向家坝工程扰动区的景观变化及其生态恢复

大型水利水电工程扰动常造成土地利用的显著变化。为研究工程扰动对景观的影响以及采取修复措施后的景观生态效果，以向家坝水利水电工程建设为例，以工程扰动区的航空摄影图像分析和野外样地调查为手段，分别针对工程区域在被扰动前（2004年）、扰动后（2006~2007年）和进行恢复重建之后（2008年）的3个代表年份展开了区域景观变化及现有生态恢复工程对生态景观恢复效应的研究。选取景观破碎化指数、多样性、优势度和景观形状指数4个参数，量化分析了向家坝工程建设区整体景观结构特征，包括不同阶段景观格局变化、景观斑块类型面积与斑块数量变化、斑块破碎化和斑块形状变化，以及各年份景观指数和各景观类型破碎化指数变化等。此外，从景观生态学原理的角度，提出了向家坝工程扰动区将来实施生态恢复重建的对策措施。其中特别强调扰动区今后的生态恢复工作应在科学规划扰动区景观格局和功能的基础上，注重景观连接性的建设，同时不断改善群落结构和丰富物种多样性

LANDSCAPE CHANGES AND ECOLOGICAL RESTORATION AT THE DISTURBED AREA OF XIANGJIABA PROJECT

Large-scale water conservancy and hydropower projects disturbance often result in the significant changes in land use.The paper aims to study the impact of disturbance on the landscape and ecological effects of landscape restoration.The construction of various facilities and changes of land use bring about significant changes in landscape at the disturbed area of large-scale water conservancy and hydropower project.Landscape changes and landscape effects of engineering construction and ecological restoration,taking Xiangjiaba large-scale water conservancy and hydropower project as an example,were evaluated through field investigation and analysis of the aerial photography images of the disturbed area during three different periods—no disturbance(2004),large-scale disturbance(2006~2007) and large-scale restoration(2008).The integrate landscape characteristics of different periods,including changes in Landscape pattern,patch number,patch area,patch shape and patch fragmentation,were quantitatively analyzed using the landscape fragmentation index,diversity index,dominance degree and shape index.The results showed that the construction of water conservancy and hydropower project significantly reduced landscape area of woodland,shrub,grassland and farmland in the disturbed area.The increasing land use in the project greatly intensified the degree of landscape fragmentation and promoted landscape diversity.The landscape area of woodland,shrub and grassland were increased with the artificial ecological restoration.However,the landscape fragmentation was still high in the disturbed area.Some suggestions were put forward from landscape ecology to improve the ecological restoration in the disturbed area of Xiangjiaba large-scale water conservancy and hydropower project.The future ecological restoration should not only stress on the scientific design of landscape function and landscape pattern,but also on the construction of landscape connectivity,community structure and biodiversity.