Variaciones en la estructura aérea y subterránea de pastos de montaña según el grado de aprovechamiento

Abstract

After carrying out a stratified sampling, ten localities which presented differences in as far as lithology, exposure and degree of explotation where chosen. The aerial and underground analysis in the pasture biomass for each of the species present, reveal differences related to the organization of these ecosystems, depending on the control exercised by grazing presure, and on the more relevant environmental conditions. The comparison between both aerial and underground biomass diversity of the different samples of each plot, results in quite an indicative parameter of an appropriate exploitation, being cióse to the unit in the more favourable cases. These generally correspond to mesofitic and very structured communities. The contrast between the ordination analysis of both the aerial and underground samples, taking into account the species biomass, serves to discuss the similarity as far as variations tendencies which show both components of the pasture, so that the coherence of these disparities according to the biological types that form the studies communities. The rate of the mencioned types is considered, as a whole, like an answer of the pasture community to the control carried out by the manner of exploitation.