黄土丘陵区典型植物种群下土壤大孔隙特征及其影响因素研究

采用亮蓝(Brilliant blue,FCF)野外染色示踪实验和图像分析技术,研究了陇中黄土高原安家坡流域典型植物种群下土壤大孔隙分布特征及其与植物种群和土壤物理性质的关系。结果表明:6种植物种群下土壤中的大孔隙流不同,大孔隙流使水分在土壤中的运移深度提高了2～3倍;随着土层深度的加深,6种植物种群下土壤的染色面积均呈减小趋势;6种植物种群下土壤中各级别大孔隙以2、3级大孔隙最多,平均占染色面积的29.3%和29.4%,其次是1级和4级大孔隙,分别占17%和19.8%,5级特大孔隙最低,占4.5%。大孔隙分布特征与土壤有机质含量和容重有关。

Soil macropore characteristics under typical vegetations and their affecting factors in Loss hilly region

By using dye tracing method and image analysis technology,the characteristics and distribution of macropores under typical vegetations in Anjiapo catchment of Longxi Loess Plateau and its relationship with plant populations and the properties of soil in study area were studied.The results showed that the macropore amount differed among 6 kinds of plant populations,the existence of macropore can accelerate the infiltration depth by 2 or 3 times at least;The vertical distribution pattern of soil macropores can be obtained by the variation of dyed area with soil depth;The dye areas of 6 soils tend to decrease with increasing of soil depth;the dyed areas at second and third dye stained level are bigger,account for 29.3% and 29.4% of total dyed area on the soil profiles,dyed area on level 1 and level 4 are 17% and 19.8%,respectively.dyed area on level 5 is the lowest,accounts for 4.5%;the characteristics and distribution of macropores are highly correlated with the organic matter content and bulk density in soil.