A5074878885- Ecology and Vegetation Dynamics Studies
- Rangeland and Wildlife Management
- Plant and animal studies
- Rangeland Management and Livestock Ecology
- Wildlife Ecology and Conservation
- Species Distribution and Climate Change
- Plant Water Relations and Carbon Dynamics
- Fire effects on ecosystems
- Soil Carbon and Nitrogen Dynamics
- Ecosystem dynamics and resilience
- Animal Ecology and Behavior Studies
- Pasture and Agricultural Systems
- Climate variability and models
- Land Use and Ecosystem Services
- Forest Management and Policy
- Forest ecology and management
- Meteorological Phenomena and Simulations
- Bioenergy crop production and management
- Conservation, Biodiversity, and Resource Management
- Botany and Plant Ecology Studies
- Agriculture and Rural Development Research
- Zoonotic diseases and public health
- African Botany and Ecology Studies
- Peatlands and Wetlands Ecology
- Sustainable Agricultural Systems Analysis
University of North Carolina at Greensboro
2015-2025
Agriculture and Forestry University
2023
Hudson Institute
2018
John Wiley & Sons (United States)
2018
Duke University
2016-2017
University of South Florida
2016-2017
Colorado State University
2013-2016
University of New Mexico
2011-2016
South African National Parks
2016
Scientific Services
2016
Climate change is intensifying the hydrologic cycle and expected to increase frequency of extreme wet dry years. Beyond precipitation amount, years may differ in other ways, such as number events, event size, time between events. We assessed 1614 long-term (100 year) records from around world identify key attributes regimes, besides that distinguish statistically In general, regions where mean annual (MAP) exceeded 1000 mm, amounts differed average by ~40% 30%, respectively. The magnitude...
Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) associated ecosystem services such as food production carbon sequestration. Frequently, experimental manipulations have linked regimes to NPP. Yet, findings been diverse uncertainty still...
Significance Accurate prediction of community responses to global change drivers (GCDs) is critical given the effects biodiversity on ecosystem services. There consensus that human activities are driving species extinctions at scale, but debate remains over whether GCDs systematically altering local communities worldwide. Across 105 experiments included 400 experimental manipulations, we found evidence for a lagged response herbaceous plant caused by shifts in identities and relative...
Summary Nutrient additions typically increase terrestrial ecosystem productivity, reduce plant diversity and alter community composition; however, the effects of P interactions between N are understudied. We added both (10 g m −2 ) three levels (2.5, 5 10 to a native, ungrazed tallgrass prairie burned biennially in northeastern K ansas, USA , determine independent interactive on composition above‐ground net primary productivity ( ANPP ). After decade nutrient additions, we found few alone...
The widespread extirpation of megafauna may have destabilized ecosystems and altered biodiversity globally. Most extinctions occurred before the modern record, leaving it unclear how their loss impacts current biodiversity. We report long-term effects reintroducing plains bison ( Bison ) in a tallgrass prairie versus two land uses that commonly occur many North American grasslands: 1) no grazing 2) intensive growing-season by domesticated cattle Bos taurus ). Compared to ungrazed areas,...
Abstract Little is currently known about how climate modulates the relationship between plant diversity and soil organic carbon mechanisms involved. Yet, this knowledge of crucial importance in times change biodiversity loss. Here, we show that positively correlated with content carbon-to-nitrogen ratio across 84 grasslands on six continents span wide gradients. The relationships as well matter quality (carbon-to-nitrogen ratio) are particularly strong warm arid climates. While biomass...
Grazing, fire, and climate shape mesic grassland communities. With global change altering all three factors, understanding how grasslands respond to changes in these combined drivers may aid projecting future ecosystems. We manipulated rainfall simulated grazing (clipping) two long‐term fire experiments North America (NA) South Africa (SA). Despite their common drivers, NA SA differ evolutionary history. Therefore, we expected community structure production differently grazing, drought....
Abstract Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this scale dependent remains to be elucidated. Here, we determine relationship between and temporal stability for 243 communities from 42 grasslands across globe quantify chronic fertilization these relationships. Unfertilized with more species exhibit greater asynchronous dynamics among response natural fluctuations,...
Abstract Univariate and multivariate methods are commonly used to explore the spatial temporal dynamics of ecological communities, but each has limitations, including oversimplification or abstraction communities. Rank abundance curves (RACs) potentially integrate these existing methodologies by detailing species‐level community changes. Here, we had three goals: first, simplify analysis developing a coordinated set R functions, second, demystify relationships among univariate, multivariate,...
Abstract Climatic extremes, such as severe drought, are expected to increase in frequency and magnitude with climate change. Thus, identifying mechanisms of resilience is critical predicting the vulnerability ecosystems. An exceptional drought (<first percentile) impacted much southern Africa during 2015 2016 growing seasons, including site a long‐term fire experiment Kruger National Park, South Africa. Prior experimental frequencies (annual, triennial, unburned) created savanna grassland...
Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system thought to influence aspects plant-herbivore biology, from ecological stability plant defense evolution. Our understanding what influences variability, however, limited by sparse data. We collected standardized surveys herbivory for 503 species at 790 sites across 116° latitude. With these data, we show that within-population increases...
Abstract Forbs (“wildflowers”) are important contributors to grassland biodiversity but vulnerable environmental changes. In a factorial experiment at 94 sites on 6 continents, we test the global generality of several broad predictions: (1) Forb cover and richness decline under nutrient enrichment, particularly nitrogen enrichment. (2) increase herbivory by large mammals. (3) less affected enrichment in more arid climates, because water limitation reduces impacts competition with grasses....
Summary 1. Precipitation is considered to be a key driver of ecosystem processes in mesic grasslands, and climate models predict changes the amount intensity precipitation under future global change scenarios. Although most experimental rainfall studies decrease precipitation, seasonal predicted increase northern Great Plains change. 2. We analysed community composition structure upland lowland native tallgrass prairie central Kansas, USA, subjected 19 years irrigation designed eliminate...
Herbivory and fire shape plant community structure in grass‐dominated ecosystems, but these disturbance regimes are being altered around the world. To assess consequences of such alterations, we excluded large herbivores for seven years from mesic savanna grasslands sites burned at different frequencies North America (Konza Prairie Biological Station, Kansas, USA) South Africa (Kruger National Park). We hypothesized that removal a single grass‐feeding herbivore Konza would decrease richness...
Summary Anthropocene defaunation is the global phenomenon of human‐induced animal biodiversity loss. Understanding patterns and process critical to predict outcomes for wildlife populations cascading consequences ecosystem function human welfare. We investigated a gradient in north‐eastern Gabon by establishing 24 transects at varying distances (2–30 km) rural villages surveying abundance composition vertebrate communities. Distance from village was positively correlated with observations...
Abstract Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas elephant‐free tropical forest. Elephants are ecological engineers that create and maintain habitat; thus, loss will have large consequences for the composition structure Afrotropical forests. Through a comprehensive literature review, we evaluated roles in seed dispersal, nutrient recycling, herbivory physical damage to predict cascading effects...
A major challenge in global change ecology is to predict the trajectory and magnitude of community response drivers (GCDs). Here, we present a new framework that not only increases predictive power individual studies, but also allows for synthesis across GCD studies ecosystems. First, suggest by quantifying dissimilarity replicates both among within treatments, can infer predictability change, respectively. Second, demonstrate utility integrating rank abundance curves with measures...
Abstract Heterogeneity is increasingly recognized as a foundational characteristic of ecological systems. Under global change, understanding temporal community heterogeneity necessary for predicting the stability ecosystem functions and services. Indeed, spatial commonly used in alternative stable state theory predictor therefore an early indicator regime shifts. To evaluate whether species composition predictive communities, we analyzed 68 data sets spanning freshwater terrestrial systems...
Summary Nitrogen (N) deposition and phosphorus (P) due to pollution land‐use change are dramatically altering biogeochemical cycles. These altered nutrient inputs affect plant communities by generally increasing dominance reducing diversity, as well community variability (heterogeneity). Less studied the effects of changes in on ecosystem functions, such productivity, or stability those functions. Here, we use a twelve‐year addition experiment tallgrass prairie determine responses N P...
Abstract Random species loss has been shown experimentally to reduce ecosystem function, sometimes more than other anthropogenic environmental changes. Yet, controversy surrounds the importance of this finding for natural systems where is non‐random. We compiled data from 16 multi‐year experiments located at a single native tallgrass prairie site. These included responses 11 changes, as well non‐random biodiversity either removal uncommon/rare plant or most common (dominant) species. As...
Abstract Global change is impacting plant community composition, but the mechanisms underlying these changes are unclear. Using a dataset of 58 global experiments, we tested five fundamental change: in evenness and richness, reordering, species gains losses. We found 71% communities were impacted by treatments, 88% that exposed to two or more drivers impacted. Further, all equally likely be affected treatments—species losses richness just as common reordering. also no evidence progression...