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生态学杂志 ›› 2020, Vol. 39 ›› Issue (9): 2851-2859.doi: 10.13292/j.1000-4890.202009.009

• 研究报告 • 上一篇    下一篇

生物炭和氮添加对亚热带常绿阔叶林土壤有机碳分解与平衡的影响

朱依凡1,2,孙兆林1,2,王清奎1,3*   

  1. 1中国科学院沈阳应用生态研究所森林生态与管理重点实验室, 沈阳 110016;2中国科学院大学, 北京 100049;3中国科学院会同森林生态实验站, 湖南会同 418307)
  • 出版日期:2020-09-10 发布日期:2021-03-10

Effects of biochar and nitrogen additions on soil organic carbon decomposition and balance in a subtropical forest.

ZHU Yi-fan1,2, SUN Zhao-lin1,2, WANG Qing-kui1,3*   

  1. (1Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; 2University of Chinese Academy of Sciences, Beijing 100049, China; 3Huitong Experimental Station of Forest Ecology, Chinese Academy of Sciences, Huitong 418307, Hunan, China)
  • Online:2020-09-10 Published:2021-03-10

摘要: 生物炭由于其稳定的化学性质及对陆地生态系统土壤碳平衡的潜在用途被广泛关注。森林火灾的发生导致大量的生物炭向森林土壤输入。但生物炭输入对森林土壤有机碳(SOC)激发效应的影响及氮有效性如何调控这一过程尚不明确。本研究通过向亚热带常绿阔叶林土壤中同时添加生物炭(相当于添加SOC含量的5%)和氮(相当于添加土壤全氮含量的0、5%、10%的硝酸铵),探讨生物炭引起的激发效应对氮添加的响应。结果表明:氮添加对生物炭分解没有影响,0、5%、10%氮处理的生物炭分解量分别为添加量的1.0%、1.0%、1.1%;激发释放的CO2量分别为9.0±2.1、8.3±2.4、5.9±0.8 g C·kg-1 SOC。生物炭显著加速SOC分解,造成强烈的正激发效应(47.2%)。氮添加在整个培养期间对SOC分解没有显著影响,但在不同培养阶段其效应有所不同,前期激发效应强度由40.3%增长至63.1%,而后期使激发效应强度由51.1%下降至17.4%。不论有无氮添加,生物炭输入造成土壤净碳增加。研究表明,生物炭在亚热带森林土壤碳固持中扮演重要角色,并可能缓解未来气候变暖。

关键词: 生物炭, 氮添加, 土壤有机碳分解, 激发效应, 碳平衡

Abstract: Biochar has aroused great attention due to its stable chemical properties and the potential benefits for soil carbon balance in terrestrial ecosystems. A large amount of biochar derived from fires accumulated in forest soils. However, little is known about the priming effect induced by biochar on soil organic carbon (SOC) decomposition, and how such effect is regulated by nitrogen availability. Here, we added biochar (B, 5% of SOC) and ammonium nitrate (0, 5%, 10% of soil total nitrogen, coded as N0, N5, N10 respectively) to the soil in a subtropical evergreen broadleaved forest to investigate the responses of priming effects induced by biochar to nitrogen addition. Results showed that nitrogen addition had little effect on biochar decomposition, with about 1.0%, 1.0%, and 1.1% of biochar being decomposed in the treatments BN0, BN5 and BN10, respectively. In addition, the priming effects induced by biochar were 9.0±2.1, 8.3±2.4, 5.9±0.8 g C·kg-1 SOC in BN0, BN5 and BN10, respectively. Biochar significantly accelerated SOC decomposition, thus caused strong positive priming effect (47.2%). There was no effect of nitrogen addition on SOC decomposition during incubation (P>0.05), whereas the nitrogen effect on priming effect was related to incubation stage. The extent of priming effect increased from 40.3% to 63.1% at the early stage, but decreased from 51.1% to 17.4% at the late stage due to nitrogen addition. The net carbon balance induced by biochar addition was generally positive regardless of nitrogen addition. Our results suggested that biochar might play an important role in soil carbon sequestration in subtropical forests and may alleviate climatewarming in future.

Key words: biochar, nitrogen addition, soil organic carbon decomposition, priming effect, carbon balance.