Wang Hui, Yuan Hangbo, Xu Xianghong, Liu Shujuan
College of Forestry, Gansu Agricultural University, Lanzhou, China.
Ying Yong Sheng Tai Xue Bao. 2006 Sep;17(9):1665-70.
This paper analyzed the spatial pattern and its characteristics of different landscape types on the desertification grassland of Maqu County in the source region of Yellow River, based on the principles of landscape ecology, with the help of GIS techniques, and by using landscape heterogeneity indices (landscape diversity and dominance) , landscape isolation indices (patch density and fragmentation), and shape indices (elongation index and fractal dimension). The results showed that on the whole, the landscape structure of this region was simple, but varied locally. Natural landscapes such as grassland, marsh and shrubs were the main body of landscape change. The regional landscape patches had a ribbon shape spatial distribution, and the differences were significant among subregions. From fluvial terrace to low hillsides and alpine grassland, the landscape patch type, landscape diversity, and landscape fragmentation degree decreased gradually, and the landscape structure presented a simplification trend. Desertification landscape, and mobile dune in particular, had great impact on landscape structure, playing an important role in the increment of landscape heterogeneity and fragmentation. Fixed sand lands, semi-fixed sand lands, and potential sand lands had different influences on regional landscape composition and its changes. Compared with desertification landscape, artificial landscape had less effect on landscape structure, but exhibited a wider potential variation range. These two types of landscape would be the dominant factors affecting the landscape structure changes of this region in the future.
本文基于景观生态学原理，借助GIS技术，运用景观异质性指数（景观多样性和优势度）、景观隔离指数（斑块密度和破碎度）以及形状指数（伸长指数和分维数），分析了黄河源区玛曲县荒漠化草原不同景观类型的空间格局及其特征。结果表明，总体上该区域景观结构简单，但局部存在差异。草原、沼泽和灌丛等自然景观是景观变化的主体。区域景观斑块呈带状空间分布，各子区域间差异显著。从河漫滩到低山坡及高寒草原，景观斑块类型、景观多样性和景观破碎化程度逐渐降低，景观结构呈简化趋势。荒漠化景观，尤其是流动沙丘，对景观结构影响巨大，在景观异质性和破碎化增加方面发挥着重要作用。固定沙地、半固定沙地和潜在沙地对区域景观组成及其变化有不同影响。与荒漠化景观相比，人工景观对景观结构影响较小，但潜在变化范围更广。这两类景观将是未来影响该区域景观结构变化的主导因素。
