Vascular plant communities in boreal herb-rich forests in Koli, eastern Finland

摘要

Herb-rich forests have aroused great interest in maintaining the biological diversity of boreal forests. The ecology and structure of these ecosystems are poorly known, and no systematic assessment of their characteristics has been made. In order to explore the structure of vascular plant communities, 101 sample plots in 57 herb-rich forest areas were studied in Koli, eastern Finland. The material was classified with two-way indicator species analysis (TWINSPAN) and ordinated with detrended correspondence analysis (DCA). The results suggest that many environmental variables; e.g. varying topography and bedrock affected the herb-rich forest vegetation. The most important compositional gradients were moisture, fertility and shading. According to species composition, the Koli area is an important patch for species dispersion from south to north. The study area is valuable for maintaining threatened forest flora and eastern elements. In particular, the unique Diplazium sibiricum communities and other taiga species deserve special attention. The site types (ecological groups) corresponded quite well to the herb-rich forest types described in literature.