The digestive capacity of elderly people. The effect of a high protein diet.

A numerical analysis of the phytosociological releves from ancient and recent woodland on a mesic forest site in central Poland was carried out. Three groups of forest stands were recognised: planted with Pinus , recent and ancient oak-hornbeam Tilio-Carpinetum . The species of ancient woodland occurred mainly in ancient oak-hornbeam forest stands, however some ferns: Dryopteris carthusiana , D. dilatata and D. filix-mas , and an orchid species Epipactis helleborine , are to be found mainly or exclusively in recent forests. The occurrence of ancient forest species in recent woods may be putatively explained by long-distance wind dispersal or by the thriving in situ in unrecognised small wood patches. Twelve ancient woodland indicators (i.e. 36% of a total number found in the region under study) occur exclusively in ancient woodland. It underlines the role of passive species protection in the maintenance of the regional species diversity.