Tanglehead (Heteropogon contortus [(L.) P. Beauv. ex Roem & Schult]) is a native grass in southwestern US rangelands; however, its prevalence as an invasive on South Texas rangelands has grown. In the last decade, large areas of tanglehead monocultures have emerged, simplifying native vegetative communities in Jim Hogg, Brooks and Kleberg counties. The dominance of this species in sandy soils is a cause for concern for many ranchers as it may have negative impacts on wildlife resources. Unfortunately, little is known regarding the spatial extent of this invasion and its impact. The goal of this project is to determine the extent and spatial distribution of tanglehead in critical areas of South Texas. To address this goal, specific tanglehead dominated areas have been identified using high-resolution aerial photography, field verification, ranch information, and data collected from previous research. This information is being cross-referenced with recent aerial photography and satellite imagery to develop a spectral signature exclusive to tanglehead in order to classify and generate maps of tanglehead at local and county scales. Historical aerial photography and satellite imagery (2004-2014) will be used to assess the spatial and temporal distribution of tanglehead and quantify its rate of increase over the last decade. Landscape metrics that describe the spatial structure and distribution of tanglehead will be used to assess its expansion in the last decade across the study area.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.