Efecto del desbroce y el pastoreo sobre el crecimiento de Daphne cneorum l., una especie amenazada de la CAPV

Abstract

Daphne cneorum is a threatened chamaephyte of the Basque Country, catalogued as a species of“special interest” with few populations in the Basque Country, probably because of two reasons:(1) D. cneorum is in the western limit of its distribution; (2) it inhabits a type of habitat in whichhuman disturbance occurs frequently (an open mosaic of gorse-heathland with mountainpastures), that traditionally have been transformed in pasture. The aim of this work is to analyzethe effect of clearing off (shrub-removal, D) and livestock grazing (herbivory, h) on the growthand development of the plant. We designed an experiment of 4 treatments, each one representedby 3 plots: D+h+, D+h-, Dh+, Dh-. A total of 150 individual plants were tagged and monitoredduring the growing seasons of 2005 and 2006. D. cneorum showed a high capability ofrecovering after clearing of, and invested its energy resources in regenerating aerial vegetativeparts. Livestock grazing seemed to enhance the horizontal spreading of plants. However, due tothe high variability of data within population, we are obliged to interpret these results withcaution, which suggest that the relationship of plant with its environment is too much complexand could be strongly related to microhabitat features of each individual plant.