贵州高原山地马尾松人工林土壤碳、氮、磷生态化学计量特性

采用空间代替时间的方法,选取贵州中部高原山地8,18,26,36年生4个林龄的马尾松人工林为研究对象,通过测定林下土壤有机碳(SOC)、全氮(TN)和全磷(TP)含量,分析不同发育阶段林分土壤养分变化规律及化学计量比特征。结果表明:马尾松人工林土壤SOC、TN、TP平均值分别为12.24,1.94,0.35g/kg,C∶N、C∶P和N∶P平均值分别为6.58,38.70和13.65,C∶N∶P的平均值为39∶6∶1,其养分含量总体不高。随土层深度增加,4个林龄土壤SOC、TN含量降低,但C∶N增加,TP、C∶P和N∶P无明显变化规律。随林龄增加,土壤SOC、TN、N∶P先降低后升高,而TP则持续降低;C∶N除在36年生林分中显著降低外,其余各林分均无显著差异;C∶P无明显变化规律。相关分析表明,SOC、TN是调控马尾松人工林土壤生态化学计量比的主要因素。研究结果可为进一步明确贵州高原山地马尾松人工林土壤养分循环特征提供重要参考。

Eco-stoichiometry Characteristics of Soil Carbon, Nitrogen and Phosphorus of Pinus massoniana Plantation in Plateau Mountainous Areas, Guizhou Province

Using the method of space instead of time, Pinus massoniana plantations of 8, 18, 26 and 36 years old were selected as the research objects on plateau mountains, central part of Guizhou Province, and the content of soil organ carbon (SOC), total nitrogen (TN) and total phosphorus (TP) were determined in the four plantations to analyze the variation law and stoichiometric characteristics of nutrient contents at different development stages. The results showed that the average value of SOC, TN and TP in four P. massoniana plantations at the different ages were 12.24 g/kg, 1.94 g/kg and 0.35 g/kg, respectively, and the average value of C:N, C:P and N:P were 6.58, 38.70 and 13.65, respectively. The average ecological stoichiometric ratio of C:N:P was 39:6:1. Generally, the soil nutrient was insufficient in the four P. massoniana plantations. Soil SOC and TN of the four plantations decreased with the increasing of soil layer depth, but C:N increased, while the change rule of TP, C:P and N:P was not obvious. With the increasing of plantations age, content of SOC and TN and N:P decreased first and then increased, and TP decreased persistently. Meanwhile, C:N significantly decreased in the 36-year-old plantation, but there was no significant difference in other plantations. There was no obvious change rule for C:P. The correlation analysis showed that soil SOC and TN were the main factors regulating the soil ecological stoichiometric ratio of P. massoniana plantations. These results could provide important reference for illuminating soil nutrient cycling of P. massoniana plantations in plateau mountains.