Invasion of Raised Bogs by the Scots Pine; a Review of Vegetation History and Case Study in Selected Peat-Bogs in Bieszczady Mts. (Eastern Carpathians)

Abstract

ABSTRACT The objective of this study was to analyse the diversity of pine and spruce bog forests on the domes of Carpathian raised bogs located in the Upper San River Valley. In order to determine the present species composition, 59 phytosociological releves were performed (32 within spruce forests, and 27 in pine forests). For all releves, the Shannon-Wiener index, evenness index and mean Ellenberg indicator values were calculated. Detrended correspondence analysis was conducted in order to determine the degree of similarity between distinct units of vegetation and to identify the main environmental gradients that have an impact on species composition. The results revealed considerable similarities between the ground vegetation of both spruce and pine forests growing on peat substrate. Within pine forests there was a greater proportion of certain plant species characteristic of raised bogs, and plants typical of bog coniferous forests. The ground flora of spruce forests was more diverse. Although spruce ...