A 'Research and Development Project' in Brandenburg (Germany) running from 1999 to 2003 aimed to define nature conservation standards for the management of lowland beech forests. The avifauna, saproxylic beetle fauna, ground beetles, saproxylic fungi, and the stand structures were investigated in twelve managed near-natural beech forests, and in six that had been unmanaged for 12 to more than 100 years near-natural beech forests to identify bioindicators for near-natural forest stands,which maintain the typical biocoenosis of beech forests. Some selected spotlight-like results are presented in this paper.
The results show, for example, striking differences in stand structures between near-natural beech stands and managed forests, close dependence of bird species on silviculture influences and effects of forest developmental phases on ground beetles of beech forests. For instance, near-natural stands are much more structured, richer in dead wood (10-20 times of the volume of managed forests) and are characterised by a much higher abundance of breeding birds, especially wood-inhabiting and beech forest indicator species, as well as some saproxylic fungi species. Saproxylic and ground beetles are characteristic of deciduous forests.
Some examples for bioindicators of natural or near-natural beech forests are:
1 High number of special tree structures (e.g. trees with severe crown damage, large cavities, clefts in the stem, scratches and bark bags with/without mould), which are typical attributes of ancient forests and a suitable structural indicator.
2 The Middle Spotted Woodpecker Dendrocopos medius was identified as a valid indicator for mature beech forests with old trees. The occurrence of D. medius depends on two typical stand structures: a) rough bark structures (typical for old beech trees >200 years), and b) dead wood in parts of the stems or branches of standing trees.
3 Carabus glabratus is suggested as a bioindicator among the ground beetles.
4 Fungi species of the genus Pluteus are significantly more frequent in unmanaged forests.
5 The number of individuals of saproxylic beetle species which are not captured in the managed forests is three times higher than in >50 year-old unmanaged beech forests.