The Research About The Ecological Benefit Value Monitoring And Evaluation Project To Forest In Ansai District ShanXi Province

Conversion from Cropland into Forest is the construction of China's ecological environment which is a important project, from the year 2000 has achieved remarkable results. Results for the Grain for Forest Project, evaluating of the ecological benefits effiectively, which continued its work under the guidance are critical.The samples were collected at the Ansai county of Shanxi Province in China, explored soil the physical and chemical properties, community diversity, Forest Hydrology that having a impact on ecological benefit value of different patterns under Conversion from Cropland into Forest. The result showed:to compare with cropland, after Conversion from Cropland into Forest, the soil bulk density reduced, total porosity and aggregation increased, the content of organic matter and available nitrate, phosphate and kalium increased greatly. The soil nutrient condition with different layers changed slightly under Conversion from Cropland into Forest, but cropland changed significantly. Sea-buckthorn showed remarkable effects for improving soil physical properties and the N,P,K and organic contents in Prunus sibirica L forestland were the highest.The difference of permeability was in various land conversion soil. Except for Amygdalus davidiana the permeability in forests was close to or excess of the level of natural meadow.Hippophae rhamnoides and Caragana korshinskii of different patterns are the most significant in plant canopy interception Caragana. Litter interception is still mainly Caragana korshinskii, showing the water storage capacity is very strong. Robinia pseudoacacia and Caragana korshinskii herb layer Interception significantly, indicating that Robinia pseudoacacia, Caragana rain forest herb layer effect of energy dissipation significantly.The status of the vegetation restoration, species diversity characteristics, and biomass of different patterns at the Ansai county of Shanxi Province in China. The results showed that Conversion from Cropland into Forest projects promote positive vegetation succession; Natural grassland is not a priority species for a single species, but by the Stipa bungeana and Cleistogenes squarrosa for species together. Shrub is better than arbor, Sea-buckthorn is the best one that have the largest diversity index, but the Prunus sibirica L is not as good as others in the diversity index. In the herb layer and litter layer, the Peashrub is the most outstanding, has formation of a more favorable formation of trees-herbal-litter complex, and the ability to enhance retention.Using opportunity cost approach, recovery expense approach, shadow project approach and so on, total eco-value after land amendment of ecological benefit value, which was 45.76 million yuan over between the 6 years by 2005. In the total eco-value, the biggest value was 11% and 13% of water and soil conservation, the smallest was 0.4% of cleaning of the environment and value of improving small climate.