Aspects of biological diversity in the ConEcoFor plots. V. Deadwood surveying experiments in alpine and mediterranean forest ecosystems

In recent years, deadwood has become more and more considered as indicator in the assessment of the biodiversity and naturalness of forest ecosystems. Its occurrence, in an appropriate proportion according to forest use, is fundamental for the maintenance of biological diversity, since it represents a microhabitat for hundred of species of invertebrates, fungi, bryophytes, lichens, amphibians, small mammals and birds. Having acknowledged its importance in forest coenoses, quantification of deadwood components in a given habitat, in relation to forest type and type of management, becomes essential. In our study, different survey designs were tested and compared for assessing deadwood components: stumps, lying coarse wood pieces and lying fine wood pieces. As expected, the experiments carried out show that sample-based estimates of ground necromass tend to be more accurate as the quantity of necromass present within the area to be surveyed and the size of the sampling units increase. The adoption of four 7-m-radius subplots in a systematic configuration has proved to be a good compromise between accuracy and survey costs for volume estimation of stumps and lying wood pieces within the examined experimental forest stand plot.