陕北生态恢复区不同草地主导服务功能时空变化

Temporal and Spatial Variation of Grassland Dominant Ecosystem Services under Major Ecological Restoration in Northern Shaanxi Province

利用生态系统分类及生态参量数据产品,运用In VEST生态服务评估模型,分析了陕北重大生态建设工程实施关键年份(2000—2010年)内草地生态系统类型及其主导服务功能的时空变化特征。结果表明:延安市和榆林市的黄土沟壑区草地生态系统面积明显增加,草地植被覆盖度整体由低覆盖向中覆盖等级转变,其中草原和草丛覆盖度呈明显增长趋势。11年间,各草地类型平均土壤保持能力逐年增加,由大到小呈现草原、草丛、稀疏草地的一致特征,分布于榆林市南部和延安市北部的草原是陕北草地土壤保持服务功能增加的主要贡献者。各类型草地产水功能变化表现为先减少后增加,稀疏草地分布区产水功能对陕北风沙滩区能源化工基地建设、城市生态安全维护以及农牧业可持续发展意义重大。

Based on the ecosystem classification and ecological parameter data, the structure and dominant services,including sediment retention and water supply,of grassland ecosystem in Northern Shaanxi Province from 2000 to 2010,which was a key period to the Grain to Green Program,were evaluated by using the integrated valuation of ecosystem services and tradeoffs（ In VEST） model. The impacts of human activities on the ecological construction of grassland area and its ecosystem service function were clarified. The results indicated that the area of grassland ecosystem in the loess gully region of Yan＇an and Yulin Cities was increased significantly,especially in steppe and scrub-grass,which showed a greening trend of the low-cover vegetation to medium-cover vegetation. During the study periods,the function of sediment retention for each types of grassland was improved and the steppe was the major contributor for sediment retention,followed by scrub-grass and sparse grass. As to the water supply,each types of grassland exhibited the tendency of decreasing firstly and then increasing. The restoration of sparse grass in north of the Great Wall of Northern Shaanxi had great value to the construction of energy and chemical industry base,and the maintenance of urban ecological security as well as the sustainable development of farming and animal husbandry. The results provided scientific basis of the major ecological construction, the sustainable development of agriculture and animal husbandry in grassland ecosystem.