Floirstic Elements Of Wild Seed Plants And Natural Vegetation Types In Tomur Grand Canyon Of Xinjiang Tianshan

Tomur Grand Canyon, which is in the warm temperate dry climate zone and is located in the southernslope of Tomur Of Xinjiang Tianshan, is an important part of one of the four main components to the worldnatural heritage ‘Xinjiang Tianshan’—Tomur. Previous scientific investigation and research work aboutTomur Grand Canyon this independent geographical unit only sporadically related in some relatedlarge-scale comprehensive survey. But in-depth research of biological resources has not been reported, andstudy on seed plant flora and natural vegetation is still blank.Tomur Grand Canyon is being planned to be a major tourist scenic area and a national geologicalpark.In order to explore the wild seed plant species, distribution, floristic composition and geographicalelements, to master the natural vegetation types, community composition and distribution, and to provide ascientific basis for the natural resources protection,future development and sustainable management, fromApril2011to August2013, investigated plant diversity and vegetation types in detail for eight times inTomur Grand Canyon, with the overall survey method, typical sample plot method and strip transectmethod. The main results are as follows:There are131species of seed plant in102genera and35families in Tomur Grand Canyon.Minor-species of family has absolute advantage and one-species of family are subdominant. There are only4families with more than10species, taking11.43％of all families．The ratios of gerera and species to thisregion are about50.00％and53.43％in the4families. In the family level, the temperate distribution(tropical-temperate, subtropical-temperate, temperate) occupies the overwhelming superiority(18families,51.43％). Genera in this area are single-species genera or minor-species genera, single-species generaaccounted for absolute advantage. In the distribution types of the genus, north temperate type and itsvariants is dominate, followed by the old world temperate type and its variants, Mediterranean, westernAsia to middle Asia type and variations is in the third place, while tropical elements just occupies tinypercentage. There are20species of rare and endangered plants, taking a higher proportion.Tomur Grand Canyon spans two altitudinal zones of the southern slope of Tomur, warm temperatedesert zone and temperate desert steppe zone. The natural vegetation can be divided into3vegetation types,6vegetation subtypes,13formations and37associations. Vegetation types include deciduous broad-leavedbrush, grassland and desert.The desert is the largest vegetation type, accounting for53.04%of the total areaof Tomur Grand Canyon. Subshrub, small shrub desert (vegetation subtype) accounts for the largestproportion (46.89%) and also has the most diverse structure. Form.Reaumuria soongorica is the mostwidely distributed formation in Tomur Grand Canyon, followed by Form. Stipa glareosa and Form.Caragana dasyphylla.