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Coal is the most abundant fossil fuel in Europe, but the excavation of hard coal has covered large areas with disposed rock waste, and turned the natural habitats into disturbed novel ecosystems with harsh conditions differ in time and space. To examine the spontaneous complex successional gradient, we studied a large number of post coalmine heaps in Upper Silesia, which differ in vegetation type and age. Cluster analysis based on plant community composition (367 species in total) separated all surveyed plots on coal mining spoil heaps with herbaceous vegetation from Late Stage (LS) forests aged 14--56 years. Furthermore, the herbaceous vegetation was sub-grouped to three stages: Initial Stage (IS) aged 2--5 years, Early Stage (ES) aged 3--8 years and Mid-Stage (MS) aged 5--12 years. MS vegetation was characterised by the highest species richness and diversity (47 and 2.79) compared to ES (30 and 2.18) and IS (9 and 1.6), but higher species number and a similar diversity index occurred in LS (37 and 2.81). Functional diversity (FD) and community weighted mean (CWM) of nine functional traits showed higher (23.1) functional richness, higher (0.72) functional divergence, higher (4.5) functional dispersion, and higher value (24.4) of Rao's quadratic entropy in LS compared to those calculated from the first three stages. Species at the initial successional stage (IS) were characterised by lower canopy height, seed mass, higher lateral spread, and specific leaf area (SLA). Additionally, the lowest (0.22 mg CO2 per hour per square metre) soil respiration (Sr) rate was recorded from IS compared to (0.53, 0.82 and 1.00) from ES, LS and MS, respectively. The soil water content (SWC) was the most important factor affecting the soil respiration, while the soil temperature (St) did not follow the well-studied relationship between soil respiration and soil temperature. Our spatial and temporal analyses illustrated changes in plant community assembly processes in the course of spontaneous vegetation succession on post coalmine spoil heaps. The importance of trait mediated abiotic filtration in community assembly in initial-, early-, and mid-stages of succession with an increase in competitive exclusion at the late successional stage was emphasized. [ABSTRACT FROM AUTHOR]

A community functional structure may respond to environmental changes such as nitrogen (N) enrichment by altering intraspecific and interspecific trait variations. However, the relative contributions of both components in determining the community response to N enrichment are unclear. In this study, we measured the plant height (H), leaf area (LA), leaf dry matter content (LDMC), and specific leaf area (SLA) based on a nine-year N addition gradient experiment in an alpine meadow on the Tibetan Plateau. We examined the intraspecific and interspecific variations within and among the communities, the responses of traits in terms of community weighted mean (CWM) and non-weighted mean (CM) to N addition, and the effects of these trait variations on aboveground net primary productivity (ANPP). Our results show that N addition increased the interspecific variation in H while decreasing that of LA within the community, whereas it had no significant effects on the intraspecific variations in the four traits within the community. In contrast, N addition significantly increased the intraspecific variation in H and decreased that of LA among the communities. Moreover, the contribution of intraspecific variation was greater than that of the interspecific variation in terms of CWM for all traits, while the opposite contribution was observed in terms of CM, suggesting that the dominant species would have greater resilience while subdominant species would become less resistant to N addition. Further, intraspecific variations of LA and LDMC within the community played an important role in explaining community productivity. Our results highlight the importance of both intraspecific and interspecific variations in mediating functional trait responses to N enrichment, and intraspecific variation within the communities has important implications for community functioning that should be considered to better understand and predict the responses of the alpine grasslands to N enrichment. [ABSTRACT FROM AUTHOR]

(1): The Upper Silesia region of Poland is one of the most extensively altered regions of Europe due to human activity, especially coal mining. (2): We used cluster analysis to examine the floristic composition of three classified forest communities: forests developed on post-coal mine mineral heaps (HF), mixed deciduous forests (DECI), and managed secondary coniferous forests (CON). Vegetation data were collected from 44 randomly selected plots, and plant traits connected with persistence, dispersal, and regeneration were taken from commonly used plant trait databases. (3): Higher species richness, species diversity, and evenness (36, 2.7, and 0.76, respectively) were calculated for HF plots compared with those plots from DECI (22, 1.9, and 0.62) and CON (18, 2.0, and 0.71) plots. Higher functional richness (0.173, 0.76) and functional divergence were determined for HF compared with those calculated for DECI (FRic 0.090, FDiv 0.71) and CON (FRic 0.026, FDiv 0.69). In contrast, the substrate from HF forests had significantly lower soil respiration (0.76 mg-CO2 h/m2) compared with substrates from both CON and DECI forests (0.90 and 0.96 mg-CO2 h/m2, respectively); (4): A set of complex abiotic stresses which plants suffer from on coal mine spoil heaps shaped different patterns of taxonomic and functional diversity. These findings demonstrate the importance of investigating successional aspects and carbon dynamics of de novo forests which have developed on post-coal mine spoil heaps in urban industrial areas. [ABSTRACT FROM AUTHOR]

Coal is the most abundant fossil fuel in Europe, but the excavation of hard coal has covered large areas with disposed rock waste, and turned the natural habitats into disturbed novel ecosystems with harsh conditions differ in time and space. To examine the spontaneous complex successional gradient, we studied a large number of post coalmine heaps in Upper Silesia, which differ in vegetation type and age. Cluster analysis based on plant community composition (367 species in total) separated all surveyed plots on coal mining spoil heaps with herbaceous vegetation from Late Stage (LS) forests aged 14–56 years. Furthermore, the herbaceous vegetation was sub-grouped to three stages: Initial Stage (IS) aged 2–5 years, Early Stage (ES) aged 3–8 years and Mid-Stage (MS) aged 5–12 years. MS vegetation was characterised by the highest species richness and diversity (47 and 2.79) compared to ES (30 and 2.18) and IS (9 and 1.6), but higher species number and a similar diversity index occurred in LS (37 and 2.81). Functional diversity (FD) and community weighted mean (CWM) of nine functional traits showed higher (23.1) functional richness, higher (0.72) functional divergence, higher (4.5) functional dispersion, and higher value (24.4) of Rao’s quadratic entropy in LS compared to those calculated from the first three stages. Species at the initial successional stage (IS) were characterised by lower canopy height, seed mass, higher lateral spread, and specific leaf area (SLA). Additionally, the lowest (0.22 mg CO2 per hour per square metre) soil respiration (Sr) rate was recorded from IS compared to (0.53, 0.82 and 1.00) from ES, LS and MS, respectively. The soil water content (SWC) was the most important factor affecting the soil respiration, while the soil temperature (St) did not follow the well-studied relationship between soil respiration and soil temperature. Our spatial and temporal analyses illustrated changes in plant community assembly processes in the course of spontaneous vegetation succession on post coalmine spoil heaps. The importance of trait mediated abiotic filtration in community assembly in initial-, early-, and mid-stages of succession with an increase in competitive exclusion at the late successional stage was emphasized.

Plant functional traits are indicative of plant responses to environmental changes, influencing ecosystem functions. Leaves, as a key focus in studying plant functional traits, present an area where the impact of nitrogen deposition and altered rainfall patterns on functional diversity remains ambiguous. To elucidate plant response mechanisms to environmental factors, we employed a canopy-based platform to add nitrogen, water, and their combination. We assessed the functional traits and community-weighted mean of the leaves of three dominant trees and three dominant shrubs. The results showed that nitrogen addition to the canopy significantly increased the leaf dry matter content of the Celtis sinensis Pers, but markedly decreased the specific leaf area of the Liquidambar formosana Hance. The nitrogen-water interaction did not notably affect the specific leaf area and equivalent water thickness of leaves. Canopy addition of nitrogen, water, and their combined interaction substantially lowered leaf nitrogen content and markedly increased leaf C/N. The structural equation model demonstrated a significant negative correlation between leaf dry matter content, equivalent water thickness, and leaf nitrogen content, as well as between equivalent water thickness and leaf phosphorus content. Our results provide evidence for the adaptation of plants to the environment and different strategies for resource and energy utilization.

Wood density (WD) is a key functional trait related to ecological strategies and ecosystem carbon dynamics. Despite its importance, there is a considerable lack of information on WD in tropical Andean forests, particularly regarding its relationship with forest succession and ecosystem carbon cycling. Here, we quantified WD in 86 upper Andean tree and shrub species in central Colombia, with the aim of determining how WD changes with forest succession and how it is related to productivity. We hypothesized that WD will increase with succession because early successional forests will be colonized by acquisitive species, which typically have low WD, while the shaded understory of older forests should favor higher WD. We measured WD in 481 individuals from 27 shrub and 59 tree species, and quantified aboveground biomass (AGB), canopy height, net primary production (NPP) and species composition and abundance in 14, 400-m², permanent plots. Mean WD was 0.513 ± 0.114 (g/cm³), with a range between 0.068 and 0.718 (g/cm³). Shrubs had, on average, higher WD (0.552 ± 0.095 g/cm³) than trees (0.488 ± 0.104 g/cm³). Community weighted mean WD (CWMwd) decreased with succession (measured as mean canopy height, AGB, and basal area); CWMwd also decreased with aboveground NPP and stem growth. In contrast, the percentage of NPP attributed to litter and the percent of shrubs in plots increased with CWMwd. Thus, our hypothesis was not supported because early successional forests had higher CWMwd than late successional forests. This was related to a high proportion of shrubs (with high WD) early in succession, which could be a consequence of: 1) a low seed availability of trees due to intense land use in the landscape and/or 2) harsh abiotic conditions early in succession that filter out trees. Forest with high CWMwd had a high %NPP attributed to litter because they were dominated by shrubs, which gain little biomass in their trunks. Our findings highlight the links between WD, succession and carbon cycling (biomass and productivity) in this biodiversity hotspot. Thus, WD is an important trait that can be used to understand upper Andean forest recovery and improve forest restoration and management practices. [ABSTRACT FROM AUTHOR]

A community functional structure may respond to environmental changes such as nitrogen (N) enrichment by altering intraspecific and interspecific trait variations. However, the relative contributions of both components in determining the community response to N enrichment are unclear. In this study, we measured the plant height (H), leaf area (LA), leaf dry matter content (LDMC), and specific leaf area (SLA) based on a nine-year N addition gradient experiment in an alpine meadow on the Tibetan Plateau. We examined the intraspecific and interspecific variations within and among the communities, the responses of traits in terms of community weighted mean (CWM) and non-weighted mean (CM) to N addition, and the effects of these trait variations on aboveground net primary productivity (ANPP). Our results show that N addition increased the interspecific variation in H while decreasing that of LA within the community, whereas it had no significant effects on the intraspecific variations in the four traits within the community. In contrast, N addition significantly increased the intraspecific variation in H and decreased that of LA among the communities. Moreover, the contribution of intraspecific variation was greater than that of the interspecific variation in terms of CWM for all traits, while the opposite contribution was observed in terms of CM, suggesting that the dominant species would have greater resilience while subdominant species would become less resistant to N addition. Further, intraspecific variations of LA and LDMC within the community played an important role in explaining community productivity. Our results highlight the importance of both intraspecific and interspecific variations in mediating functional trait responses to N enrichment, and intraspecific variation within the communities has important implications for community functioning that should be considered to better understand and predict the responses of the alpine grasslands to N enrichment.

(1): The Upper Silesia region of Poland is one of the most extensively altered regions of Europe due to human activity, especially coal mining. (2): We used cluster analysis to examine the floristic composition of three classified forest communities: forests developed on post-coal mine mineral heaps (HF), mixed deciduous forests (DECI), and managed secondary coniferous forests (CON). Vegetation data were collected from 44 randomly selected plots, and plant traits connected with persistence, dispersal, and regeneration were taken from commonly used plant trait databases. (3): Higher species richness, species diversity, and evenness (36, 2.7, and 0.76, respectively) were calculated for HF plots compared with those plots from DECI (22, 1.9, and 0.62) and CON (18, 2.0, and 0.71) plots. Higher functional richness (0.173, 0.76) and functional divergence were determined for HF compared with those calculated for DECI (FRic 0.090, FDiv 0.71) and CON (FRic 0.026, FDiv 0.69). In contrast, the substrate from HF forests had significantly lower soil respiration (0.76 mg-CO2 h/m2) compared with substrates from both CON and DECI forests (0.90 and 0.96 mg-CO2 h/m2, respectively); (4): A set of complex abiotic stresses which plants suffer from on coal mine spoil heaps shaped different patterns of taxonomic and functional diversity. These findings demonstrate the importance of investigating successional aspects and carbon dynamics of de novo forests which have developed on post-coal mine spoil heaps in urban industrial areas.

Wood density (WD) is a key functional trait related to ecological strategies and ecosystem carbon dynamics. Despite its importance, there is a considerable lack of information on WD in tropical Andean forests, particularly regarding its relationship with forest succession and ecosystem carbon cycling. Here, we quantified WD in 86 upper Andean tree and shrub species in central Colombia, with the aim of determining how WD changes with forest succession and how it is related to productivity. We hypothesized that WD will increase with succession because early successional forests will be colonized by acquisitive species, which typically have low WD, while the shaded understory of older forests should favor higher WD. We measured WD in 481 individuals from 27 shrub and 59 tree species, and quantified aboveground biomass (AGB), canopy height, net primary production (NPP) and species composition and abundance in 14, 400-m2, permanent plots. Mean WD was 0.513 ± 0.114 (g/cm3), with a range between 0.068 and 0.718 (g/cm3). Shrubs had, on average, higher WD (0.552 ± 0.095 g/cm3) than trees (0.488 ± 0.104 g/cm3). Community weighted mean WD (CWMwd) decreased with succession (measured as mean canopy height, AGB, and basal area); CWMwd also decreased with aboveground NPP and stem growth. In contrast, the percentage of NPP attributed to litter and the percent of shrubs in plots increased with CWMwd. Thus, our hypothesis was not supported because early successional forests had higher CWMwd than late successional forests. This was related to a high proportion of shrubs (with high WD) early in succession, which could be a consequence of: 1) a low seed availability of trees due to intense land use in the landscape and/or 2) harsh abiotic conditions early in succession that filter out trees. Forest with high CWMwd had a high %NPP attributed to litter because they were dominated by shrubs, which gain little biomass in their trunks. Our findings highlight the links between WD, succession and carbon cycling (biomass and productivity) in this biodiversity hotspot. Thus, WD is an important trait that can be used to understand upper Andean forest recovery and improve forest restoration and management practices.

Polychaetes play a vital role in the structure and functioning of benthic communities in mangrove ecosystems. Nevertheless, our understanding of the diversity and functional structure of polychaete assemblages across different habitats in the mangrove ecosystems along the coast of the Persian Gulf and Gulf of Oman is limited. In this study, we investigated the species and trait composition of polychaetes and environmental variables, in vegetated and mudflat habitats of three subtropical mangroves. The results showed that Neanthes glandicincta was widely distributed across all regions and habitats. The three-factor ANOVA showed that the abundance and taxonomic diversity of polychaetes differed significantly between two habitats and three mangrove ecosystems. The abundance of polychaetes was observed to be higher in mud habitats than in vegetated habitats. There was a significant difference in species and trait composition between different regions and habitats. Vegetated habitats had higher proportions of crawler predatory species that are longer lived (3–5 years), with larger body size (80–100 mm), and are upward conveyors, whereas mudflat habitats had higher proportions of mobile (burrower) omnivore species that are moderately lived (1–3 years), with larger body size (>100 mm), and are biodiffusers. The three-factor ANOVA showed a significant difference in the community weighted mean (CWM) index between two habitats and three mangrove ecosystems. Thus, the species and trait composition of polychaetes depend on the structural complexity of their respective habitats. The DistLM analysis showed that total organic carbon content of the sediment was the main predictor variable influencing species composition, while silt/clay content and salinity were the main predictor variables influencing the traits' composition. The results showed how the composition of traits and the structure of polychaete communities change in mangrove ecosystems, which can be used for future studies on conservation strategies for mangrove ecosystems throughout the world. [ABSTRACT FROM AUTHOR]

The relationship between ecosystem functions and plant functional traits has been well documented and is considered to be one of the most vital topics in ecology. However, the correlation between anthropogenic disturbance and tree functional trait diversity remains largely unclear. The present study investigates the role of anthropogenic disturbance on selected tree functional traits in Ratargul Swamp Forest (RSF) – the only remnant tropical freshwater swamp forest ecosystem in Bangladesh. We established 50 plots and collected six plant traits, i.e., tree height, specific leaf area (SLA), wood density (WD), leaf dry matter content (LDMC), seed mass, and bark thickness. A two-way analysis of variance (ANOVA) was carried out to test the interaction between plant functional traits and anthropogenic disturbance in RSF. Our study found that anthropogenic disturbance has a significant (p< 0.05) influence on deciduous swamp forest tree species’ functional traits but none on evergreen tree species’ functional traits. For deciduous trees, disturbance has a significant positive effect on CWM.SLA (p< 0.05) and CWM.Height (p< 0.05) and a negative impact on CWM.Bark-thickness and CWM.Seed-mass (p< 0.05). There were no significant effects of disturbance on CWM.WD and CWM.LDMC. We believe the present study will contribute toward improving our understanding of the effect of disturbances on tree functional trait diversity in tropical human-dominated landscapes where anthropogenic pressure is increasing at an unprecedented rate. It will also function as an essential conservation for related decision-making of Ratargul Swamp Forest in northeastern Bangladesh and elsewhere in the tropics with a similar context.

Weed community structure, including composition, taxonomic and functional diversity, may explain variability in crop quality, adding to the variability accounted by management, climatic and genetic factors. Focusing on Mediterranean rainfed wheat crops, we sampled weed communities from 26 fields in Spain that were either organically or conventionally managed. Weed communities were characterized by their abundance and taxonomic, compositional and trait-based measures. Grain protein concentration and the glutenin to gliadin ratio were used as indicators of wheat grain quality. Linear mixed effects models were used to analyze the relationship between crop quality and weed community variables, while accounting for environmental factors. Nitrogen fertilization, previous crop and precipitation explained a large portion of the variation in wheat grain protein concentration (R2marginal = 0.39) and composition (R2marginal = 0.26). Weed community measures had limited effects on grain quality (increasing R2marginal of models by 1% on average). The weed effects were related to the composition and the functional structure of their communities, but not to their abundance. Environmental conditions promoting higher protein concentration were also selecting for weed species with competitive attributes, whereas the role of weed functional diversity depended on the functional trait and on the resource limiting crop grain quality. Understanding the mechanisms of weed effects on crop quality could aid on designing sustainable weed management practices. [ABSTRACT FROM AUTHOR]

Polychaetes play a vital role in the structure and functioning of benthic communities in mangrove ecosystems. Nevertheless, our understanding of the diversity and functional structure of polychaete assemblages across different habitats in the mangrove ecosystems along the coast of the Persian Gulf and Gulf of Oman is limited. In this study, we investigated the species and trait composition of polychaetes and environmental variables, in vegetated and mudflat habitats of three subtropical mangroves. The results showed that Neanthes glandicincta was widely distributed across all regions and habitats. The three-factor ANOVA showed that the abundance and taxonomic diversity of polychaetes differed significantly between two habitats and three mangrove ecosystems. The abundance of polychaetes was observed to be higher in mud habitats than in vegetated habitats. There was a significant difference in species and trait composition between different regions and habitats. Vegetated habitats had higher proportions of crawler predatory species that are longer lived (3–5 years), with larger body size (80–100 mm), and are upward conveyors, whereas mudflat habitats had higher proportions of mobile (burrower) omnivore species that are moderately lived (1–3 years), with larger body size (>100 mm), and are biodiffusers. The three-factor ANOVA showed a significant difference in the community weighted mean (CWM) index between two habitats and three mangrove ecosystems. Thus, the species and trait composition of polychaetes depend on the structural complexity of their respective habitats. The DistLM analysis showed that total organic carbon content of the sediment was the main predictor variable influencing species composition, while silt/clay content and salinity were the main predictor variables influencing the traits’ composition. The results showed how the composition of traits and the structure of polychaete communities change in mangrove ecosystems, which can be used for future studies on conservation strategies for mangrove ecosystems throughout the world.

Freshwater phytoplankton and zooplankton are complex and diverse communities which greatly contribute to the functioning of freshwater ecosystems, constituting a path of nutrient cycling. The relationships of these communities are often driven by species' functional traits, such as defensive features and grazing adaptations. The aim of the present work was to study if the functional traits of phytoplankton (primary producers) promote specific traits of zooplankton (consumers). We calculated community weighted mean (CWM) of a trait of phytoplankton and zooplankton communities and constructed decision trees to study the relationships between the functional traits of both communities. We found that specific functional traits of zooplankton were most significantly promoted by size and shape of algal particles, followed by potential toxicity and spines possession, which had limited, however still important effects. Armor possession and motility of algae were found not to be promoting any functional traits of zooplankton. Easy-to-handle algal particles promoted greater variability of zooplankton's functional traits, while large, hard to manage algal particles (often characteristic for cyanobacteria) promoted zooplankton taxa bearing more specialized functional traits. Our study shows that phytoplankton functional traits can be considered as a biotic filter, leading to the selection of advantageous functional traits among zooplankton community. [ABSTRACT FROM AUTHOR]

Weed community structure, including composition, taxonomic and functional diversity, may explain variability in crop quality, adding to the variability accounted by management, climatic and genetic factors. Focusing on Mediterranean rainfed wheat crops, we sampled weed communities from 26 fields in Spain that were either organically or conventionally managed. Weed communities were characterized by their abundance and taxonomic, compositional and trait-based measures. Grain protein concentration and the glutenin to gliadin ratio were used as indicators of wheat grain quality. Linear mixed effects models were used to analyze the relationship between crop quality and weed community variables, while accounting for environmental factors. Nitrogen fertilization, previous crop and precipitation explained a large portion of the variation in wheat grain protein concentration (R2marginal = 0.39) and composition (R2marginal = 0.26). Weed community measures had limited effects on grain quality (increasing R2marginal of models by 1% on average). The weed effects were related to the composition and the functional structure of their communities, but not to their abundance. Environmental conditions promoting higher protein concentration were also selecting for weed species with competitive attributes, whereas the role of weed functional diversity depended on the functional trait and on the resource limiting crop grain quality. Understanding the mechanisms of weed effects on crop quality could aid on designing sustainable weed management practices.

The study of plant species and trait distributions can provide answers to many of the ecological challenges of our times, from climate change to the biodiversity crisis. Although traits are classically measured at the species level, understanding intraspecific variation is necessary to determine the type of response species will have to climate change. Here we measured and analyzed seven leaf traits (leaf area—LA, specific leaf area—SLA, leaf thickness—LT, leaf dry mass content—LDMC, venation density—VD, stomata length—SL, and stomata density—SD) across 14 locally dominant palm species (10 individuals/species) distributed along hydro-topographic gradients (1.4–37 m of terrain height above nearest drainage) of a central Amazonian forest to disentangle the role of species identity, relatedness, and local hydrology on trait variation and covariation. Our results show that trait variation is not always larger between species than within species as expected. Intraspecific variation accounted for 23–74% of trait variation depending on the trait. Most of the variation happened at species level for SL, LA, LT, and SD but not for SLA, VD, and LDMC. For a third of the traits (LDMC, SLA, and SD), we found some evidence of phylogenetic inertia. This lack of independency among traits is confirmed by the maintenance of strong correlation among some of those traits after controlling for local environmental conditions. Intraspecific variation, however, was not related to height above nearest drainage for any of the traits. Most of the trait–environment relationships were species-specific. Therefore, the change in palm trait composition detected along topography, from higher community means of SLA and LA, lower LT, LDMC, SL, and SD in the wet valleys to opposite traits in drier plateaus, is mostly due to the turnover in species composition and relative abundance variation. We conclude these palm species have well-defined hydrological niches, but their large intraspecific variation in leaf traits does not contribute to the adjustment of individuals to the local hydrological conditions in this Amazonian forest.

Abstract Various studies have shown that plant species richness can promote ecosystem functions such as biomass storage. However, it is less well known whether this is mostly driven by the dominance of a few species and their associated traits (functional identity), or by complementarity among species that highly vary in their traits (functional diversity). The relative contribution of functional diversity and functional identity on biomass and carbon storage may in part depend on the type of functional traits that are considered, and on ecosystem type. Here, we used forest inventory data from West African semi‐arid environments, and functional traits (wood density and tree maximum height) to examine the effects of functional trait identity (FI or community weighted mean; CWM) and diversity (FD or single functional divergence; FDvar) on aboveground carbon (AGC) storage in both forests and savannas. We fitted simple linear and structural equation models to test the direct and indirect effects of functional traits on AGC, while accounting for potential effects of vegetation stand structure such as stand density and basal area. When evaluated independently, CWM of tree maximum height and FDvar of wood density correlated positively with AGC, in both forests and savannas, whereas species richness was unrelated to AGC. However, structural equation models indicated different mechanisms by which these biodiversity components drove AGC in forests and savannas. In forests, species richness had an indirect, positive effect on AGC via basal area, but also an indirect, negative effect, through a reduction in CWM of maximum height. In savannas, species richness had a direct, negative effect on AGC, while both CWM of maximum height (through an increase in basal area) and FDvar of wood density had positive effects. Our study suggests that integrative models are crucial for understanding the effects of species richness, functional trait diversity, and identity on AGC across forests. Furthermore, our study shows that relationships between biodiversity and AGC differ among ecosystem types. In both forests and savannas, FI played an important role, as AGC was maximized in communities dominated by species with a high maximum height. However, only in savannas a high FD additionally promoted AGC.

As important indicators of leaf traits, leaf anatomical traits are sensitive and adaptable to environmental changes. However, how leaf anatomical traits at species and community levels vary along the altitudinal gradients is still unclear. In this study, a total of 60 woody plants from four typical vegetation zones along the 2000 m-elevation gradients in the northern slope of Taibai Mountain were selected to measure the leaf thickness (LT), epidermal thickness (ET), palisade tissue thickness (PT), spongy tissue thickness (ST), and palisade-spongy tissue thickness ratio (PST). Based on the data of the relative dominance of each species within a community, we calculated the community weighted means (CWM) of leaf traits. We aimed to investigate the variation of leaf anatomical traits at both species and community levels along the altitudinal gradients, and to explore their influencing factors. Our results showed that different elevational patterns of leaf anatomical traits occurred between the species and community levels. At the species level, LT, ET, PT, and ST increased with the altitudinal gradient, which were controlled by both of phylogenetic and environmental factors. Differently, the community-level leaf anatomical traits increased first and then decreased with elevation, and were mainly influenced by climatic factors. These results indicated that, different from species-level traits, community-level traits, which included community structure and species information, could better reflect the real plant community and their variation along the elevation. Furthermore, both of environmental factors and phylogenetic differences should be taken into account when exploring the variation in leaf anatomical traits.

Various studies have shown that plant species richness can promote ecosystem functions such as biomass storage. However, it is less well known whether this is mostly driven by the dominance of a few species and their associated traits (functional identity), or by complementarity among species that highly vary in their traits (functional diversity). The relative contribution of functional diversity and functional identity on biomass and carbon storage may in part depend on the type of functional traits that are considered, and on ecosystem type. Here, we used forest inventory data from West African semi‐arid environments, and functional traits (wood density and tree maximum height) to examine the effects of functional trait identity (FI or community weighted mean; CWM) and diversity (FD or single functional divergence; FDvar) on aboveground carbon (AGC) storage in both forests and savannas. We fitted simple linear and structural equation models to test the direct and indirect effects of functional traits on AGC, while accounting for potential effects of vegetation stand structure such as stand density and basal area. When evaluated independently, CWM of tree maximum height and FDvar of wood density correlated positively with AGC, in both forests and savannas, whereas species richness was unrelated to AGC. However, structural equation models indicated different mechanisms by which these biodiversity components drove AGC in forests and savannas. In forests, species richness had an indirect, positive effect on AGC via basal area, but also an indirect, negative effect, through a reduction in CWM of maximum height. In savannas, species richness had a direct, negative effect on AGC, while both CWM of maximum height (through an increase in basal area) and FDvar of wood density had positive effects. Our study suggests that integrative models are crucial for understanding the effects of species richness, functional trait diversity, and identity on AGC across forests. Furthermore, our study shows that relationships between biodiversity and AGC differ among ecosystem types. In both forests and savannas, FI played an important role, as AGC was maximized in communities dominated by species with a high maximum height. However, only in savannas a high FD additionally promoted AGC. [ABSTRACT FROM AUTHOR]

Introduction: Knowledge on the periphytic community is essential because of its central role in river primary production. Also, periphyton is a valuable bioindicator of the community. However, to the date, little is known about the functional ecology of these communities in Colombian rivers. Objective: This work sought to characterize functional aspects of the phycoperiphytic community of four lotic systems of the La Planada Natural Reserve, located in the Department of Nariño, Colombia. Methods: In May 2019, between one and three sampling sites were established in each river. Hydrological and physicochemical variables were measured. Periphyton was sample to determine the taxonomic composition of the benthic algae as well as some functional traits. From these traits, the community weighted mean (CWM) and community weighted variance (CWV) were calculated, and their relation with abiotic variables was explored using regressions, correlations, and a canonical correspondence analysis (CCA). Results: 59 genera of algae were recorded, from which 47 had its functional traits measured. The CWM of the siliceous exoskeleton trait was statistically higher in El Tejón creek. The other traits had similar CWM and CWV values in all rivers. However, the traits of the presence of mucilage and organization in filaments showed predominance in some streams. The fluctuating data of CWV in all rivers seem to indicate that these phycoperiphytic communities have no resource limitations, competition is low, and species tend to be functionally different. The environmental variables with the greatest influence were flow, water mineralization, pH, and water transparency. The hardness of the water and the presence of mucilage were associated, while the predominance of filamentous algae was related to transparency; pH positively influenced the surface/volume ratio (S/V). Conclusions: This study represents a baseline that will allow evaluating changes in the benthic algae communities in the face of possible interventions and providing guidelines for eventual actions to restore the river systems of this important region due to its high biodiversity. [ABSTRACT FROM AUTHOR]

Ongoing climate warming threatens the survival of bogs at the warm/dry limit of their distribution (e.g. in central Europe), and jeopardises the restoration of damaged bogs even more. Because vegetation changes can be slow, early indicators of hydrological change such as testate amoebae are useful. We used testate amoeba community structure and community weighted mean of functional traits to monitor the impact of two very hot and dry summers on a small (around 100 m2) artificial peatland constructed in the botanic garden of Neuchâtel, Switzerland. We collected analogous samples in a naturally regenerating cutover peatland at 1000 m a.s.l. in the Jura Mountains as a reference. The comparison of living and dead assemblages in the botanic garden showed an increased representation of smaller testate amoeba taxa (Corythion dubium, small Euglypha sp.) with a small pseudostome (indicative of dry conditions) and a loss of mixotrophy in 2015, followed by a weaker further shift in 2016. Nevertheless, the testate amoeba community structure in 2016 still indicated a dry Sphagnum bog. Testate amoeba analysis allows rapid assessment of peatland health and/or restoration success. The comparison of living and dead assemblages makes it possible to observe changes within a season in a single sampling campaign.

Earthworms are important for soil functioning in arable cropping systems and earthworm species differ in their response to soil tillage and crop residue management. Lumbricus terrestris (Linnaeus, 1758) are rare in intensively tilled arable fields. In two parallel field trials with either non-inversion (NIT) or conventional tillage (CT), we investigated the feasibility of inoculating L. terrestris under different crop residue management (amounts and placement). Simultaneously, we monitored the response of the existing earthworm communities to L. terrestris inoculation and to crop residue treatments in terms of earthworm density, species diversity and composition, ecological groups and functional diversity. L. terrestris densities were not affected by residue management. We were not able to infer effects of the inoculation on the existing earthworm communities since L. terrestris also colonized non-inoculated plots. In NIT and two years after trial establishment, the overall native earthworm density was 1.4 and 1.6 times higher, and the epigeic density 2.5 times higher, in treatments with highest residue application (S 100) compared to 25% (S 25) or no (S 0) crop residues, respectively. Residue management did not affect earthworm species composition, nor the functional trait diversity and composition, except for an increase of the community weighted means of bifide typhlosolis in S 0 compared to S 100. In CT, however, crop residues did have a strong effect on species composition, ecological groups and functional traits. Without crop residues (S 0), epigeic density was respectively 20 and 30% lower than with crop residues placed on the soil surface (S 100) or incorporated (I 100). Community composition was clearly affected by crop residues. Trait diversity was 2.6 to 3 times larger when crop residues were provided, irrespective of placement. Crop residues in CT also resulted in heavier earthworms and in a shift in the community towards species with a thicker epidermis and cuticle, a feather typhlosolis shape, and a higher average cocoon production rate. We conclude that earthworm communities under conventional tillage respond more strongly to the amount of crop residue than to its placement. Under non-inversion tillage, crop residue amounts affected earthworm communities, but to a smaller degree than under conventional tillage. • Inoculation of anecic earthworms was more successful in non-inversion than in conventional tillage. • Assessment of earthworm response to crop residues was consistent irrespective of ecological analysis method used. • Earthworm response to residue availability was different between tillage systems. • In conventional tillage the response to residue amount was stronger than to its placement. • In non-inversion tillage epigeics responded strongly to crop residue amount. [ABSTRACT FROM AUTHOR]

Anthropogenic activities are increasing nutrient availability and altering precipitation regimes. This may lead to critical changes in grasslands functioning. This is particularly important for grasslands in the Mediterranean Basin that have evolved in nutrient poor soils, and where more frequent and prolonged droughts are projected to occur. However, there is limited knowledge regarding the interacting effects of multiple nutrient inputs and rainfall variability on the plant functional structure and diversity of Mediterranean grasslands. We conducted a nutrient addition experiment in a Mediterranean grassland during four contrasting precipitation years. We established four treatments that varied in the number of added nutrients, from no added nutrients (control), to one added nutrient (Nitrogen-N, Phosphorus-P, or Potassium-K), two added nutrients, (NP, NK, or PK) and three added nutrients (NPK). We assessed the effect of increasing nutrient addition in wet, normal, dry, and very dry years on plant species functional traits at the community level. We determined the community functional structure (e.g., Community Weighted Mean, CWM) and functional diversity (e.g., Functional Dispersion, FDis) for eight key functional traits indicators of nutrient and water use strategies. We also assessed if CWM, FDis, and species richness were related to the aggregate grassland functioning property, i.e., productivity. We found that CWM was affected by nutrient addition and precipitation and, for some traits, by their interaction. However, FDis of most traits was affected by precipitation. The very dry year had a negative effect on FDis of most traits (e.g., dispersal modes, nutrient uptake strategies) and interacted with three added nutrients to decrease FDis of growth-forms. Conversely, FDis of reproductive traits decreased during the wet year. Species richness and FDis were not related to grassland productivity, whereas CWM was the main determinant of grassland productivity supporting the importance of species functional traits in determining ecosystem functioning. Our results highlight drought as a critical factor determining a decrease in the functional diversity of Mediterranean grasslands. Moreover, drought can also interact with nutrient addition changing the dominance of many traits and further decreasing functional diversity. This may have important implications for grasslands functioning in the context of global changes.

Ongoing climate warming threatens the survival of bogs at the warm/dry limit of their distribution (e.g. in central Europe), and jeopardises the restoration of damaged bogs even more. Because vegetation changes can be slow, early indicators of hydrological change such as testate amoebae are useful. We used testate amoeba community structure and community weighted mean of functional traits to monitor the impact of two very hot and dry summers on a small (around 100 m2) artificial peatland constructed in the botanic garden of Neuchâtel, Switzerland. We collected analogous samples in a naturally regenerating cutover peatland at 1000 m a.s.l. in the Jura Mountains as a reference. The comparison of living and dead assemblages in the botanic garden showed an increased representation of smaller testate amoeba taxa (Corythion dubium, small Euglypha sp.) with a small pseudostome (indicative of dry conditions) and a loss of mixotrophy in 2015, followed by a weaker further shift in 2016. Nevertheless, the testate amoeba community structure in 2016 still indicated a dry Sphagnum bog. Testate amoeba analysis allows rapid assessment of peatland health and/or restoration success. The comparison of living and dead assemblages makes it possible to observe changes within a season in a single sampling campaign. [ABSTRACT FROM AUTHOR]

Ecologists use approaches based on plant functional traits to tackle several fundamental and applied questions. Although a perfect characterization of functional trait structure requires the measurement of all the individuals in communities, this is prohibitively resource-consuming. Consequently, the general practice is to average the trait values of a reduced number of individuals per species. However, there are different alternatives regarding the number, identity and spatial location of the individuals chosen to calculate species-averaged trait values., In this study, we compared different strategies for sampling functional traits, using community-weighted mean trait values (CWM) and the Rao index of functional diversity (FD). We intensively sampled the functional trait structure along a topographical gradient in a Mediterranean grassland, obtaining accurate estimations of the 'real' values of these indices (CWMI and FDI) for three traits (height, leaf area and specific leaf area)., We simulated three different sampling strategies differing in the spatial location of the individuals used to estimate species-mean trait: (i) average of the whole gradient (GLO), (ii) average of the sampling unit in which the abundances of species maximize (MAX) and (iii) average of a reduced number of individuals per species and sampling unit (LOC). For each strategy, we simulated different sampling intensities (number of individuals sampled)., For each trait, we examined the ability of each strategy and sampling intensity to accurately estimate CWMI and FDI, as well as their ability to detect changes in functional trait structure along the topographical gradient., LOC outperformed the other strategies in terms of accuracy and bias, and was much more efficient to describe changes along the gradient, regardless of the traits and indicators considered. Furthermore, LOC was the only strategy that improved consistently as sampling intensity increased, especially at low levels of intensity., Our results indicate that the impact of considering intraspecific variability in trait values can be greater than commonly assumed. Strategies that neglect this source of variability can result in inaccurate or biased estimations of the functional trait structure of plant communities. Most importantly, we show that intraspecific variability can be taken into consideration without any increases in the total number of individuals measured. [ABSTRACT FROM AUTHOR]

There is a need for accurate predictions of ecosystem carbon (C) and water fluxes in field conditions. Previous research has shown that ecosystem properties can be predicted from community abundance-weighted means (CWM) of plant functional traits and measures of trait variability within a community (FDvar). The capacity for traits to predict carbon (C) and water fluxes, and the seasonal dependency of these trait-function relationships has not been fully explored. Here we measured daytime C and water fluxes over four seasons in grasslands of a range of successional ages in southern England. In a model selection procedure, we related these fluxes to environmental covariates and plant biomass measures before adding CWM and FDvar plant trait measures that were scaled up from measures of individual plants grown in greenhouse conditions. Models describing fluxes in periods of low biological activity contained few predictors, which were usually abiotic factors. In more biologically active periods, models contained more predictors, including plant trait measures. Field-based plant biomass measures were generally better predictors of fluxes than CWM and FDvar traits. However, when these measures were used in combination traits accounted for additional variation. Where traits were significant predictors their identity often reflected seasonal vegetation dynamics. These results suggest that database derived trait measures can improve the prediction of ecosystem C and water fluxes. Controlled studies and those involving more detailed flux measurements are required to validate and explore these findings, a worthwhile effort given the potential for using simple vegetation measures to help predict landscape-scale fluxes. [ABSTRACT FROM AUTHOR]

Highlights: [•] A subarctic peatland was subjected to an increase in extreme summer rain events. [•] Extreme summer rain events were simulated for three consecutive years. [•] An increase in extreme summer rain events did not affect Collembola density. [•] Extreme rain events did not affect Collembola community composition and trait means. [ABSTRACT FROM AUTHOR]

Abstract: Top-soil removal followed by species introduction through hay transfer has appeared as a method to restore drained fens. This method addresses abiotic constraints by restoring hydrology and nutrient status, and biotic constraints by removing an unwanted seed bank and counteracting dispersal-limitation. Restoration works by altering environmental filters. Knowledge about the restoration actions effect on functional traits is necessary to understand which types of species may establish. In this study we analyse which factors in top-soil removal followed by hay transfer influence selection and composition of functional traits. Top-soil removal followed by hay transfer from reference sites was conducted at two sites in the Całowanie fen, 33km SE of Warsaw, Poland. Species and abundance data were recorded for three consecutive years. These data, combined with data on functional traits were used to analyse the effect of the restoration actions on four functional diversity-indices and the community weighted mean of functional traits. Our results reveal a strong habitat filter in the restoration site that follows an elevation gradient. At low elevation this filter selects low values of autochory and specific leaf area and high values of clonal lateral spread, Ellenberg moisture values, and dispersal through hydrochory. The transferred hay differs in trait characteristics compared to the reference site vegetation by having species of higher specific leaf area, lower Ellenberg moisture value and lower dispersal by autochory and hydrochory. The result presented here has three important implications for fen restoration. First, the difference in trait-characteristics between the transferred hay and the reference site it was harvested from limits the restoration potential. Second, since for several fen species important functional traits are filtered along an elevation-gradient, careful planning regarding depth of top-soil removal is needed. Finally the results illustrate how a functional analysis can be used to detect environmental filters acting during ecological restoration. [Copyright &y& Elsevier]

Abstract: A trait-based approach was used to evaluate the restoration success of a moss layer transfer technique on the herbaceous community of a cut-over bog. In order to understand the herbaceous dynamics following restoration, the bog was monitored prior to restoration and biannually over ten subsequent years, in two initial drainage conditions (dry peat fields and wet ditches), and compared to seven undisturbed bogs. Herbaceous community found prior to and in the early stage after restoration were characterized by species associated to mesic soil conditions with a fen-like pH, ruderal or wetland species, species with mycorrhiza or exotic species. These species did not persist in the latter stage after restoration and were replaced by species that are carnivorous, are associated to variable water availability and show mostly sexual reproduction. The extent of changes in traits composition of the herbaceous community between the early and latter stages after restoration showed the importance of multiple-year monitoring to evaluate restoration projects. The trait composition found in the latter stage after restoration appeared to converge toward the reference ecosystem where the community was characterized by species with large seeds, associated to humid soil conditions and a forest or peatland habitat. Lower trait diversity was found in the latter stage after restoration than in the reference ecosystem, especially in peat fields. In addition, species and functional diversity pattern varied with the initial drainage conditions, decreasing in peat fields while remaining stable in ditches. This suggests that different initial topography for restoration might help increase species and functional diversity of a managed ecosystem. Finally, our results outline measures to improve the moss layer transfer technique: sowing herbaceous species with large seeds in the latter stage after restoration, applying the restoration technique as soon as exploitation has terminated or removing all vegetation (including seeds and rhizomes) from the site to be restored. [Copyright &y& Elsevier]

Abstract: Growing demand for alternative energy sources has led to an increased production of biomass crops. In order to limit the use of fertile agricultural land for producing bioenergy, low quality agricultural land, as well as degraded or drastically disturbed soils have been proposed for the cropping of bioenergy cultivars. Our work aimed at assessing the dynamics of soil invertebrate diversity after plantation of perennial energy crops on metal polluted soils. The results were compared with invertebrate diversity dynamics in soils of other plots, representative either for the dominant land occupancies in the study area, or for unpolluted soil situations. We investigated taxonomic, compositional and functional dimensions of diversity in soil- and surface-dwelling communities. Changes in land use from annual crops to perennial energy crops led to a higher number of individuals in soil. No or few changes in taxonomic richness were recorded with an increasing age of energy cropping. Regarding functional diversity, the proportions of resident invertebrates tended to vary with the age of energy cropping, but neither the trophic composition nor the body spectra were modified. Our findings highlighted an increase of soil carrying capacity after perennial energy crop plantation on metal polluted soils, but effects on invertebrate diversity were limited. [Copyright &y& Elsevier]