不同类型毛竹林土壤碳、氮特征及其耦合关系

Characteristics and Coupling Relationship of Soil Organic Carbon and Total Nitrogen in Different Types of Phyllostachys pubescens Stands

以江西安福毛竹纯林（Ⅰ）、竹阔混交林（Ⅱ）、竹杉混交林（Ⅲ）为研究对象,并以木荷人工林（Ⅳ）、杉木纯林（Ⅴ）以及撂荒地（Ⅵ）为对照,对其土壤碳、氮特征进行研究。结果表明：不同林分和同一林分不同层次土壤有机碳含量、碳密度均存在很大差异。土壤有机碳含量排列顺序为Ⅰ〉Ⅲ〉Ⅱ〉Ⅴ〉Ⅳ〉Ⅵ,分别为13.12,12.42,11.47,10.57,8.53,7.45 g/kg,其差异达到显著水平;剖面有机碳密度顺序依次为Ⅰ〉Ⅴ〉Ⅲ〉Ⅳ〉Ⅱ〉Ⅴ,分别为8.81,7.69,7.51,7.38,5.94,5.70 kg/m2,其差异亦达到显著水平。在所调查林分类型中,土壤有机碳含量随深度的增加而呈现逐渐递减的趋势,0-40 cm土层存贮有机碳对土壤总有机碳贡献率均大于70%,贡献率明显。不同林分类型C/N差异性显著,混交林大于纯林,平均值都在11~15之间。线性分析表明,林区内土壤有机碳含量与全氮含量呈极显著相关,遵循三次多项式拟合模型。

The characteristics of soil organic carbon and total nitrogen of three typical Phyllostachys edulis forests（P.edulis pure forest,P.edulis and broad-leaved tree mixed stands and P.edulis and Cunninghamia lanceolata mixed forest） in Anfu,Jiangxi province were studied by regarded Schima superba forest,Cunninghamia lanceolata forest and abandoned land as contrasts.The results showed that the SOC（soil organic carbon） storage and SOCD（soil organic carbon density） both are differed significantly with forest type and soil layer.SOC ranked as the following： Ⅰ（13.12 g/kg）Ⅲ（12.42 g/kg）Ⅱ（11.47 g/kg）Ⅴ（10.57 g/kg）Ⅳ（8.53 g/kg）Ⅵ（7.45 g/kg）,and there was remarkable difference among the stands.Meanwhile,there was remarkable difference in SOCD among the stands,with a rank ofⅠ（8.81 kg/m2）Ⅴ（7.69 kg/m2）Ⅲ（7.51 kg/m2）Ⅳ（7.38 kg/m2）Ⅱ（5.94 kg/m2）Ⅴ（5.70 kg/m2）.There was a negative correlation between the SOC and the depth of soil.The SOC storage in 0-40 cm accounted for more than 70% of the total.The index of C/N was different in different forest type,and was ranged 11 to 15.The mixed forest index of C/N was higher than the pure forest.There was a great significant correlation between the SOC and the total nitrogen.It can be simulated well by model of polynomial.