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生物结皮的形成与发育显著改变了土壤地表特征及下伏土壤性质,对地表蒸发过程产生深远影响。但目前已有研究对生物结皮在地表蒸发过程中的作用仍存在很大争议。文中通过覆盖结皮和模拟降水的方法对土壤蒸发过程进行研究,以期初步揭示生物结皮发育影响地表蒸发过程的机理。结果表明:生物结皮主要通过结皮层对降水的截留和阻碍扩散作用及对下伏土壤性质的改变来影响土壤蒸发。生物结皮层主要体现为抑制蒸发,但生物结皮对下伏土壤性质的改变促进蒸发。生物结皮发育对地表蒸发的影响以抑制作用为主。生物结皮随着发育程度的提高,由抑制蒸发渐转为促进蒸发。
The formation and development of biological crust significantly change the surface characteristics of the soil and underlying soil properties, which have a profound impact on the evaporation process of the surface. However, there are still some controversies on the role of biological crusts in surface evaporation. In this paper, the process of soil evaporation is studied by covering the crust and simulating precipitation, in order to reveal the mechanism of the influence of the development of biological crust on the surface evaporation. The results showed that the biological crust affected the soil evaporation mainly through the interception and retarding diffusion of precipitation and the change of the underlying soil properties. Bio-crust is mainly manifested as inhibition of evaporation, but changes in the underlying soil properties by biological crusts promote evaporation. The impact of the development of biological crust on the surface evaporation mainly inhibition. As the development of biological crusts increased, inhibition of evaporation gradually shifted to promote evaporation.