六盘山森林土壤中的砾石对渗透性和蒸发的影响

为了解山地土壤中的砾石对土壤水文循环的影响，测定了砾石土壤的贮水能力、渗透速率和蒸发速率。结果表明，砾石含量与土壤有效贮水量呈正相关关系，但与土壤最大贮水量无明显相关。在0-40cm土层，当砾石体积含量小于15％～20％时，稳渗速率随砾石含量增加而增大，当砾石体积含量大于15％-20％时，土壤稳渗速率随砾石含量增加而减小；在40cm以下土层，稳渗速率随砾石含量增加而提高。在土壤砾石含量为0～20％时，土壤蒸发速率随砾石含量增加而降低，但在砾石含量超过20％时，土壤蒸发速率基本保持稳定。土壤蒸发速率随砾石粒径增大有升高的趋势。

Effect of rock fragments on the percolation and evaporation of forest soil in the Liupan Mountains, China

The water-retaining capacity, percolation and evaporation of stony soil in the Liupan Mountains were observed in order to understand the effect of rock fragments on soil hydrological processes. The results indicated that the effective water-retaining capacity of soil is positively related with its volumetric content of rock fragments, but there is no relation between the saturated water-retaining capacity and rock fragment content. For the soil layers within 0-40cm, the steady-infiltration rate increases with increasing volumetric content of rock fragments until it reaches the range of 15%-20%, then it decreases with when the rock fragment content further increases. For the soil layers below 40cm, the steady-infiltration rate always increases increasing rock fragment content. The soil evaporation rate decreases with increasing volumetric rock fragment content when it varies in the range of 0% to 20%, however, the soil evaporation rate keeps basically stable, when the rock fragment content is higher than 20%. The soil evaporation rate shows a tendency of rising with increasing size of rock fragments.