植物生态学报 ›› 2021, Vol. 45 ›› Issue (7): 682-713.DOI: 10.17521/cjpe.2020.0331

所属专题: 生态化学计量

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植物生态化学计量特征及其主要假说

田地1(), 严正兵2, 方精云3,**()   

  1. 1森林培育与保护教育部重点实验室, 北京林业大学林学院, 北京 100083
    2香港大学生物科学学院, 香港
    3北京大学生态研究中心, 地表过程分析与模拟教育部重点实验室, 城市与环境学院, 北京 100871
  • 收稿日期:2020-10-10 接受日期:2021-01-07 出版日期:2021-07-20 发布日期:2021-10-22
  • 通讯作者: 方精云
  • 作者简介:** jyfang@urban.pku.edu.cn
    * 田地, 北京林业大学青年研究员, 硕士研究生导师, 主要从事植物生态化学计量学和全球变化生态学等方面的研究, 研究兴趣在于探索陆生植物不同器官间的化学计量关系、植物功能属性的生物地理格局及成因、陆地生态系统结构与功能对环境变化的响应及预测。在National Science Review、Ecology、Environmental Pollution等刊物发表论文35篇, 获专利2项, 出版译著1部。主持国家级和省部级科研项目共6项。 E-mail: tiandi@bjfu.edu.cn
    严正兵, 香港大学博士后, 主要从事植物生态化学计量学、植物功能性状、植物光谱学等方面的研究。在Ecology Letters、New Phytologist、Functional Ecology等刊物发表论文40余篇, 被引用950余次。主持国家级和香港地区科研项目共4项。现任《草业科学》期刊青年编委, 并任Diversity专刊编辑。
    方精云, 北京大学教授、云南大学校长、中国科学院院士。主要从事全球变化生态学、植被生态与生物多样性、生态遥感、生态草牧业等方面的研究。发表论文350余篇, 被引用4万余次。曾获国家自然科学奖二等奖、长江学者成就奖、教育部及北京市自然科学一等奖以及惠泰克杰出生态学家奖等奖项。
  • 基金资助:
    国家自然科学基金(31800397);国家自然科学基金(31901086);国家自然科学基金(31988102)

Review on characteristics and main hypotheses of plant ecological stoichiometry

TIAN Di1(), YAN Zheng-Bing2, FANG Jing-Yun3,**()   

  1. 1The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
    2School of Biological Sciences, The University of Hong Kong, Hong Kong, China
    3Institute of Ecology, Key Laboratory for Earth Surface Processes of the Ministry of Education, and College of Urban and Environmental Science, Peking University, Beijing 100871, China
  • Received:2020-10-10 Accepted:2021-01-07 Online:2021-07-20 Published:2021-10-22
  • Contact: FANG Jing-Yun
  • Supported by:
    National Natural Science Foundation of China(31800397);National Natural Science Foundation of China(31901086);National Natural Science Foundation of China(31988102)

摘要:

植物生态化学计量学是生态化学计量学的重要分支, 主要研究植物器官元素含量的计量特征, 以及它们与环境因子、生态系统功能之间的关系。19世纪, 化学家们通过室内实验, 分析了植物器官的元素含量, 开始了对植物化学元素之间关系的探索。如今, 生态学家通过野外采样和控制实验, 探索植物化学元素计量特征的变化规律、对全球变化的响应以及与植物功能属性之间的关系, 促进了植物生态化学计量学的快速发展。该文在概述植物生态化学计量学发展简史的基础上, 综述了19世纪以来该领域的研究进展。首先, 该文将植物生态化学计量学的发展历程概括为思想萌芽期、假说奠基期和理论构建期3个时期, 对各个时期的主要研究进行了简要回顾和梳理。第二, 概述了植物主要器官的化学计量特征, 尤其是陆生植物叶片氮(N)和磷(P)的计量特征。总体上, 全球陆生植物叶片N、P含量和N:P (质量比)的几何平均值分别为18.74 mg∙g-1、1.21 mg∙g-1和15.55 (与16:1的Redfield比一致); 在物种或群落水平上, 叶片N和P含量一般呈现随温度升高、降水增加而降低的趋势。不同生活型植物叶片N和P计量特征差异明显, 尤其是草本植物叶片N和P含量高于木本植物, 落叶阔叶木本植物叶片N和P含量高于常绿木本植物。与叶片相比, 细根和其他器官化学计量特征研究较少。第三, 总结了养分添加实验对植物化学元素计量特征的影响。总体上, N添加一般会提高土壤N的可利用性, 使植物器官中N含量和N:P升高, 在一定程度上提高植物生产力; P添加可能会缓解过量N输入导致的N-P失衡问题, 提高植物器官P含量。但是, 长期过量施肥会打破植物器官原有的元素间计量关系, 导致元素计量关系失衡和生产力下降。第四, 梳理总结了植物生态化学计量学的重要理论、观点和假说, 主要包括刻画化学计量特征与植物生长功能关系的功能关联假说、刻画化学计量特征与环境因子关系的环境关联假说或理论以及刻画化学计量特征与植物进化历史关系的进化关联假说。最后, 指出了植物生态化学计量学研究中存在的问题, 展望了10个未来需要重点关注的研究方向。

关键词: 化学计量, 氮, 磷, 生态, 植物, 假说, 简史

Abstract:

Plant ecological stoichiometry, as a branch of ecological stoichiometry, focuses on the study of elemental content, ratios and relationships within and across plant organs, and the underlying biotic and abiotic drivers. In the 19th century, chemists detected the elemental contents in plant organs via laboratory experiments, sprouting the exploration of plant stoichiometric characteristics. Nowadays, ecologists have explored plant ecological stoichiometric characteristics and their responses to global changes and relationships with plant functional traits, using both field investigation and manipulative experiments. These sustained efforts have largely enriched the knowledge and understanding of plant ecological stoichiometry. In this paper, we briefly introduced the history and reviewed the research progresses of plant stoichiometry since the 19th century. Firstly, we proposed the developmental history of plant ecological stoichiometry as three main periods: sprouting, hypothesis foundation, and theoretical construction periods, and introduced some representative works for each period. Secondly, we overviewed plant ecological stoichiometric characteristics across organs, life forms and environmental gradients. The geometric mean values of leaf nitrogen (N) and phosphorus (P) contents and N:P mass ratios in global terrestrial plants are 18.74 mg∙g-1, 1.21 mg∙g-1 and 15.55 (i.e. similar to the Redfield ratio of 16:1), respectively. Leaf N and P contents at either species or community level generally show a decreasing trend with increasing temperature and precipitation, and have large variations among life forms, with higher values in herbaceous than woody plants, and deciduous broad-leaved than evergreen broad-leaved and coniferous woody plants. Compared with leaves, the stoichiometric characteristics of fine roots and other organs in plants remain poorly documented. Thirdly, we reviewed the effects of nutrient addition on plant ecological stoichiometric characteristics. In general, N addition increases soil N availability, then the N content and N:P in plants, thus leading to an increase in plant productivity to some extents. P addition might alleviate the N and P imbalance induced by excessive N inputs, and then increase plant P content. However, long-term nutrient fertilization could perturb the intrinsic stoichiometric characteristics in plants, resulting in the deteriorated nutrient imbalance in tissues and then the subsequent decline in plant productivity. Fourthly, we introduced the main hypotheses of plant ecological stoichiometry. These hypotheses include function-associated hypotheses, environment-associated hypotheses and evolution-associated hypotheses, which delineate the relationships of stoichiometric characteristics with plant growth functions, environmental factors and plant evolutionary history, respectively. Finally, we made an outlook on future research in the area of plant ecological stoichiometry, and highlighted ten potential and important research themes.

Key words: stoichiometry, nitrogen, phosphorus, ecology, plant, hypothesis, brief history