VEGETATION RESPONSES TO 2-BRUSH MANAGEMENT-PRACTICES IN SOUTH TEXAS

Brush management for improving wildlife habitat in South Texas is impo rtant because of the economic value of wildlife. We determined vegetat ion responses to (1) roller chopping of guajillo (Acacia berlandieri B enth.)-blackbrush acacia (A. rigidula Benth.)-dominated rangeland and (2) heavy discing of whitebrush (Aloysia lycioides Cham.)-dominated ra ngeland to improve white-tailed deer (Odocoileus virginianus Raf.) hab itat. Canopy cover of vegetation was estimated seasonally during Augus t 1988 to April 1990. Both treatments reduced brush canopy cover, but herbaceous response depended on rainfall. Mean herbaceous cover was 65 and 136% higher on roller chopped sites than on untreated sites when averaged across all sampling dates. Heavy discing reduced relative can opy cover of whitebrush but increased cover of spiny hackberry (Celtis pallida Torr.), an important browse species. Forb species richness wa s higher on roller chopped and disced sites than on untreated sites, b ut species diversity was similar. Because herbaceous response to brush removal may depend on rainfall, other factors such as effects on brow se availability and nutritional quality may need to be considered when planning brush management strategies to improve white-tailed deer hab itat.