<正>在浙江省龙游县和庙山坞自然保护区研究了竹阔混交林阔叶树周围土壤养分空间分布及其与毛竹生长的相关性。结果表明：1竹阔混交林中阔叶树周围全竹、新竹平均胸径及新竹数存在带内差异和树种间差异，毛竹生长随距阔叶树基干距离增加而增加；2阔叶树周围不同环形带内土壤养分含量分布存在明显差异，且这种差异与其周围毛竹生长分布趋势一致；3不同阔叶树周围相同环形带内土壤养分存在显著差异，除了有机磷外其他养分均达显著或极显著水平；4阔叶树周围对新竹生长影响的各土壤因子从大到小依次为：全磷、速效氮、全氮、速效磷、有机碳、速效钾；5新竹平均胸径与阔叶树周围各土壤养分因子相关性可达显著水平，新竹平均胸径与全氮、全磷呈显著正相关，而与速效钾和C/N呈显著负相关，与各土壤参数交互因子相关不显著。

The effects of different planting densities (1000, 500, 250stem/hm2) on growth increment of juvenile and mature wood were studied in Populus×xiaohei. The result indicated that the juvenile period was about 12～13 years and there are no differences in juvenile wood growth rings at different planting densities. The effects of planting densities on widths and basal area of juvenile and mature wood were highly significant. An obvious tendency of increasing juvenile wood width and basal area with decreasing planting densities was seen. The highest mature wood growth increment was found at the planting density of 500stem/hm2. The percentage of juvenile wood area ranged from 74% to 83% depending on different planting densities. The highest juvenile wood proportion being at the lowest planting density. The growth rate of juvenile wood was about 10 times higher than that of mature wood. There were remarkable differences in the growth rate of both juvenile and mature wood at different planting densities. It’s concluded that planting densities showed various degrees of impact on the growth of juvenile and mature wood, and juvenile wood was more susceptible to planting density.