Study On The Optimization Mode Of The Restored Vegetation Community Structure In The Middle And Lower Reaches Of Tarim River

Taken present cutivated land in the middle and lower reaches of Tarim river as the research object , and chosen 10 ecolosical index , this paper aims to set up a evaluation index system and model to evaluate the best community structure modes which are situable for vesetation restoration in varions eco-regions in the middle and lower reaches of Tarim river . The analgticed hierarch precess(AHP) was employed to quantify the weights of these index.Vsing the evaluation model formed , present situation of community structures of artificial vegetation in the middle and lower reaches of Tarim river was assessed . the optimization modes of community structures for vegetation restoration in the research area were screened out utiliging the model with consideration of natural vegetation distribution situation of the area . The main results of this study are as follows: In area suited to ecological forest restoration , there are three optimization modes , arbor + shrub + gress , shrub + gress and arber + gress . For the arbor + shrub + gress mode , the best vegetation community structure can be disposed : Populus euphratica + Tamaris ramosissima + Phragmites communis ,Tamaris ramosissima+Haloxylon ammodendron+Folium Apocyni veneti for the shrub + gress mode , and Populus euphratica +Phragmites communis the arber + grass mode . In are suited to economical forests restoration , two optimization modes , arbor forest and arbor + gress , are suggested . For arbor forest mode , the best vegetation community structure can be disposed as Annona squamosa,Ziziphus jujuba,Populus alba. pyramidalis + Elaegnum angustifolia ,Lycium chinense , and Ziziphus jujube + Medicago sativa or Annona squamosa + Medicago sativa for the arbor + gress mode . In area suited to grass restoration , two optimization modes , shrub + grass and grass ,are suggested . For the shrub + grass mode , the best vegetation community structure can be disposed as Tamaris ramosissima + Glycyrrhiza uralensis , and Glycyrrhiza uralensis ,Medicago sativa or Sorghum sudanense for the grass mode . In area suited either to economical forests or to grass , four optimization modes , arbor , arbor + grass , shrub + grass and grass , are suggested . For arbor forest mode , the best vegetation community structure can be disposed as Annona squamosa ,Ziziphus jujube ,Populus alba. pyramidalis + Elaegnum angustifolia ,Lycium chinense , Ziziphus jujube + Medicago sativa and Annona squamosa + Medicago sativa for the arbor + grass mode ,Tamaris ramosissima + Glycyrrhiza uralensis for the shrub + grass mode , Glycyrrhiza uralensis ,Medicago sativa or Sorghum sudanense for grass mode.