CAREER: Tropical to temperate forest dynamics and their potential influences on plant performance strategies, a theory-data fusion approach

University Of Texas At Austin, Austin TX

Investigators

Abstract

Forests are made up of individual trees whose growth, death, and reproduction are influenced by things like rainfall, temperature, wind disturbances, and the shading by neighboring trees. Despite this diversity of traits and interactions, forests within specific biomes or habitat types (i.e., tropical rainforests, temperate forests), show striking similarities in forest structure across the globe. It is likely that these similarities are due to the commonalities of the importance of access to light for individual trees and the ubiquity of competition among trees for that light. In this project, researchers leverage the Smithsonian’s Forest Global Earth Observatory (ForestGEO), from the tropics to the temperate zone, to develop models and test hypotheses regarding the drivers of forest structure within and across biomes. As models are refined, the researchers will incorporate different plant strategies and explore the implications for biome-specific outcomes. The results of this work will be incorporated into the earth system models used to predict carbon sequestration and thus the role of forests in slowing or accelerating climate change. The project also offers training opportunities for early career scientists to develop and implement new tools for integrating empirical data and theory. The structure and dynamics of tropical and temperate forest biomes differ, but the causes and consequences of these differences are not well characterized. Recently, the researchers found that a simple model of tree competition for light that includes stochastic stand-level disturbances nicely captures qualitative and quantitative features of the tropical forest of Barro Colorado Island, Panama. The model, however, requires the addition of decreased performance of the largest trees to capture the structure of the temperate forest of Wind River, WA. This research will scale up, using an extensive global ForestGEO dataset, to test the generality of the differences between tropical and temperate forests. Moreover, this project will identify the likely causal differences in forest dynamics between these two biomes. With the refined model, the researchers aim to contribute new insights into how dynamic interactions among trees within forests will better predict stand structure over time, and how these models can improve earth system models. Further, the researchers will then draw new hypotheses about the commonalities and differences of selective pressures on key plant strategies and the potential for these differences in forest dynamics to result in differing opportunities for generating and/or maintaining species coexistence. As the integration of theory with data is critical to this research, the education plan of this CAREER project focuses on the integration of theory training into standard undergraduate and graduate coursework. Further, the inclusive teaching methodologies will be used to foster further integration of theory and empirical work within the early career community of ForestGEO researchers through a training and collaboration program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.