SOIL AND VEGETATION DEVELOPMENT IN AN ABANDONED SHEEP CORRAL ON DEGRADED SUB-ALPINE RANGELAND

Vegetation and soils inside and outside an abandoned sheep corral on d egraded subalpine range of the Wasatch Plateau were studied to determi ne the influence of approximately 37 years' use of the corral on soil and plant development. Vegetal and surface cover were estimated. Herba ge, litter, and soils were sampled inside and outside the corral and a nalyzed for C(org), N, P, and S. Soil pH, bulk density, and CO3-C also were measured. Storage (mass/unit area) of C(org), N, P, and S was de termined for each component. Yield and vegetal composition were signif icantly affected inside the corral boundary. Herbage yield was 2.2 tim es greater, litter mass 16 times greater, foliar cover of grasses 2 ti mes greater, and forb cover 70% lower inside than outside the corral. Cover of meadow barley (Hordeum brachyantherum), a component of the pr edisturbance vegetation of the Wasatch Plateau, was nearly 12 times gr eater inside than outside the corral. These and other vegetal and cove r differences reflect inside-outside differences in concentration, sto rage, and availability of soil C(org), N, P, and S. Concentrations of C(org) and total and available N, P, and S were greater in the surface 5 cm of soil inside the corral. Available P inside the corral was muc h higher in all soil layers. Because of bulk density differences, stor age was greater inside the corral only for C(org) and N at 0-5 cm and for P at 5-15 cm. Lower soil pH inside the corral appears related to s oil P distribution and CO3-C storage. Results suggest a need to reexam ine earlier conclusions that tall forbs are the climax dominants of th e Wasatch summer range.