Nutrient recycling as an ecological basis for the technologies involved in a sustainable development in semiarid mediterranean rangelands

Abstract

Recycling is the central axis for the conservaron of ecosystems ¡n the scenario of sustainable development. This subject implies the study of an important frame of interactions. Nevertheless, the complex study of nutrient recycling in agroecosystems would be reduced on the basis of the actual knowledge of the soil biocenoses, mainly represented by soil nematodes. Nematodes are indicator organisms of several processes related with the trophic structure of soil systems. This question, combined with the study of nematode interactions with the herbaceous communities growing over these soils, can provide guidelines for a more rational planning of pasture management. The results of our work show that nematode density is posrtively correlated wrth grass species richness and with the number of perennial species. Moreover, the quantity of nematodes decreases when grazing pressure is intensified. All that implies that the degree of maturity of a pasture may be intimately related to the biológica! recycling of nutrients.