Research On Degraded Vegetation Characters, Restoration And Reconstruction At The Arid Valley In The Upper Reaches Of The Minjiang River

Chinese arid valley region mainly distributed in upper reaches of Minjiang river, Jinshajiang river, Yalongjiang river and reaches of Bailongjiang river which is a branch of Jialingjiang river and they also mustered in Minjiang river, Xianshuihe river and Yalongjiang river middle reaches, which typically show in Maoxian county,Wenchuan county,Jinchuan county, Danba county, Xiangcheng county and Batang county. The area of arid valley reach 300,000 hm2, and the arid spectra of each valley is variety with the varied height of mountains. Currently with the rapid increase of population, and the enlarging stress of land use, the vegetation and forest were destroyed drastically, and then the spectra of rid valley extended upper and down along the slope of mountains and then desert landscape appeared in the region with the overgraze and the action of destroy forest for cultivation. The water and soil erosion in this region is graveness because of crashed stratum and steep slope. Erosion sand in the Minjiang river catchment, the one tenth of sand in Three Gorge of Yangtze River, reached 50,000,000 Ton, so it was urgent to restore the vegetation, improve the environment and decrease the disaster in this region. Through systematic research of the character in plant community flora, community species diversity and biomass and with the layout and species choose and silvicutural technology in the arid valley in Minjiang river drainage area, the result showed that:The arid valley of Zagunao river belongs to warm-arid valley at the upper reaches of Minjiang river, its vegetations distribute on the mountain slope of both...