锡林郭勒草原景观多样性的时间变化

CHANGING LANDSCAPE DIVERSITY WITH TIME IN XILINGUOLE STEPPE

利用锡林郭勒草原典型区段的两个不同年代的遥感信息源 ,结合实地考察目视解译研究区 1978年(MSS)、1992年 (TM)的卫片影像 ,得到研究区两张不同时期的植被图 ,以植物群落做为确定景观单元的最主要因子 ,在 ARC/ INFO软件的支持下 ,通过景观元素空间格局的变化 ,进一步分析得出在 14a的时间进程中 ,研究区景观破碎化现象加剧 ,多样性指数增加 ,优势度指数下降。人类不合理的放牧利用、农田开垦等经营活动 ,引起草原植被发生逆向演替 ,改变了景观异质性 。

In combination with field surveys, satellite images from 1978 (MSS) and 1992 (TM) were visibly interpreted and vegetation maps of the same of the study area were developed corresponding to the two different periods of time. With the support of ARC/INFO software, analysis of changes in the spatial distribution pattern of landscape elements, showed that the landscape fragmentation and diversity indices increased while the dominance index declined over the study area over the 14 years period. Management practices such as inappropriate grazing rates, farmland reclamation etc. were the driving forces behind steppe degradation and desertification as well as the changes in landscape.