Diversity And Distribution Of The Mosses And Their Relationship With The Environment In Sygera Mountain

Sygera Mountain is the representative region of sub-alpine cold temperate zone and it is also the transition zone from semi-arid region to humid region in Tibet.The study of mosses in this mountain has great significance to research mosses in the subalpine cold temperate zone and related transition zone.Through the sampling and collection of bryophytes in Sygera Mountain,more than 3000 specimens were identified with the classical classification method.The results were as follows:1.There were 216 species of mosses in 24 families and 82 genuses.Among them,there were 8 dominant families,5 dominant genus and 11 dominant species.The mosses fauna of Sygera Mountain has the temperate nature and the East Asian characters,which reflect the special geographical location of this region.2.The mosses in the study area had obvious difference in different vegetation types and slope.The species richness was the highest in Sabina saltuaria-Abiesgeorgei var.smithii forest.While ? diversity of Abiesgeorgei var.smithii forest was the highest,? diversity of Sabina saltuaria-Rhododendron forest was smaller and it was the lowest in the Alpine shrub.Diversity studies showed that ? diversity was the largest in Sabina saltuaria-Rhododendron and Rhododendron forest,while it was the smallest in Alpine shrub and Sabina saltuaria-Abiesgeorgei var.smithii forest on the east slope.However,? diversity was the largest in Abiesgeorgei var.smithii forest and it was the smallest in Alpine shrub-Abiesgeorgei var.smithii forest.3.The vertical distribution of the mosses in the region was divided into three zones:(1)Mountain temperate cool moist dark coniferous forest moss belt Mountain temperate of cool and dark coniferous forest moss belt(3600 m and below): The species composition of the moss was relatively simple.(2)Cold and wet dark coniferous moss belt in subalpine cold temperate zone(3700 ?4300 m): There formed the most abundant distribution belt of mosses.(3)Subalpine and alpine cold and wet shrub meadows of moss vegetation zones(4400 m and above): The numbers of mosses were significantly reduced.In the three zones,the Pottiaceae and Pohlia was widely distributed at an altitude of4400 m.Polytrichaceae ? Bryaceae ? Mniaceae ? Pohlia ? Pogonatum and Plagiothecium were widely distributed at an altitude of 3700?4400 m.Pohlia and Pogonatum were more widely distributed at an altitude of 3600 m.4.The moss community in this area can be divided into 5 types according to the living substrate: Soil-community?Rock-community?Tree-community?Lithosphere-community and Wet-community.Among them,the number of soil-community was the most and the wet community was the least.Life forms of mosses can be divided into five community types: Tile?Dendroid?Fan?Turf and Weft.The number of cluster type was the most and the drape type was the least.5.The relationship between mosses and environment was analyzed by canonical correspondence analysis and the results showed that the most important environmental factors were altitude,which affected the distribution of plant community and species diversity.Other factors include soil p H,air relative humidity,soil moisture content,air relative humidity and canopy density,etc.In addition to the above factors,other environmental factors such as litter coverage,matrix properties,etc.can also have a certain degree of influence on moss plants.Habitat heterogeneity and climate factors can directly or indirectly affect the distribution,diversity and growth status of the moss plants,the effect of habitat heterogeneity and climate factors on the moss plants was not only the simple effect of a certain factor,but also the results of the combined effect of several environmental factors.This paper had discussed the species diversity and distribution characteristics of the mosses in different habitats in Sygera Mountain.The conclusions had enriched the background information of bryophytes in Tibet and provided a reference for the later study of the mosses of Sygera Mountain.