Effect of management and spatial characteristics on plant species richness of Castanea sativa Mill. woodlots in the NW Iberian Peninsula

This paper analyzes the effect of the spatial characteristics and intensity of land use on vascular plant species richness in Castanea (Chestnut) woodlots of the northwestern Iberian Peninsula included in the category “9260 Castanea sativa woodland” (Annex I, DC 92/43 European Community). Digital maps were used to characterize 30 woodlots for which land use intensity was estimated and all plants found were inventoried. The results show that woodlot shape and land use intensity have a significant effect on vascular plant richness and indicator species number. However, an analysis of the interaction between woodlot characteristics and land use intensity suggests that the response of vascular plant species to land use intensity does not exhibit a uniform pattern and that it is modulated by the shape of the woodlots. We conclude that restricting the use of these types of woods to traditional practices must be determined in keeping with the specific characteristics of each woodlot, since the moderate management of Castanea sativa woodlots of the northwest Iberian Peninsula may continue to play an important role to maintaining plant species diversity in this area.