土地利用演变对国家公园生态系统服务价值的影响——以三江源国家公园为例

研判土地利用演变对国家公园生态系统服务价值的影响,是推进国家公园生态文明体制建设的重要依据。为厘清土地利用演变对生态系统服务价值的影响效应,基于2000-2020年三江源国家公园土地利用数据,首先采用生态系统服务价值修正模型测算生态系统服务价值,继而运用价值变率模型、GIS空间分析方法刻画三江源国家公园生态系统服务价值演变的空间差异特征,最后引入交叉敏感性系数揭示三江源国家公园土地利用演变对生态系统服务价值的影响趋势。结果表明：(1)20年间三江源国家公园的土地利用演变表现为荒漠、草地、水体三地类间的互相转换,变化速率最大的时间段在2015-2020年,集中发生于长江源园区西北部和北部;(2)从时间序列来看,三江源国家公园的生态系统服务价值呈现"趋好"态势,其中,2015-2020年的变化量高达82.42亿元,草地和水体对园区生态环境贡献较大,土地利用类型的演变与生态系统服务价值存在一定的关联;(3)从空间演变来看,三江源国家公园三园区(长江源、黄河源和澜沧江源)的生态系统服务价值从高值到低值依次为：长江源>黄河源>澜沧江源,呈现出从西北向东南递增的分布特征;(4)土地利用类型演变对生态系统服务价值的影响程度从大到小排序为：荒漠与水体>草地与水体>荒漠与草地,土地利用转型跨度愈大,对生态系统服务价值的影响就愈强。研究时段内土地利用演变对生态系统服务价值影响的交叉敏感性系数呈现先升高后降低的特征,表明生态系统服务价值的变化也会反作用于土地利用对生态系统服务价值影响的敏感性。

Impacts of land use evolution on ecosystem service value of national parks:take Sanjiangyuan National Park as an example

Studying and judging the impact of land use evolution on the ecosystem service value of national parks is an important basis for promoting the construction of ecological civilization system of national parks. In order to clarify the impact of land use evolution on ecosystem service value, based on the land use data of Sanjiangyuan National Park from 2000 to 2020, this paper first used the ecosystem service value correction model to calculate the ecosystem service value, and then used the value change rate model, GIS spatial analysis method to describe the spatial difference characteristics of the evolution of ecosystem service value of Sanjiangyuan National Park, finally, the cross sensitivity coefficient was introduced to reveal the impact trend of land use evolution of Sanjiangyuan National Park on ecosystem service value. The results show that:(1) in the past 20 years, the land use evolution of Sanjiangyuan National Park showed the mutual transformation among desert, grassland and water body, the time period with the largest rate of change was from 2015 to 2020, and concentrated in the northwest and north of the Yangtze River source park; (2) From the perspective of time series, the ecosystem service value of Sanjiangyuan National Park showed a trend of getting better, among them, the change from 2015 to 2020 was as high as 8.242 billion yuan, grassland and water bodies contributed greatly to the ecological environment of the park, there is a certain correlation between the evolution of land use types and ecosystem service value; (3) From the perspective of spatial evolution, the ecosystem service value of the three parks of Sanjiangyuan National Park (the source of the Yangtze River, the source of the Yellow River and the source of the Lancang River) from high to low is the source of the Yangtze River > the source of the Yellow River > the source of the Lancang River, showing the distribution characteristics of increasing from northwest to southeast; (4) The influence degree of land use type evolution on ecosystem service value was in the order of desert and water > grassland and water > desert and grassland. The larger the span of land use transformation, the stronger the impact on ecosystem service value. During the study period, the cross sensitivity coefficient of the impact of land use evolution on ecosystem service value showed the characteristics of first increasing and then decreasing, indicating that the change of ecosystem service value will also react on the sensitivity of land use to ecosystem service value.