Mapping and analysis of distribution patterns of lichens on rural medieval churches in north-eastern Germany

Abstract

Lichen communities were examined on 62 churches in Mecklenburg–Vorpommern, Germany. Ninety-six lichen species and subspecies, and three species of lichenicolous fungi identified. Tylothallia biformigera and Lecanora campestris subsp. dolomitica are reported as new Germany, and another 20 species are considered as threatened. This implies that the stone walls churches represent an extremely important habitat in Mecklenburg–Vorpommern, where natural outcrops are rare. The distribution of lichen species was analyzed quantitatively in relation to several habitat factors. Aspect, substratum and inclination were found to be important factors for 35, 34 31 species, respectively. The height of the relevé was a significant factor for many species. Twenty-three species, which are described in the literature with oceanic to suboceanic distributions, occur significantly more frequently near the coast. The ways in which microclimate affects each these habitat factors and contributes to the presence or absence of a species or group of species discussed. Some species have narrow and specific habitat demands, whereas others thrive under wide range of environmental conditions. The advantages of a strictly schematic approach with detailed statistical analysis are discussed.