北京山区典型人工林土壤水分动态研究

采用TRIME管状土壤含水率测试仪定位测定,对鹫峰国家森林公园典型林地土壤水分的垂直变化、季节性变化以及土壤水分消退规律进行研究。结果表明:1)各林地土壤水分垂直变化总体趋势基本上一致,先增加再近稳定后缓慢减少,各林地土壤含水率大小顺序为:栓皮栎>刺槐>油松>侧柏,土壤水分大致分为:表层速变层、水分利用层、水分稳定调节层。2)4块林地土壤含水率变异系数平均值随着深度的增加而降低,10cm处的变异系数最大,这可能与降水的入渗与树木的吸收两种作用有关。3)各林地土壤水分季节性变化明显,大体上在7月～9月份较高,6月份含水率较低。整个生长季土壤平均含水率差异不是很大。4)在8月3日较大规模降水后,4种林分的土壤水分消退都体现出了蒸渗型的特征。

Soil water dynamics of typical plantations in Beijing mountainous region

The TRIME tubular soil moisture tester was adopted in this research to positionally measure the soil moisture.The vertical changes,seasonal variation in soil moisture and soil moisture regression processes of typical woodlands in Beijing mountain were studied.It showed that:(1) The trend of soil moisture vertical changes were broadly consistent in different wood species.First increasing and then nearly stable after decrease slowly.The order of soil moisture content was Quercus variabilis > Roninmia pseudoscacia> Pinus tabulaeform > Platycladus orlentalis.Soil moisture generally was divided into: the surface layer of rapid change,water use level,Layer of water regulation stably.(2) Average coefficient of variation of soil moisture content in 4 woodlands decreased with the increase of depth.The maximum moisture appeared at 10cm,indicating that magnitude of changes in soil surface was the biggest.(3) Seasonal changes of soil moisture was obvious,high moisture content was in July-September,low moisture content was in June.Average moisture contents in 4 woodlands throughout the growing season showed no big differences.(4) After a larger-scale precipitation in August 3,soil moisture regression processes dissipated evaporation-leakage type.