Plant Functional Trait Diversity Research Articles

Giant root-rat engineering and livestock grazing activities regulate plant functional trait diversity of an Afroalpine vegetation community in the Bale Mountains, Ethiopia

Disturbances from rodent engineering and human activities profoundly impact ecosystem structure and functioning. Whilst we know that disturbances modulate plant communities, comprehending the mechanisms through which rodent and human disturbances influence the functional trait diversity and trait composition of plant communities is important to allow projecting future changes and to enable informed decisions in response to changing intensity of the disturbances. Here, we evaluated the changes in functional trait diversity and composition of Afroalpine plant communities in the Bale Mountains of Ethiopia along gradients of engineering disturbances of a subterranean endemic rodent, the giant root-rat (Tachyoryctes macrocephalus Rüppell 1842) and human activities (settlement establishment and livestock grazing). We conducted RLQ (co-inertia analysis) and fourth-corner analyses to test for trait-disturbance (rodent engineering/human activities) covariation. Overall, our results show an increase in plant functional trait diversity with increasing root-rat engineering and increasing human activities. We found disturbance specific association with traits. Specifically, we found strong positive association of larger seed mass with increasing root-rat fresh burrow density, rhizomatous vegetative propagation negatively associated with increasing root-rat old burrow, and stolonifereous vegetative propagation positively associated with presence of root-rat mima mound. Moreover, both leaf size and leaf nitrogen content were positively associated with livestock dung abundance but negatively with distance from settlement. Overall, our results suggest that disturbances by rodents filter plant traits related to survival and reproduction strategies, whereas human activities such as livestock grazing act as filters for traits related to leaf economics spectrum along acquisitive resource-use strategy.

Assembly of functional diversity in an oceanic island flora.

Oceanic island floras are well known for their morphological peculiarities and exhibit striking examples of trait evolution1-3. These morphological shifts are commonly attributed to insularity and are thought to be shaped by the biogeographical processes and evolutionary histories of oceanic islands2,4. However, the mechanisms through which biogeography and evolution have shaped the distribution and diversity of plant functional traits remain unclear5. Here we describe the functional trait space of the native flora of an oceanic island (Tenerife, Canary Islands, Spain) using extensive field and laboratory measurements, and relate it to global trade-offs in ecological strategies. We find that the island trait space exhibits a remarkable functional richness but that most plants are concentrated around a functional hotspot dominated by shrubs with a conservative life-history strategy. By dividing the island flora into species groups associated with distinct biogeographical distributions and diversification histories, our results also suggest that colonization via long-distance dispersal and the interplay between inter-island dispersal and archipelago-level speciation processes drive functional divergence and trait space expansion. Contrary to our expectations, speciation via cladogenesis has led to functional convergence, and therefore only contributes marginally to functional diversity by densely packing trait space around shrubs. By combining biogeography, ecology and evolution, our approach opens new avenues for trait-based insights into how dispersal, speciation and persistence shape the assembly of entire native island floras.

Plant functional trait diversity and structural diversity co-underpin ecosystem multifunctionality in subtropical forests

Tree species diversity is assumed to be an important component in managing forest ecosystems because of effects on multiple functions or ecosystem multifunctionality. However, the importance of tree diversity in determining multifunctionality in structurally complex subtropical forests relative to other regulators (e.g., soil microbial diversity, stand structure, and environmental conditions) remains uncertain. In this study, effects of aboveground (species richness and functional and structural diversity) and belowground (bacterial and fungal diversity) biodiversity, functional composition (community-weighted means of species traits), stand structure (diameter at breast height and stand density), and soil factors (pH and bulk density) on multifunctionality (including biomass production, carbon stock, and nutrient cycling) were examined along a tree diversity gradient in subtropical forests. The community-weighted mean of tree maximum height was the best predictor of ecosystem multifunctionality. Functional diversity explained a higher proportion of the variation in multifunctionality than that of species richness and fungal diversity. Stand structure -played an important role in modulating the effects of tree diversity on multifunctionality. The work highlights that species composition and maximizing forest structural complexity are effective strategies to increase forest multifunctionality while also conserving biodiversity in the management of multifunctional forests under global environmental changes.

Landscape structure shapes the diversity of plant reproductive traits in agricultural landscapes in the Brazilian Cerrado

The replacement of native vegetation by crops and pasturelands compromises the functional diversity of plants and negatively influence ecosystem functions such as pollination and seed dispersal. Here, we investigate the effects of landscape structure on the diversity of functional traits in agricultural landscapes in the Brazilian Cerrado. We sampled the woody plant community in 49 sites in forests and savannas, and analyzed the density and richness of pollination and seed dispersal syndromes. We performed model selection using Akaike Information Criterion to test whether landscape variables such as habitat amount, percentage of agriculture and pasture, patch and edge densities, and compositional heterogeneity at different spatial scales influence the density and richness of woody plant functional traits related to seed dispersal and pollination syndromes. The amount of forest and patch density were the landscape predictors that explained most of the diversity of plant functional traits. The amount of agricultural and savanna as well as edge density and landscape heterogeneity also affected functional traits. Our results suggest that habitat amount and configuration in the landscapes drive the diversity of functional traits, pointing that maintaining habitats within Cerrado agricultural landscapes is determinant for the plant’s functional traits diversity. Furthermore, a heterogeneous mosaic may favor the density or richness of plants pollinated by insects and hummingbirds. The continuous loss and fragmentation of habitats may lead to loss of ecological functions compromising the provision of ecosystems services in agricultural landscapes in the Cerrado ecoregion.

The role of plant functional traits and diversity in soil carbon dynamics within riparian agroforests.

Restoration of agricultural riparian buffers with trees (agroforestry) provides an elegant solution to enhance carbon storage while also augmenting local biodiversity. Yet the scope and role of riparian plant community diversity in key soil dynamics remain unresolved. Operationalizing riparian age (young [<10 yr] and mature [>30 yr] since establishment] and forest stand type (coniferous and deciduous dominant) to capture the potential extent of plant diversity, we measured plant functional trait diversity and community weighted mean trait values, microbial composition, abiotic soil conditions, and rates of soil CO2 efflux (mg CO2 -C m-2 h-1 ). We used piecewise structural equation modeling (SEM) to further refine the role of biotic indices (leaf, root, and microbial characteristics), and abiotic factors (soil physio-chemical metrics) on soil C cycling processes in riparian systems. We found significantly lower rates of CO2 efflux (F=8.47; p<.01) over one growing season and higher total soil C (F=3.46; p=.03) in mature buffers compared with young buffers. Using SEM, we describe influences on soil C content (marginal r2 =61) and soil CO2 efflux (marginal r2 =53). Within young buffers, soil C content was significantly predicted by fungal/bacterial ratio and root length density, whereas in mature buffers, tree leaf characteristics were associated with soil C content. Soil CO2 efflux was predicted by soil moisture, soil carbon content, and herbaceous root characteristics. Evidently, leaf and root functional traits in combination with broad soil parameters significantly describe soil C dynamics in the field; however, significant pathways are not the same throughout the life cycle of a riparian agroforest.

Intraspecific trait variation improves understanding and management of cover crop outcomes

AbstractUnderstanding links between functional trait diversity and ecosystem services can inform more sustainable management of agroecosystems. The use of cover crops (i.e., non‐harvested crops) is a key strategy for increasing plant functional trait diversity in crop rotations. Variation in functional traits can be assessed in multiple ways—within a species (intraspecific), across species (interspecific), and across communities (community trait metrics). Recent evidence from the field of trait‐based research suggests that the role of intraspecific trait variation (ITV) in explaining ecological dynamics deserves greater attention. We conducted a systematic literature review to determine whether this also applies to cover crops. While fewer than one‐third of the 30 studies we reviewed explicitly tested intraspecific trait questions, together they demonstrated that significant ITV occurs across populations and in response to environmental and management conditions. ITV is thus an understudied yet important aspect of cover crop performance. To address research gaps identified by the literature review, we conducted a complementary field experiment to evaluate cover crop functional trait variation and assess relationships between traits and ecosystem services. Significant ITV occurred among three cover crop species (buckwheat, cowpea, and sorghum sudangrass) planted alone and in mixtures, indicating that interactions between functionally diverse species in mixtures induced trait plasticity. We expected that traits such as plant height, root:shoot ratio, shoot C:N ratio, and specific leaf area (SLA) would be positively related to cover crop nitrogen (N) assimilation. Using community‐weighted means per common practice, our hypothesis was supported for the former three traits, while SLA was unexpectedly negatively associated with N assimilation. However, ITV revealed that this unexpected relationship was driven by higher SLA and lower N assimilation values of the broadleaf compared with the grass species. Across treatments, SLA for the grass species was positively related to N assimilation, as expected. In sum, we demonstrate that assessing ITV is critical for refining understanding and management of cover crop outcomes.

Integrating perennial bahiagrass into the conventional rotation of cotton and peanut enhances interactions between microbial and nematode communities

Integrating two years of bahiagrass (Paspalum notatum Flugge) into the peanut (Arachis hypogea L.) and cotton (Gossypium hirsutum L.) cropping system improves soil quality and crop production as compared to a conventional peanut-cotton-cotton rotation (CR). However, it is unclear if this system, known as a sod-based rotation (SBR), affects soil biological communities (e.g., soil microorganisms and nematodes) and their trophic interactions. Furthermore, how soil trophic groups respond to agricultural management (e.g., irrigation) is understudied. In April 2017, we collected pre-planting soil samples (0–30 cm) from cotton plots located in Quincy (Florida, United States) that had been under CR (cotton grown in two consecutive years) and SBR (cotton grown only once) for 17 years. We used amplicon sequencing to investigate soil microbial communities and an inverted microscope technique to quantify nematodes. Compared to CR, SBR significantly increased nematode alpha diversity (one-way ANOVA; P < 0.05) and induced different nematode communities. In contrast, there were no significant differences in the diversity and structure of bacterial communities between SBR and CR. SBR plots were significantly enriched in Nitrospira, while the second of two consecutive years of cotton growth in CR had a higher relative abundance of Alphaproteobacteria (one-way ANOVA; P < 0.05). Plant-parasitic (848 counts per 100 g dry soil) and bacterial-feeding nematodes (798 counts per 100 g dry soil) had a similar abundance in SBR, while plant-parasitic nematodes (7772 counts per 100 g dry soil) were predominant in CR (<1000 counts per 100 g dry soil for all other taxa). SBR exhibited a greater number of significant paired Pearson correlations (P < 0.05) among functional groups of bacteria and nematodes compared to CR systems. Irrigation had no effect on the diversity and structure of bacterial and nematode communities in SBR, although some soil bacterial and nematode groups responded to irrigation. Overall, these results suggest that integrating bahiagrass to diversify the conventional peanut-cotton rotation is a sustainable approach to enhance soil biodiversity, with more diverse nematode communities and complex soil trophic interactions that will affect the response to crops and irrigation. Thus, future crop rotations should increase plant functional trait diversity (e.g., by adding perennial grasses) to maximize benefits to soil communities.

Leaf Morphological and Nutrient Traits of Common Woody Plants Change Along the Urban-Rural Gradient in Beijing, China.

An increasing number of studies have found differences in the diversity of plant functional traits between urban and rural sites as a result of urbanization. However, the results remain inconsistent. In this study, we measured morphological and nutrient traits of 11 common woody plants along a continuous urban–rural gradient in Beijing, China. Leaf size (e.g., length, width, and area), specific leaf area, and leaf nitrogen and potassium contents decreased gradually and significantly along the urban–rural gradient, indicating that urbanization can enhance the capacity of plants to acquire resources for growth and production. Furthermore, soil nutrients and air temperature decreased along the urban–rural gradient, while air relative humidity increased. A structural equation model showed that these alterations in physical factors attributable to urbanization contributed directly or indirectly to changes in leaf functional traits, implying that changes in soil nutrients and micro-climate induced by urbanization may affect plant growth and production because of the improvement in resource acquisition capacity.

Crop functional diversity drives multiple ecosystem functions during early agroforestry succession

Abstract We still lack practical guidelines for diversifying cropping systems that consider both yield and regulating functions of agroecosystems. Recent studies have suggested that maximizing functional diversity (FD, the distribution of species with different functional traits in the niche space) may lead to agroecosystems with greater multifunctionality due to niche complementarity. Therefore, scientists are now advocating the use of a trait‐based approach to develop multifunctional sustainable agroecosystems. In order to assess the effects of crop FD on key agroecosystem functions and to consider trade‐offs and synergies among them, we established, in late 2016, permanent experimental field plots of successional agroforestry systems (SAFS), in humid subtropical Southern Brazil. The experiment represents a gradient of plant functional trait diversity (designed FD based on leaf nitrogen concentration), while maintaining crop species richness constant across all treatments. Our hypothesis is that the observed FD of crops (hereafter, crop FD) drives multiple agroecosystem functions. We determined the observed FD by quantifying traits of crops and weeds (maximum plant height, leaf area, specific leaf area) and performed two data collections (March and September 2017) at the end of the summer and winter crops respectively. We used structural equation modelling to test a hypothetical causal model to explain how crop FD affects three functions: weed suppression, soil protection (soil cover by either crops or weeds) and crop yield. Our results support the hypothesis that high crop FD drives agroecosystem processes and contributes to the provision of multiple ecosystem functions. We found that with greater crop FD in SAFS, crop plants occupied a large niche space, thereby increasing the total photosynthetic light intercepted in the agroecosystem, that in turn, increased crop yield. Additionally, greater FD increased soil protection by crops and decreased weed cover. This greater FD also reduced the FD of the weed community. Synthesis and applications. Crop mixtures based on complementary plant traits can increase the multifunctionality of agroecosystems through their sustainable use. A more heterogeneous structure and projection of crop leaf area drives greater resistance to competition with weeds and produces higher crop yields in young diversified crop mixtures.

Evidence for the importance of land use, site characteristics and vegetation composition for rooting in European Alps

Plant rooting strongly affects most hydrological, biogeochemical and ecological processes in terrestrial ecosystems, as it presents the main pathway for carbon, water and nutrient transfer from soil to the atmosphere and is a key factor in stabilizing the soil layer. Few studies have actually investigated the link between phytosociological and structural vegetation composition and diversity in soil rooting parameters. Our study provides a comprehensive evaluation of plant cover and diversity effects on rooting parameters dependent on different land-use types along a north–south transect in the Eastern Alps. We conducted field studies of root biomass, rooting density and rooting depth for the six main land-use types: intensively and lightly used hay meadows, pastures, arable land, agriculturally unused grasslands and forests. The variation in rooting parameters was explained by different aspects of species and functional richness, species and functional composition, functional traits, abundance of key species and site variables depending on the land-use types. Our results showed that different characteristics of biodiversity explained the variance in root parameters (mass, density and depth) to a high degree (determination coefficient R2 values varied between 0.621 and 0.891). All rooting parameters increased with increasing plant species richness, as well as with a higher diversity of plant functional traits. The inclusion of site parameters significantly increased the explained variance, while we could not find evidence for key species and their abundance to provide additional explanatory power. Allowing the effects to vary depending on land-use types turned out to be a necessity supporting the importance of considering land-use types for rooting. The findings indicate that vegetation composition has a clear relationship with rooting parameters across different habitats in the European Alps. As the effect of plant composition differs with respect to the land-use type, rooting can be monitored by land management to achieve the desired benefits. For example, intensified rooting through extensive management decreases erosion risk and increases carbon uptake.

Linking plant and animal functional diversity with an experimental community restoration in a Hawaiian lowland wet forest

Testing how plant restoration influences animal taxonomic and functional diversity can shift restoration projects beyond mainly plant community considerations. We incorporated multi-trophic interactions into restoration by describing an ongoing functional trait-based restoration experiment in Hawaiian lowland tropical wet forest (Liko Nā Pilina Experiment), where litter arthropods are examined from a functional perspective thereby linking plants and higher trophic levels. We hypothesized that (1) communities with greater plant functional trait diversity would have cascading effects through food webs, increasing animal diversity and network complexity, and (2) increases in animal species and network complexity would be stronger for restoration efforts in plant communities with more complementary functional traits than those with more redundant traits. We examined experimental treatments of planted communities with the same species richness but with different plant functional trait profiles based on (1) rates of expected carbon turnover (slow or moderate), and (2) the similarity of their functional trait measurements (redundant or complementary), as determined by functional dispersion calculations. Initial data on arthropod communities and leaf litter decomposition rates revealed linkages between plant functional traits and arthropod community diversity. Overall, we argue that a more comprehensive evaluation of restoration accounts for both functional diversity and the multi-trophic nature of animal and plant communities. Developing restoration projects based on plant functional traits that influence both plant and invertebrate species provides a new paradigm, and the incorporation of both native and non-native (but non-invasive) plants shows promise in restoring ecosystem function in disturbed lowland tropical forests.

Impoverished soil supports more plateau pika through lowered diversity of plant functional traits in Tibetan alpine meadows

Frequent outbreaks of plateau pika (Ochotona curzoniae) have become a major challenge for the sustainability of Tibetan rangeland, although top-down control has been widely employed since the 1960s over the plateau. Based on studies on plant trait-mediated soil-plant-herbivore relations, we hypothesized that impoverished soil was a consequence of rangeland degradation as well as a cause of increasing pika numbers through lowered functional trait diversity (FD) of the plant community that provides advantages for pika fitness. At three sites of alpine meadows on the eastern Tibetan Plateau, we counted active burrows of pika in 27 plots (i.e., 9 plots per site) distributed along a gradient of soil fertility. For every plant species within each plot, we measured five functional traits (e.g., mature height, SLA: specific leaf area, LDMC: leaf dry matter content, and leaf N and P: leaf nitrogen and phosphorus concentrations), indicating plant performance in response to changing soil fertility and impacting the fitness of pika. We employed Bayesian regression, structural equation modeling and network analyses to assess causal relations from soil fertility to FD and burrow density. The results show i) there was no significant difference in burrow density between three sites; spatial variation among plots in terms of soil fertility, plant species diversity and FD accounted for 57%–72%, 26%–41% and 59%–73%, respectively, of the variation in burrow density; ii) the burrow density was associated positively with soil moisture and organic matter, plant coverage, forb abundance and FD of leaf P, but negatively with soil nutrients, plant species diversity and FD for SLA, height and leaf N; and iii) deficiency of soil P potentially resulted in an increase in pika density, likely through lowered FD of SLA and height, with other soil factors and FD of leaf nutrients indirectly associated with burrow density. Our study suggested that under the joint effect of intensive grazing by livestock and output of livestock products from region, deficiency of soil P potentially increased pika density, likely by supporting more and diverse food resources while decreasing the risk of being preyed upon. Control of pika outbreak should pay more attention to bottom-up restoration of degraded soil and vegetation via traditional rotational grazing and promotion of recycling and compensation of lost soil P and plant trait diversity.

Relationships between plant traits, soil properties and carbon fluxes differ between monocultures and mixed communities in temperate grassland.

The use of plant traits to predict ecosystem functions has been gaining growing attention. Above‐ground plant traits, such as leaf nitrogen (N) content and specific leaf area (SLA), have been shown to strongly relate to ecosystem productivity, respiration and nutrient cycling. Furthermore, increasing plant functional trait diversity has been suggested as a possible mechanism to increase ecosystem carbon (C) storage. However, it is uncertain whether below‐ground plant traits can be predicted by above‐ground traits, and if both above‐ and below‐ground traits can be used to predict soil properties and ecosystem‐level functions.Here, we used two adjacent field experiments in temperate grassland to investigate if above‐ and below‐ground plant traits are related, and whether relationships between plant traits, soil properties and ecosystem C fluxes (i.e. ecosystem respiration and net ecosystem exchange) measured in potted monocultures could be detected in mixed field communities.We found that certain shoot traits (e.g. shoot N and C, and leaf dry matter content) were related to root traits (e.g. root N, root C:N and root dry matter content) in monocultures, but such relationships were either weak or not detected in mixed communities. Some relationships between plant traits (i.e. shoot N, root N and/or shoot C:N) and soil properties (i.e. inorganic N availability and microbial community structure) were similar in monocultures and mixed communities, but they were more strongly linked to shoot traits in monocultures and root traits in mixed communities. Structural equation modelling showed that above‐ and below‐ground traits and soil properties improved predictions of ecosystem C fluxes in monocultures, but not in mixed communities on the basis of community‐weighted mean traits. Synthesis. Our results from a single grassland habitat detected relationships in monocultures between above‐ and below‐ground plant traits, and between plant traits, soil properties and ecosystem C fluxes. However, these relationships were generally weaker or different in mixed communities. Our results demonstrate that while plant traits can be used to predict certain soil properties and ecosystem functions in monocultures, they are less effective for predicting how changes in plant species composition influence ecosystem functions in mixed communities.

Hydraulic diversity of forests regulates ecosystem resilience during drought.

Plants influence the atmosphere through fluxes of carbon, water and energy1, and can intensify drought through land-atmosphere feedback effects2-4. The diversity of plant functional traits in forests, especially physiological traits related to water (hydraulic) transport, may have a critical role in land-atmosphere feedback, particularly during drought. Here we combine 352 site-years of eddy covariance measurements from 40 forest sites, remote-sensing observations of plant water content and plant functional-trait data to test whether the diversity in plant traits affects the response of the ecosystem to drought. We find evidence that higher hydraulic diversity buffers variation in ecosystem flux during dry periods across temperate and boreal forests. Hydraulic traits were the predominant significant predictors of cross-site patterns in drought response. By contrast, standard leaf and wood traits, such as specific leaf area and wood density, had little explanatory power. Our results demonstrate that diversity in the hydraulic traits of trees mediates ecosystem resilience to drought and is likely to have an important role in future ecosystem-atmosphere feedback effects in a changing climate.

Biodiversity across trophic levels drives multifunctionality in highly diverse forests

Human-induced biodiversity change impairs ecosystem functions crucial to human well-being. However, the consequences of this change for ecosystem multifunctionality are poorly understood beyond effects of plant species loss, particularly in regions with high biodiversity across trophic levels. Here we adopt a multitrophic perspective to analyze how biodiversity affects multifunctionality in biodiverse subtropical forests. We consider 22 independent measurements of nine ecosystem functions central to energy and nutrient flow across trophic levels. We find that individual functions and multifunctionality are more strongly affected by the diversity of heterotrophs promoting decomposition and nutrient cycling, and by plant functional-trait diversity and composition, than by tree species richness. Moreover, cascading effects of higher trophic-level diversity on functions originating from lower trophic-level processes highlight that multitrophic biodiversity is key to understanding drivers of multifunctionality. A broader perspective on biodiversity-multifunctionality relationships is crucial for sustainable ecosystem management in light of non-random species loss and intensified biotic disturbances under future environmental change.

Phylogeny and the prediction of tree functional diversity across novel continental settings

AbstractAimMapping the distribution and diversity of plant functional traits is critical for projecting future changes to vegetation under global change. Maps of plant functional traits, however, are scarce due very sparse global trait data matrices. A potential solution to this data limitation is to utilize the known levels of phylogenetic signal in trait data to predict missing values. Here we aim to test existing phylogenetic comparative methods for imputing missing trait data for the purpose of producing continental‐scale maps of plant functional traits.LocationNorth America and Europe.MethodsPhylogenetic imputation models and trait data from one continent were used to predict the trait values for tree species on the other continent and to produce trait maps. Predicted maps of trait means, variances and functional diversity were compared with known maps to quantify the degree to which predicted trait values could estimate spatial patterns of trait distributions and diversity.ResultsWe show that the phylogenetic signal in plant functional trait data can be used to provide robust predictions of the geographical distribution of tree functional diversity. However, predictions for traits with little phylogenetic signal, such as maximum height, are error prone. Lastly, trait imputation methods based on phylogenetic generalized least squares tended to outperform those based on phylogenetic eigenvectors.Main conclusionsIt is possible to predict patterns of functional diversity across continental settings with novel species assemblages for most of the traits studied for which we have no direct trait information, thereby offering an effective method for overcoming a key data limitation in global change biology, macroecology and ecosystem modelling.

Plant functional trait diversity regulates the nonlinear response of productivity to regional climate change in Tibetan alpine grasslands.

The biodiversity-productivity relationship is still under debate for alpine grasslands on the Tibetan Plateau. We know little about direct and indirect effects of biotic and abiotic drivers on this relationship, especially in regard to plant functional trait diversity. Here, we examine how aboveground net primary productivity (ANPP) and precipitation use efficiency (PUE) respond to climate, soil and community structure across alpine grasslands on the Northern Tibetan Plateau. We found that both ANPP and PUE showed nonlinear patterns along water availability and site altitude variation, which together accounted for 80.3% and 68.8% of variation in ANPP and PUE, respectively, by optimal generalized additive models. Functional trait divergence (FTD) and community weighted mean (CWM) of plant functional traits were as important as plant species diversity (PSD) for explaining the nonlinear productivity-climate relationship. These findings were confirmed by results from principal component analyses and structural equation models. We also found that FTD was negatively correlated with PSD across different alpine grasslands. Our results implicate: first, the combinatorial influences of temperature and precipitation gradients are important for predicting alpine grassland dynamics; second, the convergence and divergence of plant functional traits may have the potential to elucidate the effect of plant diversity on ecosystem functionality.

Plant functional traits, functional diversity, and ecosystem functioning: current knowledge and perspectives

Increasing attention has recently been focused on the linkages between plant functional traits and ecosystem functioning. A comprehensive understanding of these linkages can facilitate to address the eco- logical consequences of plant species loss induced by human activities and climate change, and provide the- oretical support for ecological restoration and ecosystem management. In recent twenty years, the evidence of strong correlations between plant functional traits and changes in ecosystem processes is growing. More importantly, ecosystem functioning can be predicted more precisely, using plant functional trait diversity (i.e., functional diversity) than species diversity. In this paper, we first defined plant functional traits and their im- portant roles in determining ecosystem processes. Then, we review recent advances in the relationships be- tween ecosystem functions and plant functional traits and their diversity. Finally, we propose several impor- tant future research directions, including (1) exploration of the relationships between aboveground and belowground plant traits and their roles in determining ecosystem functioning, (2) incorporation of the im- pacts of consumer and global environmental change into the correlation between plant functional traits and ecosystem functioning, (3) effects of functional diversity on ecosystem multifunctionality, and (4) examina- tion of the functional diversity-ecosystem functioning relationship at different temporal and spatial scales.

Forecasting functional implications of global changes in riparian plant communities

Riparian ecosystems support mosaics of terrestrial and aquatic plant species that enhance regional biodiversity and provide important ecosystem services to humans. Species composition and the distribution of functional traits – traits that define species in terms of their ecological roles – within riparian plant communities are rapidly changing in response to various global change drivers. Here, we present a conceptual framework illustrating how changes in dependent wildlife communities and ecosystem processes can be predicted by examining shifts in riparian plant functional trait diversity and redundancy (overlap). Three widespread examples of altered riparian plant composition are: shifts in the dominance of deciduous and coniferous species; increases in drought‐tolerant species; and the increasing global distribution of plantation and crop species. Changes in the diversity and distribution of critical plant functional traits influence terrestrial and aquatic food webs, organic matter production and processing, nutrient cycling, water quality, and water availability. Effective conservation efforts and riparian ecosystems management require matching of plant functional trait diversity and redundancy with tolerance to environmental changes in all biomes.

Functionally and phylogenetically diverse plant communities key to soil biota

Recent studies assessing the role of biological diversity for ecosystem functioning indicate that the diversity of functional traits and the evolutionary history of species in a community, not the number of taxonomic units, ultimately drives the biodiversity--ecosystem-function relationship. Here, we simultaneously assessed the importance of plant functional trait and phylogenetic diversity as predictors of major trophic groups of soil biota (abundance and diversity), six years from the onset of a grassland biodiversity experiment. Plant functional and phylogenetic diversity were generally better predictors of soil biota than the traditionally used species or functional group richness. Functional diversity was a reliable predictor for most biota, with the exception of soil microorganisms, which were better predicted by phylogenetic diversity. These results provide empirical support for the idea that the diversity of plant functional traits and the diversity of evolutionary lineages in a community are important for maintaining higher abundances and diversity of soil communities.