|Friedel, A; von Oheimb, G; Dengler, J; Härdtle, W: Species diversity and species composition of epiphytic bryophytes and lichens - a comparison or managed and unmanaged beech forests in NE Germany., Feddes Repertorium, 117, 172-185 (2006), doi:10.1002/fedr.200511084|
The impact of forest management on the species diversity and species composition of epiphytic bryo- phytes and lichens in beech forests (Fagus sylvatica) of NE Germany was analysed. The investigations were carried out in one unmanaged and in one man- aged forest, with 45 sample plots of 400 m2 each. In the sample plots, the presence of the epiphytes on 2 – 4 randomly chosen trees (100 trees per forest) and seven environmental variables were recorded. The total number of species and the mean lichen density per mantle area was higher in the unmanaged forest than in the managed forest. Regression analyses and DCA revealed the diameter at breast height (dbh) as the most important factor affecting the species diversity and species composition in both forest types. The dbh was positively correlated with the number of growth anomalies and with the bark roughness of the phoro- phytes and thus a good indicator for the habitat quality. Moreover, the light conditions had a significant impact on the species composition in both forests types and on the species diversity in the managed forest. In particu- lar, epiphytes demanding shady conditions and a con- sistent humidity may suffer from the abrupt exposition to radiation and the lower humidity after logging. Species typical for the unmanaged forest and most rare species must be considered as stenoecious as they demand the shady and humid conditions of the forest interior and grow on old, large trees. With the aim of sustaining the diversity of epiphytic bryophytes and lichens, forest management should ensure the con- tinuous occurrence of big trees above the target diameter. In addition, a single tree selection felling method should be applied to minimise strong chan- ges in the microclimate.