Since 1986 the multiple benefits of moso-bamboo forest, a special forest type found mainly in south China, have been investigated in a small 11.7 ha watershed in Fenyi County, Jiangxi Province. The mean annual precipitation in the study area is 1593.3mm. For the 0-60cm soil layer the average soil bulk density is 1.00g/cm3, and the mean values for other soil properties are: total porosity 71.74%; non-capillary porosity 5.81 %; and water retention capacity 430 mm. The maximum effective water retention capacity of 313mm is 28% higher than that for Chinese fir (Cunningharnia lancedata) plantations and natural broadleaved forest in the neighbouring area. The parameters fb, j i and k, in Horton's infiltration equation, measured using the double-ring method under drought conditions, are 29.10 mm/min, 8.28 mm/min and 0.239 1, respectively. These infiltration properties are more favourable than those under nearby Chinese fir plantations.
Compared with a Chinese fir plantation, the canopy interception ratio of moso-bamboo is lower, but the stemflow ratio is higher. The annual canopy interception ratio is 11.1%. Because of snowfall, the interception ratios in January, February and March are higher, with values of 12.1-17.2%, whereas during the period of leaf fall in April, May and June the interception ratios are lower with values of 9.2-9.5%. During the other months they are relatively constant. The annual stemflow ratio is 4.4%. Again, because of snowfall, the stemflow ratios in January, February and March are lower with values of 2.8-2.9%, whereas during the remaining months they are fairly constant.
Runoff analysis shows that the annual runoff ratio in this research watershed is 54.8%, but the ratio for quick runoff, composed of direct runoff and surface runoff, is only 0.8%. The upper interflow ratio is 15% and the ratio for the slow runoff composed of deeper interflow and underflow is 39%. The moso-bamboo forest is very effective in reducing peak runoff and increasing low flows.
The annual nutrient element inputs (kg/ha) to the moso-bamboo forest ecosystem associated with throughfall and