贵州月亮山5种森林类型土壤生态化学计量特征研究

为了解贵州省月亮山森林土壤的化学计量特征,分层采集5种森林类型的土壤,测定C、N、P含量并分析化学计量特征。结果表明,5种森林类型0~20 cm土壤中变异最大的是P,20~100 cm土壤中变异最大的是C,最小的是N。5种森林类型0~10 cm土壤的C、N含量远高于中国陆地0~10 cm土壤的平均含量,而P含量远低于其平均含量。硬阔和软阔自然林土壤C、N、P含量存在明显差异,C含量为硬阔自然林软阔自然林,N和P含量基本呈现为软阔自然林硬阔自然林。不同森林类型土壤的C∶N为硬阔自然林软阔自然林,针阔混交林杉木和马尾松纯林。硬阔和软阔自然林、针阔混交林的C∶P、N∶P均随土层深度的增加而下降,而杉木和马尾松纯林的C∶P、N∶P随土层深度增加呈先下降后升高再下降的趋势,且均在30~50 cm处出现累积峰。相关分析表明0~100 cm土壤的C、N、P含量呈极显著正相关关系,土壤C含量、N含量与C∶N、C∶P、N∶P均呈极显著的正相关关系,P含量与C∶N呈极显著正相关关系(P0.001)。因此,贵州月亮山5种森林类型和不同土层的C、N、P含量及其化学计量特征存在显著差异。

Soil Stoichiometry Characterization of Five Forest Types in Moon Mountain, Guizhou Province

In order to understand the soil stoichiometry of forests in Moon Mountain, Guizhou Province, the contents of C, N and P in soil collected from five forest types were studied, and their stoichiometry characters. The results showed that the largest variability in surface soil (0-20 cm) was P content, and that in 20-100 cm soil was C content, the smallest was N content. The C, N contents in 0-10 cm soil of 5 forest types were much higher than mean contents in 0-10 cm soil of China lands, while P content was much lower than that. There were significant differences in C, N and P contents between hard broad and soft broad nature forests. Soil C content in hard broad nature forest was bigger than that in soft broad nature forest, while soil N, P contents were diametrical. The soil C:N in hard broad nature forest was significantly greater than that in soft broad nature forest, and the soil C:N in coniferous and broad mixed forest was significantly higher than that in Chinese fir plantation and Pinus plantation. The soil N:P and C:P in hard broad nature forest, soft broad nature forest, coniferous and broad mixed forest decreased with the depth of soil layer. However, the soil C:P and N:P in Chinese fir plantation and Pinus plantation decreased at first then increased and decreased again with depth of soil layer. All of them had accumulation peaks at 30-50 cm layer. Correlation analysis showed that there were significantly positive correlations among contents C, N, and P in 0-100 cm soil, as well as contents of C, N and C:N, C:P, N:P, and P content with C:N. Therefore, the soil nutrient contents and stoichiometry characteristics of five forest types and different soil layers in Moon Mountain are significantly different.