中文摘要：

以现有42年生的马尾松（Pinus massoniana）人工纯林，经过采伐形成4种不同大小有效面积的林窗（100、400、900和1600m2）为研究对象，以未经采伐的42年生马尾松人工纯林为对照样地，采用凋落叶分解袋法，研究不同大小有效面积林窗对马尾松凋落叶、土壤C、N、P及化学计量比和养分损失率的影响。研究结果表明：（1）不同大小有效面积林窗下的马尾松凋落叶、土壤C、N、P含量及养分损失率除土壤P含量和马尾松凋落叶P养分损失率外，均存在显著差异。随着林窗有效面积Gl—G4的增大，马尾松凋落叶C、N、P含量均呈降低趋势，三者均在G3林窗体现出较小值。马尾松凋落叶C、N、P养分损失率、土壤C、N、P养分含量多呈抛物线趋势，且均在G2或G3林窗体现出最大值。（2）不同大小有效面积林窗下的马尾松凋落叶、土壤C／N／P均存在显著差异。随着林窗有效面积G1～C4的增大，马尾松人工林土壤C／N／P基本呈抛物线变化趋势，土壤C／N在G3林窗出现最大值，土壤C／P、N／P均在G2林窗体现出最大值；土壤C／N、C／P、N／P变异系数分别为13．3l％、16．51％、17．21％。马尾松凋落叶C／N、C／P均在G3体现出最小值。（3）马尾松凋落叶C、N含量与土壤C、C／N／P及环境因子的相关性较强，P含量与它们的相关性较弱；C／N与土壤P、C／N／P及环境因子的相关性较强，C／P、N／P与土壤C／P及环境因子的相关性较强；C、N养分损失率与土壤C、C／N、C／P及环境因子的相关性较强，P养分损失率与土壤C、N、P含量及其化学计量比和环境因子的相关性较弱。土壤C、N、P含量及其化学计量比与环境因子的相关性较强。

英文摘要：

In order to study the organic carbon nitrogen phosphorus nutrients content, loss of these nutrients, C/N/P stoichiometric ratio of Pinus massoniana litter and soil in different sized P. massoniana forest gaps. In the present study, with existing 42 years of P. massoniana plantation, by cutting, formed four different sized P. massoniana forest gaps about 100, 400, 900, 1 600 m2 and without cutting as usual. Bying leaf litter decomposition method. The results showed that： （1）With different sized forest gaps, the organic carbon nitrogen phosphorus nutrients content, loss of these nutrients and C/N/P stoichiometric ratio of P. massoniana litter and soil had significant differences, in addition to the phosphorus nutrients content of soil and phosphorus nutrient loss. With the increasing of gap size G1 - G4, the content organic carbon nitrogen phosphorus nutrients content of P. massoniana litter all showed a decreasing trend and had smaller values in G3. Most index of the content organic carbon nitrogen phosphorus nutrients content of soil, the content organic carbon nitrogen phosphorus nutrient loss showed a parabolic trend and had the maximum value in G2 or G3 ; （2） With different sized forest gaps, the C/N/P stoichiometric ratio of P. massoniana litter and soil had significant differences. With the increasing of gap size G1 - G4, the C/N/P stoichiometric ratio of soil showed a parabolic trend, C/N had the maximum value in G3, both C/P and N/P had the maximum value in G2. The Soil C/N, C/P and N/ P coefficient of variation were 13. 31%, 16. 51% and 17. 21% respectively. Both C/N and C/P of P. massoniana litter had the minimum value in G3 ; （3） There were a strong correlation relationship between the organic carbon nitrogen nutrients content of P. massoniana litter and the organic carbon nutrients content, C/N/ P stoichiometric ratio of soil, environmental factors, while a weaker correlation relationship between phosphorus nutrients content of P. massoniana litter and them. There were a strong correlatio