Quantitative analysis on land use structure at village level in farming-pastoral fragile steppe zone

Abstract: Ecological fragile zone is also called the ecological ecotone, and refers to the transition area between the 2 different types of ecological systems. Ecological fragile areas in China are mainly distributed in the northern arid or semi-arid region, southern hilly region, southwest mountainous region, the Tibetan Plateau and the eastern coastal land-water interactive region. The northern farming-pastoral ecological fragile areas are mainly distributed in the northern arid or semi-arid steppe region, where the annual rainfall is 300-450 mm, the dry degree is 1.0-2.0, and the administrative areas involve Inner Mongolia, Jilin, Liaoning, Hebei, Shanxi, Shaanxi, Ningxia and Gansu, totally 8 autonomous regions or provinces of China. Village level planning is the extension and improvement of the current land use planning, and fully disclosing the village domain characteristics of land use structure is one of the essential premise conditions for village level land use plan. This article took the farming-pastoral fragile steppe zone as study area, which consists of 8 townships and 54 villages, and is distributed in middle part of Siziwang Banner and southwestern part of Wulanchabu hilly region. The characteristics of land use structure at village level were quantitatively analyzed through quantitative geographical method such as Gibbs-Martin diversity index model, centralization index, Weaver-Thomas combination coefficient method, comprehensive index of land use degree and location index model, and GIS (geographical information system) technique such as ArcGIS. Finally we got the following findings: Mean value of land use diversity index was 0.71 in study area, and land use diversity indices of all of the administrative villages were from 0 to 0.77, which had obvious difference, and land use diversity degree was in the level from medium to high; simultaneously the centralization index had wide distribution range that was from -0.33 to 1 for all of the administrative villages, and overall the centralization level was from medium to low. Combination of land use types was relatively abundant; the first major land use combination was cropland-woodland-pasture that occurred in above 50% of administrative villages in study area, and then the second major land use combination was cropland-woodland that occurred in 37% of administrative villages. A central region comprising the most single and the most complete combinations was basically formed, and it also had 5 north-south zonal areas with this central region as the center; cropland, woodland and pasture were alternately distributed in the above different combination zones of land use types. Mean value of comprehensive index of land use degree was 243.05, and comprehensive indices of land use degree of all of the administrative villages in study area were from 213.83 to 400, indicating that the study area had a high land use degree overall. And due to the terrain, altitude and human production input level, land use types had different location meaning in the administrative villages of study area, among them the cropland and woodland had relatively outstanding location meaning, but the pasture did not have corresponding prominent location meaning although our study area was located in a fragile steppe zone. According to the above result, we put forward the following suggestions: We should not only build a perfect shrub ecological system on the ecological environment recovery, but also protect the existing grassland and gradually stabilize the grassland net primary productivity, which aims to ensure the grassland ecological security, stability and economic development; in the farming-pastoral fragile steppe zone, to strengthen the construction of basic farmland and to raise the level of land use intensity are necessary choices to further improve the comprehensive benefit of land use on the basis of fully considering topography and other nature conditions.