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opencc-zeroNov 2020View details →

Data from: Mycorrhizal suppression and phosphorus addition influence the stability of plant community composition and function in a temperate steppe

Nutrient enrichment can reduce ecosystem stability, typically measured as the temporal stability of productivity that has multiple underlying mechanism including species resistance and resilience to nutrient pulses and the resulting compositional change. Moreover, nutrient enrichment can alter plant-soil interactions (e.g. mycorrhizal symbiosis) that determine plant productivity and diversity. Thus, it is likely that nutrient enrichment and interactions between plants and their soil communities co-determine the stability in plant community composition and productivity. Yet our understanding as to how nutrient enrichment affects the multiple facets of ecological stability and the role of above-belowground interactions are still lacking. We tested how mycorrhizal suppression and phosphorus (P) addition influenced functional and compositional stability of plant community in a three-year field study. Here functional stability is the temporal community variance in primary productivity; compositional stability is represented by compositional resistance, turnover, species extinction and invasion. Compared with mycorrhizal suppression, the intact AM fungal communities reduced community variance in primary productivity by reducing species synchrony at high levels of P addition. Species synchrony and population variance were linearly associated with community variance when mycorrhiza were not suppressed, while these relationships were decoupled or weakened by mycorrhizal suppression. The intact AM fungal communities promoted the compositional resistance of plant communities by reducing compositional turnover, but this effect was suppressed by P addition. P addition increased the number of species extinctions and thus promoted compositional turnover. Our study shows P addition and AM fungal communities can jointly and independently modify the various components of ecosystem stability in terms of plant community productivity and composition.

zenodo32/100

Dataset used for the submitted manuscript "The hump-shaped effect of plant functional diversity on the biological control of a multi-species pest community"

Dataset

opencc-by-4.0Dec 2020View details →

opencc-zeroApr 2020View details →

Contrasting responses of different functional groups stabilise community responses to a dominant shrub under global change

1. Changes in precipitation regimes and nitrogen deposition levels due to global change are altering terrestrial ecosystems worldwide. Most attempts at understanding how biotic interactions affect plant species and community responses to global change have focused on biotic interactions measured at the community-level. However, these approaches ignore that communities include functionally dissimilar species that might respond differently to changes in the effects of dominant neighbours along environmental gradients. We test the hypothesis that plant species with differences in functional traits may exhibit contrasting interactions with a dominant shrub species within a single community, thereby stabilizing community-level responses to the effects of global change. 2. We manipulated water and nitrogen applications in a semi-arid dune community in northern China, quantified the biomass of herbaceous species occurring below the dominant shrub, Artemisia ordosica, and in adjacent open patches (without the shrub), and measured herbaceous species height and leaf dry matter content. The effects of A. ordosica were quantified at the species, group, and community levels using the relative interaction index (RII). Redundancy analysis was performed on species traits and the RII values to assess the relationships between functional differences in species and plant-plant interactions. Species were then grouped using a cluster analysis and the RII values were recalculated at the group level. 3. The redundancy analysis showed that species height and leaf dry matter content were significantly correlated to the changes in species' responses to the effect of A. ordosica along treatments. The four groups of species identified by the cluster analysis showed contrasting variations in competitive or facilitative responses depending on species traits and environmental treatments. However, the interactions measured at the group level balanced the community-level responses, as we found no significant changes in the effects of A. ordosica along treatments for community biomass, richness, and functional diversity indices. 4. Synthesis. Our findings indicate that species with different functional strategies within a community exhibit contrasting responses to a dominant shrub along environmental gradients. These contrasting changes in plant-plant interactions of functionally different species may balance the responses of community-level metrics. This suggests that functional differences between species groups and the balance of plant-plant interactions stabilize community responses to global change.

opencc-zeroDec 2016View details →

Data from: Trophic position determines functional and phylogenetic recovery after disturbance within a community

1. The roles that functional traits and/or evolutionary history of species from co-occuring trophic groups have in determining community recovery following disturbance are poorly understood. Functional traits help determine how species interact with their environment, thus functional traits are likely to change with time since logging. However, traits of species may also be phylogenetically constrained depending on their evolutionary history. Because beetles are trophically diverse, the effects of phylogenetic and functional aspects of community recovery can be compared between co-occuring trophic groups. 2. Using a chronosequence of forest ages following logging, we applied a novel combination of functional trait and phylogenetic approaches to assess the extent to which taxonomic, functional and phylogenetic composition recovered after logging, and if these dimensions of composition approached those characteristic of mature forests, for both predators and decomposers/primary consumers. We also examined to what extent functional traits of both trophic groups were phylogenetically conserved. 3. Predator functional compostion had recovered ~45 years after logging, and this recovery preceded taxonomic recovery. Neither taxonomic nor functional composition had recovered for the decomposer/primary consumer communites by this time. 4. In contrast to decomposers/primary consumers, predator community recovery had no distinct phylogenetic signature, yet predator functional traits were more phylogenetically conserved than decomposers/primary consumer functional traits. 5. Trait syndromes that characterise forest recovery stages are identified and provide a basis for future work on community re-assembly following disturbance. 6. We demonstrate differential recovery of co-occuring beetle trophic groups following disturbance. We show that functional and phylogenetic composition may be disconnected from taxonomic composition; highlighting the advantages of integrating understanding of these three potentially independent components of ecological diversity to enable deeper understanding of animal community composition.

Data from: Functional responses of multi-taxa communities to disturbance and stress gradients in a restored floodplain

1. Trait-based approaches can reveal the mechanisms through which disturbances or stress impact communities, allowing comparisons of the role of different mechanisms in shaping communities among taxonomic groups. Such information can lead to higher comparability, transferability and predictability of the outcome of restoration projects. However, multitaxa trait-based approaches were rarely used in the context of ecosystem restoration. 2. We investigated the responses to environmental gradients of seven taxa (vascular plants, staphylinid and carabid beetles, spiders, isopods, diplopods and earthworms) in a restored floodplain using a species traits approach. We assessed the impact of flood disturbances and soil hydric stress on the functional diversity (FD) and community-weighted mean (CWM) response of traits for each taxon. 3. Ordination of hydrological variables revealed two main gradients. The first was related to the spatiotemporal dynamics of flood disturbances and the second to the average changes in soil hydric conditions. 4. The analysis of CWM revealed that larger, poorly mobile species with narrow ecological tolerances were filtered by regular floods and/or changes in soil hydric conditions. 5. Functional diversity patterns differed between the two gradients: decreasing with increasing flood disturbance, but increasing along the soil hydric stress gradient. This suggests that the mechanisms shaping community composition differ between the two gradients with environmental filtering being dominant with increasing flood disturbances and competition decreasing with more soil hydric stress. 6. Synthesis and applications. Our study shows that the impact of restored flood disturbances and soil hydric stress on plant and invertebrate functional diversity and community-weighted mean can be positive, negative or more complex depending on the taxonomic group and environmental gradient considered. The patterns can to some extent be explained by the specific characteristics of each group. Larger, poorly mobile species with narrow ecological tolerances were particularly vulnerable to changes in disturbance and stress regime following floodplain restoration. These species may therefore be lost in the initial phases of restoration projects, but other more characteristic species of dynamic floodplains will be favoured. Understanding the consequences of these contrasted responses for biodiversity conservation and ecosystem functioning constitutes the next challenge for ecosystem restoration.

Data from: The bacterial community structure and functional profile in the heavy metal contaminated paddy soils,surrounding a nonferrous smelter in South Korea

The pollution of agricultural soils by the heavy metals affects the productivity of the land and has an impact on the quality of the surrounding ecosystems. The present study investigated the bacterial community structure in the heavy metal contaminated sites along a smelter and a distantly located paddy field to elucidate the factors that are related to the alterations of the bacterial communities under the conditions of heavy metal pollution. Among the study sites, the bacterial communities in the soil did not show any significant differences in their richness and diversity. The soil bacterial communities at the three study sites were distinct from one another at each site, possessing a distinct set of bacterial phylotypes. Among the study sites, significant changes were observed in the abundances of the bacterial phyla and genera. The variations in the bacterial community structure were mostly related to the general soil properties at the phylum level, while at the finer taxonomic levels, the concentrations of arsenic (As) and lead (Pb) were the significant factors, affecting the community structure. The relative abundances of the genera Desulfatibacillum and Desulfovirga were negatively correlated to the concentrations of As, Pb, and cadmium (Cd) in the soil, while the genus Bacillus was positively correlated to the concentrations of As and Cd. According to the results of the prediction of bacterial community functions, the soil bacterial communities of the heavy metal polluted sites were characterized by the more abundant enzymes, involved in DNA replication and repair, translation, transcription, and the nucleotide metabolism pathways, while the amino acid and lipid metabolism, as well as the biodegradation potential of xenobiotics, were reduced. Our results showed that the adaptation of the bacterial communities to the heavy metal contamination was predominantly attributed to the replacement process, while the changes in community richness were linked to the variations in the soil pH values.

Data from: Maintained functional diversity in benthic communities in spite of diverging functional identities

Ecological studies based on time-series often investigate community changes centered on species abundance or biomass but rarely expose the consequential functional aspects underlying such changes. Functional diversity measures have proven to be more accurate predictors for ecosystem functioning than traditional taxonomic approaches and hence gained much attention. There are only limited studies available that analyse the functional implications behind decadal changes of entire communities. We studied zoobenthic communities of two habitats, sheltered and exposed, of a coastal system subject to contrasting changes in community composition over the past four decades. Besides eutrophication and climate-related impacts, the system has been invaded by a non-native polycheate Marenzelleria spp., adding altered functional properties to the communities. The functional dispersion (FDis) metric was used as a measure for comparing the functional diversity of the contrasting habitats, with special focus on the role of Marenzelleria for the entire communities. We highlight changes in the functional identity of the communities, expressed as community-weighted means of trait expression (CWM), using multivariate techniques, and investigate the relationship between taxonomic and functional changes. Despite contrasting community developments in the two habitats, with characteristics traditionally suggesting different environmental quality, we found that the FDis in both habitats remained similar and increased with the introduction of Marenzelleria. Although showing maintained functional diversity across time and space, the functional identity (CWM) of communities changed irrespective of taxonomical differences. Examples include inter alia alterations in palatability proxies, feeding position and sediment transportation types, indicating changed functionality of zoobenthos in coastal systems. We show, when focussing on qualitative functional changes of communities, it is important to evaluate the underlying functional identity, and not only rely on measures of the diversity of functions per se, as the quality indication of expressed functional traits can be concealed when using multi-functionality approaches.

Data from: Functional outcomes of mutualistic network interactions: a community-scale study of frugivore gut passage on germination

1. Current understanding of mutualistic networks is grounded largely in data on interaction frequency, yet mutualistic network dynamics are also shaped by interaction quality—the functional outcomes of individual interactions on reproduction and survival. The difficulty of obtaining data on functional outcomes has resulted in limited understanding of functional variation among a network's pairwise species interactions, of the study designs that are necessary to capture major sources of functional variation, and of predictors of functional variation that may allow generalization across networks. 2. In this community-scale study, we targeted a key functional outcome in plant-frugivore networks: the impact of frugivore gut passage on seed germination. We used captive frugivore feeding trials and germination experiments in an island ecosystem, attaining species-level coverage across all extant native frugivores and the plants they consume to 1) assess sources of functional variation, 2) separate effects of pulp removal from those of scarification via gut passage, and 3) test trait-based correlates of gut passage effect sizes. 3. We found antagonistic seed predation effects of a frugivore previously assumed to be a seed disperser, highlighting the need to consider functional outcomes rather than interaction frequency alone. The other frugivores each exhibited similar impacts for individual plant species, with benefits primarily caused by pulp removal rather than scarification, supporting the use of animal functional groups in this context. In contrast, plant species varied widely in impacts of gut passage on germination. Species with smaller seeds and more frugivore partners had larger benefits of gut passage, showing promise for network metrics and functional traits to predict functional variation among plants. 4. Synthesis. Combining network and demographic approaches, we assessed the degree and sources of variation in a key functional outcome of plant-frugivore interactions across an entire network. Using a detailed study design, our work shows how simpler study designs can capture primary sources of functional variation and that functional traits and network metrics may allow generalization across networks. Efficiently measuring and generalizing sources of functional variation within mutualistic networks will strengthen our ability to model network dynamics and predict mutualist responses to global change.

Data from: Configurational landscape heterogeneity shapes functional community composition of grassland butterflies

1. Landscape heterogeneity represents two aspects of landscape simplification: (i) compositional heterogeneity (diversity of habitat types) and (ii) configurational heterogeneity (number, size and arrangement of habitat patches); both with different ecological implications for community composition. 2. We examined how independent gradients of compositional and configurational landscape heterogeneity, at eight spatial scales, shape taxonomic and functional composition of butterfly communities in 91 managed grasslands across Germany. We used landscape metrics that were calculated from functional maps based on habitat preferences of individual species during different life stages. The relative effects of compositional and configurational landscape heterogeneity were compared with those of local land use intensity on butterfly taxonomic diversity, community composition and functional diversity of traits related to body size, feeding breadth and migratory tendency. 3. As expected, compositional heterogeneity had strong positive effects on taxonomic diversity while configurational heterogeneity had strong positive effects on trait dominance within the community. When landscapes had smaller mean patch size and greater boundary area, communities were dominated by species with more specialized larval feeding, decreased forewing length and limited migratory tendency. 4. The positive effects of increased configurational landscape heterogeneity outweighed the negative effects of local land use intensity on larval feeding specialization, at all spatial scales, highlighting its importance for specialists of all dispersal capabilities. 5. Synthesis and applications. We show that landscapes with high compositional heterogeneity support communities with greater taxonomic diversity, while landscapes with high configurational heterogeneity support communities that include vulnerable species (feeding specialists with larger body size, sedentary nature and more negatively affected by local management intensity). A decline in functional community composition can lead to functional homogenization, affecting the viability of the ecosystems by decreasing the variability in their responses to disturbance and altering their functioning. A landscape management for grasslands that promotes the maintenance of small patch sizes and a diversity of land-uses in the surrounding landscape (within 250–1000 m) is recommended for the conservation of diverse butterfly communities. These strategies could also benefit Government programs such as the EU 2020 Biodiversity Strategy in their efforts to reduce the loss of biodiversity in agricultural landscapes.

opencc-zeroDec 2016View details →

Data from: Nurse species and indirect facilitation through grazing drive plant community functional traits in tropical alpine peatlands

Facilitation among plants mediated by grazers occurs when an unpalatable plant extends its protection against grazing to another plant. This type of indirect facilitation impacts species coexistence and ecosystem functioning in a large array of ecosystems worldwide. It has nonetheless generally been understudied so far in comparison with the role played by direct facilitation among plants. We aimed at providing original data on indirect facilitation at the community scale to determine the extent to which indirect facilitation mediated by grazers can shape plant communities. Such experimental data are expected to contribute to refining the conceptual framework on plant–plant–herbivore interactions in stressful environments. We set up a 2-year grazing exclusion experiment in tropical alpine peatlands in Bolivia. Those ecosystems depend entirely on a few, structuring cushion-forming plants (hereafter referred to as "nurse" species), in which associated plant communities develop. Fences have been set over two nurse species with different strategies to cope with grazing (direct vs. indirect defenses), which are expected to lead to different intensities of indirect facilitation for the associated communities. We collected functional traits which are known to vary according to grazing pressure (LDMC, leaf thickness, and maximum height), on both the nurse and their associated plant communities in grazed (and therefore indirect facilitation as well) and ungrazed conditions. We found that the effect of indirectly facilitated on the associated plant communities depended on the functional trait considered. Indirect facilitation decreased the effects of grazing on species relative abundance, mean LDMC, and the convergence of the maximum height distribution of the associated communities, but did not affect mean height or cover. The identity of the nurse species and grazing jointly affected the structure of the associated plant community through indirect facilitation. Our results together with the existing literature suggest that the "grazer–nurse–beneficiary" interaction module can be more complex than expected when evaluated in the field.

opencc-zeroDec 2015View details →

Data from: The value of trophic interactions for ecosystem function: dung beetle communities influence seed burial and seedling recruitment in tropical forests

Anthropogenic activities are causing species extinctions, raising concerns about the consequences of changing biological communities for ecosystem functioning. To address this, we investigated how dung beetle communities influence seed burial and seedling recruitment in the Brazilian Amazon. First, we conducted a burial and retrieval experiment using seed mimics. We found that dung beetle biomass had a stronger positive effect on the burial of large than small beads, suggesting that anthropogenic reductions in large-bodied beetles will have the greatest effect on the secondary dispersal of large-seeded plant species. Second, we established mesocosm experiments in which dung beetle communities buried Myrciaria dubia seeds to examine plant emergence and survival. Contrary to expectations, we found that beetle diversity and biomass negatively influenced seedling emergence, but positively affected the survival of seedlings that emerged. Finally, we conducted germination trials to establish the optimum burial depth of experimental seeds, revealing a negative relationship between burial depth and seedling emergence success. Our results provide novel evidence that seed burial by dung beetles may be detrimental for the emergence of some seed species. However, we also detected positive impacts of beetle activity on seedling recruitment, which are probably because of their influence on soil properties. Overall, this study provides new evidence that anthropogenic impacts on dung beetle communities could influence the structure of tropical forests; in particular, their capacity to regenerate and continue to provide valuable functions and services.

opencc-zeroDec 2015View details →

Data from: Functional homogenization of flower visitor communities with urbanization

Land-use intensification and resulting habitat loss are put forward as the main causes of flower visitor decline. However, the impact of urbanization, the prime driver of land-use intensification in Europe, is poorly studied. In particular, our understanding of whether and how it affects the composition and functioning of flower visitor assemblages is scant, yet required to cope with increasing urbanization worldwide. Here, we use a nation-wide dataset of plant-flower visitor (Coleoptera, Diptera, Hymenoptera, Lepidoptera) interactions sampled by citizen scientists following a standardized protocol to assess macroecological changes in richness and composition of flower visitor communities with urbanization. We measured the community composition by quantifying the relative occurrence of generalist and specialist flower visitors based on their specialisation on flowering plant families. We show that urbanization is associated with reduced flower visitor richness and a shift in community composition toward generalist insects, indicating a modification of the functional composition of communities. These results suggest that urbanization affects not only the richness of flower visitor assemblages but may also cause their large-scale functional homogenization. Future research should focus on designing measures to reconcile urban development with flower visitor conservation.

opencc-zeroDec 2015View details →

Data from: Mammalian engineers drive soil microbial communities and ecosystem functions across a disturbance gradient

The effects of mammalian ecosystem engineers on soil microbial communities and ecosystem functions in terrestrial ecosystems are poorly known. Disturbance from livestock has been widely reported to reduce soil function, but disturbance by animals that forage in the soil may partially offset these negative effects of livestock, directly and/or indirectly by shifting the composition and diversity of soil microbial communities. Understanding the role of disturbance from livestock and ecosystem engineers in driving soil microbes and functions is essential for formulating sustainable ecosystem management and conservation policies. We compared soil bacterial community composition and enzyme concentrations within four microsites: foraging pits of two vertebrates, the indigenous short-beaked echidna (Tachyglossus aculeatus) and the exotic European rabbit (Oryctolagus cuniculus), and surface and subsurface soils along a gradient in grazing-induced disturbance in an arid woodland. Microbial community composition varied little across the disturbance gradient, but there were substantial differences among the four microsites. Echidna pits supported a lower relative abundance of Acidobacteria and Cyanobacteria, but a higher relative abundance of Proteobacteria than rabbit pits and surface microsites. Moreover, these microsite differences varied with disturbance. Rabbit pits had a similar profile to the subsoil or the surface soils under moderate and high, but not low disturbance. Overall, echidna foraging pits had the greatest positive effect on function, assessed as mean enzyme concentrations, but rabbits had the least. The positive effects of echidna foraging on function were indirectly driven via microbial community composition. In particular, increasing activity was positively associated with increasing relative abundance of Proteobacteria, but decreasing Acidobacteria. Our study suggests that soil disturbance by animals may offset, to some degree, the oft-reported negative effects of grazing-induced disturbance on soil function. Further, our results suggest that most of this effect will be derived from echidnas, with little positive effects due to rabbits. Activities that enhance the habitat for echidnas or reduce rabbit populations are likely to have a positive effect on soil function in these systems.

Data from: Quantifying the importance of functional traits for primary production in aquatic plant communities

1. Aquatic plant meadows are important coastal habitats that sustain many ecosystem functions such as primary production and carbon sequestration. Currently, there is a knowledge gap in understanding which plant functional traits e.g. leaf size or plant height underlie primary production in aquatic plant communities. 2. To study how plant traits are related to primary production, we conducted a field survey in the Baltic Sea, Finland, which is characterized by high plant species and functional diversity. 30 sites along an exposure gradient were sampled (150 plots) and nine plant morphological and chemical traits measured. The aim was to discern how community-weighted mean traits affect community production and whether this relationship changes along an environmental gradient using structural equation modelling (SEM). 3. Plant height had a direct positive effect on production along the exposure gradient (r = 0.33) and indirect effects through two leaf chemical traits, Leaf δ15N and Leaf δ13C (r = 0.24 and 0.18 respectively) resulting in a total effect of 0.28. In plant communities experiencing varying exposure, traits such as root N concentration and leaf δ15N had positive and negative effects on production, respectively. 4. Synthesis: Our results demonstrate that the relationship between plant functional traits and community production is variable and changes over environmental gradients. Plant height generally has a positive effect on community production along an exposure gradient, while the link between other traits and production changes in plant communities experiencing varying degrees of exposure. Thus, the underlying biological mechanisms influencing production differ in plant communities, emphasizing the need to resolve variability and its drivers in real-world communities. Importantly, functionally diverse plant communities sustain ecosystem functioning differently and highlight the importance of benthic diversity for coastal ecosystem stability.

Data from: Re-growing a tropical dry forest: functional plant trait composition and community assembly during succession

A longstanding goal of ecology and conservation biology is to understand the environmental and biological controls of forest succession. However, the patterns and mechanisms that guide successional trajectories, especially within tropical forests, remain unclear. We collected leaf functional trait and abiotic data across a 110-year chronosequence within a tropical dry forest in Costa Rica. Focusing on six key leaf functional traits related to resource acquisition and competition, along with measures of forest stand structure, we propose a mechanistic framework to link species composition, community trait distributions, and forest structure. We quantified the community-weighted trait distributions for specific leaf area, leaf dry matter concentration, leaf phosphorus concentration, leaf carbon to nitrogen ratio, and leaf stable isotopic carbon and nitrogen. We assessed several prominent hypotheses for how these functional measures shift in response to changing environmental variables (soil water content, bulk density and pH) across the chronosequence. Increasingly, older forests differed significantly from younger forests in species composition, above ground biomass and shifted trait distributions. Early stages of succession were uniformly characterized by lower values of community-weighted mean specific leaf area, leaf stable nitrogen isotope, and leaf phosphorus concentration. Leaf dry matter concentration and leaf carbon to nitrogen ratio were lower during earlier stages of succession, and each trait reached an optimum during intermediate stages of succession. The leaf carbon isotope ratio was the only trait to decrease linearly with increasing stand age indicating reduced water use efficiency in older forests. However, in contrast to expectations, community-weighted trait variances did not generally change through succession, and when compared to null expectations were lower than expected. The observed directional shift in community-weighted mean trait values is consistent with the 'productivity filtering' hypothesis where a directional shift in water and light availability shifts physiological strategies from 'slow' to 'fast'. In contrast to expectations arising from niche based ecology, none of the community trait distributions were over-dispersed. Instead, patterns of trait dispersion are consistent with the abiotic filtering and/or competitive hierarchy hypotheses.

Data from: Crop rotational diversity enhances belowground communities and functions in an agroecosystem

Biodiversity loss, an important consequence of agricultural intensification, can lead to reductions in agroecosystem functions and services. Increasing crop diversity through rotation may alleviate these negative consequences by restoring positive aboveground–belowground interactions. Positive impacts of aboveground biodiversity on belowground communities and processes have primarily been observed in natural systems. Here, we test for the effects of increased diversity in an agroecosystem, where plant diversity is increased over time through crop rotation. As crop diversity increased from one to five species, distinct soil microbial communities were related to increases in soil aggregation, organic carbon, total nitrogen, microbial activity and decreases in the carbon-to-nitrogen acquiring enzyme activity ratio. This study indicates positive biodiversity–function relationships in agroecosystems, driven by interactions between rotational and microbial diversity. By increasing the quantity, quality and chemical diversity of residues, high diversity rotations can sustain soil biological communities, with positive effects on soil organic matter and soil fertility.

Data from: A taxonomic, functional and phylogenetic perspective on the community assembly of passerine birds along an elevational gradient in southwest China

Integrating multiple-facets of biodiversity to describe spatial and temporal distribution patterns is one way of revealing the mechanisms driving community assembly. We assessed the species, functional and phylogenetic composition and structure of passerine bird communities along an elevational gradient both in wintering and breeding seasons in the Ailao Mountains, southwest China, in order to identify the dominant ecological processes structuring the communities and how these processes change with elevation and season. Our research confirms that the highest taxonomic diversity, and distinct community composition, was found in the moist evergreen broadleaf forest at high elevation in both seasons. Environmental filtering was the dominant force at high elevations with relatively cold and wet climatic conditions, while the observed value of mean pairwise functional and phylogenetic distances of low elevation were constantly higher than expectation in two seasons, suggested interspecific competition could played the key role at low elevations, perhaps because of relative rich resource result from complex vegetation structure and human-induced disturbance. Across all elevations, there was a trend of decreasing intensity of environmental filtering whereas increasing interspecific competition from wintering season to breeding season. This was likely due to the increased resource availability but reproduction-associated competition in the summer months. In general, there is a clear justification for conservation efforts to protect entire elevational gradients in the Ailao Mountains, given the distinct taxonomic, functional and phylogenetic compositions and also elevational migration pattern in passerine bird communities.

opencc-zeroDec 2012View details →

Data from: A novel multi-scale assessment of community assembly across time, space, and functional niche

A basic ecological tenet is that organisms in a community occupy different niches and have different traits, but how consistently competition, selection, and phylogenetic effects structure communities remains uncertain. Are all communities created equal? We examine how mammalian carnivoran communities are assembled with regard to mass, diet, and locomotion. Here, we use a multivariate nearest-neighbor framework to examine multiple North American localities spanning 3 million years to determine whether community assembly is consistent through time and four modern localities around the world to assess the effects of habitat. Additionally, we examined how trait patterns differ among families and how family-level evolutionary effects affect them. We found some broadly consistent patterns, although differences are more pronounced than similarities. Diet is more affected by evolutionary constraints than by time or place. Locomotion is most affected by habitat, and the ability to partition niches is related to habitat heterogeneity. Mass is influenced by family, but also by habitat and the mass-selective extinction events at the end-Pleistocene. These findings indicate that assembly patterns are not largely determined by within-community interactions but instead show that each community is a product of its independent variables.

opencc-zeroDec 2018View details →

Data from: Long-term recovery of the functional community assembly and carbon pools in an African tropical forest succession

On the African continent, the population is expected to expand fourfold in the next century, which will increasingly impact the global carbon cycle and biodiversity conservation. Therefore, it is of vital importance to understand how carbon stocks and community assembly recover after slash-and-burn events in tropical second-growth forests. We inventoried a chronosequence of 15 1-hectare plots in lowland tropical forest of the central Congo Basin and evaluated changes in aboveground and soil organic carbon stocks and in tree species diversity, functional composition and community-weighted functional traits with succession. We aimed to track long-term recovery trajectories of species and carbon stocks in secondary forests, comparing 5 to 200+ year old secondary forest with reference primary forest. Along the successional gradient, the functional composition followed a trajectory from resource acquisition to resource conservation, except for nitrogen-related leaf traits. Despite a fast initial recovery of species diversity and functional composition, there were still important structural and carbon stock differences between old-growth secondary and pristine forest, which suggests that a full recovery of secondary forests might take much longer than currently shown. As such, the aboveground carbon stocks of 200+ year old forest were only 57% of those in the pristine reference forest, which suggests a slow recovery of aboveground carbon stocks, although more research is needed to confirm this observation. The results of this study highlight the need for more in-depth studies on forest recovery in Central Africa, to gain insight into the processes that control biodiversity and carbon stock recovery.