不同植被恢复模式土壤水分生态效应研究

采用野外调查、定点观测与室内分析相结合的方法,对渭北旱塬丘陵沟壑区不同植被恢复模式(A组为刺槐林1和荒坡,B组为封育和未封育,C组为刺槐林2和农田)土壤水分的变化规律进行了研究。结果表明,不同植被恢复模式土壤水分的季节动态变化趋势基本一致,近似于抛物线形,但也存在一定的差异。10月份以前,A、B两组植被恢复模式的土壤含水量均小于对照,此后较对照明显提高,说明在降水较少的月份,尤其是旱季,保水效果好;C组中,刺槐林2土壤含水量表现出和农田基本相似的变化趋势,且土壤含水量始终较农田高。3组不同植被恢复模式土壤水分平均值总体上随土层深度的增加而逐渐增加,当年降水对土壤水分的补偿作用均较好;其变异系数总体上随着土层的增加而逐渐减小;3组不同植被恢复模式不同层次土壤水分的变化幅度差异较大,随着土层深度的加大,土壤水分含量随时间的变化幅度呈减少趋势。

Ecological Effect of Soil Moisture in Different Modes of Vegetation Rehabilitation

The paper studies the variation law of soil moisture of different vegetation rehabilitation modes(Group A:locust trees1 waste slopes,Group B:closing hillsides to facilitate afforestation non-closing hillsides to facilitate afforestation,Group C:locust trees2 farmland)of gullied rolling loess area in the north of arid table land of the Weihe River by using the combined method of field survey,fixed point observation and indoor analysis.The outcomes show that the seasonal dynamic variation trend of soil moisture in different vegetation rehabilitation modes is basically the same and approximates a parabolic shape,but it still exists a certain difference.Before October,the soil moisture of vegetation rehabilitation mode of Groups A and B is all smaller than that of the check and obviously increased thereafter,showing that is in the dry months,especially during the dry season,the effect of water conservation is good.In Group C,the variation trend of soil moisture of locust trees2 is similar with that of the farmland and the soil moisture is always higher than that of the farmland.The mean value of soil moisture of different vegetation rehabilitation modes of three groups is gradually increased along with the increase of soil depth and the same year precipitation has better function of soil moisture compensation;the coefficient of variation is gradually reduced along with the increase of soil layer and;the variation range of soil moisture in different layers of different vegetation rehabilitation modes of the three groups is great and is in the trend of reduction along with the time and the increase of soil depth.