[Analysis of the landscape diversity dynamics of small watershed in the Loess Plateau].

Taking Zhifanggou Gully as the study area, some landscape diversity indexes were attained under the support of GIS technology. Utilizing the indexes such as patch size, average fractal dimension, diversity index, dominance, evenness, fragmentation and conglomeration, the changes of landscape diversity in the small watershed in Loess Plateau during the past 40 years were studied. The landscape diversities had been increasing for the recent 40 years due to the effect of both human activity and plants' endogenesis succession. The patches number increased, and the dryland matrix was substituted gradually by other matrixes such as meadow and woodland. The landscape pattern trended to be fragmentized and the indexes of landscape type diversity and evenness increased, while landscape diversities changed greater during 1978-1998 than during 1958-1978. Homogeneous dryland matrix landscape ecosystem in 1958 had already changed into heterogeneous meadow and woodland matrix landscape ecosystem, which had greater structure stability and stronger function than before.