植物生态学报 ›› 2015, Vol. 39 ›› Issue (5): 433-441.DOI: 10.17521/cjpe.2015.0042

• •    下一篇

落叶松原始林树木生长对氮添加的响应

刘修元1,2, 杜恩在3, 徐龙超1,2, 沈海花1, 方精云1, 胡会峰1*()   

  1. 1中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
    2中国科学院大学, 北京 100049
    3北京大学城市与环境学院, 北京大学地表过程分析模拟教育部重点实验室, 北京 100871
  • 收稿日期:2015-03-16 接受日期:2015-04-22 出版日期:2015-05-01 发布日期:2015-05-26
  • 作者简介:

    *作者简介:E-mail:chengliu6542@gmail.com

  • 基金资助:
    国家重大科学研究计划(2010CB950- 600)、国家自然科学基金(31330012)和中国科学院战略性先导科技专项(XDA05050300和XDA0505- 0700)

Response of tree growth to nitrogen addition in a Larix gmelinii primitive forest

LIU Xiu-Yuan1,2, DU En-Zai3, XU Long-Chao1,2, SHEN Hai-Hua1, FANG Jing-Yun1, HU Hui-Feng1,*()   

  1. 1State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    and 3College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
  • Received:2015-03-16 Accepted:2015-04-22 Online:2015-05-01 Published:2015-05-26
  • Contact: Hui-Feng HU
  • About author:

    # Co-first authors

摘要:

氮沉降对树木生长的影响是全球变化研究的一个核心问题。该文通过设置4种氮添加水平(对照(0)、低氮(20 kg N·hm-2·a-1)、中氮(50 kg N·hm-2·a-1)和高氮(100 kg N·hm-2·a-1)), 研究了模拟氮沉降对落叶松(Larix gmelinii)原始林树木胸径生长的影响。结果表明: 中氮和高氮添加对落叶松胸径相对生长率有显著影响, 而且这种影响随施氮年限的增加而增强。不同高度的树木对氮添加的响应有很大差异, 较低树木(树高<16.5 m)的生长对氮添加无显著响应, 而较高(树高>16.5 m)的树木在中氮和高氮处理下胸径生长有显著加速(胸径相对生长率增幅>79.5%), 但随着树木高度的进一步增加, 这种加速作用明显下降。研究结果显示氮添加会促进落叶松胸径生长, 这种促进作用主要发生在较高的落叶松个体中。

关键词: 北方森林, 胸径, 落叶松, 氮沉降, 树木生长

Abstract: Aims

Global nitrogen (N) deposition has been consistently enhanced and significantly influenced the carbon (C) cycle of forest ecosystem. However, studies on the quantitive response of C sequestration to N deposition in China’s boreal forest ecosystem still remains insufficient. Tree growth is one of important components of C sequestration in forest ecosystem. In order to accurately evaluate the influence of N deposition on C sequestration in China’s boreal forest ecosystem, This study was designed to investigate how N deposition influenced the tree diameter at breast height (DBH) growth of a Larix gmelinii primitive forest.

Methods

We carried out a N enrichment experiment in an L. gmelinii primitive forest in Greater Khingan Mountains with four N addition levels (control (0), low N (20 kg N·hm-2·a-1), medium N (50 kg N·hm-2·a-1) and high N (100 kg N·hm-2·a-1)). DBH was measured from 2012-2014 within all treatments.

Important findings

Medium N and high N additions significantly influenced the relative DBH growth of L. gmelinii, and the influence became more pronounced through time. N deposition significantly affected the DBH growth among different tree height classes: low height class (tree height <16.5 m) did not show significant response to N deposition, while high height class (tree height >16.5 m) showed significantly accelerated growth under medium and high N additions (the relevant DBH growth rate >79.5%), and this acceleration effect decreased as the tree height increased. This study indicated that N addition did enhance the DBH growth of L. gmelinii, but this enhancement mainly affected taller L. gmelinii trees.

Key words: boreal forest, diameter at breast height, Larix gmelinii, nitrogen deposition, tree growth