Vegetative and Arthropod Responses to Discing ) Implications for Bobwhites

J. Lane Roberson, Fidel Hernandez, Leonard A. Brennan, Timothy E. Fulbright, Ralph L. Bingham, and Robert Perez

Discing of rangelands has become a recommended management practice to improve northern bobwhite habitat since the early 20th century. Rangeland discing can improve bobwhite habitat by increasing the percentage of bare ground, stimulating growth of important food plants, and creating plant structural diversity necessary for invertebrates. Therefore, the objective of this study is to evaluate vegetation and arthropod responses to various discing regimes typically used to improve bobwhite habitat in Texas.

We are conducting a study in 3 ecoregions of Texas (i.e. Rolling Plains, Rio Grande Plains, and Gulf Coast Prairies and Marshes) during 2003­­−05. In each ecoregion, we evaluated time of discing (Sept.−March) on 2 soil types (sandy and clay). Our experiment consists of soil-delineated blocks, each comprised of 24 subplots (10 × 100 yds). During each month from October 2003 to March 2004, 3 subplots were randomly selected for discing. We collected data on plant species diversity, percentage canopy cover (forbs, grasses, and bare ground), and visual obstruction 1-year and 2-years post-treatment during March, May, and July.

We are currently analyzing data. Preliminary results indicate that species diversity (mean number of species) following discing was greater on sandy soils (m = 10.7) compared to clay soils (m = 9.0) in the Rio Grande Plains. However, species diversity did not differ between sandy soils (m = 5.3) and clay soils (m = 5.2) in the Rolling Plains. We emphasize the preliminary and tentative nature of these results.

Findings of this study will be useful to land managers seeking to improve bobwhite populations using fall and winter month discing.

Cooperative funding provided by the Texas Parks and Wildlife Department.