黄土丘陵沟壑区人工刺槐林土壤水分物理性质

Soil Hydro-physical Properties of Artificial Robinia pseudoacacia Forests in Loess Hilly-Gully Region

为黄土丘陵沟壑区退耕地的植被恢复重建及生态环境建设评价提供科学依据,对晋西黄土丘陵沟壑区不同密度的刺槐人工林土壤水分物理性质的变化进行了研究。结果表明:刺槐林分的土壤平均密度都低于农田,密度为1 600株/hm2的林分土壤密度最小,为1.225 9 g/cm3;土壤密度随土壤深度的增加而增大;刺槐林分的孔隙度和通气度都大于农田,退耕还林后,土壤质量明显得到改善,密度为1 600株/hm2的林分孔隙度最大。刺槐林分土壤持水量都要好于农田,土壤平均最大持水量和毛管持水量随林分密度的增大先增加后减少,密度为1 600株/hm2的林分持水性能最好;持水量随土壤深度的增加而下降。密度为1 600株/hm2的刺槐林土壤饱和蓄水量和非毛管蓄水量最高,分别为558.12和52.45 mm,水源涵养能力最强;土壤表层蓄水能力好于中、下层;密度为1 800株/hm2的刺槐林土壤涵蓄降水量和有效涵蓄量最大。

A survey was conducted to study the soil hydro-physical properties of artificial Robinia pseudoacacia forests of different densities in the hilly-gully region of western Shanxi Province in order to provide theoretical basis for the evaluation of ecological function rehabilitation and vegetation construction.Results showed that,compared with farmland,R.pseudoacacia forestlands exhibited a lower soil bulk density,especially for the stand with 1 600 stems/hm2,which showed the lowest one.The bulk density increased with soil depth.The soil porosity and aeration capability tended to increase after returning farmland to forests,and the soil porosity of the stand with 1 600 stem/hm2 was higher than that of the other stands.The water retaining capacity of the soil in R.pseudoacacia stands was better than that in the farmland.The maximum soil moisture capacity and capillary capacity initiated with an increasing trend,and then decreased with the increase of the standing density.The water-retention property of the stand with 1 600 stems/hm2 was the best,and the water-retention capacity of the soils decreased with soil depth.For the stand with 1 600 stems/hm2,the saturated soil water content and the non-capillary water-holding capacity reached 558.12 and 52.45 mm respectively,which were higher than those of the other stands.The water retention capacity of the surface soil was superior to that of the soils in middle and lower layers.However,the precipitation retained in soil and the effective retention were the highest in the stand with 1 800 stems/hm2.