Ground flora communities in Ireland's plantation forests : their diversity, structure and composition

Abstract

Ireland is committed to the principles of Sustainable Forest Management (SFM). Inherent to these principles is the conservation and appropriate enhancement of biological diversity in the country’s plantation forests. Identifying how this may best be achieved is currently a priority since government policy aims to increase the forested area of Ireland from 9% to 17% by the year 2030. Little information has been published on the biodiversity of conifer and broadleaved plantation forests in Ireland, and this study represents the most extensive appraisal of their ground flora communities undertaken to date. Ground flora communities (vascular plants and bryophytes) beneath tree species important to the Irish forestry industry were examined, viz. Sitka spruce (Picea sitchensis), ash (Fraxinus excelsior) and larch (Larix spp.). By adopting a chronosequence approach, these forest types were surveyed at the main stand structural stages of the forest management cycle. Fifty-nine forests distributed around Ireland were selected so that a comparative study of the ground flora in contrasting geographical regions, and on a varied range of site types, would be possible. In order to account for differences in ground flora diversity and composition among study sites, a wide range of forest management, geographical and edaphic information was collected for each site. To complement the data collected in the field, a greenhouse experiment was undertaken to assess the different effects of Sitka spruce, ash and larch leaf litter on woodland specialist species.