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Inner Mongolia Agricultural University (2016)

Study on land Ecological Evaluation of Xilinguole Grassland

杨霞

Titre : Study on land Ecological Evaluation of Xilinguole Grassland

Auteur : 杨霞

Grade : Doctoral Dissertation 2016

University : Inner Mongolia Agricultural University

Résumé
In Xilinguole Grassland, the survey and evaluation system were established to assess the ecological status and the ecological condition rating to determine its security status based on factors affecting land ecological status of climatic conditions, soil conditions, land use/ cover conditions. The paper took principal component analysis method to analyze the influence of the various indicators of a comprehensive assessment of the outcome, by introducing obstacles index, the paper made an in-depth study of the impact of land ecosystems healthy development constraints to provide empirical research for the future development of grassland ecological protection measures. Meanwhile, ecological service value was studied by choosing typical steppe areas based on land use/cover change. The main conclusions are as follows :(1) Xilinguole Grassland evaluation system of land ecological status was constructed and 36 assessment indicators including average annual rainfall, soil carbon storage, land use diversity index were determined from the aspect of ecological status of the natural, economic, ecological and other factors.(2) The ecological status of land values reflected it is controlled by natural climatic conditions and obvious weak from the eastern, southeastern to the west and northwest. There showed different degradation characteristics of land ecological situation affected by land use in some areas.(3) The integrated range of ecological status value was in 0.0549-0.2708, it reflected the overall quality of the ecological status was poor and in a relatively unsafe condition, the proportion was up to 80% of the study area, and the area of ecological status quality increased from high to low.(4) Principal component analysis showed that the 13 indicators included average annual rainfall, soil organic matter content, slope, land use diversity index, the proportion of woodland and shelterbelts, ecological infrastructure land ratio, compression ratio of occupied land, forest annual degradation rate, grassland annual degradation rate, the water average annual reduction rate, annual growth rate of development and utilization of unused land area, population and ecological land contribution growth rate, regional GDP, ecological land growth contribution rate were the most important indicators in ecological assessment system.(5) The correlation analysis of element indexes and comprehensive score showed that the scores size are extremely significant linear correlation with the average annual precipitation, soil organic matter, slope, land use diversity index, the proportion of woodland and shelterbelts indicators, and significant linear correlation with regional GDP growth and ecological land elasticity indicators, while was no obvious correlation with the remaining seven indicators. The main obstacles affecting the ecological status of the Xilin Gol Grassland were basic ecological status and structural indicators, which illustrate the vulnerable climate conditions, poor soils due to irrational land use patterns is the major obstacle factor to restrict local land ecological status.(6) Land use in typical area (Xilinhot) changed significantly, its indexes showed 10 years in 2000-2005 and 2005-2010 were the greatest change in land use, the national policy has become a major factor affecting land use change.Both of variable quantity and change rate of land use degree were> 0 in typical area (Xilinhot), the extent of land use has gradually increased which indicating City of Xilinhot is currently in the rising period of land-use development, it will have an increased intensification in further.There had an increasing ecosystem services value in typical areas (Xilinhot) in 1980-2010, especially in 2005-2010, was larger than the previous two sessions

Mots clés : Xilinguole Grassland; Land ecology; The land use/cover change; Ecosystem services value; Evaluation;

Présentation (CNKI)

Page publiée le 30 janvier 2017, mise à jour le 11 septembre 2017