Influence of honey mesquite and its control on zonal vegetation patterns

Abstract

A study initiated in 1973 explored relationships between honey mesquite (Prosopis glandulosa Torr. var. qlandulosa) and understory vegetation on a deep hardland range site in northcentral Texas. Forage production and secondary succession were monitored on brush control treatments applied in 1973, 1974, and 1976. Treatments included untreated (control), sprays of 2,4,5-T + picloram herbicide, and mechanical treatment (tree grubbing 1973, 1976 and root plowing 1974). Aerial and edaphic environmental factors that influence rate and direction of succession were measured and related to vegetation responses. Cool and warm season plants occupied a canopy zone beneath the untreated honey mesquite. A narrow transitional zone contained sparse stands of vegetation and extended from the canopy dripline into the interstitial areas of the honey mesquite stand. Arizona cottontop (Digitaria californica (Benth.) Henr.) and Texas wintergrass (Stipa leucotrica Trin & Rupr.) (24% and 29% composition, respectively) were major components of the untreated canopy zone. Transition zone vegetation was composed of Texas wintergrass (28%), and buffalograss (Buchloe dactyloides (Nutt.) Engelm.) (46%). Buffalograss was the dominant species of the untreated interstitial zones (77% composition)..