Keywords: 
• forest ecology /
• hot-dry valley /
• Terminalia franchetii community /
• species diversity /
• seedling regeneration

Abstract: The hot-dry Yuanmou valley is a typical ecological system in the fragile Jinshajiang River area. To research the community structure and regeneration of Terminalia franchetii forest，a vitally important and typical natural forest ecosystem in Yunnan Province，China，Three T. franchetii communities were investigated using the quadrat survey procedure in 100 m2 with seven repeats for species diversity and seedling regeneration and analyzed using the Shannon-Wiener，Simpson，and Pielou indexes. Results showed that these communities，having 32 species belonging to 16 families and 28 genera，had a relatively low richness with dominant species of Heteropogon contortus and Arthraxon lancifolius. Recordings for the indexes were：Shannon-Wiener 1.35 － 2.82，Simpson 0.63 － 0.81，and Pielou 0.68 － 0.85. The Shannon-Wiener and Pielou in community Ⅰ was markedly low to community Ⅱ which was remarkably low to community Ⅲ，but the Simpson in community Ⅰwas slightly high to community Ⅱ which markedly high to community Ⅲ. Seedling regeneration in the T. franchetii community occurred at the start and in the middle of the rainy season；then it gradually decreased towards the end of the rainy season and ceased with the beginning of the dry season. During drought，the number of one-year-old seedlings was sharply declined to 0.5 in 1.0 m2 which maybe survived in shielded during the dry season that was most serious in March and April. Less drastic changes for the year occurred with two-year-old and older seedlings，which implied that they were more stable and showed better adversity resistance in the differing community environments. Thus，reducing disturbances would improve the community environment making seedling establishment of T. franchetii possible，then allowing a viable spontaneous recovery of the native vegetation through natural regeneration.［Ch，2 fig. 2 tab. 16 ref.］