Effects of artificial seabuckthorn forest on soil and water conservation in loess hilly region
黄土丘陵区人工沙棘林水土保持作用机理及效益

Seabuckthorn is regarded as a main eco-economical tree species, and plays an increasing important role in eco-environmental construction in Northwest, Northeast and North China. Our study on artificial seabuckthorn forest in loess hilly region showed that the average rainfall interception rate of 7-10 ages seabuckthorn canopy was 8.5%, and the litter layer of 5-10 ages seabuckthorn forest could intercept 0.89 mm rainfall. Seabuckthorn forest could improve soil infiltration and anti-strike ability through improving soil physical and chemical properties, and the numbers of its hair roots and the depth of its litter layer were the main indices of soil anti-strike ability. The effects of seabuckthorn forest on soil and water conservation increased with its increasing age. In 2-3 ages stage, the effects were weak, and the runoff and sediment were mainly affected by the characters of rainfall. In 4-5 ages stage when the forest became maturing, the annual runoff depth and annual erosion modulus were 1.8-3.2 mm and 24.64 t x km(-2), respectively. In 6-12 ages stage when the forest matured, the runoff and sediment on seabuckthorn woodland changed slowly, the annual runoff depth and annual erosion modulus being 0.3 -3.4 mm and 0-6.75 t x km(-2), respectively, and the characters of rainfall had much less effect on them. In the stage from young (2-5 ages) to mature forest, the sediment charge in runoff changed sharply, ranged from 77. 31 kg x m(-3) to 9.12 kg x m(-3), but in 6-12 ages stage, the sediment content in runoff changed very slowly, and the range was 0-5.09 kg x m(-3).