泸沽湖生态系统格局变化及其驱动力

运用遥感影像与地理信息系统技术结合,采用生态系统信息分类提取方法和景观指数方法对1990年至2015年泸沽湖风景区生态系统构成与格局变化进行分析,并进一步探析引起各类生态系统变化的驱动力因素,为泸沽湖风景区进一步生态与环境规划提供科学和理论依据。25年间,泸沽湖风景区内主要生态系统类型可分为农田、森林、草地、水域和人居环境等五类生态系统,1990年至2005年,主要表现为农田、森林、草地3个生态系统之间相互转化;2005年至2015年,主要表现为森林、草地、水域生态系统整体流向农田、人居环境系统。总体上泸沽湖景观破碎化与复杂程度呈下降趋势,连通性和整体性逐渐增强,但各生态系统类型之间比例差异增大。农田生态系统变化的主要驱动力是政策导向;森林与草地生态系统变化的主要驱动力是退耕还林还草工程与人类活动;水域生态系统变化主要驱动因素是湿地造林与人类活动入侵;人居环境系统变化的主要驱动因素为人类用地需求的增涨。针对泸沽湖生态系统变化存在的问题提出了相应的规划建议。

Ecosystem spatial changes and their driving forces in the Lugu Lake Area

The composition and spatial changes of the ecosystems in the Lugu Lake Scenic Area from 1990 to 2015 were analyzed in this study. With the goal of providing a scientific and theoretical basis for ecological and environmental planning in the Lugu lake area, we used the classification and extraction of ecosystem information method and landscape index method to explore the ecosystem spatial changes and their pattern by integrating remote sensing with GIS technology. Furthermore, we analyzed the driving forces behind those changes. During this 25-year period, the main type of ecosystems in the Lugu Lake scenic area could be divided into five types, including farmland ecosystem, forest ecosystem, grassland ecosystem, water ecosystem, and human settlement system. From 1990 to 2005, the conversion between farmland, forest, and grassland ecosystems occurred. However, from 2005 to 2015, extensive areas of forest, grassland, and water ecosystems changed to farmland and human settlement systems. Landscape fragmentation and the complex degree declined, whereas connectivity and integrality of the scenic area was gradually enhanced. However, there was a larger difference between the proportion of each ecosystem type. Policy guidance was the main driving force for the farmland ecosystem. The Returning Farmland to Forest and Grass Project and human activities were the main driving forces for the forest and grassland ecosystems. Wetland afforestation and human activities were the main driving forces for water ecosystem. The increasing demand for human settlements was the main driving force for the human settlement systems. Finally, several planning suggestions were proposed to solve the existing problems in the Lugu lake ecosystems.