A5064211132- Ecology and Vegetation Dynamics Studies
- Fire effects on ecosystems
- Ecosystem dynamics and resilience
- Rangeland and Wildlife Management
- Plant Water Relations and Carbon Dynamics
- Sustainability and Ecological Systems Analysis
- Species Distribution and Climate Change
- Tree-ring climate responses
- Economics of Agriculture and Food Markets
- Animal Ecology and Behavior Studies
- Wildlife Ecology and Conservation
- Agroforestry and silvopastoral systems
- Global Energy and Sustainability Research
- Forest Management and Policy
- Land Use and Ecosystem Services
- Climate change impacts on agriculture
- Forest Biomass Utilization and Management
- Remote Sensing in Agriculture
- Rangeland Management and Livestock Ecology
- Disaster Management and Resilience
- Plant and animal studies
- Hydrology and Watershed Management Studies
- Sustainable Agricultural Systems Analysis
- Agriculture Sustainability and Environmental Impact
- Forest ecology and management
Kansas State University
2011-2024
University of Wisconsin–Madison
2017-2023
London School of Economics and Political Science
2019
University of Virginia
2016-2017
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,...
Summary This review synthesizes evidence that altered fire frequency drives discontinuous ecosystem transitions from mesic grasslands to shrublands or woodlands in the C entral G reat P lains, USA . Long‐term manipulations reveal grassland shrubland are triggered when fire‐free intervals increase 1–3 years ≥ 3–8 years, and longer returns (˜10 more) result woodlands. Grazing soil properties alter these thresholds. Grassland abrupt exhibit nonlinear relationships between driver state...
Ensuring food security requires production and distribution systems function throughout disruptions. Understanding the factors that contribute to global system's ability respond adapt such disruptions (i.e. resilience) is critical for understanding long-term sustainability of human populations. Variable impacts shocks on supply between countries indicate a need national-scale resilience indicators can provide comparisons. However, methods tracking changes in have had limited application...
Ecosystems with alternative attractors are susceptible to abrupt regime shifts that often difficult predict and reverse. In this study, we quantify multiple system dynamics determine whether the transition of mesic grassland shrubland, a widespread phenomenon, represents linear reversible process, nonlinear but threshold or between is prone hysteresis. Using 28‐yr data set annual resolution extensive spatial replication, found shrub cover correlated distinct thresholds fire C 4 grass cover,...
While a growing proportion of global food consumption is obtained through international trade, there an ongoing debate on whether this increased reliance trade benefits or hinders security, and specifically, the ability systems to absorb shocks due local regional losses production. This paper introduces model that simulates short-term response supply shock originating in single country, which partly absorbed decreases domestic reserves consumption, transmitted adjustment flows. By applying...
Abstract Changing climate and disturbance regimes are increasingly challenging the resilience of forest ecosystems around globe. A powerful indicator for loss is regeneration failure, that is, inability prevailing tree species to regenerate after disturbance. Regeneration failure can result from interplay among changes (e.g., larger more frequent fires), altered conditions increased drought), functional traits method seed dispersal). This complexity makes projections challenging. Here we...
Abstract Hysteresis is a fundamental characteristic of alternative stable state theory, yet evidence hysteresis rare. In mesic grasslands, fire frequency regulates transition from grass‐ to shrub‐dominated system states. It uncertain, however, if increasing can reverse shrub expansion, or grass‐shrub dynamics exhibit hysteresis. We implemented annual burning in two infrequently burned grasslands and ceased annually. With fires, grassland composition converged on that long‐term annually...
Over the last century, many grasslands worldwide have transitioned from a graminoid to tree/shrub-dominated state in short period of time, phenomenon referred as woody encroachment. Positive feedbacks and bi-stability are thought be important drivers encroachment, but there is little empirical evidence suggest that positive accelerate encroachment mesic grasslands. In tallgrass prairie, shrub establishment does not directly facilitate seedling establishment. Yet, may clonal spread existing...
Abstract Regime shifts are difficult‐to‐reverse transitions that occur when an ecosystem reorganizes around a new set of self‐reinforcing feedbacks. predicted to the intensity some exogenous driver variable, such as temperature, annual harvest rate, or nutrient addition gradually approaches and crosses threshold value, initiating transition alternative state. However, many variables now change rapidly presses pulses, not gradually, requiring conceptual frameworks for understanding predicting...
Abstract In restoration ecology, the transition from desired to degraded state is based solely on composition of aboveground plant community, whereas belowground propagules are often neglected. We developed a conceptual framework integrating seed bank dynamics into alternative stable theory, highlighting important relationship between and composition. This integration emphasizes role resilience in systems that appear have shifted an “undesirable” state. Belowground propagules, especially...
Abstract As temperatures continue rising, the direction, magnitude, and tempo of change in disturbance‐prone forests remain unresolved. Even long resilient to stand‐replacing fire face uncertain futures, efforts project changes forest structure composition are sorely needed anticipate future trajectories. We simulated (incorporating fuels feedbacks) dynamics on five landscapes spanning Greater Yellowstone Ecosystem (GYE) ask following questions: (1) How where likely with 21st‐century warming...
Summary State transitions are changes in ecosystem structure and self‐reinforcing feedbacks that initiated when an exogenous driver variable crosses a threshold. Reversing state is difficult costly. While some relatively rapid, many take years to decades. Outside of theoretical models, very little known about slower how they unfold time space. We quantified spatial variance as mesic grassland shifts shrub‐dominated state, using long‐term experiments simulations maintain grasslands with...
Resilience has become a common goal for science-based natural resource management, particularly in the context of changing climate and disturbance regimes. Integrating varying perspectives definitions resilience is complex often unrecognized challenge to applying concepts social-ecological systems (SESs) management. Using wildfire as an example, we develop framework expose separate two important dimensions resilience: inherent properties that maintain structure, function, or states SES human...
Abstract Winter climate is expected to change under future scenarios, yet the majority of winter ecology research focused in cold‐climate ecosystems. In many temperate systems, it unclear how relates biotic responses during growing season. The objective this study was examine weather plant and animal communities a variety terrestrial ecosystems ranging from warm deserts alpine tundra. Specifically, we examined association between phenology, species richness, consumer abundance, richness 11...
Abstract Animals must track resources over relatively fine spatial and temporal scales, particularly in disturbance‐mediated systems like grasslands. Grassland birds respond to habitat heterogeneity by dispersing among sites within between years, yet we know little about how they make post‐dispersal settlement decisions. Many methods exist quantify the resource selection of mobile taxa, but data used these models are frequently not collected at same location or time that individuals were...
Woody plant encroachment (WPE)-a phenomenon similar to species invasion-is shifting many grasslands and savannas into shrub evergreen-dominated ecosystems. Tracking WPE is difficult because shrubs small trees are much smaller than the coarse resolution of common remote sensing platforms (> 10 m2) impassibility encroaching woody thickets slows ground-based approaches. Many agencies have been investing in fine (< 2 through programs such as United States Department Agriculture (USDA)...