Cork oak forests in the NW Iberian Peninsula: phytosociological reassessment and new proposals

Abstract

The phytocenotic variability of the cork oak forests present in the northwesternmost Iberian Peninsula was studied through the analysis of a dataset of 145 new and 39 previously published relevés. The results allowed the recognition of four associations: (1) Arenario montanae-Quercetum suberis ass. nova: thermotemperate xerophytic forests of the Navia River valley (Galice/Asturias boundary); (2) Hedero hibernicae-Quercetum suberis stat. nov.: thermo-(meso-)temperate forests with oceanic influence of the Galician-Portuguese and Inland Galician territories; (3) Physospermo cornubiensis-Quercetum suberis: forests of the mesomediterranean territories of the Sil valley and Lower Bierzo, more thermic and less oceanic than the aforementioned communities; (4) Junipero lagunae-Quercetum suberis: mesomediterranean forests of areas of dry ombroclimate in the NE Portugal. Based on these results, a new interpretation is suggested for the Portuguese cork oak forests that have been considered as belonging to the typical subassociation of Physospermo cornubiensis-Quercetum suberis. The first two associations are part of the phytocenotic transition between the northernmost Mediterranean cork oak forests of the Iberian Peninsula and those present at the SW end of France. The new associations increase the knowledge of the phytosociological variability of habitat type 9330 of Annex I of CD92/43/EEC in the EU.