Abstract:

A comprehensive analysis was conducted on the long-term observation data from the five groups of runoff plots set up in Chinese fir young plantation at the Experimental Center of Subtropical Forestry, CAF in Fenyi, Jiangxi.The results showed that the range of surface runoff was 1.47 ~ 13.22mm with average of 5.46 mm, the range of runoff coefficient is 0.098 %~ 0.852 % with average of 0.369 %, the range of soil erosion is 0.0051 ~ 0.2510 t/hm² a year with an average of 0.1005 t/hm².During the w hole juvenile stage of the plantation, the total surface runoff is 546.0m³/hm², the total soil erosion was 1005.0 kg/hm², the nutrient loss was 1.9560 kg/hm² for N, 2.2370 kg/hm² for P, 26.777 kg/hm² for K, and 50.049kg/hm² for organic mater.We conclude that for the sites with red or yellow soil derived from shale, especially with the well structured soil and thick humus layer, it has strong resistance to soil erosion, and there are no significant influences on soil erosion no matter what the ways are adopted in sites preparation. Comparatively speaking, the hole site proparation way is better than others.Therefore, soil erosion may not be the main reason for the site fertility degradation of Chinese fir plantation at the sites with this type of soil.

Key words: Chinese fir plantation, Site preparation ways, Surface runoff, Soil erosion