模拟氮沉降对鼎湖山典型森林地表烷烃、烯烃通量的影响  

Effects of simulated nitrogen deposition on alkane and alkene fluxes from forest floor at Dinghushan

作　　者：张丽丽[1] 印亮 郑丽丽[1] 黄幸然[1] 易志刚[1] 

机构地区：[1]福建农林大学资源与环境学院/土壤环境健康与调控福建省重点实验室,福州350002

出　　处：《生态学杂志》2017年第12期3462-3469,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41473083和41173090)资助

摘　　要：烷烃和烯烃类挥发性有机化合物(volatile organic compounds,VOCs)参与大气光化学反应并且影响全球碳循环,在大气化学中扮演重要角色。氮沉降持续增加会改变森林土壤生态过程,从而影响森林地表VOCs通量。本研究使用静态箱采样,大气预浓缩GCMS联用仪分析了鼎湖山两种典型森林——马尾松林(pine forest,PF)和季风常绿阔叶林(monsoon evergreen broadleaf forest,BF)地表烷烃和烯烃通量对模拟氮沉降的响应。结果表明,自然氮沉降下,PF地表是烷烃的"汇",烯烃的"源";其中正十一烷吸收量最大(-117.616±73.048 pmol·m^(-2)·s^(-1)),α-蒎烯释放量最大(220.301±159.543 pmol·m^(-2)·s^(-1))。BF地表是烷烃和烯烃的"源"。施氮使森林地表VOCs源汇功能发生转变,PF地表变为烷烃的"源",氮处理促进烷烃的释放,且随着氮水平的升高,促进效果显著增强。施氮后PF地表变为烯烃的"汇",氮处理抑制烯烃的释放,且低氮处理的抑制效果更为显著。BF地表变为二者的"汇"。两林型间烷烃通量差异显著,烯烃通量在同林型中因化合物不同而差异显著。Alkane and alkene, two major types of volatile organic compounds （VOCs）, play criti- cal roles in atmospheric chemistry and have great effect on global carbon cycle. Continuing ele- vated nitrogen deposition will change forest soil ecological processes, which will then influence VOCs fluxes from the forest floor. Static chambers and preconcentrator-GC-MS technique were used to investigate the responses of alkane and alkene fluxes to the simulated nitrogen deposition from the floor of two typical forest ecosystems, namely masson pine forest （PF） and monsoon ev- ergreen broadleaf forest （BF） in Dinghushan. The results showed that for the natural nitrogen deposition, PF floor acted as a sink for alkane and a source for alkene, with the maximum uptake rate of- 117.616＋73.048 pmol ~ m-2 ~ s-~ for undcane and the maximum emission rate of 220.301~159.543 pmol ~ m-2 ~ s-1 for c^-pinene. BF floor acted as a source of both alkane and alkene. Simulated nitrogen deposition promoted the emission of alkane, changed the function of PF forest floor from alkane ＂sink＂ to ＂source＂, and the effect became more significant with the elevating nitrogen level. On the contrary, the emission of alkene was restrained in PF, or even PF floor changed from alkene ＂source＂ to ＂sink＂, and the low level of nitrogen input had a sig- nificant influence. Simulated nitrogen deposition changed the BF floor from ＂source＂ to ＂sink＂ for both alkane and alkene. Additionally, alkane flux differed significantly between the two for-ests, and the alkene flux differed among compounds in the same forest.

关 键 词：氮沉降 挥发性有机物 通量 鼎湖山 森林地表 

分 类 号：X51[环境科学与工程—环境工程]