不同松栎混交林土壤溶解性有机碳氮的差异分析

为揭示北亚热带地区不同林分类型的土壤活性碳氮分布特征,在驻马店市南部山区选取4处具有代表性的松栎人工混交林为研究对象,对其0—20cm土壤的溶解性有机碳(DOC),溶解性有机氮(DON)等组分进行研究。结果表明:4种林型土壤DOC的含量为麻栎纯林湿地松麻栎混交林火炬松麻栎混交林马尾松麻栎混交林,DON的含量为马尾松麻栎混交林麻栎纯林湿地松麻栎混交林火炬松麻栎混交林,不同林分类型间整体上差异性显著(p0.05);在垂直剖面上,4种林型土壤DOC和DON均随土层深度的增加而显著性下降(p0.05)。4种林分类型DOC/SOC,DON/TN,DOC/DON分别以麻栎纯林、马尾松麻栎混交林、麻栎纯林最高,在垂直空间分布上,差异性整体上不显著。土壤DOC和DON与土壤含水率、土壤硬度、速效钾、全氮均呈显著(p0.05)或极显著(p0.01)相关性。

Differences of Dissolved Organic Carbon and Nitrogen in Soils of Four Mixed Pine-Oak Plantations

In order to reveal the distribution characteristics of soil active carbon and nitrogen in different forest types in the north subtropics,four typical representative mixed plantations of Pine and Quercus acutissima in the southern mountainous area of Zhumadian were selected,and the components of 0-20 cm soil layer such as dissolved organic carbon (DOC),dissolved organic nitrogen (DON),and so on were studied.The experimental results showed that the detail contents of soil DOC in four forest sites decreased in the order:pure Quercus acutissima ＞ mixed Quercus acutissima and mongolica＞mixed Pinus taeda and Quercus acutissima ＞mixed Pinus massoniana and Quercus acutissima,the contents of soil DOC decreased in the order:mixed Pinus massoniana and Quercus acutissima ＞pure Quercus acutissima ＞mixed Quercus acutissima and mongolica ＞mixed Pinus taeda and Quercus acutissima,and the statistics differences between different forest types are significantly(p＜0.05).In the vertical profile,the contents of soil DOC and DON for the four forest types decreased significantly with increase of soil depth (p＜ 0.05).The max proportion of DOC/SOC,DON/TN,DOC/DON was found in pure Quercus acutissima,mixed Pinus massoniana and Quercus acutissima,pure Quercus acutissima,respectively.There were no significant differences in the vertical spatial distribution,soil DOC and DON are significantly (p＜0.05) or extremely significantly (p＜0.01) related with soil water content,soil hardness,available potassium and total nitrogen.