Message - 7th IAL Symposium

Lichen: from genome to ecosystem in a changing world
2B-P
(2B-P14) Submission ID: IAL0135-00001
THE VERTICAL GRADIENT OF EPIPHYTIC LICHENS IN CONIFEROUS FOREST CANOPIES
Marmor L. 1 , Tõrra T. 1 , Randlane T. 1
1 Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
The vertical gradient of epiphytic lichens was studied in coniferous forests in Estonia, northern Europe;
lichens were recorded in height ranges from tree bottom to the top. (1) All lichen species were recorded
in three spruce (Picea abies) and three pine (Pinus sylvestris) sample plots in a relatively unpolluted area. (2)
Macrolichen species were recorded in four spruce and four pine plots in different distances from oil shale power
plants, sources of alkaline dust pollution. Altogether 70 trees were sampled. In unpolluted sample plots, acidophilic
lichen species dominated in species composition. Several species, e.g. Hypogymnia physodes, Platismatia
glauca and Pseudevernia furfuracea, were frequent across the height ranges, while the occurrence of many
species changed with height. Some lichens, e.g. Micarea melaena, were recorded mainly in the lower part of tree
trunks; but for example Cladonia species that are also usually associated with trunk bases grew on decorticated
branches in pine canopies too. Many species, e.g. several Usnea species growing mainly on spruce branches,
were added with the height. Upper canopy had a distinct lichen composition with high frequency of Melanohalea
exasperatula and Scoliciosporum chlorococcum on both tree species. In polluted areas, lichens growing in upper
canopy were clearly more affected by dust deposition. Lichen species composition changed with both distance
from the pollution sources and height in the canopy. The proportion of dust indicator species, e.g. Physcia adscendens,
P. dubia, P. stellaris, Xanthoria parietina and X. polycarpa, was highest in the treetops in the sample
plot located closest to the pollution sources, whereas there were no dust indicators in the lowest height range.
The results confirm that the occurrence of many species changes vertically on trees. Therefore, the total lichen
species richness on trees is significantly underestimated when only the first meters near the ground are studied.
In addition, upper canopy lichens proved to be more informative dust indicators compared to lower canopy
lichens in relatively dense coniferous forests.
(2B-P15) Submission ID: IAL0151-00001
ENVIRONMENTAL FACTORS INFLUENCING THE DIVERSITY AND THE COMPOSITION OF
THE EPIPHYTIC LICHEN COMMUNITIES IN MANAGED FORESTS OF SOUTHERN BELGIUM
Ertz D. 1 , Van den Broeck D. 1 , Van Rossum F. 2
1 Bryophytes-Thallophytes, National Botanic Garden of Belgium, Meise, Belgium
2 Vascular Plants, National Botanic Garden of Belgium, Meise, Belgium
Lichens are widely used as indicators of environmental changes caused by air pollution, climate change
and forest management. The establishment of a baseline of the lichen vegetation and subsequent monitoring
is one way to investigate the effects of those changes. The diversity and composition of the epiphytic lichen
communities in 30 forest plots in ecologically diverse and managed forests of Wallonia (southern Belgium) were
investigated in relation to 22 environmental variables used to characterize those forest plots: 10 abiotic environmental
variables, two variables related to tree species and 10 lichen ecological indices based on the lichens.
ANCOVA and RDA revealed that increasing light, moisture and bark pH have a positive influence on the lichen
diversity while the key factors affecting the species composition in the different forest types are light, moisture,
temperature and eutrophication.
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