Abstract: The diurnal patterns of transpiration of 6 kinds of understory shrubs in an artificial Acaia mangium stand which is common in Guangdong hilly lands are measured, and the relation between leaf transpiration and microclimatic factors such as light, temperature, heredity inside the feat is analysed. The shrubs have a similar diurnal variation of water consumption through transpiration. Among the shrubs measured. Rhodomyrtus tomentosa, a sunny species which can still pew well in shady environment, exhibits the highest transpiration rate. Another sunny species Litsea cubeba takes the second place. Other shrubs transpire modestly. The transpiration of all shrubs is negatively correlated with air humidity and positively with air temperature, full radiation, and photosynthetically active radistion in forest. Two ecophysiolo- gical factores, leaf temperature and stomatal diffusive resistance, are positively and negatively correlated with iran₈Piratbo, respectivesy.

Key words: Acacia mangium forest, Shrubs, Transpiration, Microclimate, bamboo forest, habitat, correlation analysis, potential habitat, population