Problemy fitogeograficzne i syntaksonomiczne kserotermów Wyżyny Śląskiej

Abstract

The subject of this paper is xerothermic flora and communities of xerothermic grasslands in the area of the Silesian Upland — the region of the southern Poland uplands which is most exposed to the west. Triassic limestone and dolomites are important components of the geological structure of the southern and middle parts of the Upland. They create favourable conditions for relief diversity and the presence of xerothermic habitats. The Silesian Upland is located a relatively short distance from the northern outlet of the Moravian Gate. Moreover, its eastern regions have a junction with xerothermic vegetation centres from eastern Poland and beyond its boundaries. Therefore, the distribution of xerotherms in the Silesian Upland seems to be particularly interesting for phytogeography. The main purposes of the studies were: • receiving an actual distribution pattern of xerotherms and explaning the reasons, • description of the geographic character the Upland's xerothermic flora and indicating the migration routes of its components, with particular attention being paid to the role of the Moravian Gate, • presentation of actual differentiation and distribution of the Upper Silesian xerothermic grasslands; their phytosociological, ecological and dynamics characteristic, • distinguishing regionally rare, endangered and extinct taxa and indicating their most important threats, which in the nearest future can lead to significant changes in the xerothermic vegetation of the Upland.