祁连山国家公园植被时空变化及其对人类活动的响应

祁连山国家公园地处青藏、蒙新、黄土三大高原交汇地带的祁连山北麓,作为国家公园体制试点之一,是我国重要的生态功能区、水源涵养地和生物多样性保护优先区域,其生态功能不可忽视。以祁连山国家公园2000—2019年归一化植被指数(NDVI)和净初级生产力(NPP)数据为基础,结合气温、降水、土地利用、矿产开采和旅游发展数据,利用泰尔-森趋势分析(Theil-Sen趋势分析)、曼-肯德尔检验(Mann-Kendall显著性检验)、土地转移概率矩阵和多元残差分析方法,分析该区域的植被时空分布特征、变化趋势特征及其对气候变化和人类活动的响应。结果表明：(1)2000—2019年祁连山国家公园内NDVI和NPP在空间上呈现出东南高西北低,由东南向西北递减的格局。时间上呈现上升趋势,上升速率分别为0.0053/a和0.0014/a;(2)祁连山国家公园内NPP提高、降低和稳定区域分别占总面积的87.29%、0.40%和12.30%。降低区域零星分布于整个国家公园,其中在走廊南山和冷龙岭交汇处,靠近甘青两省交界边缘分布最为集中。提高区域分布广泛,尤其以国家公园东部最为明显;(3)祁连山国家公园NDVI与气...

Spatial and temporal changes in vegetation cover and response to human activities in Qilian Mountain National Park

Qilian Mountain National Park is located in the north piedmont of Qilian Mountains at the intersection of Qinghai-Tibet, Mongolian-Xinjiang and Loess. As one of the national park system pilots, Qilian Mountain National park is an important ecological function area, a water retention area and a priority area for biodiversity conservation in China, and its ecological functions cannot be ignored. Based on the Normalized Difference Vegetation Index (NDVI) and Net Primary Productivity (NPP) of Qilian Mountain National Park from 2000-2019, combined with temperature, precipitation, land use, mineral extraction and tourism development data, we used the Theil-Sen slope estimation, Mann-Kendall test, land transfer matrix and multivariate residual analysis methods to analyze the spatial and temporal distribution characteristics of vegetation, change trend characteristics and its response to climate change and human activities. The results showed that (1) NDVI and NPP in Qilian Mountain National Park from 2000 to 2019 showed a spatial pattern of high in the southeast and low in the northwest, decreasing from southeast to northwest. Temporally, they showed an increasing trend, with an increase rate of 0.0053/a and 0.0014/a, respectively. (2) The improved, decreased and stable areas of NPP in Qilian Mountain National Park accounted for 87.29%, 0.40% and 12.30% of the total area, respectively. Decreased areas are scattered throughout the national park, with the most concentrated distribution at the intersection of Zoulang South Mountains and Lenglongling, near the border edge of Gansu and Qinghai provinces. The improved areas are widely distributed, especially the most obvious in the eastern part of the national park. (3) The NDVI of Qilian Mountain National Park shows a significant positive correlation with temperature in about 40.18% of the area, and a positive correlation with precipitation in about 25.70% of the area, the increase in temperature and precipitation promotes the growth of vegetation in the national park, and a suitable combination of hydrothermal conditions is more favorable to the growth of vegetation.(4) The impact of human activities on vegetation changes was two-sided:Approximately 28.91% of mining, tourism and hydroelectric power stations in the national park still had poor vegetation growth after rectification and regulation, and the ecological environment has not recovered significantly; The cropland to forest and grassland conversion projects and ecological forest projects have been effective, the area of forest and grassland has increased, in the past three years.(5) Most of the vegetation cover changes in Qilian Mountain National Park were caused by a combination of climate change and human activity.