Response of herbaceous vegetation to summer fire in the western south Texas plains

With increases in wildlife related enterprises and ecological restoration efforts in southern Texas, there is an increased interest in utilizing summer fire to achieve management goals; yet, there is little data on the effects of summer burning on vegetation and wildlife. Herbaceous vegetation diversity, productivity, density and frequency were estimated on five summer burned and five nontreated sites utilizing 20 by 50 cm quadrats. Forb density and frequency was monitored for two growing-seasons postburn. Grass indices were measured three months postburn. Grass and forb yields were estimated in 0.25 m 2 plots during the first growing-season postburn. Croton (Croton sp.) responded positively to summer burning during the first growing-season postburn for all indices measured. During the second growing season postburn, Croton densities were similar among treatments. Densities of erect dayflower (Commelina erecta) and beach groundcherry (Physalis cinerascens) were greatest on burned sites throughout the study. Silky evolvulus (Evolvulus alsinoides) and hoary blackfoot (Melampodium cinereum) were more common on nontreated sites. Grass densities were lowest on burned sites three months postburn, and yields were similar between treatments by the middle of the first postburn growing season. Summer burning does not appear to provide any additional benefits in forb response over dormant-season burning. The long-term effect of a regimented burning regime on vegetation and influence of burn season on wildlife is not clearly understood and warrants further investigation.