Evaluate Effect Of Converting Cultivated Land To Forest In North Shaanxi Province Of Loess Plateau

To protect and improve the ecological environment in western and central regions of China, converting cultivated land to forest and grass project is an important and costly ecological restoration project implemented by Chinese government. Therefore, it has guiding significance for its effective implementation, practical meaningful and theoretical value to evaluate effect of this ecological construction.This paper took the typical regions-severe soil erosion and fragile ecological environment, the North Shaanxi Loess Platea as example, which was arable to forest project focused most on. With the RS and GIS technology, the classification data of land use was obtained. Then making classification map and analyze changes of the ecological environment through landscape pattern indices and ecological environment indices to evaluate effect after land use converting. The main results of this study were as follows:(1)Based on the classification map of land use in different years formed through the method of supervision and non-supervision, ecological effect could be quantitatively studied introducing the theory of landscape ecology and ecological service value. It was considered ecological benefits from changes of land use in the entire region caused by returning farmland to forest.(2)Ecosystem components in the North Shaanxi Loess Platea rationalized and diversified and the structure of landscape became complicated. From 1997 to 2006, area of grassland and woodland accounted for 50.37%. Compared with 1997,overall landscape diversity index decreased, the degree of landscape fragmentation decreased. The whole ecosystem of study area was effectively protected and restored so that it was good for keeping the balance of local ecosystem.(3)Ecological environment index rose up significantly from 0.145 of 1997 to 0.157 of 2006 with an increase of 8.28 percent, which indicated that this ecological restoration project had brought good ecological effect. High relative ecological value of forest and grassland with significant increase contributed to increase of ecological environment index. The local environmental quality greatly improved.(4)Land degradation had been under control. Area of woodland grew little by little, and large area of low coverage grassland turned into high coverage one. Soil erosion and land desertification were eased. Components of ecological service value all increased greatly. the total ecosystem service value increased 7.67×106 yuan and the annual increasing ratio is 0.2 percent, ecological environment has been a certain improved and overall environmental quality has been remarkably improved. The ecosystems in the county tended to develop healthily in North Shaanxi Loess Plateau with the development of the Conversion of Farmland to Forest Project.