Study On The Liverwort Flora And Ecological Distribution Of Bryophytes In Evergreen Broadleaved Forests Of Daweishan Nature Reserve

Daweishan Nature Reserve in the southern Yunnan Province, with plenitudinous quantity of heat and rich precipitation, lies between 22°28-22°45'N and 103°39'-103° 51 'E, The liverwort flora and ecological distribution of bryophytes in evergreen broadleaved forests of Daweishan Nature Reserve have been poorly investigated.In May of 2002, the author made a bryophytic survey in the region, where about 650 specimens of liverworts were collected. The liverwort flora contains 196 species (including subspecies and varieties) in 51 genera of 29 families, based on the author's collections and additional 170 specimens which were collected by R.-L Zhu et al. in evergreen broadleaved forests of the region in 1988. Among them, one species, Riccardia multifida subsp. decrescens, is newly recorded in China and 10 species (Calypogeia muelleriana, Scapania bolanderi, Plagiochilon oppositum, Schistochila blumei, Radula oyamensis, Lejeunea japonica, Lejeunea pallide-virens, Fossombronia cristula, Riccardia nagasakiensis and Metzgeria mauina) are new to Yunnan.For understanding the liverwort flora in Daweishan Nature Reserve, and the relationships between it and those of the adjacent or related areas such as Jianfengling, Shiwandashan, Nanling etc., the author studied its geographical elements, compared the species abundance, the generic similarity coefficient, floristic spectrum and flora of the epiphyllous liverworts. Moreover, the author investigated ecological distribution of bryophytes in evergreen broadleaved forests of Daweishan Nature Reserve. The conclusions are as follows:The liverwort flora in the Daweishan Nature consists of 11 geographical elements. Tropical elements have 76 species, approximating to 39.58% of the whole liverwort flora, East Asiatic elements (including Himalaya-Japan, Sino-Himalaya and Sino-Japan) with 75 species, approximating to 39.06%. The proportion of Temperate elements are low, approximating to 10.94% of the whole liverwort flora. Among East Asiatic elements, Sino-Japan distribution type and Sino-Himalaya distribution type consist of 22 species and 21 species, respectively. Characteristics of the liverwort flora of Daweishan Nature Reserve show its transitional nature, and also reveal "Tanaka Line" may appear in the liverwort flora of China.There are 43 epiphyllous species belonging to 11 genera of four families in Daweishan Nature Reserve. Among them, Tropical elements (58.14%) of epiphyllous liverworts are more abundant than its Asia elements (32.56%). The epiphyllous liverwort flora of the region reveals strong tropical nature of the liverwort flora.The types of ecological distribution of evergreen broadleaved forests of Daweishan Nature Reserve can be divided into four types: epixylophytia, geophytia, petrophytia, and epiphyllitia. Among them, epixylophytia are dominant, geophytia and epiphyllitia are common, while petrophytia being few.According to distribution of bryophytes on different substances, the frequencies of Bazzania albifolia, Heteroscyphus coalitus and Homaliodendron scalpellifolium in evergreen broadleaved forests of Daweishan Nature Reserve are highest; those of Macrothamnium macrocarpum, Bazzania fauriana, Ptychanthus striatus, Pogonatum cirratum and Thuidium cymbifolium are higher. Additionally, Aerobryum speciosum, Trachycladiella sparsa, Taxiphyllum subarcuatum, Aerobryidium levieri, Lepidozia wallichiana, and Leucobryum bowringii are relatively common.In addition, a checklist of liverworts of Daweishan Nature Reserve is also presented as an appendix to the paper. All specimens are kept in HSNU (the herbarium of East China Normal University).