Forest communities of the relict Balkan endemic Aesculus hippocastanum

Abstract

Aesculus hippocastanum L. (European Horse-chestnut) constitutes a biogeographical relict species of the Balkan Peninsula, occurring in isolated and topographically distinct localities in Albania, Bulgaria, Greece and North Macedonia. Despite its great botanical, ornamental and pharmaceutical value, a thorough investigation of Ae. hippocastanum habitat diversity in its native distribution range has not been conducted yet. The present study aims at the syntaxonomic classification and ecological features of plant communities dominated by this species across its overall native distribution range. On the basis of 55 phytosociological relevés, five ecologically, floristically, and spatially well differentiated clusters were identified, with the main revealed gradients of differentiation being geographic location (longitude, latitude), altitude, annual precipitation and precipitation seasonality. The distinct microhabitats with a special refugial character where these plant communities occur meet the species’ requirement for relatively high air and soil humidity. They have allowed the preservation of Ae. hippocastanum through time highlighting their great conservational value. The last one could be useful for the implementation of some appropriate measures for effective conservation of these communities.