Study On Taxonomy And N-fixation Of Ubiquitous Species Of The Lichen Genus Leptogium In China

Leptogium is a cyanolichen genus that belongs to Collemataceae, Peltigerales, Lecanomycetidae, Lecanoromycetes, Ascomycota, Fungi.More than 500 specimens, deposited in Lichen section of Herbarium of Mycology, Academia Sinica (HMAS-L) and Lichen Section of Botanical Herbarium, Shandong Normal University (SDNU), are comprehensively studied with multiple methods including morphology, anatomy, geography and ecology. On the basis of specimens examination, 18 species are reported in the present thesis including 9 ubiquitous species, among which 6 are new to China and 3 are new to continental China. To our knowledge, this is a first special taxonomical and geological study on the ubiquitous Leptogium species from China. All taxa treated in this thesis are described in detail, and the related species are also discussed. Keys to the species of Leptogium from China are also given.Leptogium is a widespread cyanolichen group in forest ecosystem and plays important role in the N-cycling in forest ecosystems. Although Leptogium is a rather large genus containing 189 species in the world, only 32 species are reported in China, and its geological . Now the studies of the local distribution and ecological role N-fixation of this genus are not well understood yet. To furtherly understand, protect and utilize this important lichens resource, it is necessary to study taxonomy, distribution and N-fixation of this genus. On the basis of taxonomical study, 5 ubiquitous species of Leptogium, 2 species of Collema and 3 species of Peltigera were selected forN-fixation study. In general, Leptogium is higher in nitrogen-fixing activity than Peltigera. Morphological and anatomic photos of the 18 species of Leptogium in this thesis are provided. This study enriched species composition of this genus in China and provided basic data for Flora Lichens Sinicarum.