Characteristics Of Vascular Plant Flora Of Altun Mountain

Altun Mountain is located at E 85°53??94°20?,N 37°30??39°25?,and across the three provinces of Xinjiang,Qinghai and Gansu.Together with the Kunlun Mountains and Qilian Mountains,they form the northern mountains of the Qinghai-Tibet Plateau.The westernmost end is bounded by the Cheerchen River,and the easternmost end is separated from the Qilian Mountains by Dangjin Mountain Pass.The north and south are the Qaidam Basin,Tarim Basin and the western part of the Hexi region.The mountain range is approximately east-west.Altun Mountain is located at the junction of the Asian desert area and the Qinghai-Tibet Plateau.The special geographical environment has bred a number of rare and unique plants.Through detailed investigation of 33 community sample plots on the 4 vertical belts set up from wast to east in Altun Mountain,as well as the collection and identification of specimens in different habitats in the area,combined with existing research data,based on previous work.The systematic analysis of the quantitative characteristics and geographical components of Altun Mountain family and species,as well as the comparison with the surrounding mountain flora,draws the following conclusions:1.The vegetation distribution of Altun Mountain is significantly different.The vegetation types on the northern slope are mainly desert communities and mountain grassland communities in central Asia.The southern slope is more affected by the Qinghai-Tibet Plateau,and the alpine grasslands in the belt spectrum are particularly prominent;In terms of horizontal differentiation,the Altun Mountain belt spectrum is gradually simplified from the east and west ends to the middle section.The middle section is the simplest.The temperate desert is directly linked to the alpine desert.The western section is the most distinctive mountainous Festuca olgae grassland and the most representative one in the eastern section is the desert community of Brachanthemum pulvinatum,which respectively end in the middle section of Altun Mountain.2.Due to the influence of the arid climate,the relationship between the species diversity of the Altun Mountain plant community and the altitude gradient is not significant.3.Altun Mountain has 41 families,151 genera,and 356 species of vascular plants(including subspecies).Among them,ferns have 1 family,1 genus,and 1 species according to the PPG system,and gymnosperms have 1 family,1 genus and 4species according to the Christenhusz system.According to APG? statistics,there are 39 families,149 genera and 351 species of angiosperms.Its dominant families are mainly distributed in the world,such as Asteraceae,Poaceae,Amaranthaceae,Leguminosae,and the dominant genera are Artemisia,Astragalus,Taraxacum,and Elymus.In this investigation and research in Altun Mountain,9 new provincial distribution record species,2 provincial new distribution record subspecies,1 provincial new distribution record variety,and 186 new distribution record species in Altun Mountain were discovered;endemic and near-endemic plants 5 species,10 species of national second-level protected plants.4.Plant life forms are dominated by perennial herbs,followed by semishrubs and shrubs;water ecological types are dominated by xerophytes,followed by mesophytes.5.The flora of the families and genera is the most prominent of the temperate distribution types,which fully reflects the temperate nature of the flora.The flora of the species is mainly composed of E.Asia element.Temp.Aisa element and Ancient Mediterranean element also have certain advantages,which fully reflect the nature of the temperate desert area in the Altun Mountains.6.The comparison of the flora of Altun Mountain with the West Kunlun Mountains,Qilian Mountains and Beishan shows that Altun Mountain has the highest similarity with the West Kunlun Mountains and Beishan.7.As the natural boundary between the desert in central Asia and the Qinghai-Tibet Plateau,the Altun Mountain is more affected by the deserts in central Asia.The Qinghai-Tibet Plateau only affects the southern slope at an altitude of about4000 m.