Doctoral Dissertation Research: Vegetation Dynamics of Endangered Pine Rockland Communities in the Lower Florida Keys

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

South Florida slash pine (Pinus elliottii var. densa) is the dominant woody species and sole canopy tree in pine rocklands of the Lower Florida Keys. These globally endangered communities support a diverse subcanopy of West Indian hardwoods and palms as well as a variety of endemic herbs that are alternately encouraged or held back by fire. This doctoral dissertation research project will use dendrochronology to investigate the structure and disturbance history of declining pine rockland communities in the Lower Florida Keys. The ecological and climatological factors contributing to the distribution of South Florida slash pine at the southern extent of its range will be examined. In addition, the reconstruction of spatial and temporal variability of past fire regimes will provide a better understanding of how fire affects the structure and extent of these communities. This project also will investigate the interaction between regional climate oscillations (e.g. the El Nino-Southern Oscillation) and wildfire activity. Quantitative information on the historical fire occurrence and climate response of slash pine communities is essential to the long-term management and restoration of pine rockland communities. This project will increase basic understanding of how human-related and natural disturbance events have decreased the spatial distribution of South Florida slash pine in the Lower Florida Keys. This project will apply techniques of dendrochronology in extreme southern Florida, in a subtropical region where tree?]ring science has never been applied, and it will produce climate proxy datasets that will add to the growing global network of low?]latitude climate proxy data. Results from this research will contribute to the understanding of how climate oscillations affect the region, particularly South Florida, and they will advance understanding of the complex dynamics of pine rocklands that will aid management efforts aimed at preserving these declining communities. The vegetation data produced by this project will provide valuable information regarding stand age distribution and composition in relation to natural and human-related disturbance regimes, and data on the association between pre-settlement wildfire and climate mechanisms will provide a better understanding of how fires shaped pine rocklands and the extent to which climate oscillations affected fire occurrence. As a Doctoral Dissertation Research Improvement award, this award will provide support for a doctoral student to establish a strong independent research career.