CHANGES IN VEGETATION STRUCTURE AND HYDROLOGICAL FUNCTION IN RESPONSE TO RANGELAND REST

Abstract

An experiment was carried out to evaluate the effects of grazing rest on the vegetation structure, the hydrological function, and the ecological status in grasslands of regular condition for cattle. The study area is located at 4 095 meters above sea level, in the Cordillera Blanca peasant community, Ancash Region, Peru. The experimental design was factorial 2 x 2 in blocks, where the factors were: a) two grazing systems P1: Uncontrolled grazing on communal usufruct lands and P2: Rest or total exclusion of grazing, and b) three years of monitoring between 2011 and 2013. At the end of the study, the vegetation structure changed according to the regime of the rangeland use, where the rest favored the increase of native gramineae species and to the detriment of herbs, pseudogramineae, and shrubs. Resting increased the vegetation cover, the accumulation of biomass and mulch on the ground with respect to grazing (P < 0.01). The hydrological function improved with the application of rest compared to grazing, which was reflected in a higher infiltration capacity and soil moisture content (P < 0.01). The ecological processes improved with resting compared to grazing expressed by the increase of the ecological status of the pasture, in response to the improvement of the components that determine its value, such as forage species and vigor (P < 0.01).