The Study On The Bryoflora Of Dujingyan Region

The bryoflora of Dujiang region is discussed in this paper. Dujiangyan region is situated in the western border mountain of Sichuan Basin (30°44'54''- 31°22'09''N, 103°25'42'-103°47'E). It belongs to Hengduan Mts. running from Tibet, Yunnan to Sichuan and is a transition region from Chengdu plain to Qinghai-Xizang plateau. The highest peak, Mt. Guanguang, located in Dujiangyan region is 4582 m above the sea level. The plain in the southeastern of Dujingyan region is about 700 m above the sea level. Climatically, it lies the transferring region between Mid-subtropical zone, North subtropical zone and Qingzang plateau region. The vegetation of this region shows the features of the vertical distribution, i,e the evergreen broad-leaved forest, deciduous broad-leaved and coniferous forest, coniferous forest and mountain shrub-meadow.In 2002, Jia Yu, Wang Mei. -Zhi., Liu yang held the third expedition to Dujiangyan region. From about 2000 packages of mosses collected there, 41 families, 149 genera and 373 species (including 3 subspecies and 5 varieties) are identified and among them 88 species are firstly record for Sichuan Province.Concerning the elements of the mossflora of Dujiangyan region, East-Asiatic type (33.14%) are the most important one and the North Temperate type(27.48%) are also abundant; then the Endemic to China type (12.18%) are the third one. 9 East-Asiatic endemic genera have been found in this region.Comparison between the bryoflora of Dujiangyan region and those of the other regions (including Mt. Jinfu, Shennongjia, Yushu, Mt. Jiuwan, Mt. Jizu, Mt. Jiufeng), the similarity coefficients of moss genera and species between Dujiangyan region and Mt. Jinfu are the higherst one (67.37% and 33.45% individually), while that between Dujiangyan region and Shennongjia are the second one (60% and 30% individually).The ordination method has been used for calculating the bryofloras of 7 major mountains or regions (including Dujiangyan region). The relationships of the bryoflora between those of Dujianyan region , Mt. Jinfu and Shennongjia are very close. These bryofloras represent not only the transitional characteristic between North and South China, but also Sino-Japanese type and Sino-Himaiayan one.