摘要
以黄河源区玛曲县沙化草地为对象,运用景观生态学原理,借助地理信息系统技术,选取景观异质性指数(景观多样性、景观优势度)、景观破碎化指数(斑块密度、分离度)、形状指数(伸长指数、分维数)3类指标,分析了黄河源区沙化草地不同景观类型的空间分布及景观格局现状特征.结果表明,区域整体景观结构简单,局部变化复杂,自然景观仍是景观变化的主体,景观结构受草地、湿地、灌木林地等少数自然景观类型控制.区域景观斑块呈条带状分布,各景观条带差异较大,从河流阶地带到低山草地带到高山草甸带,景观斑块类型减少,景观多样性减小,景观破碎化程度减弱,景观结构呈简单化趋势.沙化景观尤其是流动沙地对景观结构的影响较大,在区域景观异质性增强及破碎化加剧过程中起主要作用.固定沙地、半固定沙地和潜在沙化土地也不同程度地影响着景观的构成及变化;人工景观比沙化景观对景观结构的影响小,但其潜在变化空间较大.人工景观和沙化景观将是未来区域景观结构变化的共同主导因素.
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.
出处
《应用生态学报》
CAS
CSCD
北大核心
2006年第9期1665-1670,共6页
Chinese Journal of Applied Ecology
基金
国家林业局荒漠化监测专题资助项目.
关键词
沙化草地
斑块
空间格局
GIS
景观指数
Desertification grassland, Patch, Spatial pattern, GIS, Landscape index.
