SPATIAL AND TEMPORAL DYNAMICS OF CO2 CONCENTRATION AND ITS CAUSES IN XISHUANGBANNA TROPICAL SEASONAL RAIN FOREST, CHINA STEM RESPIRATION RATES OF DOMINANT TREE SPECIES IN A TROPICAL SEASONAL RAIN FOREST IN XISHUANGBANNA, YUNNAN, SOUTHWEST CHINA Seasonal variation of soil respiration and its components in tropical rain forest and rubber plantation in Xishuangbanna, Yunnan. DIURNAL AND SEASONAL CO2 EXCHANGE ON CLEAR DAYS IN A TROPICAL SEASONAL RAINFOREST OF XISHUANGBANNA