摘要
以华北石质山地侧柏林为研究对象,运用氢稳定同位素(δD)技术,结合大气、土壤的温湿度,探讨雨季和旱季降雨对不同深度土壤温湿度动态及水分运移的影响。结果表明:土壤温度在雨季随降雨产生先减小后增大,随土壤深度增加而降低,而旱季初期则随降雨持续减小,且随土壤深度的增加而升高。雨季和旱季,土壤湿度随降雨先增大后减小,且均随土壤深度的增加而下降。雨季前期土壤湿度较低时,中雨可使表、中层土壤湿度增加较多,且该层土壤水δD贫化,即降雨优先补给表、中层土壤;而前期降雨充足时,中雨使下层土壤湿度增加较多,而所有土壤水δD均贫化,即降雨可较快入渗到深层土壤。大雨使所有土层湿度增加且差异较小、δD贫化,即降雨可迅速入渗全部土层。旱季初期,中雨使表层湿度增加较多,即使前期土壤湿度较低时,雨后全部土壤水δD均贫化,即中雨也可较快入渗到深层土壤,进一步补给地下水。表层枯落物水δD值受降雨δD值直接影响,随降雨产生先贫化后富集;而浅层、深层地下水δD值皆较稳定,几乎不受短期降水影响,可为干旱季节植被生长提供重要水源。
By using stable isotope techniques, the Platycladus orientalis grown on the rocky hilly area of North Chi- na were chosen to investigate air temperature, soil temperature, moisture and 8D value in order to discuss the effect of seasonal rainfall on soil temperature, moisture and water movement. The results indicated that： the soil tempera- ture following rainfal decreased first and then increased in the rainy season, and decreased with the increases of depths, whereas in the early dry season the temperature continued to decrease but increased with the depth. No matter in the rain or dry season, the soil moisture increased at first and then decreased after the rain, but dropped with the depth of soil. In rain season, when the early soil moisture was low, the low intensity rainfall could further increase the moisture of surface and deep soil and made the water 8D value deplete, which showed rainfall could re- charge the surface and middle soil. However, in prior plentiful rainfall period, low intensity rainfall could further increased the deep soil moisture, and all the soil water 8D value were depleted, which indicated that rainfall could rapidly infiltrate into the deep soil. High intensity rainfall increased all the soil moisture and the increments had small differences, meanwhile all the water BD value were depleted, which showed that rainfall could quickly infil- trate into all the soil. In the early dry season, low intensity rainfall may further increase the surface soil moisture. Even if the prior soil moisture were low, the soil water 8D value were all depleted, which pointed that rainfall could rapidly infiltrate into the deep soil and further recharged groundwater. Directly affected by rainfall 8D value, the lit- ter water 8D value were depleted at first and then enriched. The 8D value of spring and groundwater were not affect- ed by short-term rainfall, so they could supply water for plant in the dry season.
出处
《林业科学研究》
CSCD
北大核心
2015年第3期365-373,共9页
Forest Research
基金
林业公益性行业科研专项项目(201404206)
国家自然科学基金青年基金项目(31100321)
关键词
季节性降雨
土壤温度
土壤湿度
氢稳定同位素
土壤水分运移
seasonal rainfall
soil temperature
soil moisture
hydrogen stable isotope
soil water movement
