模拟氮沉降对荆条灌木“肥岛”土壤养分的影响  

Effects of simulated nitrogen deposition on soil nutrients of Vitex negundo L. var. “fertile islands”

作　　者：赵河[1] 张志铭[1] 赵勇[1] 祝忆伟 杨文卿[1] 杨喜田[1] 

机构地区：[1]河南农业大学林学院,郑州450000

出　　处：《生态学报》2017年第18期6014-6020,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(31270750)

摘　　要：氮沉降的增加,可能会对土壤养分造成更为显著的影响,目前关于大气氮沉降对植物"肥岛"效应中土壤养分的影响鲜有报道。于河南省太行山南麓地区,以NH_4NO_3为供施氮源,按土层深度采集土样,以模拟氮沉降方法(3个水平,无氮CK、低氮2g N m^(-2)a^(-1)处理、中氮12g N m^(-2)a^(-1)处理和高氮24g N m^(-2)a^(-1)处理),分析了氮沉降对太行山荆条灌木(Vitex negundo L.var.)"肥岛"土壤中有机质、全氮和速效磷含量的影响。结果表明:灌木"肥岛"中全氮和速效磷含量,总体表现出随氮沉降量增长而增加的趋势;氮沉降显著增加了土壤表层有机质、氮、磷的含量;高氮沉降与CK相比引起的各土层间养分差异更显著;随着氮沉降水平的增加,冠幅内外和土层间养分差异增大,土壤养分的增长率随之加大;氮沉降在一定程度内加剧了"肥岛"的富集效应,且氮沉降量越大,这种富集效应越显著。这些研究结果可为研究灌木"肥岛"对外源氮的响应机制及保育作用提供参考。Nitrogen deposition may have a significant effect on soil nutrients; however, research regarding the influence of atmospheric nitrogen deposition on the soil nutrients of the plant ＂fertile islands＂ is limited. In this field study, we analyzed the Vitex negundo L. var. ＂fertile islands＂ distributed in the southern foot of the TaiHang Mountain Range, Henan Province. Simultaneously, ammonium nitrate （NH4NO3） was selected as the nitrogen source, and soil samples were collected from different soil depths. The research simulated nitrogen deposition （three levels, including a low-nitrogen treatment, 2 gN m^-2a^-1 ; secondary-nitrogen treatment, 12 gN m ; and high-nitrogen treatment, 24 m^-2a^-1） to analyze the impacts on organic matter, total nitrogen, and available phosphorus contents embedded in the ＂ fertile islands ＂. The results demonstrated that the amount of total nitrogen and available phosphorus contents in ＂fertile islands＂ increased with the increase in nitrogen deposition. Organic matter, nitrogen, and phosphorus contents on the soil surface increased obviously with increased nitrogen deposition. Compared with that of the control, the differences in the nutrient contents of soil layers caused by high nitrogen deposition were more obvious. Nutrient differences between the crown and soil layers increased, and the soil nutrients increased with the increase in nitrogen deposition. Nitrogen deposition intensified the ＂fertile island＂ aggregation effect to a certain extent, which became more prominent as a result of the increased nitrogen deposition. The results provide a baseline to analyze the response mechanisms and conservation function of nitrogen fertilization in ＂fertile islands＂.

关 键 词：荆条 氮沉降 肥岛 影响 土壤养分 

分 类 号：S714.8[农业科学—林学]