In order to evaluate the effects of stand structures on runoff characteristics, precipitation, surface runoff and underground water discharge were measured for 20 years at a small Chinese fir plantation watershed in Huitong Ecosystem Research Station of Central South University of Forestry and Technology of China. During this period, the Chinese fir stand developed from the early-growth stage through the timber-growth stage to the mature stage, based on the features of growth and development of the community.

Results/Conclusions Our results showed that a single peak curve in surface runoff was observed in the small watershed. The lowest values occurred in the early-growth and mature stages and the highest ones in the timber-growth stage. However, total runoff coefficient (ratio of runoff to rainfall) decreased with increasing growth and development stages. Total runoff coefficient was about twice as high in the early-growth stage (30.8%) than in the mature stage (15.8%). High underground and total runoff coefficients found in the young stands was mainly attributed to soil disturbance by human management activities. Both mid-aged and mature Chinese fir plantations played significant role in regulating water distribution at small watershed scales. These results provide useful information regarding the effects of forest management practices on hydrological processes in forest plantations.