Studies On Biodiversity Of Bryophytes In Tianmu Mountains,China

Tianmu Mountains,118°36'-120°06'E,29°52'-30°55'N,are located between Zhejiang and Anhui provinces.Mountain ranges direction from southwest to northeast,with the terrain decreasing gradually from south to north.The main peak of Qingliangfeng is 1787.4 m above sea level.As one of the most biodiverse areas of bryophytes in Zhejiang,sparse studies on bryophyte diversity have been conducted in some areas in Tianmu Mountains.The species diversity,floristic analysis,and ecological characters of bryophytes in Tianmu Mountains was reported in this paper,to provide the theoretical bases for the protection of bryophyte diversity in Tianmu Mountains.The main results as follows:1.Studies on species diversity of bryophytes in Tianmu Mountains.2425 specimens collected from Tianmu Mountains were studied by morphological and anatomical methods,with a total of 681 species(including subspecies and varieties)in 227 genera of 81 families,including 552 species of 177 genera and 52 families of mosses,128 species of 49 genera and 28 families of liverworts,and one species of one genus and one family of hornworts,are reported in Tianmu Mountains.The phytogeographical distribution patterns of bryophytes in Tianmu Mountains can be classified into 13 areal-types.The results show that the dominant Asian areal-type component is 51.17%,while components endemic to China accounts for 6.61%,indicating a strong East-Asian tint and distinctive Chinese characteristics of the floristic elements for bryophytes in Tianmu Mountains.In addition,the other three important floristic elements,including North-Temperate,East-Asian,and Temperate-Asian elements,account for 31.80%,30.88% and 7.07%,respectively.The species similarity of four mountain bryophytes in the Tianmu Mountains varies with the geomorphological climates types.A total of 101 species of epiphytic bryophytes(including subspecies and varieties)in 58 genera of 30 families,including 81 species of 47 genera and 20 families of mosses,20 species of 11 genera and 10 families of liverworts,were found in Tianmu Mountains.2.Ecological study on epiphytic bryophytes.The distribution of epiphytic bryophytes is affected by the elevation gradient,which is characterized by the trend of increasing and then decreasing the number of species,indicating that the species diversity in the middle altitude is highest.It fully reflects the high diversity of epiphytic bryophytes in Tianmu Mountains.Comparison of the diversity of epiphytic bryophytes between the northern and southern slopes showed that there were significant differences in the composition of the bryophytes.The epiphytic bryophytes species diversity is richer in the southern slope(Tianmu Mountain)than the northern one(Longwang Mountain).The distribution of epiphytic bryophytes tends to be distributed at the base of the trunk and the species number decreasing with the epiphytic height increasing.But the ? diversity showed no significant difference among different heights,indicating that the epiphytic species showed no obvious specificity to the epiphytic height.The distributions of epiphytic bryophytes in different orientations of the trunks were different,with the species number in the east direction the most while the least in west,but the difference was unobvious.The ? diversity index analysis showed no significant differences,and the reason may be due to the broad niche breadths of the epiphytic bryophytes.Some epiphytic bryophytes were related to the host trees,showing that epiphytic bryophytes have the preferences to the host trees to a certain extent.Most epiphytic bryophytes have broad niche breadths and significant niche overlaps,indicating that the competition for resources among species was intense.Based on their frequencies and coverages,the epiphytic bryophytes communities in 18 sites in Tianmu Mountains were clustered into four types by TWINSPAN.The distribution patterns of 101 species epiphytic bryophytes showed the four types by Detrended Correspondence Analysis(DCA).Canonical Correspondence Analysis(CCA)was applied to study the relationships between the 18 sites(or 101 species of bryophytes)and the environmental factors and the results showed that the distribution pattern of epiphytic bryophytes were related with the influences of altitude,epiphytic orientations and epiphytic height to a certain degree.