Dawn Browning
I am a spatial ecologist interested in quantifying how species are distributed across heterogeneous landscapes and understanding the ecological basis for those distributions and how they vary through time. My work integrates information and techniques from the fields of plant ecology, landscape ecology, range management, and remote sensing while capitalizing on a wealth of information on land use practices.
Changes in land cover and land use are recognized as predominant drivers of global change. Grasslands and savannas, also known as rangelands, are one of the most widespread land cover types on Earth and are home to approximately 20% of the world's human population. These actively managed landscapes encompass a markedly complex matrix of land use footprints (e.g., fire, brush management, and agriculture) superimposed upon the underlying geomorphic template (as illustrated in the 1977 aerial photograph above). A most striking shift in land cover change in rangelands over the past 150 years has been the proliferation of trees and shrubs at the expense of perennial grasses.
My Ph.D. research is focused on tracking changes in the abundance of woody plants in Sonoran Desert grasslands and evaluate the role that soil properties and past land uses have had on changes in woody cover and associated patch dynamics. I achieve this using geographic information systems (GIS) and spatial statistics to evaluate historic aerial photography and satellite imagery collected over the last 75 years.
Field validation is a key component to generating estimates of cover and biophysical parameters from satellite imagery and aerial photography. I link field measurements of cover and woody plant population structure with those derived from aerial photography in an effort to bridge the gap between fine scale plot-based studies with broad-scale landscape estimates of cover and plant biomass.
Publications
Browning, D.M., S.R. Archer, G.P. Asner, M.P. McClaran, and C.A. Wessman. 2008. Woody plants in grasslands: Post-encroachment dynamics. Ecological Applications 18(4):928-944.
Browning, D.M., S.J. Beaupre, and L. Duncan. 2005. Using Partitioned Mahalanobis D2(k) to formulate a GIS-based model of timber rattlesnake hibernacula. Journal of Wildlife Management 9:33-44.
Taylor, E., M. Malawy, D.M. Browning, S. Lamar, and D. DeNardo. 2005. Effects of food supplementation on the physiological ecology of female Western diamond-backed rattlesnakes Crotalus atrox). Oecologia 144:206-213.
Smith, B., J. Kolbe, and D. Browning. 2002. Burrow use by tiger salamanders (Ambystoma tigrinum) at a black-tailed prairie dog (Cynomys ludovicianus) town in southwestern South Dakota. Herpetological Review 33:95-99.
