Hydraulic properties and eco-hydrology effects of clay interlayer in oasis-desert ecotone of Minqin
Hydraulic property is an important part of soil hydrological functions,which influences the soil moisture distribution and the intensity and rate of soil hydrological circulation strongly.Although the clay interlayer is discontinuously distributed in the arid area,the vegetation coverage in this area is often higher than that of non-clayed soils under the same climatic conditions.In this paper,the soil physical properties,soil water holding capacity and hydraulic conductivity of clay interlayer in Minqin desert oasis ecotone were measured.Meanwhile,the root system of Tamarix ramosissima,a deep root native species with 15 years old in this area,was assessed by trenching method.The variation characteristics of hydraulic properties of clay interlayer and its influencing factors were analyzed,and the eco-hydrological significance of clay interlayer for vegetation restoration and reconstruction in arid areas was discussed.The results showed that:1)Soil particle composition and organic matter content are the important factors affecting soil water holding capacity and water conductivity.2)The root biomass(d＜2mm)of 15-year-old T.ramosissima increases rapidly close to clay interlayer.3)The clay interlayer has higher water holding capacity,which can rechange other soil layer through capillary action.At the same time,the clay interlayer forms a barrier to prevent soil moisture from migrating to other soil layers,and the combined effect of the two improves the soil water content at the interface of the clay interlayer.Clay interlayer influences the soil environment for water migration and storage,indicating that the clay interlayer is advantageous for the restoration and construction of sand-stabilizing vegetation.This study provides data support for understanding the soil hydrological process,ecological restoration and reconstruction in the desert-oasis ecotone.
clay interlayersoil hydraulic propertyeco-hydrology significanceoasis-desert transitional zone
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