Message - 7th IAL Symposium

1A-O
Lichen: from genome to ecosystem in a changing world
(1A – O5) Submission ID: IAL0214-00001
LICHENS OF CALCAREOUS ROCKS IN FINLAND
Pykala J. 1
1 Natural Environment Centre, Finnish Environment Institute, Helsinki, Finland
Calcareous rocks are rare and threatened habitat types in Finland. The total area of calcareous rocks
is estimated to be ca. 500-2,000 hectares. Lichens of calcareous rocks in Finland have been previously insufficiently
known. During the years 2003-2010 295 calcareous rocks and lime quarries have been studied, and the
field work is continuing in 2011. Distribution and habitat characteristics of lichens of calcareous rocks and lime
quarries are studied. The main aim is to produce data for a more precise evaluation of threat status of calcicolous
lichens as well as to evaluate the need of conservation and management practices of calcareous rocks and lime
quarries. Over 15,000 specimens have been collected and 137 lichens new to Finland have been determined.
The total number of calcicolous lichens is ca. 280 species, which is 16% of all lichens reported to occur in Finland.
The proportion of lichen species on calcareous rocks is more than 100-fold compared to the area of calcareous
rocks. New localities have been found for most threatened lichens of calcareous rocks (e.g. Nephroma
helveticum, Peltigera retifoveata). Five species considered extinct from Finland have been refound. The number
of identified pyrenocarpous lichens is very high compared to previously known, although a large number of
pyrenocarpous species still remain unidentified. Particularly Verrucaria is extremely species-rich, and 60 species
new to Finland have been identified. Species composition of calcareous rocks differs strongly between southern
and northern Finland. Many lichens on calcareous rocks have proved to very rare. Small populations are typical
to many species. Shading by trees seems to restrict the occurrence of most calcicolous lichens. Lime quarries
(both abandoned and those in use) are very important for many calcicolous lichens. Several rare pioneer calcicolous
lichens disperse rather effectively to lime quarries. Calcareous rocks are threatened by building, mining
and forestry. Conservation and management measures need to be intensified to preserve the rich lichen flora of
calcareous rocks.
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