Soil and Grazing Influences on a Salt-desert Shrub Range in Western Colorado

Abstract

Responses of vegetation and ground cover to winter grazing by livestock and to exclusion of livestock for 10 years were observed on soils derived from shale, sandstone, and a mixture of shale and sandstone. Although distinct soil-vegetation relationships were evident, changes attributable to grazing were relatively small. Vegetation and other cover on nongrazed range was practically the same at the end as at the beginning of the study. Overall reductions in galleta, shadscale, and snakeweed were attributed to drought, while differential responses of Salina wildrye, Gardner saltbush, Greenes rabbitbrush, and annual plants were ascribed to grazing. Inherently low site capability and subnormal precipitation were believed responsible for the general lack of response of vegetation to exclusion of livestock./En el estudio se compararon zonas pastoreadas en invierno con exclusiones de diez años de edad. Se concluyó que había poca influencia del pastoreo sobre le vegetación. La composición vegetal dentro de las exclusiones fué la misma al principio y al final del estudio. Hubo una disminución de las especies Atriplex confertifolia, Hilaria jamesii y Gutierrezia sarothrae por causa de las sequías. Hubo varias respuestas diferenciales de las especies Elymus salinus, Atriplex nuttallii, Chrysothamnus greenei y plantas anuales debido al pastoreo. El autor piensa que la vegetación no mejoró sin pastoreo porque el potencial fué bajo en los suelos y también hubo un bajo promedio de precipitación pluvial.