【摘要】 【目的】研究栽植密度对毛白杨Populus tomentosa林地土壤养分的影响。【方法】在3种不同栽植密度[行距×株距分别为2 m×2 m（T₁）、 4 m×3 m（T₂）和4 m×5 m（T₃）]下,对10年生毛白杨速生丰产林试验地0～5、 5～10、 10～20、 20～40、 40～60和60～100 cm共6个土层的有机质、碱解氮、有效磷和速效钾质量分数进行了分析。栽植密度对土壤养分的影响用单因素分析法,数据间的多重比较用Ducan法。【结果】0～20 cm土层有机质、碱解氮、有效磷和速效钾所占比例分别为69%、 79%、 71%和74%;不同栽植密度下土壤养分质量分数不一致:T₂栽植密度下有机质在0～5 cm处最高,为15.44 g·kg^-1,显著高于T₁,在5～20 cm土层处3栽密度间有机质差异显著（P<0.05）,大小依次为T₃、 T₂、 T₁,在20～100 cm土层处T₁显著低于T₃和T₂（P<0.05）;碱解氮在T₂下为14.5～142.7 mg·kg^-1,高于T₁和T₃（除5～10 cm）;有效磷为1.3～12.4 mg·kg^-1, 5～40 cm土层T₂显著高于T₁和T₃（P<0.05）, 40～100 cm土层大小依次为T₃、 T₂、 T₁;栽植密度对速效钾无显著影响（P>0.05）。【结论】10年生毛白杨林地土壤养分富集在0～20 cm土层,栽植密度为2 m（行距）×2 m（株距）的养分低于栽植密度为4m×3m和4m×5m,养分质量分数随栽植密度和不同土层的变化而变化。图5表2参31更多还原

【Abstract】 [Objective] To explore the effects of planting densities on soil nutrients of different soil layers for a Populus tomentosa plantation. [Method] 10-year-old S86 clones were used to study the soil nutrient characteristics with three planting densities（T₁: 2 m × 2 m; T₂: 4 m × 3 m; and T₃: 4 m × 5 m） for six soil layers（0-5,5-10, 10-20, 20-40, 40-60, and 60-100 cm）. In mid-October 2016, soil samples were collected, and the contents of carbon（C）, available nitrogen（N）, available phosphorus（P）, and available potassium（K） were determined and in total there were 3 treatments with 3 replicates, then one-way ANOVA and Duncan’s multiple comparison tests were used to determine significant differences. [Result]The proportions of nutrients in the 0-20 cm layer compared to the 0-100 cm layer were: C（69%）, N（79%）, P（71%）, and K（74%）. The content of soil nutrients varied for the three planting densities. The highest C content found in T₂(15.44 g·kg^-1 in the 0-5 cm layer) was significantly higher（P<0.05） than T₁; the C content in the 5-20 cm layer was significantly different（P<0.05） than other densities in the order of T₃>T₂>T₁; and in the 40-100 cm layer, the T₁ content was significantly lower（P<0.05） than other densities. The N content in T₂ was 14.5-142.7 mg·kg^-1. The P content was 1.3-12.4 mg·kg^-1 with the content of T₂ being significantly higher（P<0.05） than other layers from 5-40 cm; however, in the 40-100 cm layers the content was T₃>T₂>T₁. Planting density, though, had no significant effect on K content（P>0.05）. [Conclusion] Nutrient content varied according to planting density and soil layers with the soil nutrient content of 10-year-old P. tomentosa clone S86 gathered in the 0-20 cm layer for the 2 m × 2 m density having a lower nutrient content than the 4 m × 3 m and 4 m × 5 m densities.[Ch, 5 fig. 2 tab. 31 ref.]更多还原