黄河源区生态环境系统格局与服务功能演变

Evolution of Pattern and Service Functions of Ecosystem in the Source Region of the Yellow River

基于2017年以来的水质监测数据、1980—2020年土地利用类型数据以及1956—2020年的水文数据,对黄河源区水资源、水环境、水生态和生态系统格局及服务功能等生态环境全要素演变特征进行了分析研究。结果表明:黄河源区1956—2020年唐乃亥站年径流量呈现不显著波动增加趋势,在整个65 a的研究尺度上,源区径流存在2次较大尺度的丰枯交替变化,即枯(1956—1965年)—长丰(1966—1989年)—长枯(1990—2005年)—偏丰(2006—2020年);近10 a黄河源区水质整体呈良好状况,底栖动物多样性总体表现为α多样性低、β多样性高的特征;黄河源区河流演变丰富了底栖动物栖息地类型,提高了底栖动物的丰度、密度和生物量,且黄河源区河流生态系统处于长期变化的动态平衡状态;1980—2020年黄河源区综合土地利用动态变化幅度较小,景观生态格局总体表现为异质性增强,破碎化程度上升,连通度下降;1980—2020年黄河源区生态系统服务功能整体向好,其水源涵养功能、碳储功能、生境质量和洪水调蓄功能均在稳步提升。

Based on the actual monitoring data from 2017 to 2020,the land use type data from 1980 to 2020,the hydrological data from 1956 to 2020,the evolution characteristics of all elements of the ecological environment in the source region of the Yellow River(SRYR)were analyzed and studied.The results show that the annual average runoff at Tangnaihai Station in the SRYR shows no significant fluctuation increase trend from 1956 to 2020.On the entire 65⁃year research scale,there are two large-scale alternating changes of wet and dry in the source area runoff,that is,“dry(1956-1965)⁃long wet(1966-1989)⁃long dry(1990-2005)⁃wetter(2006-2020)”.The water quality in the SRYR has been generally good in the past 10 years,The overall diversity of benthos is characterized by low α diversity and high β diversity.The river evolution in the SRYR has enriched the habitat types of benthos and increased the abundance,density and biomass of benthos,the river ecosystem in the SRYR is in a state of dynamic equilibrium with long-term changes.In the past 40 years,the range of dynamic changes in comprehensive land use in the SRYR has been relatively smaller,and the landscape ecological pattern has generally shown en⁃hanced heterogeneity,increased fragmentation and decreased connectivity.In the past 40 years,the ecosystem service function of the SRYR has been generally improved,and its water conservation function,carbon storage function,habitat quality and flood regulation and storage function have all been steadily improved.