Las estaciones ecológicas actuales y potenciales de los encinares españoles peninsulares

Holm oak (Quercus ilex L.) woodlands occupy around 3 million hectares in Spain. Thus, the importance of this species justifies the task of achieving the knowledge of its autecological features. Physiographic, climatic and edaphic habitats of Q. ilex have been defined using environmental envelope techniques. The whole set of ecological parameters was used to apply multivariate analysis and five ecological gradients were defined. The two most important are the termic and the hydric gradients. The climate area currently occupied by this species falls within the Mediterranean area, mainly living on Cambisols or Luvisols. When compared with other species, the holm oak has the second highest textural valency, also confirmed as the most cosmopolite species. The potential distribution of the species was defined by projecting the current habitat in Spain and four hierarchical classes were defined. Over ten million hectares of potentially optimal area could be considered. An analysis of the relationship between ecological parameters and silvicultural variables was made. Basal area showed significant correlations, although its ability as predictor is weak. Reasons for such low predictive power are thought to be related to past management.