Herbaceous Vegetation-Lotebush (Ziziphus obtusifolia (T. & G.) Gray var. obtusifolia) Interactions in North Texas

Abstract

Basal cover and standing crop of herbaceous vegetation were measured during 1979 and 1980 at 0.3-m intervals along transects radiating from individual lotebush canopies in each cardinal direction. Basal covers and standing crops were generally least near the shrubs, regardless of season. However, buffalograss was less abundant in the shrub-free zones than near the lotebush plants. Texas wintergrass basal cover and standing crop were greatest in shrub-free areas except at the north and east driplines, where environmental conditions were apparently ameliorated by the lotebushes. Japanese brome and sand dropseed were most abundant in those zones where buffalograss and Texas wintergrass influences were least. These results indicate that lotebush has a minimal influence on grass cover, and that the major impact is concentrated beneath the shrub canopies.