October 28, 2020

12:00pm Zoom Webinar

Nathan Kraft
Department of Ecology and Evolutionary Biology, UCLA

" Functional trait-based approaches to understanding plant community dynamics, from tropical forests to annual grasslands "

Ecologists and geographers have long been fascinated with the striking changes in plant community composition and function across latitudinal and environmental gradients, but resolving the drivers of these patterns has been challenging, particularly in high-diversity communities. Here I will share research from my lab over the last five years focused on better understanding these broad scale patterns and the underlying ecological drivers, with a particular focus on the use of plant functional traits to help probe the mechanisms shaping dynamics at the community level.

 

At the broadest geographic scales, our group has contributed to global efforts to compile, standardize, and synthesize patterns of plant diversity across the planet, with a particular focus on understanding the drivers of patterns of species turnover (beta diversity) across geographic gradients. These analyses focus on testing long-held hypotheses that community assembly processes differ in tropical versus temperate regions. Next, I will explore some of my group’s recent work on tropical forest community dynamics, bringing new analytic techniques to a hyperdiverse forest plot in Ecuador to explore the extent to which responses to small scale environmental variation as well as plant-plant competition influence forest dynamics. Finally, I will pivot to recent projects in California serpentine plant communities, where we use detailed experimental manipulations to test the extent to which species trait differences influence coexistence outcomes across a range of spatiotemporal scales. The relatively simple life histories of these annual plants make them ideal for exploring key questions about how trait differences shape coexistence that are difficult or impossible to directly test in longer lived organisms such as tropical trees.

 

Taken together, the work in our group seeks to recast classic community ecology questions in the functional perspectives offered by plant ecophysiology. Our aspiration is that a robust understanding of the phenotypic basis of community processes will help to resolve the messiness and context dependence that often plagues community ecology, as well as offering new insights into how communities may respond to ongoing global changes.

Host: Lawren Sack