The Study Of Soil Anti-scourability Of Different Vegetation In The Loess Plateau Of Western Shanxi

Soil erosion is a very serious problem in Loess Plateau due to nature and anthropogenic factors, such as lower coverage, torrential rain, deforestation and so on. The Loess Plateau is the key area of prevention and control of soil erosion. Soil antiscouribility is an index which objectively reflect soil resistance to water erosion and is one of the important aspects of studying soil erosion mechanism. The study of soil anti-scouribility can not only reflect the benefit of vegetation improving the soil structure, but also provide scientific basis for the evaluation on ecological benefits of soil and water conservation forest in Loess Plateau.In this study, standard plot selection, forest stand investigating, field water erosion experiment and laboratory analysis were combined to discuss soil anti-scouribility under6different forest land use patterns in Caijiachuan watershed in Ji county of Shanxi Province. Pinus tabulaeformis forest, Platycladus orientalis forest, Robinia pseudoacacia forest, secondary forest, Robinia pseudoacacia and Platycladus orientalis mixed forest, apricot forest, which were used to be as reseach objects, grassland and farmland as the control. Slope, litters, and biodiversity were used to be impact factors. The main conclusions are as follows:(1) Soil anti-scouribility varies greatly under different forest land use patterns in Loess Plateau of western Shanxi province.. The anti-scourability of different forest land use patterns followed the trend:secondary forestland> Robinia pseudoacacia and Platycladus orientalis mixed forestland> Pinus tabulaeformis forestland> Robinia pseudoacacia forestland> Platycladus orientalis forestland> grassland> Prunus armeniaca forestland> cropland..(2) Slope is one of main factors which affect soil anti-scourability. The soil anti-scourability varis with slope under different forest land use patterns. Under all of land use patterns, the soil anti-scourability decreased as the slope increased. The soil erosion amount will become extremely great when the slope beyond the boundary slope. (3) Soil erosion amount in the runoff decreased as the thickness of litter increased under different land use patterns. When the litters layer thick enough, soil erosion amount in the runoff will begin to stabilize and close to zero. The thickness of litter layer has an important significance to reducing soil erosion amount, and the soil anti-scourability increased as the litter thickness increased..(4) Biodiversity also is an important factor affecting the soil resistance to erosion. Under same forest age and slope conditions, soil erosion amout in the runoff decreased as biodiversity increased in each land use patterns. That is means the soil anti-scourability enhanced as biodiversity increased..(5) Slope, litter, biodiversity are the major factors influencing soil anti-scourability under each land use patterns, which has slightly different correlation with soil anti-scourability. Under Pinus tabulaeformis forest land, Robinia pseudoacacia forest land, Platycladus orientalis forest land, and secondary forest land, the impact factors followed the trend:biodiversity> litter> slope. Under Robinia pseudoacacia and Platycladus orientalis mixed forest land, the impact factors followed the trend:biodiversity> slope> litter. Under Prunus armeniaca forest land, the impact factors followed the trend:slope> litter> biodiversity.