Abstract:
Manglicolous lichens are specific group of lichens growing on the mangrove plants. Although
the island of Sri Lanka harbors a diverse floristic biodiversity there is no systematic study have
been carried out on Manglicolous lichen diversity.In Sri Lanka conservation of lichen diversity
is essential due to the important values of lichens. During the current study the lichen community on mangrove species and effects of tree factors (Bark pH, DBH, height of the tree, Tree
aspect) on the distribution and Diversity of Manglicolous lichens in Galle district, Sri Lanka
were examined. Lichen species were determined by using standard methods. Correlations of
the Manglicolous lichen diversity with tree factors were examined with Spearman correlation
test. Relationships among variables were examined by using Regression analysis. The study
of the diversity and distribution of Manglicolous lichens at 10 plots within Galle district, in Sri
Lanka, revealed 226 species including 175 crustoses, 18 folioses and 33 sterile crusts, belonging
to 85 genera. Absence of fruticose lichens were significant in all sites. The highest lichen diversity has been recorded from the Madu Ganga Ramsar site while the lowest was at Unawatuna
area. The mangrove species of Rhizophora apiculata was identified as the most common host
mangrove species for the lichens. Genus Graphis was the most abundant lichen Genus within
the studied area. Lichen diversity and the tree height showed the insignificant positive correlation (p ≥ 0.05) and the intermediate height of trees showed the highest lichen diversity.
Lichen species were higher in the pH values of the bark within the range of 4.9-5.1. Most
lichens were distributed within North, Northwest, Southwest directions. DBH was the putative
key factor controlling the diversity and distribution and showed Strong positive correlation with
significant difference (p ≤ 0.05). The results of this study can be used for conservation and
management of lichens and these unique habitats within the changing world.
