Analysis of the Saxicolous Lichen Communities in Măcin Mountains National Park

Abstract

Abstract The assemblage of saxicolous lichenized fungal communities in Măcin Mountains National Park was assessed during a biodiversity study developed between 2006 and 2008. Fifty three species of saxicolous lichenized fungi were identified on Hercynic granites and granitoid outcrops characterized by intense weathering process. Apparently, competition was not the main mechanism in community assemblage as calculated C score showed (non-significant difference between mean calculated and simulated score). Niche overlap assessment showed that lichens avoided competition by spatial niche partition (mean Pianka index of 0.07 for sampling quadrats and 0.20 for locations). The estimation of nestedness index (N=0.63 at local scale and N=0.88 at sampling quadrat scale) indicated that local communities were subsets of a larger, regional scale metacommunity. Similarities in community composition across locations were assessed by means of Ward algorithm, results indicating that the most dissimilar communities were encountered at Pietrele Mariei, a residual inselberg and Suluc foothill. Conservation of saxicolous communities containing endangered species such as Umbilicaria grisea, critically endangered Ramalina obtusata and vulnerable Acrocordia gemmata, Pertusaria hemisphaerica, Pertusaria pertusa will be challenged in the future by anthropogenic impact coming from agriculture, sheep grazing and quarries operating in the proximity of the reserve area.