野生马缨杜鹃林土壤化学计量特征

Stoichiometric characteristics of different soil layers in wild Rhododendron delavayi forest

以贵州百里杜鹃国家森林公园内野生马缨杜鹃(Rhododendron delavayi)林下的土壤为研究对象,通过测定不同土层中土壤有机碳(SOC)、全氮(TN)、全磷(TP)和全钾(TK)等养分含量,计算其化学计量比,分析不同土层中土壤养分含量与化学计量特征的变化规律。结果表明:随着土层深度的增加,SOC、TN和TP含量均表现出递减趋势,pH值表现出升高趋势,TK含量则表现为先升高后降低;不同土层深度土壤的化学计量比为C∶P>C∶N>C∶K>N∶P>N∶K>P∶K,0~10 cm的土壤层C∶P、N∶P、C∶K、N∶K与其他土壤层均差异显著,10~20 cm土壤层的C∶P、C∶K与其他土壤层均差异显著。TK、pH与其他指标均为负相关关系,其中pH与C∶P、N∶P、C∶K、N∶K为极显著负相关关系。聚类分析发现TP和TN是区分各土层差异的主要组分。

Taking the soil in the wild Rhododendron delavayi forest in Baili Dujuan National Forest Park as the research object,we measured the soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP)and total potassium(TK)in different soil layers,calculated their stoichiometric ratio,and analyzed the changing laws of soil nutrient content and stoichiometric characteristics in different soil layers.The results showed that:with the increase of soil depth,the contents of SOC,TN and TP all showed a decreasing trend,the pH value showed an increasing trend,and the TK content firstly increased and then decreased;the stoichiometric ratio at different soil depths was C∶P>C∶N>C∶K>N∶P>N∶K>P∶K,the C∶P,N∶P,C∶K,N∶K of the 0~10 cm soil layer were significantly different from those of other soil layers,and the C∶P and C∶K of the 10~20 cm soil layer were significantly different from those of other soil layers.TK,pH and other indicators were all negatively correlated,among which pH and C∶P,N∶P,C∶K,N∶K had extremely significant negative correlations.Cluster analysis found that TP and TN were the main components distinguishing each soil layer.