The Zoning Evaluation Of Grassland Change In China And Its Effect On Ecological Security

Grassland as the main ecosystem-types in our country, is not only playing a key role in maintaining the natural ecological system structure, function and process, but also be the foundation of the ecological security protection in China. Due to the extensive management of grassland resources with long time, about ninety percent of the grassland in China appeared degradation with different degrees, and the ecological environment of grassland degrade seriously, which caused more and more prominent ecological problems in the region. With deeper and deeper understanding ofhuman beings about theirreplaceability of grassland ecosystem services. China have implemented a series of major projects on ecological construction and protection of grassland which include the project ofreturning farmland to forest (grass), and grassland protection in the recent ten years in order to solve the problem of grassland degradation. The implementation of these measures has considerable effects on the ecosystem restoration of grassland in our country. However, situation of local improvement and overall deterioration of grasslandin China has not been reversed.Therefore, the analysis of core ecological service function and its effect on China’s ecological security strategy is of great significance for formulating the reasonable regional ecological protection and economic development decision-making and the preservation and restoration of grassland resources utility.The study was aim to understand the status quo of the grassland resource utilization and the change of core ecosystem services of grassland and analyze its effect on ecological security situation in China.And based on which put forward the relative policy recommendations for Chinese civilization construction of grassland multi-level space compatibility and spatial superimposed methods based on GIS technology were adopted to evaluate the ecological security role of grassland in China from the macroscopic aspect. Thenbased on the possible trend of grassland use in the future driven by the social and economic development, we design the scenario of priority development, environment conservation and baseline scenario and AGLU module of the Global Change Assessment Model (GCAM Model, Global Change Assessment Model) was used to estimate the demand of grassland in China over the next20years. Then the land system dynamic simulation system (DLS) is applied to forecast the spatial distribution characteristics and change tendency of grassland in China over the next20years in baseline scenario, preferential development scenario and environmental conservation scenario.Additionally, based on the data requirement of RCPs released by IPCC, the C-FIX model was used to simulate thechange of China’s grassland NPP in AIM climate patterns of the change of China’s grassland NPP over the next20years. Then, the spatial superimposed method based on GIS to analyzeecological security role of grassland over the next20years. And finally based on the above evaluation and forecast result, the relevant policy recommendations about the utilization and management of grassland resource as well as the construction and protection of grassland ecosystem in China were put forward. The basic conclusions of this study are as follows:(1) The results of statistical analysis about the grassland area and the total amount of grassland NPP showed that from1988to2010, the area of grassland inChina appeared a fluctuate decrease trends in the time scale,and showed decreasing trend from northwest to southeast in the spatial scale. The distribution and variation of grassland NPP has obvious regional differentiation characteristics in the past two decades. On time scales, the grassland NPP in China wholy shows the relatively obvious fluctuations, it significantly reduced from1988to2000, but showed a modest increa trend from2000to2010. In the spatial scales, the grassland NPP of China showed the characteristics of wave growth and obvious regional differentiation, which as a whole presents the obvious decreasing trend from1988to1995and overall present a slightly increase trend from1995to2008. (2)Based on the remote sensing retrieval data of grassland area and NPP, the statistical analysis of grassland area and NPP in both the core ecological function of grassland in our country and each ecological function areas of the Liang ping san dai was made.and the results of which showed that in the past two dacades, the grassland ecosystem services of water conservation,windbreak and sand-fixation, supply of agricultural products degraded obviously, but the services of biodiversity conservation, soil conservation, and forest products supply appeared slight strengthening. What’s more, in the past two decades security assurance of grassland ecosystem in the northeast forest zone, southern hills zone and the north sand beltall presented an obviously decreasing trend, but the security assurance of grassland cocsystem in the ecological barrier of loess plateau, sichuan and yunnan strengthened slightly.(3) The results ofsimulation about the Net Primary Productivity and area of grassland in the next two dacades indicated that in thebaseline scenario,the grassland area would present a fluctuation decrease trend, and in scenario of priority development, the grassland area would present a relatively decrease trend. What’s more, in the environment conservation scenario, thegrassland area would increase as a whole and slightly decrease insome areas. And the change of the Net Primary Productivity of grassland would present the decreasing trend with different degree in all of the scenarios during the next two decades. And among which the decrease of grassland NPP would be most obvious in the scenario of priority development. While the descend range of grassland NPP in theenvironment conservation scenario would decline.(4) Based on the stimulated data of grassland area and NPP, the statistical analysis of grassland area and NPP in both the core ecological function of grassland in our country and each ecological function areas of the Liang ping san dai was made, and the results of which showed that in the next two dacades under both of the baseline scenario and the scenario of priority, grassland ecosystem services of water conservation,windbreak and sand-fixation, supply of forest products degraded obviously, and under the environment conservation baseline scenario,the grassland ecosystem services of biodiversity conservation, soil conservation, water conservation,windbreak and sand-fixation degradated obviously.(5) Based on the stimulated data of grassland area and NPP in the next two decades, the statistical analysis of grassland area and NPP in ecological function areas of the Liang ping san dai was made, and the results of which showed thatunder both of the baseline scenario and the scenario of priontythe security assurance of grassland ecosystem in the north sand beltall and the ecological barrier of loess plateau, sichuan and yunnan presented an obviously decreasing trend. While the security assurance of grassland coc system in the ecological function areas of the Liang ping san daistrengthened as whole and degraded in some areas.