Leguminosas y gramineas como base para la tipificación de pastos. II comunidades de caracter subhúmedo y xerofítico

Abstract

Using only legume and grass species, we pretend to characterize a group of pastures, subhumid and xerophytic by means of an ordination analysis. This analysis differentiates clearly the communities with mesomediterranean bioclimatic characteristics from those with supramediterranean ones. The transition between both bioclimatic environments is defined by the "tomillar- pasto" (al. Brachypodion phoenicoidé) and 'lastonares" (al. Festuco-Poion ligulatae) according to topographic and soil characteristics. Given the complex character of these subhumid pastures, in the southem limit of their distribution área, the use of only these species belonging to the above mentioned families, is not sufficient to differentiate the main types of communities described for the studied área, although it does make clear some main variation tendencies. The great homogeneity in these pastures is due to the repetition of very few species, whose high frecuency in the supramediterranean pastures on limestone, is related to the traditional management based on sheep grazing.