title: [Niche characteristics of plants on four environmental gradients in middle reaches of Tarim River].
abstract: Tarim River is the longest continental river in China. Along its either bank, the natural vegetation belts are composed of arbors, shrubs and grasses. In this paper, the niche breadths and overlaps of nineteen species on four environmental gradients in the middle reaches of Tarim River were calculated and analyzed. The results showed that the nineteen species could be divided into three groups, based on their average niche breadths. Group one included Populus euphratica, Tamarix ramosissima, T. hispida, Lycium ruthernicum, Alhagi sparsifolia and Phragmites australis, which were constructive species in Tarim River and their niche breadths were greater. Group two included T. leptostachys, Aeluropus pungens, Poacynum hendersonii, Cynanchum sibiricum, Karelinia caspica, Inula salsoloides, Taraxacum sp., and Hexinia polydichotoma, and their niche breadths were smaller than that of group one. Group three included Halimodendron halodendron, Glycyrrhiza inflata, Calamagrostis pseudophragmites, Salsola sp., and Sophora alapecuroides. Based on the niche overlaps matrix, the niche overlaps of the plant species pairs were generally smaller on all the four environmental gradients, because of their probable niche shift or the demand for different environmental resources. Soil moisture and soil salinity were the important environmental factors limiting the plant distribution in the middle reaches of Tarim River.
authors.affiliation: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China. kljkzx@sohu.com
authors.forename: Jiazhen
authors.initials: J
authors.lastname: Liu
authors.forename: Yaning
authors.initials: Y
authors.lastname: Chen
authors.forename: Yuanming
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002681:China; D017753:Ecosystem; D006863:Hydrogen-Ion Concentration; D009930:Organic Chemicals / Q000032:analysis; D063245:Plant Development; D045483:Rivers; D012965:Sodium Chloride / Q000032:analysis; D012987:Soil / Q000032:analysis; D013045:Species Specificity; D014867:Water / Q000032:analysis
chemical_list: D009930:Organic Chemicals; D012987:Soil; D014867:Water; D012965:Sodium Chloride