应用^(15)N示踪研究欧美杨对PM_(2.5)无机成分NH_4^+和NO_3^-的吸收与分配  

Absorption and Distribution of PM_(2.5)NH_4^+ and NO_3^- in Populus euramericana Neva

作　　者：刘庆倩 石婕[1] 安海龙[1] 曹学慧[1] 刘超[1] 尹伟伦[1] 夏新莉[1] 郭惠红[1] 

机构地区：[1]北京林业大学生物科学与技术学院,北京100083

出　　处：《生态学报》2015年第19期6541-6548,共8页Acta Ecologica Sinica

基　　金：国家林业公益性行业科研专项(201304301)

摘　　要：通过气溶胶发生系统模拟PM2.5颗粒的发生,运用15N示踪技术研究了欧美杨107(Populus euramericana Neva.)对PM2.5中水溶性无机成分NH+4和NO-3的吸收与分配规律。结果表明,欧美杨能够有效吸收PM2.5中的NH+4和NO-3。轻度和重度污染下,欧美杨叶片对NH+4和NO-3的吸收速率均于处理后第1天达到峰值,之后,轻度污染下对NH+4和NO-3的吸收速率迅速降低以后趋于稳定,而重度污染下对NH+4和NO-3的吸收速率缓慢下降至趋于稳定。轻度污染下的欧美杨叶片的15N含量在处理后第1天达到峰值,15N(NH+4)的含量为0.11 mg/g,干重,15N(NO-3)的为0.14 mg/g,干重,之后15N含量迅速下降至趋于稳定。重度污染下的叶片15N含量在处理第1天迅速增长,之后缓慢增长至处理后第7天达到最高值,15N(NH+4)的含量为0.11 mg/g,干重,15N(NO-3)的为0.13 mg/g,干重。处理7 d后,欧美杨不同组织器官吸收或通过再分配获取的15N含量存在差异。轻度污染下,细根对NH+4和NO-3的吸收量最高,树皮、叶柄、叶片次之,髓最低。而重度污染下,叶片对NH+4和NO-3的吸收量最高,细根、叶柄、树皮次之,髓最低。欧美杨各组织器官中NH+4和NO-3的含量均表现为重度污染大于轻度污染,且两种污染程度下的欧美杨各组织器官对NO-3的吸收均大于对NH+4的吸收。重度污染下,欧美杨茎木质部对15N(NH+4和NO-3)的吸收征调能力(Ndff,Nitrogen derived from fertilizer)最大,其次为髓,叶片最小;欧美杨各组织器官中的15N分配率表现为叶片>细根>叶柄>树皮>粗根>茎木质部>髓。研究结果对进一步揭示植物吸收PM2.5的机制及有效利用植物降低颗粒物污染、净化环境提供了重要的科学理论依据。PM2.5 particles,with a diameter of 2. 5 μm or less,are the primary pollutant in the air. In this study,PM2.5particles were generated with an aerosol generator,and absorption of NH4^＋and NO3^-in PM2.5 and their distribution in Populus euramericana seedlings were studied using ^15N tracing techniques. The results showed that water-soluble inorganic components（ NH4^＋and NO3^-） in PM2.5 can be absorbed effectively by P. euramericana. Absorption rates of NH4^＋and NO3^-by P. euramericana leaves peaked one day after treatment,in both low and severe pollution treatments. Subsequently,the absorption rates of NH4^＋and NO3^-in the low pollution treatment decreased rapidly and then leveled off,while the absorptionrates in the severe pollution treatment decreased slowly to a stable level. At the low pollution level,^15N content of P.euramericana leaves peaked one day after treatment,when ^15N（ NH4^＋） content was 0.11 mg/g and that of ^15N（ NO3^-） was0.14 mg / g,DW. Following this peak,^15N content decreased rapidly and remained relatively steady. At the severe pollution level,^15N content of P. euramericana leaves increased quickly in the first day of treatment before increasing slowly to reach its maximum 7 days after treatment,when15N（ NH4^＋） content was 0.11 mg/g and that of15N（ NO3^-） was 0.13 mg/g,DW.^15N content differed among tissues and organs of P. euramericana 7 days after treatment. In the low pollution treatment,NH4^＋and NO3^-content was highest in fine roots,followed by that in bark,petiole and leaf,with the lowest content in pith.However,in the severe pollution treatment,NH4^＋and NO3^-content in various tissues and organs was ranked as leaf fine root petiole bark pith. The NH4^＋and NO3^-content of all tissues and organs of P. euramericana in the severe pollution treatment were higher than those in the low pollution treatment. Moreover,more NO3^-was absorbed by P. euramericana than NH4^＋in both low and severe pollution treatments,which correlated well with NH4^＋and NO3^-

关 键 词：欧美杨 ^15N示踪 PM2.5 NH4^+ NO3^- 吸收 分配 

分 类 号：S792.11[农业科学—林木遗传育种] X51[农业科学—林学] X173[环境科学与工程—环境工程]