Saxicolous bryophyte communities of mountain areas of Greece - Phytosociology, ecology, life forms and life strategies

摘要

A phytosociological study on the bryophytes colonizing rocky high mountain habitats of Greece was carried out. The surveyed associations include the Syntrichio calcicolae-Grimmietum anodontis and Orthotricho anomali-Grimmietum pulvinatae (class Grimmietea anodontis), the Ctenidietum mollusci, the Encalypto streptocarpae-Fissidentetum cristati, the Pseudoleskeetum incurvatae and the Solorino saccatae-Distichietum capillacei (class Ctenidietea mollusci). The associations were examined from a synecological, synhierarchical and chorological point of view. The Syntrichio calcicolae-Grimmietum anodontis and the Pseudoleskeetum incurvatae are here first signaled from the Mediterranean region. A life form and a life strategy analysis of all communities reflect the response of plant functional types towards environmental demands. Only two life strategies dominate the communities. Acrocarpous, cushion-forming colonists (especially pauciennial colonists) clearly prevail on pure rocky sites, bare of a soil layer which are exposed to direct sun light (increasing aridity) and drought stress. They provide the main functional type within pioneering communities and communities of first successional stages. By contrast, fan, weft and mat-forming pleurocarpous mosses and liverworts, following a perennial stayer strategy reach maxima on shady rocks with increasing humidity and the accumulation of a soil layer. This functional type dominates later successional stages and sites with more or less stable and long-lasting ecological site conditions. The key stones characters outlined ensure a successful dispersal, establishment and habitat maintenance of the species and associations.