Propuesta metodológica de evaluación del territorio para su uso pascícola. Parque natural de Aiako Harria

Résumé

The 'Aiako Harria' Natural Park is located in the northeastern córner of the Basque Country (northern Spain). So far, forestry appears to be the main activity carried out in this Park. The transformation of those áreas covered by shrubs-ferns and ferns into pastures would allow to meet the nutritional needs of the cattle bred in that área, leading concomitantly to an increase in biological and landscape diversity. In this work, the methodology used to choose the most approriate áreas to be converted into pastures, taking always into account that the rate of potential erosión, insofar as it is possible, must not be increased, is described. The method shown here is based on the Universal Soil Loss Equation (USLE) combined with the utilization of a Geographic Information System (SIG), which compelled us to map the soils and vegetation of the área. Likewise, every vegetation unit was thoroughly sampled so that the valué of the protection factor corresponding to the plant cover of each unit could be determined. Herbaceous biomass was estimated, finding out that it was insufficient to meet the nutritional needs of the cattle that regularly grazes in that área. Therefore, it was proposed to increase the surface of the Park covered by pastures. In order to do so, the new áreas covered by pastures were chosen according to the following factors (among others): current use (shrubs, ferns, Pinus radiola D. Don, Pinus nigra J.F. Arnold and Larix kaempferi (Lam.) Carr. plantations), rate of potential erosión after pasture establishment (lower than 10 tonnes/ha/year), and the recommendations given by the local Natural Resources Regulation Plan (PORN) in this respect (i.e., the áreas were cattle raising was envisaged in this Plan).