植物生态学报 ›› 2007, Vol. 31 ›› Issue (2): 205-218.DOI: 10.17521/cjpe.2007.0025

• 论文 • 上一篇    下一篇

陆地生态系统氮沉降增加的生态效应

吕超群1,4, 田汉勤2,*(), 黄耀3   

  1. 1 中国科学院地理科学与资源研究所,北京 100101
    2 美国奥本大学林业与野生生物学院,生态系统与区域研究实验室,奥本 AL36849,美国
    3 中国科学院大气物理研究所,北京 100029
    4 中国科学院研究生院,北京 100049
  • 收稿日期:2006-11-15 接受日期:2006-12-17 出版日期:2007-11-15 发布日期:2007-03-30
  • 通讯作者: 田汉勤
  • 作者简介:* E mail: tianhan@auburn.edu
  • 基金资助:
    中国科学院海外知名学者计划资助项目;国家自然科学基金海外合作研究资助项目(40128005);美国NASA交叉学科计划资助项目(NNC04CM39C);美国能源部全球变化资助项目(DUKE UN-07-SC-NICCR-1016)

ECOLOGICAL EFFECTS OF INCREASED NITROGEN DEPOSITION IN TERRESTRIAL ECOSYSTEMS

LÁ Chao-Qun1,4, TIAN Han-Qin2,*(), HUANG Yao3   

  1. 1Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    2Ecosystem Science and Regional Analysis Laboratory, School of Forestry and Wildlife Sciences, Auburn University, Auburn AL36849, USA
    3Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
    4Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2006-11-15 Accepted:2006-12-17 Online:2007-11-15 Published:2007-03-30
  • Contact: TIAN Han-Qin

摘要:

人类活动在全球范围内极大地改变着氮素从大气向陆地生态系统输入的方式和速率,人为固定的氮素正在不断积累,并对生态系统的结构和功能产生显著影响。该文从以下几个方面综述了大气氮沉降增加对陆地生态系统的影响:1)氮输入增加可能影响植物生产力和生态系统碳蓄积能力,生态系统响应的方向和程度取决于系统的初始氮状况(氮限制或氮饱和)以及当地的植被和土壤特征;2)持续氮输入有可能改变土壤氮循环过程,降低土壤固持氮的能力,甚至导致土壤酸化、盐基离子损耗,进而影响到土壤有机碳的分解;3)高的氮沉降速率和持续氮输入都可能加速含氮痕量气体的释放,但其影响程度受生态系统初始状态的影响(例如磷限制和氮限制);4)氮沉降增加会影响生态系统的物种丰富度、植物群落结构和动态,促进森林扩张,改变菌根真菌的物种多样性;5)持续氮输入带来的植物群落结构和植物生理特征的变化可能影响昆虫取食特性,进而通过食物链改变生态系统的营养结构;6)氮沉降增加对生态系统的影响并不是孤立存在的,它与CO2浓度升高和O3浓度变化有协同作用,但难以从其协同效应中区分出各自的影响。最后,该文总结了我国的氮沉降研究现状,并对今后的研究前景提出了展望。

关键词: 氮沉降, 陆地生态系统, 氮限制, 氮饱和, 碳固定

Abstract:

Human activities have greatly changed the pathway and rate of nitrogen transferred from atmosphere to terrestrial ecosystems worldwide. Anthropogenic nitrogen enrichment, as a result of chronic nitrogen deposition, has caused a wide range of impacts on ecosystem structures and functions. In this paper, we summarize the main effects of anthropogenic nitrogen addition on terrestrial ecosystems as follows:

1) Increased nitrogen input may have influences on plant production and ecosystem carbon storage, and the direction and magnitude of responses are determined by initial nitrogen status of ecosystems (N-limited or N-saturated) and local properties of vegetation and soil;

2) Chronic nitrogen addition can also alter soil nitrogen cycling, decrease the capability of soil to retain N, even lead to soil acidification, depletion of base cation, and affect decomposition of SOC;

3) Both high rate of nitrogen deposition and chronic low nitrogen addition may accelerate losses of N-contained gas, but the magnitude of influences depends on initial status of ecosystem (N-limited or P-limited);

4) N enrichment will affect species richness in terrestrial ecosystems, plant communities' structures and dynamics. It may also contribute to forest expansion into grasslands, alter species composition and diversity of mycorrhizal fungi;

5) Continuous N input and the resulting changes in plant composition and physiological feature may have effects on consumption rate and population dynamics of herbivorous insects, and eventually change ecosystem trophic structure through food chain;

6) Since the influences of N addition, increased concentration of CO2 and O3 on ecosystem properties and processes are interdependent, it is difficult to distinguish each effect.

We also summarized the current status of researches on N deposition in China, and proposed the potential research activities and recommendations.

Key words: nitrogen deposition, terrestrial ecosystems, nitrogen limited, nitrogen saturated, carbon storage