Abstract: Rapid Rural Appraisal (RRA) and Participatory Rural Appraisal(PRA) methods were applied to study the settlement patterns and their changes at different historical stages. The formation and the change of settlement patterns in Mengyang Nature Reserve of Xishuangbanna were resulted from the intergrate interaction between ecological environment and social development. The heterogeneous ecological environment was considered as the important cause steering the population of residential areas and the orientation of change in settlement patterns. The early indigenous people inhabited at high mountains to avoid malaria and other germs spread in lower altitude valleys. When local diseases were under control with the social development, they moved into valleys with abundant available natural resources, resulting in the change in settlement patterns and the possibility of sustainable development. Cultivated fields in mountains were abandoned and recovered by forests. Serious conflicts between people and protected wildlife and between rain forest degradation and grain production emerged, when more immigrants moved into valleys. To solve these conflicts, more attentions should be paid to the immigrant control and the harmony of development and conservation at scale of residential area.

Key words: Settlement pattern, Ecological environment, Conservation and development, Nature reserve, Xishuangbanna, Amorphophallus xiei, fluorescence characteristics, light intensity, photosynthetic characteristics., energy partitioning