川西亚高山针叶林植物群落演替对土壤性质的影响

研究了川西亚高山针叶林人工重建过程中土壤物理性质,结果表明:随着人工云杉林龄的增加,土壤表层粉粒、粘粒、物理性粘粒、团聚度和结构系数降低,砂粒含量增高,土壤饱和持水量、毛管持水量及总孔隙和毛管孔隙在人工云杉林演替过程中表现出"U"型变化,即人工云杉从幼林向成熟林演替阶段,土壤饱和持水量、毛管持水量及总孔隙和毛管孔隙则减少,在40年生云杉林达最低值之后,随着云杉自疏而有上升的趋势,毛管持水量是决定林地土壤自然含水量的主要因子。为了加速该区域植被恢复和重建过程,建议营造针阔混交林和对人工成熟林和过熟林进行间伐抚育,增加物种多样性,减少水土流失,为植物生长创造良好的土壤物理环境。

Influence of Plant Community Succession on Soil Physical Properties during Subalpine Coniferous Plantation Rehabilitation in Western Sichuan

Soil physical properties were studied during subalpine coniferous plantation rehabilitation in western Sichuan. The results showed that soil silt, clay, physical clay, aggregate degree and structure coefficient in topsoil decreased with increasing of spruce plantation age and soil sand increased. Soil saturated water capacity, capillary water capacity, total porosity and capillary porosity showed the trend of the "U" during the successional course of spruce plantation, namely, they reduced on the early successional stages and recovered slowly with improvement of forest micro-environment after spruce plantation reached mature forest. The content of soil natural water was mainly controlled by capillary porosity. In order to accelerate the course of plant restoration and rehabilitation, the strategy and measures to increase plant diversity and to decrease water and soil loss were put forward, including application of thinning rationally for existing dense plantations and establishment of mixture forest of conifer and broadleaf trees for new plantations, which would create good soil physical environment for plant growth.