Abstract: Based on fixed field monitoring data,soil water potential dynamics and water consumption in the oil-tea camellia woods on slope land of red soil were studied. Results show that during the rainy season in 2007 soil water potential and its variation coefficient at the upper slope was greater than at the lower slope. Soils,0-50 cm in depth in the upper slope and 0-40 cm in the down slope were obviously exposed to dual impacts of evaporation and transpiration,and the soil water potential at 90 cm in depth varied more sharply than in other soil horizons nearby. Soil physical properties and root distribution affected significantly water potential and water consumption. At 40 and 90 cm in depth,where the soil was turning from clay horizon into gravel horizon,and from gravel horizon to mottling horizon,respectively,water tended to accumulate and roots were apt to extend towards there. A significant exponential-correlation between dry weight of fine roots (d_r<1 mm) and depth of soil layer was observed and about 46.95% of the fine roots were distributed in the 90 cm soil layer. The proportion of fine roots was significantly and positively related to soil water potential(70-110 cm). Zero flux plane analysis revealed that during the continuous dry period in the rainy season,water moved upwards from the deep layers,with water potential varying the most sharply at 90 cm in depth. It was also confirmed that the soil layer around 90 cm is the leading zone of water consumption in the oil-tea camellia woods during the rainy season.

Key words: slope land in red soil region, oil-tea camellia wood, soil water potential, root, water consumption