祁连山国家自然保护区生境质量时空特征及驱动因素分析

Spatial and temporal characteristics and driving factors of habitat quality in Qilian Mountain National Nature Reserve

借助InVEST模型分析了祁连山国家自然保护区生境质量和生境退化度的时空特征,同时利用空间关联的localMoran’sI方法和地理探测器,明确了其热点分布状况,深入探讨了生境质量时空分异的影响因素和驱动机制.结果表明:从东南到西北,生境质量逐渐减低,2000~2020年,高生境质量区域逐年减少,低和较低生境质量区域明显增加,生境退化区域主要集中在威胁源(耕地、建设用地、未利用地、道路)附近的草地和林地;生境质量热点区域集中于研究区中部,且呈连片分布,东部和西部热点区域多被冷点分割,生境退化热点区域面积较少,占研究区总面积的6.72%~8.22%,但多在生态条件较好的区域;影响祁连山国家自然保护区生境质量时空分异的主要驱动因子是海拔、年均NDVI和人口数量,且各因子间呈非线性增强关系;生境质量与年均NDVI和降水呈显著正相关,与人口数量呈显著负相关,在不同海拔梯度上生境质量和生境退化程度具有明显差异,1751~2400m海拔梯度上生境质量和生境退化度均较低,海拔在2400~2950m区间内生境质量较高,但由于强烈的人类活动,其生境退化度也较大.在未来区域环境保护和土地资源利用中,更应防止低海拔区域(1751~2400m)生境质量的进一步恶化,在减少人类活动的同时,更应增强应对气候变化的保护措施,同时特别关注中海拔区域(2400~2950m)生境质量和生境退化度,从整体上提高区域生境质量,研究成果可为祁连山国家自然保护区精准制定环境保护策略和未来土地利用空间规划提供参考和借鉴.

This study analyzed the temporal and spatial characteristics of habitat quality and degradation degree in Qilian Mountain National Nature Reserve with the help of InVEST model,and used the spatial correlation of local Moran's I method and geographical detector to clarify the hot spot distribution,and the influencing factors and driving mechanism of the spatial and temporal differentiation of habitat quality were deeply discussed.The results indicate the following:the habitat quality gradually decreased from southeast to northwest.From 2000 to 2020,the areas of high habitat quality decreased year by year,while the areas of low and low habitat quality increased significantly.The habitat degradation areas were mainly concentrated in grassland and forest land near the threat sources(cultivated land,construction land,unused land,road);The hot spots of habitat quality were concentrated in the middle of the study area and distributed in a contiguous way.The hot spots in the east and west were mostly divided by cold spots.The area of the hot spots of habitat degradation was small,accounting for 6.72%~8.22%of the total area of the study area,but most of them were in the areas with good ecological conditions;The main driving factors affecting the spatial and temporal variation of habitat quality in Qilian Mountain National Nature Reserve were altitude,annual NDVI and population,and the relationship among these factors was nonlinear;Habitat quality was significantly positively correlated with average annual NDVI and precipitation,and negatively correlated with population.There were significant differences in habitat quality and degradation degree at different altitude gradients.The habitat quality and degradation degree were lower at the altitude gradient of 1751~2400m,while the habitat quality was higher at the altitude of 2400~2950m,The degree of habitat degradation is also large.In the future regional environmental protection and land resource utilization,further deterioration of habitat quality in low-altitude areas(1751~2400m)should be prevented.While reducing human activities,protection measures against climate change should be strengthened.Meanwhile,special attention should be paid to habitat quality and habitat degradation in middle-altitude areas(2400~2950m)to improve regional health as a whole.The research results can provide reference for the precise formulation of environmental protection strategies and future land use spatial planning in Qilian Mountain National Nature Reserve.