Message - 7th IAL Symposium

The 7 th International Association for Lichenology Symposium 2012
(2B-O2) Submission ID: IAL0104-00001
CORTICOLOUS LICHEN COMMUNITIES AS INDICATORS OF VEGETATION TYPES ALONG
ENVIRONMENTAL GRADIENTS IN KNUCKLES MOUNTAIN RANGE - SRI LANKA
Weerakoon G. S. 1 , Mccune B. 2 , Wolseley P. 3 , Wijeyaratne S. C. 1
1 Department of Botany, University of Sri Jayawardenepura, Colombo, Sri Lanka
2 Department of Botany and Plant Pathology, Oregon State University, Oregon, United States
3 Department of Botany, Natural History Museum, London, United Kingdom
Knuckles Mountain Range is a world heritage site within the central massif of Sri Lanka covering 21,000
ha and ranging from 400 to 1,900m altitude. At the higher altitudes montane and submontane forests occur giving
way to disturbed secondary forests and to plantations of tea, Acacia and Pinus. This study of corticolous
lichens was undertaken in all forest and plantation types in order to determine differences in assemblages and
their association with environmental and microclimatic conditions, and to test for potential indicator species.
Eighteen plots of 100x100 m were set up representing 8 vegetation types and 6 altitude classes. Lichen species
and percentage cover were recorded in five microplots on 10 randomly selected tree trunks. Environmental
parameters included bark type and pH, DBH, canopy cover and light intensity. Nonmetric multidimensional scaling
(NMS) provided a graphical depiction of community relationships and habitat variables among 146 species
recorded, using Beals smoothing to compensate for high beta diversity. Nonmetric-Multi-Response Permutation
Procedure (MRPP) and Indicator Species Analysis (ISA) was carried to test for differences between groups and
to identify species associated with the groups. The first axis of the NMS represented 33.4% of the variation in
species composition coinciding with vegetation types and altitude classes. Highest diversity was recorded in
montane forest including low frequency species belonging to Chlorophyceae and consistent contribution by
tropical family Graphidaceae and genus Sticta. Rapidly invasive species were found in exotic plantations with
lowest diversity. ISA indicated that forty percent of the lichen species recorded occurred frequently throughout
and significant indicator values were recorded for 46 species that are exclusive to one habitat type or to one
elevation class. This study has shown that lichens are potentially useful bioindicators to assess degree of disturbance
and ecological continuity in the montane tropics.
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2B-O