火干扰对马尾松人工林土壤物理性质的影响

Effects of Fire Disturbance on the Soil Physical Properties of Pinus massoniana Plantation

研究了马尾松人工林在强度、中度、轻度和无火干扰情况下林地土壤的物理性质.结果表明:轻度火干扰林地土壤中大团聚体数量增加,小团聚体和原生土粒减少,表层土壤总孔隙度、毛管孔隙度和非毛管孔隙度上升,土壤最大持水量和有效水含量增加,其保水能力增强;随着火干扰强度(中度、强度火干扰)的增大,土壤中细土减少,质地变粗,土壤中大团聚体数量减少,小团聚体和原生土粒增加,表层土壤总孔隙度、毛管孔隙度和非毛管孔隙度下降,大孔隙对火干扰更为敏感,土壤最大持水量、毛管持水量、自然含水量和有效水含量减少,其中,中度、强度火干扰林地表层土壤有效水含量较无火干扰林地土壤分别低32.4%和36.3%,其保水能力下降.

A study was conducted of the soil physical properties of Pinus massoniana plantation under different intensities of fire disturbance. The results show that under slight fire disturbance, the amount of small soil particles and large aggregates increases; the amount of soil micro-aggregates and natural soil particles decreases; the soil porosity, the capillary porosity and the non-capillary porosity all increase in the superficial soil;the moisture capacity and the available water increase 0. 5% and 20%, respectively; and the ability of water-holding is enhanced l that with the increase of fire intensity, the amount of small soil particles and large aggregates decrease, and the amount of soil micro-aggregates and natural soil particles increase~ the soil porosity, the capillary porosity and the non-capillary porosity decrease in the superficial soil; and especially, the large porosity becomes more sensitive to the intensity of fire disturbance; and that the content of moisture capacity, natural water and available water is reduced ; the available water reduces to 32.4% and 36.3% respectively in intermediate and intense fire disturbance stands; and the ability of water-holding drops.