Spatio-temporal analysis of central Texas savannas : integrating field data with remotely-derived data sources to inform ecosystem function and management
Alteration of savanna systems is driven by a wide range of natural and anthropogenic disturbance regimes. This research investigates seasonal trends in vegetation cover and productivity within central Texas environments. Through a combined methodological approach that utilizes vegetation transect fieldwork and satellite imagery analysis, this project provides insight into the influence of management strategies on savanna vegetation. Both a protected area and privately owned land were assessed in order to determine differences between the management strategies employed. Multiple spatial and temporal analysis approaches were employed to better understand vegetation patterning and function within central Texas’ savanna environments. Regression analysis of woody vegetation structural canopy data resulted in significant relationships existing between the presence of graminoid ground cover and the use of prescribed burn management. Time-series analysis of vegetation productivity using a remotely-sensed vegetation index provided insight into the influence of variable precipitation trends and drought conditions on this system. A comparison of functional group diversity and species diversity also investigated the ability of such metrics to predict productivity in these systems, ultimately leading to the suggestion of a combined approach. Lastly, remotely-sensed vegetation indices were included with species distribution modeling of central Texas’ golden-cheeked warblers, allowing for an investigation into strategies to better identify suitable habitats. These findings will inform land management strategies for land owners, land managers, and park managers for a variety of goals including support of grazing capacity, reduction of encroachment, reduction of invasive species, and habitat provision for key species.