Epiphytic lichens in a riparian Natural Reserve of northern Italy: Species richness, composition and conservation

In Italy several natural reserves include riparian habitats, whose role in lichen conservation is still poorly known. This work aims at evaluating the importance for lichen conservation of a riparian natural reserve in NE Italy surrounded by a highly disturbed landscape, and at exploring the relations between lichen composition and different forest types. Epiphytic lichens were surveyed by a standard assessment protocol in: (1) alluvial Salix alba forests, (2) Alnus sp.pl. and Populus sp.pl. riparian forests, and (3) lowland Carpinus betulus and Quercus sp.pl. forests. One-way ANOVA was used to test differences between forest types. Species composition was explored by means of Redundancy Analysis. The overall lichen flora is relatively poor and rather homogeneous due to a group of disturbance-tolerant lichens, which are frequent in all forest types. This suggests a strong influence of the landscape context on species richness and composition, independently of the local habitat quality. However, the three forest types have rather different lichen floras, the least interesting for conservation being the riparian Alnus stands, while the alluvial Salix stands host a more sensitive flora and are worthy of lichen conservation. In spite of the disturbance and of its small extension, the reserve is still able to host several rare lichens.