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Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.

Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis-that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally.

The wild pig is well known for its generalist diet, a contributing factor to its successful invasion around the globe. We used DNA metabarcoding analyses of scat to examine wild pig diet on a cow-calf operation in south-central Florida. This 4,249-ha ranch is comprised of improved pastures and semi-native pastures that contain a mosaic of vegetation types. Both pasture types contain numerous wetlands and ditches as well as oak-palm woodlands. Fecal sampling was conducted along transects from March 2016 to February 2017. The study site was divided into five sampling areas to ensure dispersed sampling across the ranch. At least five freshly deposited scats were collected every two months from each sampling area and frozen. Regions of multiple genes that targeted either animal or plant DNA (CO1, trnL, and 12S rRNA marker genes) were selected for high throughput sequencing. Sequences were identified using the GenBank reference database. Two hundred nineteen fecal samples were collected and 196 were analyzed. Consensus lineages were retained if they could be confidently identified to family and were likely intentionally consumed by a pig. Between the three marker genes, 66 plant, 68 animal, and 12 fungal families were identified. Plant species dominated the diet with oak, torpedograss, joyweed, Bahiagrass, dayflower, and other grasses occurring in over half the samples analyzed. Animals were present across a wide taxonomic breadth, but encountered less frequently than plants with the exception of an exotic earthworm. Cattle, house mouse, cotton mouse, raccoon, mole cricket, Virginia opossum, and six species of fly were recorded from over 10% of fecal samples. This represents the first study to employ DNA metabarcoding to examine the dietary composition of this invasive vertebrate across an entire year.

Questions: Grasslands provide important provisioning services worldwide and their management has consequences for these services. Management intensification is a widespread land‐use change and has accelerated across North America to meet rising demands on productivity, yet its impact on the relationship between plant diversity and productivity is still unclear. Here, we investigated the relationship between plant diversity and grassland productivity across nine ecoclimatic domains of the continental United States. We also tested the effect of management intensification on diversity and productivity in four case studies. Methods: We acquired remotely sensed gross primary productivity data (GPP, 1986–2018) and plant diversity data measured at different spatial scales (1, 10, 100, 400 m2), as well as climate variables including the Palmer drought index from two ecological networks. We used general linear mixed models to relate GPP to plant diversity across sites. For the case study analysis, we used linear mixed models to relate plant diversity to management intensity, and tested if the management intensity influenced the relationship between GPP (mean and temporal variation) and drought. Results: Across all sites, we observed positive relationships among species richness, productivity, and the temporal stability of mean annual biomass production. These relationships were not affected by the scale at which species richness was observed. In three out of the four case studies, we observed that management effects on species richness were only significant at broader scales (i.e., ≥10 m2) with no clear effect found at the commonly used 1‐m2 quadrat scale. In one case study, species‐poor, intensively managed pastures presented the highest productivity but were more sensitive to dry conditions than less intensified pastures. However, in other case studies, we did not observe significant effects of management intensity on the magnitude or stability of productivity. Conclusions: Generalization across studies may be difficult and require the development of intensification indices general enough to be applied across diverse management strategies in grazilands. Understanding how management intensification affects grassland productivity will inform the development of sustainable intensification strategies. [ABSTRACT FROM AUTHOR]

Biodiversity impacts are rarely included in systems analyses of livestock production. We piloted two approaches toward quantifying biodiversity impacts, pressure‐state‐response (PSR) and potential species loss (PSL), at a cow–calf operation in Florida for which extensive environmental data were available. Using these approaches, we compared livestock production on two vegetation types, semi‐native pasture (SNP) and improved pasture (IMP), and we found fewer deleterious effects on biodiversity associated with SNP (characterized by low stocking rates and no fertilizer) than with IMP, as evidenced by a lower PSL and greater biotic integrity under PSR. Both approaches agreed in the direction of the outcome, but we argue that, when possible, they should be applied complementarily to inform both absolute and per‐unit product biodiversity impacts of livestock production. This research demonstrates how to incorporate biodiversity into life‐cycle perspectives of livestock sustainability assessments when data availability varies, supporting the expansion of multi‐metric, holistic evaluations that are absent from most livestock system analyses. [ABSTRACT FROM AUTHOR]

Seasonally inundated wetlands are threatened ecosystems worldwide and increasingly important targets for wetland restoration programs. However, restoring such ecosystems is difficult, as it requires mimicking the historical shifts between dry and flooded states. In this study, we evaluate the responses of agriculturally impacted seasonal wetlands to pasture-scale hydrological restoration. We selected 15 seasonal wetlands in central Florida (10 within restoration easements and five in unrestored pastures) and excluded cattle from five of the restored wetlands. We monitored each wetland from 2011 to 2016 to document potential changes in water levels, plant species richness, beta diversity, floristic quality, and cover of obligate wetland species. Vegetation responses to restoration were gradual and subtle, becoming detectable only five years following restoration. By 2016, restored wetlands had significantly lower cover of facultative upland species and higher cover of obligate wetland species. Species richness was higher in unrestored wetlands due to the presence of many facultative upland species. Beta diversity within wetlands and floristic quality based on coefficient of conservatism were not affected by restoration. We did not find strong effects of cattle exclusion on post-restoration diversity metrics, but we observed a large increase in the native grass, Panicum hemitomon Schult. This study showed mixed outcomes when measured against the goals of restoring wetland communities. It also highlighted the need for more active restoration approaches to regain historical communities or promote target species (e.g. Coleataenia abscissa (Swallen) LeBlond). We emphasize the need for costly restoration activities to be coupled with long-term monitoring to assess success. [ABSTRACT FROM AUTHOR]

Isolated, seasonal wetlands within agricultural landscapes are important ecosystems. However, they are currently experiencing direct and indirect effects of agricultural management surrounding them. Because wetlands provide important ecosystem services, it is crucial to determine how these factors affect ecological communities. Here, we studied the long‐term effects of land‐use intensification, cattle grazing, prescribed fires, and their interactions on wetland plant diversity, community dynamics, and functional diversity. To do this, we used vegetation and trait data from a 14‐year‐old experiment on 40 seasonal wetlands located within seminatural and intensively managed pastures in Florida. These wetlands were allocated different grazing and prescribed fire treatments (grazed vs. ungrazed, burned vs. unburned). Our results showed that wetlands within intensively managed pastures have lower native plant diversity, floristic quality, evenness, and higher nonnative species diversity and exhibited the most resource‐acquisitive traits. Wetlands embedded in intensively managed pastures were also characterized by lower species turnover over time. We found that 14 years of cattle exclusion reduced species diversity in both pasture management intensities and had no effect on floristic quality. Fenced wetlands exhibited lower functional diversity and experienced a higher rate of community change, both due to an increase in tall, clonal, and palatable grasses. The effects of prescribed fires were often dependent on grazing treatment. For instance, prescribed fires increased functional diversity in fenced wetlands but not in grazed wetlands. Our study suggests that cattle exclusion and prescribed fires are not enough to restore wetlands in intensively managed pastures and further highlights the importance of not converting seminatural pastures to intensively managed pastures. Our study also suggests that grazing levels applied in seminatural pastures maintained high plant diversity and prevented tree and shrub encroachment and that in the absence of grazing, prescribed fire became crucial to maintaining higher species evenness. [ABSTRACT FROM AUTHOR]