大兴安岭不同恢复年限落叶松人工林土壤水分涵养特性研究

Soil Water Storage Capacity and Infiltration Properties of Larix Gmelinii Plantation in Different Growth Age after Burned in Greater Khingan Mountains

以大兴安岭火烧迹地不同恢复年限的落叶松人工林为研究对象,以天然更新林地为对照,对不同恢复年限下林地土壤的贮水能力和土壤入渗性能进行了研究。研究结果表明:1989年落叶松人工林的土壤容重最小,有机质含量、非毛管孔隙度、初渗速率和稳渗速率均最大。土壤的吸持贮水量和饱和贮水量从高到低依次为1989年、1992年落叶松人工林、天然更新林地、1997年、1995年落叶松人工林,这与土壤孔隙度的变化趋势相一致。随着恢复年限的增长,土壤有机质含量总体趋势逐渐增大。土壤初渗速率的变化范围为3.59~11.50 mm min-1,稳渗速率的变化范围为2.30~7.01 mm min-1。1989年、1992年落叶松人工林林地土壤容重、毛管孔隙度、吸持贮水量、稳渗时间分别与1995年、1997年落叶松人工林差异显著,火烧后一定时间范围内,植被恢复年限的增长有利于土壤环境的改良,人工植被恢复效果好于天然植被恢复。通过土壤入渗速率实测值与4种模型的拟合值的对比分析,霍顿模型更适合描述本研究区域土壤的入渗特征。

In this paper, with the subjective of Larix gmelinii plantation in burned areas which had been restored for different years in Great Xing′an Mountains, with the natural regeneration of forest as control, we studied the soil water storage capacity and infiltration capability under different years of plantation restoration. The results showed that soil bulk density of Larix gmelinii planted in 1989 was the lowest, whereas the soil organic matter, non-capillary porosity,initial infiltration rate and the steady infiltration rate were highest. The descending order of soil retention storage volume and the amount of saturated water storage were as follows: Larix gmelinii planted in 1989 and 1992, natural regeneration of forest land, Larix gmelinii plantation growed in 1997 and 1995. The trends were consistent with the soil porosity. With the increase of restoration years, the content of soil organic matter increased. The soil initial infiltration rate ranged from 3.59 ~ 11.50 mm min-1, and steady infiltration rate ranged from 2.30 ~ 7.01 mm min-1.The soil bulk density, capillary porosity, soil retention storage volume and steady infiltration time of Larix gmelinii planted in 1989 and 1992 were significantly different from 1995 and 1997. Within a specific restoration time span after burning, the increase of vegetation restoration years contributed to the improvement of the soil quality, and artificial vegetation recovery was better than the natural vegetation recovery. By contrast analysis of soil infiltration rates measured value and the fitted values of the four models, the Houghton model was mostly suitable to describe the soil infiltration characteristics of this area.