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对２９年生五种造林密度生物量结构及土壤肥力进行了全面研究，结果表明：平均单株及其各器官生物量随密度增加呈递减趋势；单位面积不同密度的杉木林分生物量及其生产力基本趋于一致；各种密度单位面积现存枯枝落叶量随密度增加而增加，而林下植被生长及其生物量则相反；五种密度林分土壤自然含水量、最大持水量和毛管持水量基本上以２８０５株／ｈｍ２和３７５０株／ｈｍ２较大；土壤非毛管孔隙度，毛管孔隙度和总孔隙度均随密度增加而增大；土壤有机质、全Ｎ、全Ｐ、水解Ｎ和速效Ｐ的含量随密度增加而下降；而速效钾含量变化规律性不明显。因此，杉木初植密度尽量控制在２８０５—３７５０株／ｈｍ２之间，以利于杉木产量提高和地力维护。
The biomass and biomass of five afforestation plants under 29 years old were studied comprehensively. The results showed that the biomass of individual plants and their organs tended to decrease with the increase of planting density. The biomass and productivity of Chinese fir plantations with different densities per unit area The density of litterfall per unit area increased with the increase of density, while the growth of understory vegetation and its biomass were opposite. The soil natural water content, maximum water holding capacity and capillary water holding capacity Basically with 2805 plants / hm2 and 3750 plants / hm2. Soil non-capillary porosity, capillary porosity and total porosity all increased with the increase of soil density. Soil organic matter, total N, total P, hydrolyzed N and available P Content decreases with the increase of density; while the content of available potassium is not obvious. Therefore, as early as possible planted in the density control in the 2805-3750 plants / hm2 between, in order to facilitate the improvement of fir production and soil conservation.