<i>LITTER DECOMPOSITION IN OLIGOTROPHIC MEDITERRANEAN GRASSLAND OF THE CENTER OF THE IBERIAN PENINSULA</i>

Abstract

The decomposition of plant litter from legume and grass species was studied in a Mediterranean grassland of the center of the Iberian Peninsula. As study variables, the yearly evolution of the remaining dry biomass in litter from buried litterbags and their chemical composition (total nitrogen and organic carbon) were considered. The results indicated that litter biomass was lost faster in the shrub legume (k = 0.55 year^–1) that in the other two plant litter types (clover and grass litter), being the grass litter more resistant to decomposition (k = 0.34 year^–1). The loss of organic carbon and nitrogen from the litter was also different among the litter types, the grass litter showing the smallest variations nitrogen content variations throughout the study period. However there were not remarkable differences in litter organic carbon at the end of the experiment. The nitrogen input to the ecosystem through litter decomposition was higher for the grass litter than for legumes and it was different depending on the considered zone of the topographic gradient studied. The contribution of the clover species to that nitrogen input was higher in the lower zones of the gradient whereas the grass species showed higher values in the upper parts of the gradient, where their relative abundance was also higher.