科尔沁沙地雨后黄柳灌丛内外土壤水分动态分析

Soil moisture dynamics of Salix gordejevii shrub area after rainfall in Horqin Sandy Land

以科尔沁沙地半固定沙丘不同冠幅的黄柳为对象,利用Diviner2000对降雨后(65.9mm)灌丛内外土壤水分动态进行监测。结果表明:降雨后0.5d内,灌丛内外0-90cm的土壤含水量均明显增加,降雨在灌丛基部的入渗深度(110cm)大于中部(90cm)和外部(100cm);灌丛中部0-20cm和0-80cm储水量在0.5d-15.5d内的变化速率分别为0.88mm.d-1和2.64mm.d-1,分别低于灌丛外部的0.90mm.d-1和2.88mm.d-1,说明灌丛中部土壤具有较强的保水能力。降雨后7.5d时,灌丛基部储水量增加(12.20mm)显著高于中部(8.79mm)和外部(7.29mm)(P<0.05)。随着灌丛冠幅的增加,灌丛下0-80cm土壤截留降雨能力和保水能力有逐渐增强的趋势,而降雨的入渗能力逐渐减弱。

Soil moisture dynamics under the Salix gordejevii shrubs canopy on semi-fixed dune of Horqin Sandy Land were monitored with Diviner 2000 after a rainfall（65.9mm）.The result showed that during 0.5 day after the rainfall,the soil moisture at 0-90cm depth increased obviously,and the infiltration depth at shrub base（110cm） was deeper than that under shrub canopy（90cm） and the open space（100cm）,the change rates of the water storage at 0-20cm and 0-80cm soil layer under shrubs were 0.88mm·d-1 and 2.64mm·d-1 respectively,which was slower than that in the open space（0.90mm·d-1 and 2.88mm·d-1,respectively）,indicating that the water retention ability at these two soil layers were higher than that in the open space.The increase of soil water storage at 80-120cm layer at shrub base was 12.20mm,which was significantly higher than that under shrub canopy（8.79mm） and in the open space（7.29mm） during 7.5 d.With the shrubs canopy scaling up,the soil water retention ability at 0-80cm layer under shrub canopy increased,while the rainfall infiltration ability decreased.