The mountain woodlands of western Crete - plant communities, forest goods, grazing impact and conservation

Abstract

The aim of this study is to classify and describe plant communities of mountain woodlands in the western half of Crete and to relate their species composition to environmental factors with particular reference to grazing. From a total of 232 original phytosociological releves we classified eight plant communities (plus several subunits). The plant communities were assigned to associations of the class Quercetea ilicis, herein specifically to the alliances Erico-Quercion ilicis, Quercion calliprini and Accri-Cupression sempervirentis. Correspondence analysis revealed a separation of the chiefly calcifuge Quercus ilex and Q. pubescens associations with more favourable water supply from the woodlands dominated by Q. coccifera, Acer sempervirens, Cupressus sempervirens and Pinus brutia, growing on hard limestone under drier conditions. Species composition in the latter group of woodlands follows an altitudinal gradient, expressing favourable moisture and, on Plattenkalk, nutrient supply at higher elevations. An ecogram was drawn displaying the relative ecological range of each community along moisture and temperature gradients. Silvopastoral impact was different at species response level, and 'tolerators', 'indicators', and 'avoiders' of grazing may be distinguished. Floristic differentiation related to wood-pasture within given associations was not found, indicating high grazing pressure throughout the stands. In most wood-pastures, especially broadleaved (semi-)evergreen, stands are structurally unbalanced, lack tree rejuvenation and require periods of regeneration from browsing. To allow regeneration and monitoring, we advocate sets of sizable exclosures in different areas and elevations, representing all relevant associations.