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应用生态学报 ›› 2017, Vol. 28 ›› Issue (4): 1094-1102.doi: 10.13287/j.1001-9332.201704.020

• 目次 • 上一篇    下一篇

亚热带湿地松叶片多元素化学计量与养分回收对氮添加的短期响应

陈微微1,2, 寇亮1,2, 蒋蕾1,2, 高文龙1,2, 杨浩1, 王辉民1, 李胜功1,2*   

  1. 1中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室, 北京 100101
    2中国科学院大学, 北京 100049
  • 收稿日期:2016-08-07 出版日期:2017-04-18 发布日期:2017-04-18
  • 通讯作者: * E-mail: lisg@igsnrr.ac.cn
  • 作者简介:陈微微,女,1992年生,硕士研究生.主要从事氮沉降背景下植物的响应研究.E-mail:chenweiwei736@126.com
  • 基金资助:
    本文由国家重点研发计划项目(2016YFD0600202)和国家自然科学基金项目(31130009,31570443)资助

Short-term responses of foliar multi-element stoichiometry and nutrient resorption of slash pine to N addition in subtropical China

CHEN Wei-wei1,2, KOU Liang 1,2, JIANG Lei1,2, GAO Wen-long1,2, YANG Hao1, WANG Hui-min1, LI Sheng-gong1,2*   

  1. 1Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-08-07 Online:2017-04-18 Published:2017-04-18
  • Contact: * E-mail: lisg@igsnrr.ac.cn
  • Supported by:
    This work was supported by the National Key Research & Development Plan (2016YFD0600202) and the National Natural Science Foundation of China (31130009,31570443)

摘要: 在我国南方亚热带湿地松人工林设置了3个水平的野外氮添加控制试验(0、40、120 kg N·hm-2·a-1),于2014和2015年生长季高峰期(7月底)和末期(10月底)采集湿地松成熟绿叶和落叶,分析外源氮添加对湿地松叶片碳(C)、氮(N)、磷(P)、钾(K)、钙(Ca)、镁(Mg)、铝(Al)、铁(Fe)、锰(Mn)9种元素浓度及其养分回收的影响.结果表明: N添加显著增加了湿地松绿叶中N、Al、Mn浓度,降低了P和2014年的Ca浓度,而对C、K、Mg、Fe 浓度无显著影响.N添加显著提高了绿叶N/P,且该比值及绿叶养分浓度(N、P、Mn)对N添加的响应依赖于N的剂量(高N条件下响应更强).N添加显著降低了2015年N的回收效率,提高了2014年K的回收效率.相比于养分回收效率,回收能力对增加的可利用氮响应更强.N添加显著降低了N的回收能力,提高了P、K的回收能力,降低了枯叶中的Fe浓度,而对枯叶中Ca、Mg、Al、Mn浓度无显著影响.这表明,N添加对叶片化学计量的影响因不同元素而异,植物会通过调整自身的养分内循环(养分回收)来应对环境变化.N添加提高了绿叶N/P和K/P,说明氮添加条件下植物生长可能由N、P共同限制转变为P限制.氮添加增加了绿叶中Al、Mn浓度,表明N添加下湿地松面临潜在的金属离子毒性风险升高.

Abstract: We conducted a field experiment with three levels of N addition (0, 40 and 120 kg N·hm-2·a-1) in a Pinus elliottii plantation in subtropical China and collected green and senesced needles of P. elliottii at the peak (July) and the end (October) of each growing season in 2014 and 2015 for clarifying effects of nitrogen additions on concentrations of nine elements (C, N, P, K, Ca, Mg, Al, Fe and Mn) in the green and senesced needles and their corresponding resorption efficiency and resorption proficiency. Our results showed that N addition had positive effects on concentrations of N, Al and Mn, negative effects on the P concentration and the Ca concentration in 2014, and neutral effects on concentrations of C, K, Mg and Fe in green needles. N addition signifi-cantly increased foliar N/P. These stoichiometric responses were N level-dependent (stronger at high N rate). N addition significantly decreased N resorption efficiency in 2015 and increased that of K in 2014. Compared with the resorption efficiency, resorption proficiency responded more strongly to increased available N. N addition significantly decreased resorption proficiency of N, and increased that of P, K, and the concentration of Fe in senesced needles, however, there were no significant effects on the concentrations of Ca, Mg, Al and Mn in senesced needles. We concluded that responses of foliar stoichiometry to N addition were element-specific, and plants might cope with changing environments via adjusting internal nutrient cycle (resorption). The elevated foliar N/P and K/P suggested a shift from N and P co-limitation to P limitation with N additions, and increased concentrations of Al and Mn might imply potential toxicity of metal ions to P. elliottii.