local extinctions may occur. Finally, the study shows how cities’ fragmentation history and biogeographic settings provide an important context influencing plant functional responses to urbanization‐related processes. [ABSTRACT FROM AUTHOR]

Human selection, changes in environmental conditions and management practices drove the phenotypic trajectory of crops during domestication. The characterization of the crop domestication syndrome lies mostly on reproductive characters. However, biophysical and ecophysiological constraints during vegetative growth are also at play and can strongly impact crop phenotypes. It has been argued that a broadened examination of crop phenotypes through a functional trait-based lens should improve our understanding of the domestication syndrome., We used a collection of 39 genotypes representative of key steps during tetraploid wheat domestication and grew them in a common garden experiment. We quantified the vegetative phenotype of each genotype through the measurements of 13 functional traits related to root, leaf and whole-plant dimensions., In modern cultivars, compared to ancestral forms, leaf longevity was shorter, while net photosynthetic rate, leaf production rate and nitrogen content were higher. Modern cultivars had a shallower root system and exhibited a larger proportion of fine roots, preferring to invest biomass above-rather than below-ground. We found ancestral forms to be integrated phenotypes characterized by coordination between above- and below-ground functioning. Conversely, in modern forms, human selection appeared to have broken this coordination and to have generated a new type of network of trait covariations., Synthesis and applications. The examination of leaf, root and whole-plant traits of wheat accessions indicated a strong shift in plant functional strategies over the course of domestication. Elite genotypes tended to better optimize resource-use acquisition strategies than ancestral ones. The characterization of the crop phenotype based on vegetative traits thus suggests a much more complete domestication syndrome. Our findings highlight the benefits of using a functional trait-based characterization of crop phenotypes to document the extent of domestication syndrome and to further advance the agroecological management of cereals. [ABSTRACT FROM AUTHOR]

The majority of studies that investigate plant functional trait effects on ecosystem properties use traits obtained from databases. However, we know little regarding their explanatory power proportionate to that of the semi-quantitative vegetation properties, and much less still is known when considering their temporal changes in a chronosequence. We determined whether soil chemical and biological properties were associated with plant functional traits, observed vegetation properties (“patch type” = bare soil, grassy, woody), and site age (10, 18, 28, and 55 years), at four spontaneously overgrown post-mining locations in the Czech Republic. Abiotic soil properties were expected to be closely related to the site age, while above and below ground macrofauna (epigeic and endogeic, respectively), mesofauna, and microbial biomass were expected to be related to the plant functional traits and patch types. Site age and plant functional traits were more important explanatory factors for most of the chemical, microbial, and macrofaunal soil properties than the patch types. Patch type was the only plant-related factor capable of explaining the mesofauna community variations. Epigeic macrofauna were found to correlate more strongly with the plant functional traits than endogeic macrofauna. The abundance of most fauna correlated positively with an increase in plant cover and litter input and was significantly higher in vegetated patches and old sites. [ABSTRACT FROM AUTHOR]

The ecological niche is a multi-dimensional concept including aspects of resource use, environmental tolerance, and interspecific interactions, and the degree to which niches overlap is central to many ecological questions. Plant phenotypic traits are increasingly used as surrogates of species niches, but we lack an understanding of how key sampling decisions affect our ability to capture phenotypic differences among species. Using trait data of ecologically distinct monkeyflower ( Mimulus) congeners, we employed linear discriminant analysis to determine how (1) dimensionality (the number and type of traits) and (2) variation within species influence how well measured traits reflect phenotypic differences among species. We conducted analyses using vegetative and floral traits in different combinations of up to 13 traits and compared the performance of commonly used functional traits such as specific leaf area against other morphological traits. We tested the importance of intraspecific variation by assessing how population choice changed our ability to discriminate species. Neither using key functional traits nor sampling across plant functions and organs maximized species discrimination. When using few traits, vegetative traits performed better than combinations of vegetative and floral traits or floral traits alone. Overall, including more traits increased our ability to detect phenotypic differences among species. Population choice and the number of traits used had comparable impacts on discriminating species. We addressed methodological challenges that have undermined cross-study comparability of trait-based approaches. Our results emphasize the importance of sampling among-population trait variation and suggest that a high-dimensional approach may best capture phenotypic variation among species with distinct niches. [ABSTRACT FROM AUTHOR]

Spatial environmental heterogeneity is considered a fundamental factor for the maintenance of plant species richness. However, it still remains unclear whether heterogeneity may also facilitate coexistence at fine grain sizes or whether other processes, like mass effects and source sink dynamics due to dispersal, control species composition and diversity at these scales. In this study, we used two complimentary analyses to identify the role of heterogeneity within 15 m × 15 m plots for the coexistence of species-rich annual communities in a semi-arid environment along a steep precipitation gradient. Specifically, we: (a) analyzed the effect of environmental heterogeneity on species, functional and phylogenetic diversity within microsites (alpha diversity, 0.06 m 2 and 1 m 2 ), across microsites (beta diversity), and diversity at the entire plot (gamma diversity); (b) further we used two null models to detect non-random trait and phylogenetic patterns in order to infer assembly processes, i.e. whether co-occurring species tend to share similar traits (trait convergence) or dissimilar traits (trait divergence). In general, our results showed that heterogeneity had a positive effect on community diversity. Specifically, for alpha diversity, the effect was significant for functional diversity, and not significant for either species or phylogenetic diversities. For beta diversity, all three measures of community diversity (species, functional, and phylogenetic) increased significantly, as they also did for gamma diversity, where functional measures were again stronger than for species or phylogenetic measures. In addition, the null model approach consistently detected trait convergence, indicating that species with similar traits tended to co-occur and had high abundances in a given microsite. While null model analysis across the phylogeny partly supported these trait findings, showing phylogenetic underdispersion at the 1m 2 grain size, surprisingly when species abundances in microsites were analyzed they were more evenly distributed across the phylogenetic tress than expected (phylogenetic overdispersion). In conclusion, our results provide compelling support that environmental heterogeneity at a relatively fine scale is an important factor for species co-existence as it positively affects diversity as well as influences species assembly. Our study underlines the need for trait-based approaches conducted at fine grain sizes in order to better understand species coexistence and community assembly. [ABSTRACT FROM AUTHOR]

• Phylogeny and functional trait analyses were used to test community assembly. • The relative importance of dominant ecological processes changed during succession. • Soil P content has a important impact on community assembly during succession. • Both environmental filtering and competitive exclusion played a role during succession. • The test of ecological processes could be biased if used one functional strategy. Understanding community assembly process could enhance forest conservation and restoration, while which dominant ecological process drives the community assembly during forest succession is still controversial. In this study, the phylogeny-based and functional trait-based indicators were used to investigate the community assembly processes during forest succession in southern China. 30 dominant species and 33 functional trait indicators related to plant competition, reproduction, and defense strategies, 7 environmental factors related to light availability and soil nutrients, and species richness were selected to explore the dominant ecological processes during succession via Monte Carlo method, structural equation model, multiple linear regression, and one-way ANOVA analysis. Results showed that both the community phylogenetic and functional trait structures changed during succession. Phylogenetic structure clustering and functional trait clustering were evident in early succession. In middle succession, the phylogenetic structure and functional trait structure were randomly dispersed. In middle and later succession, the phylogenetic structure clustering, functional trait clustering, and functional trait evenly dispersed were found. The environmental factors, especially the soil P content, and species richness were found to have significant effects on the community assembly processes during succession. Dominant species in early succession always occupied acquisitive strategies and had high light-use ability and low investment in defense, but dominant species in later succession showed more conservative strategies and exhibited diverse defense strategy, reproductive strategy, and light and nutrient resource-use strategy, apparently in order to adapt changing and more complex environments. The results demonstrate that the relative importance of ecological processes changed during succession. Environmental filtering mainly dominated in early succession, and its strength gradually decreased as succession progressed. Both environmental filtering and competitive exclusion had important effects on community assembly in later succession. The assessment of the relative importance of ecological processes during succession could be biased if only based on one plant functional strategy. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Current ecological theory can provide insight into the causes and impacts of plant domestication. However, just how domestication has impacted intraspecific genetic variability (ITV) is unknown. We used 50 ecotypes and 35 cultivars from five grassland species to explore how selection drives functional trait coordination and genetic differentiation. METHODS: We quantified the extent of genetic diversity among different sets of functional traits and determined how much genetic diversity has been generated within populations of natural ecotypes and selected cultivars. KEY RESULTS: In general, the cultivars were larger (e.g., greater height, faster growth rates) and had larger and thinner leaves (greater SLA). We found large (average 63%) and trait-dependent (ranging from 14% for LNC to 95.8% for growth rate) genetic variability. The relative extent of genetic variability was greater for whole-plant than for organ-level traits. This pattern was consistent within ecotypes and within cultivars. However, ecotypes presented greater ITV variability. CONCLUSIONS: The results indicated that genetic diversity is large in domesticated species with contrasting levels of heritability among functional traits and that selection for high yield has led to indirect selection of some associated leaf traits. These findings open the way to define which target traits should be the focus in selection programs, especially in the context of community-level selection. [ABSTRACT FROM AUTHOR]

Impatiens parviflora (Balsaminaceae) is one of the most widespread invasive plant species in Central Europe. Nevertheless, both mechanisms and consequences of its invasion are still poorly understood. In this study we attempt to understand the impact of this species on native vegetation. The impact of I. parviflora on native vegetation was studied using removal experiment on permanent plots in oak-hornbeam forests in central Bohemia, Czech Republic. Nine pairs of plots were established in invaded vegetation, one plot in each pair stayed invaded and the other served as removal plot and all I. parviflora individuals were repeatedly removed from the plot. Species composition in 4 subsequent years was recorded in the plots. Species response to I. parviflora removal was correlated to plant traits to reveal trait characteristics of species suppressed by the invasion. Significant increase in both numbers and cover of native species was observed in removal plots in comparison with invaded plots during the experiment, with the greatest change in first two years after invader removal. Species composition also significantly differed between invaded and removal plots. Species with high affinity to removal plots, i.e. species that are most restricted by I. parviflora invasion, were mostly species with small releasing height and early start of flowering. Our results indicate that I. parviflora has negative impact on native vegetation but that the vegetation can recover within few years after the invader removal. Due to its extensive distribution and high turnover, removal of the species from larger plots is, however, not realistic in practice. [ABSTRACT FROM AUTHOR]

We assessed whether diversity in plant hydraulic traits can explain the observed diversity in plant responses to water stress in seasonally dry tropical forests ( SDTFs)., The Ecosystem Demography model 2 ( ED2) was updated with a trait-driven mechanistic plant hydraulic module, as well as novel drought-phenology and plant water stress schemes. Four plant functional types were parameterized on the basis of meta-analysis of plant hydraulic traits. Simulations from both the original and the updated ED2 were evaluated against 5 yr of field data from a Costa Rican SDTF site and remote-sensing data over Central America., The updated model generated realistic plant hydraulic dynamics, such as leaf water potential and stem sap flow. Compared with the original ED2, predictions from our novel trait-driven model matched better with observed growth, phenology and their variations among functional groups. Most notably, the original ED2 produced unrealistically small leaf area index ( LAI) and underestimated cumulative leaf litter. Both of these biases were corrected by the updated model. The updated model was also better able to simulate spatial patterns of LAI dynamics in Central America., Plant hydraulic traits are intercorrelated in SDTFs. Mechanistic incorporation of plant hydraulic traits is necessary for the simulation of spatiotemporal patterns of vegetation dynamics in SDTFs in vegetation models. [ABSTRACT FROM AUTHOR]

Community dynamics is influenced by multiple ecological processes such as environmental spatiotemporal variation, competition between individuals and demographic stochasticity. Quantifying the respective influence of these various processes and making predictions on community dynamics require the use of a dynamical framework encompassing these various components. We here demonstrate how to adapt the framework of stochastic community dynamics to the peculiarities of herbaceous communities, by using a short temporal resolution adapted to the time scale of competition between herbaceous plants, and by taking into account the seasonal drops in plant aerial biomass following winter, harvesting or consumption by herbivores. We develop a hybrid inference method for this novel modelling framework that both uses numerical simulations and likelihood computations. Applying this methodology to empirical data from the Jena biodiversity experiment, we find that environmental stochasticity has a larger effect on community dynamics than demographic stochasticity, and that both effects are generally smaller than observation errors at the plot scale. We further evidence that plant intrinsic growth rates and carrying capacities are moderately predictable from plant vegetative height, specific leaf area and leaf dry matter content. We do not find any trade-off between demographical components, since species with larger intrinsic growth rates tend to also have lower demographic and environmental variances. Finally, we find that our model is able to make relatively good predictions of multi-specific community dynamics based on the assumption of competitive symmetry. [ABSTRACT FROM AUTHOR]

A central issue of community ecology is finding rules that explain the composition and abundance of coexisting species. Nowadays two main processes, environmental filtering and limiting similarity, are thought to play the main roles in structuring communities. Their relative importance under different environmental conditions, however, is still not properly clarified., We studied the strength and the effect of environmental filtering (causing convergence) and limiting similarity (causing divergence) in 137 sample plots along an extremely long environmental gradient ranging from open sand grasslands to highly productive marshes, using a trait-based approach. The main environmental gradient (i.e. productivity) was characterized by the Normalized Difference Vegetation Index, an indicator of above-ground live biomass. Cover of the plant species was estimated visually. Values of 11 plant traits were collected from field measurements and data bases. Mean and dispersion of the trait values of the plots were quantified by community-weighted means and Rao's quadratic entropy. Trait convergence and divergence were tested by randomization tests, followed by the study of changes in effect size along the productivity gradient by fitting generalized additive mixed models ( GAMM)., For vegetative traits we found mainly convergence, indicating the filtering effect of environmental constraints, while traits related to regeneration showed divergence., The strength of convergence in vegetative traits generally decreased as productivity grew, indicating that while under harsh conditions environmental constraints strongly limit the possible trait values, under more benign conditions various water and nutrient use strategies are adaptable. At high productivity, the strength of divergence in regenerative traits decreased. Since the larger diversity of vegetative traits found here reduces competition, the importance of diverse reproductive strategy is probably lower., Synthesis. Our results partly support the stress-dominance hypothesis, but reveal that assembly rules are more complex. The relative importance of environmental filtering and limiting similarity depends on the trait and on the environmental conditions of the habitat. Traits related to resource use are generally limited by environmental filtering, and this restriction is weakening as conditions become more favourable, while traits related to regeneration are constrained by limiting similarity and are more diverse under harsh conditions. [ABSTRACT FROM AUTHOR]

Numerous grassland experiments have found evidence for a complementarity effect, an increase in productivity with higher plant species richness due to niche partitioning. However, empirical tests of complementarity in natural forests are rare. We conducted a spatially explicit analysis of 518 433 growth records for 274 species from a 50-ha tropical forest plot to test neighborhood complementarity, the idea that a tree grows faster when it is surrounded by more dissimilar neighbors. We found evidence for complementarity: focal tree growth rates increased by 39.8% and 34.2% with a doubling of neighborhood multi-trait dissimilarity and phylogenetic dissimilarity, respectively. Dissimilarity from neighbors in maximum height had the most important effect on tree growth among the six traits examined, and indeed, its effect trended much larger than that of the multi-trait dissimilarity index. Neighborhood complementarity effects were strongest for light-demanding species, and decreased in importance with increasing shade tolerance of the focal individuals. Simulations demonstrated that the observed neighborhood complementarities were sufficient to produce positive stand-level biodiversity-productivity relationships. We conclude that neighborhood complementarity is important for productivity in this tropical forest, and that scaling down to individual-level processes can advance our understanding of the mechanisms underlying stand-level biodiversity-productivity relationships. [ABSTRACT FROM AUTHOR]

Recent studies have shown that accounting for intraspecific trait variation ( ITV) may better address major questions in community ecology. However, a general picture of the relative extent of ITV compared to interspecific trait variation in plant communities is still missing. Here, we conducted a meta-analysis of the relative extent of ITV within and among plant communities worldwide, using a data set encompassing 629 communities (plots) and 36 functional traits. Overall, ITV accounted for 25% of the total trait variation within communities and 32% of the total trait variation among communities on average. The relative extent of ITV tended to be greater for whole-plant (e.g. plant height) vs. organ-level traits and for leaf chemical (e.g. leaf N and P concentration) vs. leaf morphological (e.g. leaf area and thickness) traits. The relative amount of ITV decreased with increasing species richness and spatial extent, but did not vary with plant growth form or climate. These results highlight global patterns in the relative importance of ITV in plant communities, providing practical guidelines for when researchers should include ITV in trait-based community and ecosystem studies. [ABSTRACT FROM AUTHOR]

Aim Functional traits of organisms are key to understanding and predicting bio-diversity and ecological change, which motivates continuous collection of traits and their integration into global databases. Such trait matrices are inherently sparse, severely limiting their usefulness for further analyses. On the other hand, traits are characterized by the phylogenetic trait signal, trait--trait correlations and environmental constraints, all of which provide information that could be used to statistically fill gaps. We propose the application of probabilistic models which, for the first time, utilize all three characteristics to fill gaps in trait databases and predict trait values at larger spatial scales. Innovation For this purpose we introduce BHPMF, a hierarchical Bayesian extension of probabilistic matrix factorization (PMF). PMF is a machine learning technique which exploits the correlation structure of sparse matrices to impute missing entries. BHPMF additionally utilizes the taxonomic hierarchy for trait prediction and provides uncertainty estimates for each imputation. In combination with multiple regression against environmental information, BHPMF allows for extrapolation from point measurements to larger spatial scales. We demonstrate the applicability of BHPMF in ecological contexts, using different plant functional trait datasets, also comparing results to taking the species mean and PMF. Main conclusions Sensitivity analyses validate the robustness and accuracy of BHPMF: our method captures the correlation structure of the trait matrix as well as the phylogenetic trait signal--also for extremely sparse trait matrices--and provides a robust measure of confidence in prediction accuracy for each missing entry. The combination of BHPMF with environmental constraints provides a promising concept to extrapolate traits beyond sampled regions, accounting for intraspecific trait variability. We conclude that BHPMF and its derivatives have a high potential to support future trait-based research in macroecology and functional biogeography. [ABSTRACT FROM AUTHOR]

The effect of biodiversity on ecosystem functioning has been widely acknowledged, and the importance of the functional roles of species, as well as their diversity, in the control of ecosystem processes has been emphasised recently. However, bridging biodiversity and ecosystem science to address issues at a biogeographic scale is still in its infancy. Bridging this gap is the primary goal of the emerging field of functional biogeography. While the rise of Big Data has catalysed functional biogeography studies in recent years, comprehensive evidence remains scarce. Here, we present the rationale and the first results of a country-wide initiative focused on the C 3 permanent grasslands. We aimed to collate, integrate and process large databases of vegetation relevés, plant traits and environmental layers to provide a country-wide assessment of ecosystem properties and services which can be used to improve regional models of climate and land use changes. We outline the theoretical background, data availability, and ecoinformatics challenges associated with the approach and its feasibility. We provide a case study of upscaling of leaf dry matter content averaged at ecosystem level and country-wide predictions of forage digestibility. Our framework sets milestones for further hypothesis testing in functional biogeography and earth system modelling. [ABSTRACT FROM AUTHOR]

Aim Do plant trait databases represent a biased sample of species, and if so, can that bias be corrected? Ecologists are increasingly collecting and analysing data on plant functional traits, and contributing them to large plant trait databases. Many applications of such databases involve merging trait measurements with other data such as species distributions in vegetation plots; a process that invariably produces matrices with incomplete trait and species data. Typically, missing data are simply ignored and it is assumed that the missing species are missing at random. Methods Here, we argue that this assumption is unlikely to be valid and propose an approach for estimating the strength of the bias regarding which species are represented in trait databases. The method leverages the fact that, within a given database, some species have many measurements of a trait and others have few (high vs low measurement intensity). In the absence of bias, there should be no relationship between measurement intensity and trait values. We demonstrate the method using five traits that are part of the TRY database, a global archive of plant traits. Our method also leads naturally to a correction for this bias, which we validate and apply to two examples. Results Specific leaf area and seed mass were strongly positively biased (frequently measured species had higher trait values than rarely measured species), leaf nitrogen per unit mass and maximum height were moderately negatively biased, and maximum photosynthetic capacity per unit leaf area was weakly negatively biased. The bias-correction method yielded greatly improved estimates in the validation tests for the two most biased traits. Further, in our two applications, ecological interpretations were shown to be sensitive to uncorrected bias in the data. Conclusions Species inclusion in trait databases appears to be strongly biased in some cases, and failure to correct this can lead to incorrect conclusions. [ABSTRACT FROM AUTHOR]

Cover crops are used during fallow periods to produce ecosystem services, especially those related to N management such as (i) capturing mineral-N from soil to reduce nitrate leaching, and (ii) improving N availability for the next main crop (green manuring). Bispecific mixtures consisting of legume and non-legume species could simultaneously produce these two services of nitrate saving and green manuring. The magnitude of these services can be estimated from indicators of agroecosystem functions such as crop growth rate, crop N acquisition rate and the C:N ratio of the cover crop. We developed a conceptual model for each indicator which was described using general linear models. A three-step procedure was used: (1) represent the behavior of each species based on a sub-model and calibrate each species in bispecific mixtures; (2) validate the complete-mixture models, corresponding to the sum of the two species sub-models, and the proportion of each species in the whole cover, and (3) validate the generality of sub-models and complete-mixture models to predict the agroecosystem function indicators of species in mixture not used for calibration. The combined use of (i) potential agroecosystem functions measured in sole crop in non-limiting conditions, (ii) difference in leaf functional traits, as indicators of plant strategies and (iii) environmental factors, was efficient in fitting and predicting the level of agroecosystem functions provided by a cover crop species in mixture in actual conditions. The models fitted for bispecific mixtures were efficient to represent the behavior of each species in mixture and to estimate the legume proportion which expressed the species dominance. The models were evaluated as satisfactory for crop growth rate and C:N ratio for their generality in predicting the agroecosystem functions provided in mixtures by other species not used in the model calibration step, which illustrates the relevance and robustness of the approach. [ABSTRACT FROM AUTHOR]

We used a conjoint analysis to reveal the preferences of experts with respect to plant attributes under three different restoration scenarios (high-level conservation, functional native vegetation, perennial native pasture) and to generate prioritized lists for restoration of grassy woodland species. Nineteen experts participated in the conjoint analysis. The sample comprised researchers and practitioners with local knowledge of grassy ecosystems. The survey involved repeated pairwise ranking of the relevance of attributes of seven ecological criteria. The relative weightings of the attributes were then used to generate the 50 top-ranked species for each of the three scenarios. Overall phosphorus tolerance was considered the most important criterion, followed by grazing tolerance. Species favoured for high-level conservation management included nutrient- and grazing-intolerant plants with narrower distributions and some species of threatened status. The two scenarios with histories of fertilization and varying levels of ongoing grazing were most similar in that their lists were dominated by graminoids and did not contain any shrubs or geophytes. The ranking of species provides an initial list that could be tailored to take into account specific site conditions and additional knowledge of species. This approach to the selection of species shows promise as either a repeatable process to select species for particular sites, or to generate a classification of species that could be used generically for a small number of common situations. [ABSTRACT FROM AUTHOR]

Functional trait databases are powerful tools in ecology, though most of them contain large amounts of missing values. The goal of this study was to test the effect of imputation methods on the evaluation of trait values at species level and on the subsequent calculation of functional diversity indices at community level using functional trait databases. Two simple imputation methods (average and median), two methods based on ecological hypotheses, and one multiple imputation method were tested using a large plant trait database, together with the influence of the percentage of missing data and differences between functional traits. At community level, the complete-case approach and three functional diversity indices calculated from grassland plant communities were included. At the species level, one of the methods based on ecological hypothesis was for all traits more accurate than imputation with average or median values, but the multiple imputation method was superior for most of the traits. The method based on functional proximity between species was the best method for traits with an unbalanced distribution, while the method based on the existence of relationships between traits was the best for traits with a balanced distribution. The ranking of the grassland communities for their functional diversity indices was not robust with the complete-case approach, even for low percentages of missing data. With the imputation methods based on ecological hypotheses, functional diversity indices could be computed with a maximum of 30% of missing data, without affecting the ranking between grassland communities. The multiple imputation method performed well, but not better than single imputation based on ecological hypothesis and adapted to the distribution of the trait values for the functional identity and range of the communities. Ecological studies using functional trait databases have to deal with missing data using imputation methods corresponding to their specific needs and making the most out of the information available in the databases. Within this framework, this study indicates the possibilities and limits of single imputation methods based on ecological hypothesis and concludes that they could be useful when studying the ranking of communities for their functional diversity indices. [ABSTRACT FROM AUTHOR]

Resprouting of woody species after above-ground damage may help plants to persist longer at a given site and quickly reoccupy disturbed sites, thereby strongly influencing forest dynamics. Resprouting has been discussed from two adaptation perspectives: recovery from damage by catastrophic disturbance and survival in frequently disturbed shaded understorey. However, few studies have comprehensively dealt with both adaptation types to understand resprouting strategies., To understand the adaptive significance of resprouting, we assessed the size dependence of resprouting ability after stem clipping for 24 deciduous broad-leaved species, including shrubs, sub-canopy and canopy trees, in a cool-temperate forest in Japan. The community assembly includes species adapted to past catastrophic disturbances (e.g. fire, logging) and to stable forest with intermittent treefall (currently the dominant disturbance). We correlated resprouting ability with life-history strategies based on demographic parameters and plant functional traits, such as leaf mass per area ( LMA), leaf toughness and wood density., All the studied species could resprout in juveniles, and resprouting ability increased as stump size increased. Most sub-canopy and canopy trees lost their ability to resprout after attaining a particular stump size, whereas shrub species retained the ability to resprout throughout their lifetimes., The relative growth rate, LMA and foliar nitrogen did not greatly influence the resprouting ability of a species. In contrast, species with smaller maximum size, lower leaf toughness and lower wood density had better juvenile resprouting ability. This better resprouting ability may have evolved because these characteristics make them more vulnerable to shaded understorey. However, species with larger maximum size and lower leaf toughness retained their ability to resprout to a larger size., Synthesis. A better resprouting ability is related to the ability to survive frequent disturbances, in juveniles, which are characteristics of both forest understorey and frequent fire or drought. To retain resprouting ability until grown seems to be an adaptation to survive infrequent large disturbances. Light-demanding species, which generally have better resprouting ability than shade-tolerants both in juveniles and adults, are adapted to disturbances of various scale and frequency; however, shade-tolerants could survive well in the understorey due to a combination of stronger physical defences and resprouting ability. [ABSTRACT FROM AUTHOR]