Study On Ecology Restoration Effect Of Conversion Cropland To Forest And Grassland In Wuqi County, Shannxi Province

Shannxi Wuqi county located in the midstream of Huanghe rivera in Loessal plateau is the earlier trial region which implementing the restore the reclaimed land to forest project. he paper taking the Chaigou small watershed in Wuqi county in Loessal mound as the studying region, analyzing the analyzing the ecological benefit variation of typical region in Wuqi county which implemented the restoring the reclaimed land to forest project in 1999 in the aspect of the relationship between people and the land, vegetation, soil, and soil erosion control, the conclusions as following:(1) The land-use structure of Wuqi county varied reasonablely, the land-use varied from farmland to forest land to grassland to 1:10:4 to 9:5:1 after the reclaimed land to forest project done..(2) The large labor released from the agriculture transferring to other industry, it promoted the increase of the GDP, the farmer income increased too.(3) The number of horse, donkey, mules decreased, but the number of sheep increased, the reclaimed land to forest project impetusing the adjustment of the rural livestock, driving the development of the rural economic.(4)The regression of the land which had not enclosed is very badly, the vegetation cynanchum thesioides,agriophyllum arenarium,peganum harmala,polygonum sibiricum,cynanchum komarovii, the coverage is 20%. When the land enclosed 7a, the vegetation of zonal grassland is Stipa bungeana, artemisia gmelinii, lespedeza davurica,thymus kitagawianus,aneurolepidium dasystachys, the coverage is 75%.(5)The biodiversity index increased during the vegetation restoration stage, the species biodiversity changed lower attribute to the regression of the annual weeds, the community dominance decreased after enclosed, the community evenness decreased little after enclosed 7 years, it meaned that with succession of the vegetation restoration, the composition of the community changed evenly and stablely.(6) The similarity is higher in the restoration stage of vegetation from unenclosed to enclosed 7 years, with the increasing of enclosed time, the similarity decreased, it meaned that the variation of the plant composition was a continuous process.(7) After enclosed, each familyof plant encroached, the proportion of asclepiadaceae, zygophyllaceae,chenopodiaceae decreased rapidly, the dominance of pea family and gramineae vegetation increased gradually, the composite family vegetation decreased apparently after enclosed, it meaned that the grassland vegetation increased, the meadow mass improved, the feeding value varied highly.(8) The vegetation succession experienced 3 stage after the reclaimed land to forest(grassland) project done 7 years, it varied from annual weeds to perennial ground stem vegetation to zonal vegetation. The inception of the succession trace was the regression vegetation, the end was the zonal vegetation in this region.(9) With the increasing of the enclosed stage, the soil pore changed better, the soil infiltration increased, the soil water content was higher, soil fertility was also improved except phosphorus, it means that the reclaimed land to forest(grassland) project had the surface gathering and fertility cultivation effects on soil.(10) The soil erosion mode number reduced 3948.65t/ (km~2·a) when the enclosed measured done, it varied from 12367.61t/ (km~2·a) to 8418.96t/ (km~2 · a) in 2005.