An ecological comparison between ancient and other forest plant species of Europe, and the implications for forest conservation

An analysis is presented of the ecological characteristics of ancient forest plant species in deciduous forests of Europe. Twenty-two literature sources were used to generate a list of 132 ancient forest plant species, described from at least eight countries in Europe. The affinity for ancient forests of these species differs considerably from country to country, but they have a definite ecological profile. There is a significant difference in the response of the ancient forest plant species compared with other forest plant species for a variety of ecological characteristics, based on Ellenberg indicators, plant strategies and phytosociological associations. Ancient forest plant species tend to be more shade-tolerant than the other forest plant species; dry and wet sites are avoided. They are typical of forest sites with an intermediate pH and nitrogen availability. Geophytes and hemicryptophytes are more frequent amongst ancient forest plant species. The stress-tolerant plant strategy type is significantly more abundant under the ancient forest species than expected when compared with other forest plant species and vice versa for the competitive plant strategy. This distinct ecological profile suggests that ancient forest plant species may be considered as a guild. The poor ability of these species to colonize new forest sites may be attributed to a complex of interacting variables: limited dispersal abilities (many have a short-distance dispersal strategy), low diaspore production and recruitment problems (e.g. low competitive ability). The regional variation in ancient forest plant species suggests that regional lists are more appropriate for assessing the nature conservation value of forests than one global European list. Due to their distinct ecological profile and low colonizing abilities, ancient forest plant species may be considered as important biodiversity indicators for forests. (C) 1999 Elsevier Science Ltd. All rights reserved.