摘要
人口增加、经济发展导致滇南热带地区西双版纳土地利用／土地覆被发生显著变化，这些变化对该区的生态环境及生物多样性保护有着重要影响。基于RS和GIS方法，通过对1976、1988和2003年三个时期遥感影像解译分析，试图了解西双版纳近27a间土地利用／土地覆被时空变化特征及影响因素。结果表明，近27a间有林地在西双版纳分布最广、占绝对优势，其中以亚热带常绿阔叶林面积最大；但在研究时段内，有林地面积不断减少、呈现破碎化，尤其是热带季节雨林、山地雨林面积减少最为明显和破碎化最为严重。相应，橡胶园、灌木林面积不断扩大并聚集成片，其中橡胶园在1988—2003年间是面积增长最快、最多的地类，其面积扩张主要来源于对热带季节雨林的砍伐。轮歇地面积在1976—1988年是所有地类中增长最快、最多的，在1988—2003年由于向橡胶园转变而大幅度减小。粗放式的刀耕火种和橡胶种植园的不断扩大是主导本区土地利用／土地覆被变化的主要因素，土地利用变化导致了本区生态环境的退化和生物多样性的丢失。
Xishuangbanna, located in the watershed of upper Mekong River, is the northern margin of the tropical zone in South-East Asia. It maintains large areas of tropical rainforest. Like most tropical rainforest region all over the world, with population pressure and economy development the land use/land cover has been changed. While tropical forest loss is recognized as a global problem, little is known on a local scale about the complex relationships between environmental, economic, social and policy factors that induce changes in land use patterns. The spatial and temporal change patterns in land use were quantified by interpreting Landsat images from 1976, 1988, and 2003 and using geographical information system, and various landscape metrics were calculated by using the spatial pattern analysis software （FRAGSTATS） at class and landscape levels. During the past 27 years, the forest types are the main dominant type in the landscapes, with the subtropical evergreen broadleaf forest being the most significant. However, the rate and the intensity of land use and land cover change were very high. There was a decrease in tropical seasonal rain forest, mountain rain forest, subtropical evergreen broadleaf forest and warm conifer forest area and increase in area under rubber plantations and shrublands between 1976 and 2003. Fallow lands increased drastically during the first half （ 1976 - 1988） of the study period and decreased in the other half （ 1988 - 2003 ）. Conversion of shrublands, subtropical evergreen broadleaf forest and tropical seasonal rain forest into fallow land contributed to the rapid increase in fallow lands cover during the first half of the study period, while conversion of tropical seasonal rain forest and fallow lands into rubber plantations contributed to the rapid increase in rubber plantations during the second half. The results of landscape spatial pattern analysis showed that the patterns and components of land use in this study area have changed typically by human activities. The pattern of land use has become more diverse and homogeneous in the study area. The dramatic actives of swidden agriculture and expansion of rubber plantations are the main reasons induced pattern of land use change. The overspreading of rubber plantations and shrublands made tropical seasonal rain forest and mountain rain forest become more fragmented： the number of the patches increased, the patches sizes become smaller and the shape of patch become more simplified. All of these changes in landscape pattern would lead to the deterioration of the region environment and biodiversity loss.
出处
《山地学报》
CSCD
北大核心
2007年第3期280-289,共10页
Mountain Research
基金
中国科学院创新工程重大项目(KZCX1-SW-01-01A)
国家重点基础研究发展计划(国家973项目)(2002CB412501)资助~~
