| Mt. Gongga which is the highest mountain in Sichuan Province, southwest ofChina, is at the southeastern Tibet within29o20’-30o00’N in latitude and101o30’-102o10’ E in longitude from1680m to7556m above sea level. It is thetransition zone between Sichuan Basin and Qinghai-Tibet Plateau, and also anintersection region in a variety of natural elements, with sub-tropical, temperate andfrigid zones with plenty of plants and animals in the mountain. The biodiversityresources here are very unique and rich. It is a great scientific significance to carryout the basic research on bryophyte.In order to know the characteristics of flora and communities of the mossesfrom Hailuogou, eastern slope of Mt. Gongga, we went there3times collectingalmost2000specimens in14areas during Sep.2009to Aug.2010, and spent about1year to identified the mosses in lab. The methods of traditional classification,coefficient of similarity, quantitative classification and ordination analasis, and so onwere applied to study the geographical flora and communities of mosses in Mt.Gongga. The main results are as follows:1. Species biodiversity of mosses in Mt. GonggaBased on comprehensive collecting and identifying of specimens,359speciesbelonging to144genera and40families of mosses were reported for the first timefor Mt. Gongga. Among them12species of mosses are new to Sichuan, they areDicranum setifolium Card., Dicranodontium porodictyon Card. et Ther., Campylopusatrovirens De Not., Hydrogonium javanicum (Doz. Et Molk.) Hilp., Ulotagymnostoma Guo Shui-liang, Enroth&Virtanen, Aerobryopsis yunnanensis X.J.Li etD.C.Zhang, Hypopterygium formosanum Nog., Pseudoleskeopsis tosana Card., Bryhnia hultenii Bartr., Entodontopsis wightii (Mitt.) Buck et Ireland, Hypnumrecurvatum (Lindb. et Arn.) Kindb., Macrothamnium javense Fleisch.. Thecharacteristics of dominant families and genera in Mt. Gongga were also discussed.2. Floristic analysis of bryophytes in Mt. GonggaThe mosses in Mt. Gongga are complex and diverse.The geographical elementsof mosses from Mt. Gongga can be divided into9types. North temperate element(34%) and East Asia element (33%) are dominant in Mt. Gongga exceptCosmopolitan element. Endemic to China and Tropical Asia element account for11%and9%of the total. The floristic components showed temperate zonecharacteristics as a whole, and the tropical elements reflect the relict. The altitudinalgradient changes of the major geographical elements are different from each other.Sino-Japan elements are widely distributed in the lower elevations compared to theSino-Himalaya elements which are much easier to be collected in colder areas. Theresults of comparison of mosses in Gongga Mountain with other10areas in Chinashowed that the moss flora on Mt. Gongga is close related to those of Dujiangyan,Mt. Emei, Mt. Jinfo in the same Sichuan Province, and much more different fromNabanhe(Yunnan Province), Mt. Jiuwan(Jinagxi Province), Shennongjia(HubeiProvince). Based on the frequency of the mosses, the result of DCA showed that allof the study sites could be divided into4groups, and it is closely related to its actuallatitude, annual temperature and other factors.3Ecological communities of mosses in Mt. GonggaThe main communities of mosses on Gongga Mountain include hydrophytia,petrophytia, geophytia, epixylophytia. Different types of altitude has different typesof moss communities. A high proportion of epixylophytia is in the mid-elevationareas compared to the petropytia which has a large proportion at low and highaltitudes. The distribution of hydrophytia and geophytia are smaller than the othertwo due to their habitat. The relations between mosses and native vegetationsuccession were studied at a sample area, Chengmendong. The result showed thatwith the changes of vegetation types, the mosses are from mainly droupht-tolerantspecies, gradually transformed into the hygrophilous species with distinct treesuccessional characteristics which has a certain academic value. |
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