Study of lichen biodiversity at two sites in the Mila region

Abstract

The present study aims to assess the diversity and distribution of corticolous lichens in the forests of Baïnan and Tamentout, located in the Mila region (Northeastern Algeria). Field surveys were carried out on different host-tree species in order to establish a lichen inventory and evaluate the influence of ecological factors on lichen communities. The inventory revealed the presence of 17 corticolous lichen species belonging to 14 genera, 8 families, 7 orders and one class (Lecanoromycetes). The results showed a higher species richness in Tamentout forest (15 species) compared to Baïnan forest (11 species), associated with a greater lichen coverage and a more diversified lichen community. The analysis of host trees indicated that Quercus afares supported the highest lichen diversity, whereas Quercus zeen showed lower values. Ecological indices revealed a more balanced and stable community structure in Tamentout forest. The Jaccard similarity index indicated a moderate similarity between the two forests, reflecting the influence of both common regional conditions and local ecological factors. The occurrence of sensitive species such as Lobaria pulmonaria, Evernia prunastri and Hypogymnia physodes suggests relatively favorable environmental conditions and satisfactory ecological quality, particularly in Tamentout forest. The observed differences in lichen diversity appear to be mainly related to altitude, humidity, microclimatic conditions and host-tree characteristics. These results highlight the ecological importance of Mediterranean oak forests as reservoirs of lichen biodiversity and confirm the value of lichens as bioindicators of environmental quality.