欢迎访问《生态学杂志》官方网站,今天是 分享到:

生态学杂志 ›› 2021, Vol. 40 ›› Issue (11): 3730-3741.doi: 10.13292/j.1000-4890.202111.010

• 综合评述 • 上一篇    下一篇

氮沉降对森林生态系统土壤微生物、酶活性以及细根生产与周转的影响研究进展

郭超1,3,王霖娇1,2*   

  1. (1贵州师范大学喀斯特研究院, 贵阳 550001; 2国家喀斯特石漠化治理工程技术研究中心, 贵阳 550001;3贵州省喀斯特石漠化防治与衍生产业工程实验室, 贵阳 550001)
  • 出版日期:2021-11-10 发布日期:2022-05-10

Effects of nitrogen deposition on soil microbes, enzyme activities, fine root production and turnover in forest ecosystems: A review.

GUO Chao1,3, WANG Lin-jiao1,2*   

  1. (1Institute of Karst Research, Guizhou Normal University, Guiyang 550001, China; 2National Engineering Research Center for Karst Rocky Desertification Control, Guiyang 550001, China;  3Guizhou Engineering Laboratory for Karst Rocky Desertification Control and Derivative Industry, Guiyang 550001, China).
  • Online:2021-11-10 Published:2022-05-10

摘要: 全球氮沉降普遍呈现逐年增加的趋势,并显著影响森林生态系统的碳氮循环过程。土壤微生物、土壤酶及细根作为森林地下生态系统的重要组成,在森林生态系统的物质循环与能量流动中具有极其重要的地位和功能,其对氮沉降的响应已成为全球气候变化领域的研究热点。本文综述了氮沉降对不同森林生态系统土壤微生物、酶活性以及细根生产与周转的影响。结果表明,氮沉降导致了土壤酸化,保持了土壤养分以及改变了地下碳氮的分配格局。氮沉降对土壤微生物结构的影响主要体现在土壤细菌与真菌比值的升高或者不变以及土壤微生物相对丰度的变化,对土壤微生物功能的影响主要体现在促进或抑制了土壤微生物呼吸、改变了固氮类群以及降低了土壤底物氮利用率,其影响因素主要与土壤pH、土壤可利用养分以及施氮时间等因素高度相关。氮沉降可以促进或抑制森林生态系统土壤酶活性,其影响因素主要与土层深度、土壤pH以及森林生态系统内的碳氮磷等限制元素显著相关。在氮沉降增加背景下,细根生物量普遍逐渐减少,细根周转表现为加快和变慢两种变化,细根分解呈现出由快到慢的转变特征,其影响因素主要与土壤养分有效性、土壤氮储量以及细根化学性质等因素密切相关。针对该领域亟待解决的关键科学问题,本文最后探讨了未来研究的重要方向。研究结果对进一步探明氮沉降对森林生态系统土壤微生物与酶活性及细根特性的内在影响机理具有重要意义,对氮沉降增加背景下森林生态系统的保护与恢复具有明显价值。

关键词: 土壤微生物, 土壤酶活性, 细根生物量, 细根分解

Abstract: Global nitrogen deposition is generally increasing year by year, with substantial effects on carbon and nitrogen cycling in forest ecosystems. Soil microbes, soil enzymes, and fine roots are important belowground components, playing crucial roles in the material circulation and energy flow of forest ecosystems. Their responses to nitrogen deposition have become a hot topic in the research field of global climate changes. Here, we summarized the effects of nitrogen deposition on soil microbes, enzyme activities, fine root production and turnover in forest ecosystems. Results showed that nitrogen deposition caused soil acidification, preserved soil nutrients, and changed the distribution pattern of belowground carbon and nitrogen. Effects of nitrogen deposition on the structures of soil microbial communities were mainly reflected in the increase or no change of soil bacteria/fungi ratio and changes in the relative abundance of soil microbes. Effects of nitrogen deposition on the functions of soil microbes were mainly reflected in promoting or inhibiting soil microbial respiration, changing nitrogenfixation groups, and reducing nitrogen use rate of soil substrate, and were significantly affected by soil pH, soil available nutrients, and the time of nitrogen application. Nitrogen deposition could promote or inhibit soil enzyme activities, which were significantly affected by soil depth, soil pH, and soil limiting elements (such as carbon, nitrogen and phosphorus). Along with increasing nitrogen deposition, fine root biomass decreased, fine root turnover speeded up or slowed down, fine root decomposition shifted from stimulating to inhibiting, which were significantly affected by soil nutrient availability, soil nitrogen storage, and fine root chemical properties. Focusing on the key scientific issues needed to be solved urgently in this research field, eventually we discussed important directions for future research. This review has great significance for further clarifying the mechanisms underlying the impacts of nitrogen deposition on soil microbes, enzyme activities, and fine root in forest ecosystems, and thus for the protection and rehabilitation of forest ecosystems under the background of increasing nitrogen deposition.

Key words: soil microbes, soil enzyme activity, fine root biomass, fine root decomposition.