中国北方农牧交错带生态系统服务空间格局及影响因子——以内蒙古中西部地区为例

Spatial patterns and influence factors of ecosystem services in the agro-pastoral ecotone of northern China:Taking the central and western regions of the Inner Mongolia as an example

中国北方农牧交错带是我国重要的生态安全屏障之一,面临经济发展与脆弱生态环境保护间的突出矛盾。生态系统服务的定量研究是生态可持续管理的重要科学依据,也是当前的研究热点之一。以北方农牧交错带的核心区域--内蒙古中西部地区为例,结合中高分辨率遥感数据和生物物理模型准确量化了2000-2018年关键生态系统服务,基于Getis-Ord G*方法分析了生态系统服务的空间格局,考虑地理数据的空间自相关性选取了空间回归模型探索其影响因子。结果表明:(1)净初级生产力(NPP,Net primary productivity)、土壤水蚀控制服务(SC,Soil conservation)、产水量(WY,Water yield)及三层土壤含水量(SM1,Soil moisture of top layer;SM2,Soil moisture of middle layer;SM3,Soil moisture of bottom layer)在东部较高,防风固沙服务(SF,Sand fixation)在南部和西部较高;(2)以上生态系统服务受气候变化、景观格局、地形和土壤条件等综合影响,不同影响因素对生态系统服务的作用存在差异。NPP受森林景观格局和归一化植被指数的影响最为显著;WY、SM1、SM2、SM3及SC受降水量的影响较为显著;风速和表层土壤砂粒含量对SF影响最为显著。研究结果可以为优化景观格局和土地系统,缓解中国北方农牧交错带的社会-生态矛盾提供科学依据和案例参考。

The agro-pastoral ecotone of northern China is one of the important barriers for Chinese ecological security.However,the region is facing the serious contradictions between the economic development and the conservation of the fragile environment.Quantitative assessment on ecosystem services and the influence factors is the significant foundation for ecological management and sustainable development,and is also one of the hot spots for the current research.Taking the central and western Inner Mongolia as study area,which is the core area of the agro-pastoral ecotone of northern China,this study simulated the regional key ecosystem services during 2000-2018 using the remote sensing data with medium or high resolution and the biophysical models.The models included the Carnegie-Ames-Stanford Approach,the Distributed Hydrology Soil Vegetation Model,the Revised Universal Soil Loss Equation,and the Revised Wind Erosion Equation.The Getis-Ord G*method was adopted to explore the spatial hot and cold spots of the ecosystem services.With the consideration of the spatial autocorrelation in the geographic data,the spatial regression models were selected to explore the influence factors for the spatial patterns of the ecosystem services.The results indicated that net primary productivity(NPP),soil conservation(SC),water yield(WY),soil moisture of top layer(SM1),soil moisture of middle layer(SM2),and soil moisture of bottom layer(SM3)in the eastern area were higher than those in the other areas.While sand fixation(SF)was higher in the southern and western areas,which were usually covered by sandy topsoil.Secondly,the key ecosystem services were not only influenced by changes in climatic factors and landscape patterns,but also by topographical conditions and soil texture.The influences of the factors were different for different ecosystem services.For NPP,the landscape metrics of forests and the Normalized Difference Vegetation Index had more significant effects than the other influence factors.Precipitation was one of the most significant influence factors for WY,SM1,SM2,SM3,and SC.While SF was mainly influenced by wind speed and sand percent of the topsoil.The study revealed the spatial characteristics of the key ecosystem services in the typical agro-pastoral ecotone of northern China,as well as the influence factors behind the spatial changes.The conclusions in this study were able to provide the quantitative scientific support and case reference for how to alleviate the contradictions between the economic development and the environmental conservation in the agro-pastoral ecotone of northern China and other similar areas through landscape planning and land optimization.