The overarching goal of my lab’s research is to better understand the consequences of human-caused global changes, especially the impacts of climatic changes, biological invasions, eutrophication (e.g., increased N deposition), and altered disturbance regimes for biodiversity and ecosystem structure and function. Within this context, our research addresses long-standing, yet highly relevant questions about the functional roles of species in ecosystems (e.g., Smith & Knapp 2003, Smith et al. 2004), the causes and impacts of loss (extinctions) and gain (invasion) of genetic and species diversity at the population, community and ecosystem level (e.g., Smith et al. 2004, Avolio et al. submitted, Smith in prep), the factors that influence species coexistence and patterns of species abundance (e.g., Collins & Smith 2006, Veen et al. 2008), and the relative strength of bottom-up (resources) vs. top-down (consumers) controls in structuring communities (e.g., Cebrian et al. 2009, Smith et al. in prep).
Over the past several years, I have established a diverse, extramurally funded research program focused on elucidating the key mechanisms that underlie and determine community and ecosystem responses to human-caused global changes (Smith et al. in press). These efforts are complementary to my more basic research addressing fundamental ecological questions about communities and ecosystems. In addition to making broader conceptual advances, my lab employs a mixture of empirical approaches (observational, experimental, comparative and synthetic) and utilizes grassland ecosystems, in particular those in North America (NA) and South Africa (SA), as experimentally tractable and dynamic model systems. Such research by necessity requires substantial breadth, both within ecology and across all biological scales of organization. As a consequence, our research is highly integrative, interdisciplinary, and collaborative in nature, which I believe is critical for solving the most pressing and complex issues that ecology as a discipline and society faces today.
The core of my research program consists of a suite of on-going and complementary field projects all aimed at accomplishing my lab’s overarching research goal and testing and advancing fundamental ecological theory. These projects include:
- A suite of research projects examining the interactive effects of warming and altered precipitation regimes on plant community dynamics and ecosystem functioning with focus on elucidating the mechanisms underlying community and ecosystem responses to climate change,
- Comparative studies testing theory concerning the impacts of altered disturbance regimes, specifically fire and herbivory, in determining grassland structure and function,
- A multi-year study aimed at testing theory concerning the role of resource availability in determining invasion and assessing how climatic changes may interact to influence invasibility of ecosystems,
- Research aimed at assessing the role of dominant plant species in the structure and functioning of ecosystems,
- Research examining the interactive effects of resources (N and P) on community and ecosystem dynamics, and
- A continental-scale experiment testing theory concerning the role of multiple resource limitation and bottom-up and top-down controls in structuring communities. This research is part of a global research initiative – the Nutrient Network – in which I am a founding steering committee member.
- An integrative gene-to-ecosystem understanding of the ecological consequences of climate change
- Implications of altered disturbance regimes for grasslands: a comparative approach
- Impacts of climate change (increased temperature, altered precipitation regimes) on invasion
- The role of dominant plant species in the structure and function of ecosystems
- The Climate Extremes Experiment (CEE): Examining threshold responses of the tallgrass prairie ecosystem to temperature and precipitation extremes.
- Global warming impacts on CT salt marsh ecosystems and consequent effects on salt marsh vulnerability to sea level rise