Notes sobre el passat, el present i el futur de les pinedes de pi roig (Pinus sylvestris L.) de les Muntanyes de Prades: resultats d'un estudi dendroecològic

Abstract

The demographic structure, primary production and tree vigor of the population of Pinus sylvestris covering the upper slopes of the Poblet forest (Prades mountains, in the precoastal Catalan range) is analyzed from a successional point of view. Tree ages reveal that they form a single cohort which started invading the site by 1848, thus indicating a severe disturbance period probably related to the 1835 disentailment law. The lack of regeneration of P. sylvestris and the extremely low production and vigor of adult pine trees suggest that the population of this species, although now dominant in the landscape, is actually undergoing a clear decline, and its replacement by two shade-tolerant species (Quercus ilex and Q. pyrenaica), now abundant in the understory, can be predicted to occur soon. The ring-width series of sampled trees and their age and size distributions indicate the different development stages undergone by the forest, which are a reflection of the interaction between the natural dynamics of the vegetation and the different types of human intervention. Finally, the knowledge that a single disturbance episode allows a pine population to establish and persist for at least 150 years may be of interest not only for the Prades mountains, and it may help in the interpretation of most of the present mediterranean landscape of Catalonia.