摘要
为了解亚热带典型森林土壤氮素和有机氮素特征,采集大围山森林公园典型森林土壤剖面(0~100 cm),按每10 cm一层采集土壤样品,研究土壤氮素和有机氮变化规律及其与土壤理化性质的关系.结果表明:1土壤全氮、酸解性有机氮、可溶性有机氮含量均随剖面深度增加而呈下降趋势,受海拔高度影响,高海拔山地花岗岩黄棕壤土壤全氮和有机氮组分含量较高;2土壤有机氮占全氮比平均97.39%±1.17%,酸解性有机氮占全氮比平均64.38%±10.68%,酸解性有机氮各组分均随剖面深度增加而降低;3土壤可溶性有机氮含量范围为9.92~23.45 mg·kg-1,游离氨基酸氮(1.62~12.02 mg·kg-1)占可溶性有机氮比为27.36%±9.95%;4酸解性有机氮、可溶性有机氮与土壤全氮、可溶性总氮、无机氮均达到显著的正相关关系(P<0.05),与土壤容重、有机碳和全磷具有极显著的相关关系(P<0.01).亚热带典型森林土壤中有机氮是土壤全氮的主体,受海拔高度和土壤理化性质的影响,各组分随土壤剖面深度的增加呈下降趋势,有机氮组分与各氮素形态间的转化关系密切,土壤有机氮特征将深刻影响森林生态系统氮的循环过程.
To clarify altitudinal gradient of subtropical forest soil total nitrogen and organic nitrogen,soil samples were collected per 10 cm on soil profile( 0-100 cm) in Dawei Mountain,researched the variation of soil organic nitrogen and correlation with soil physical and chemical properties. The results showed that: 1 Total nitrogen,acid hydrolysable organic nitrogen and soluble organic nitrogen decreased with the increase of depth,content of each component in mountain granite yellow-brown soils was much higher affected by altitude; 2 The average percentage of soil organic nitrogen to total nitrogen was 97. 39% ± 1. 17%,and soil acid hydrolysable organic nitrogen was 64. 38% ± 10. 68%,each component decreased with the increase of soil depth; 3 Soil soluble organic nitrogen content was 9. 92-23. 45 mg·kg- 1,free amino acids( 1. 62-12. 02 mg·kg- 1) accounted for about 27. 36% ± 9. 95% of soluble organic nitrogen; 4 Soil acid hydrolysable organic nitrogen and soluble organic nitrogen were significantly positively correlated with total nitrogen,total soluble nitrogen and inorganic nitrogen( P < 0. 05),were highly significantly correlated with soil bulk density,organic carbon,and total phosphorus( P < 0. 01). Organic nitrogen was the main body of soil nitrogen in typical subtropical forest,each component showed a downward trend increase with soil depth affected by altitude and soil physical and chemical properties. There was a close conversion relationship between soil organic nitrogen and other nitrogen forms,the characteristics of soil organic nitrogen will have profound impact on nitrogen cycling of forest ecological system.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2015年第10期3809-3815,共7页
Environmental Science
基金
国家自然科学基金项目(31470629)
湖南省环境科学重点学科建设项目
中南林业科技大学研究生创新基金项目(CX2014B22)
关键词
森林土壤
有机氮
酸解性有机氮
可溶性有机氮
垂直分布
forest soil
organic nitrogen
acid hydrolysable nitrogen
soluble organic nitrogen
vertical distribution