1980—2015年秦岭地区景观格局变化及其对人为干扰的响应

Landscape pattern change and its response to anthropogenic disturbance in the Qinling Mountains during 1980 to 2015

了解景观格局变化及其对人为干扰的响应对于生态系统保护和管理具有重要意义.本研究利用秦岭地区1980—2015年土地利用数据,基于景观格局指数和地表覆盖分类系统,构建景观格局脆弱度指数和人为干扰度,研究了秦岭地区景观格局时空变化及其对人为干扰的响应.结果表明:1980—2015年,秦岭地区景观破碎化程度逐渐增加,景观形状变得复杂,景观聚集度、连通性降低,景观格局指数空间分布呈现明显的地形分异特征;景观格局脆弱性整体呈下降趋势,其中,低脆弱区空间格局变化比较明显,主要以西安市、汉中市为中心向周围区域扩张;景观格局人为干扰程度逐渐增加,空间分布表现为东部高、西部低,北坡高、南坡低,周边高、中间低;人为干扰度越大,景观格局脆弱度、斑块密度、Shannon多样性指数越大,聚集指数、最大斑块指数越小;人为干扰程度对景观格局脆弱度影响逐渐减弱,对Shannon多样性指数、最大斑块指数的影响逐渐增强,而对斑块密度、聚集指数的影响变化不明显.

Understanding landscape pattern change and its response to anthropogenic disturbance is of great significance for ecosystem conservation and management. Based on high-precision land use data from 1980 to 2015, we studied the spatial and temporal changes of landscape patterns in the Qinling Mountains and its response to anthropogenic disturbance by using the landscape pattern vulnerability index and human disturbance degree constructed by the landscape pattern index and the surface coverage classification system. The results showed that the degree of landscape fragmentation gradually increased in the Qinling Mountains. The landscape shape became more complex, the degree of landscape aggregation and connectivity decreased, and the spatial distribution of the landscape pattern index showed distinct features of topographic differentiation from 1980 to 2015. The fragility of the landscape pattern in the Qinling Mountains was on a downward trend as a whole. The spatial pattern of the low-vulnerable region had changed significantly, which mainly expanded from Xi’an and Hanzhong to the surrounding areas. The degree of anthropogenic disturbance in the landscape pattern of Qinling Mountains gradually increased. The spatial distribution was “high in the east, low in the west, high in the north-slope, low in the south-slope, high on the periphery, low in the middle”. The fragility of landscape pattern, patch density and Shannon diversity index increased with the increases of anthropogenic disturbance, while the aggregation index and maximum patch index decreased. In the past 35 years, the impacts of anthropogenic disturbance, which gradually weakened the vulnerability of landscape pattern, also increased Shannon diversity index and the largest patch index gradually, while it had not significantly changed the patch density and the aggregation index.