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应用生态学报 ›› 2019, Vol. 30 ›› Issue (5): 1536-1542.doi: 10.13287/j.1001-9332.201905.013

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长白山苔原带土壤碳、氮矿化对氮沉降的响应

陈红1,2, 唐杨1,2, 童跃伟1,2, 朱琪1,2, 周旺明1*, 周莉1, 于大炮1, 代力民1   

  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
  • 收稿日期:2018-12-22 修回日期:2018-12-22 出版日期:2019-05-15 发布日期:2019-05-15
  • 通讯作者: E-mail: zhouwangming@126.com
  • 作者简介:陈 红,女,1992年生,硕士研究生.主要从事森林生态学和土壤碳、氮循环方面的研究.E-mail: chenhongtjk@163.com
  • 基金资助:
    国家自然科学基金项目(41877549,41701052)

Responses of soil carbon and nitrogen mineralization to nitrogen deposition in tundra zone of the Changbai Mountain, China.

CHEN Hong1,2, TANG Yang1,2, TONG Yue-wei1,2, ZHU Qi1,2, ZHOU Wang-ming1*, ZHOU Li1, YU Da-pao1, DAI Li-min1   

  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
  • Received:2018-12-22 Revised:2018-12-22 Online:2019-05-15 Published:2019-05-15
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (41877549,41701052).

摘要: 高山苔原生态系统的土壤无机氮含量较低,对氮的缓冲性弱而易受外源氮输入的影响.本研究以长白山北坡苔原带土壤为研究对象,通过室内培养试验,以NH4NO3为外加氮源,设置3个施氮水平:对照(CK,0 kg·hm-2),低氮(N1,25 kg·hm-2),高氮(N2,50 kg·hm-2),分析长白山苔原带土壤碳、氮矿化对氮沉降的响应.结果表明: 氮添加处理对长白山苔原带土壤碳矿化速率影响不显著,但对土壤碳矿化累积矿化量影响显著,N2抑制了土壤的碳矿化作用.培养40 d后,氮添加处理提高了土壤无机氮含量;而培养80 d后,N2与N1的无机氮含量差异不显著,但都明显高于CK,氮输入促进了土壤氮的矿化.培养过程中,N1处理下的微生物生物量碳、氮高于N2和CK处理,说明低氮输入对土壤微生物活性的促进作用更明显.在未来氮沉降增加的背景下,长白山苔原土壤碳、氮周转可能加快,提高土壤无机氮含量.土壤中无机氮含量增加,虽然可以为植物生长提供更多生长所需的氮素,但也提高了土壤氮素的流失风险.

Abstract: The alpine tundra ecosystem, with low soil inorganic nitrogen (N) availability, has a weak buffer against nitrogen and is susceptible to exogenous N enrichment. Here, with a laboratory incubation experiment, we investigated the response of soil carbon and nitrogen mineralization to N deposition with soil samples from the tundra zone on the northern slope of the Changbai Mountain. We set three N levels, control (CK, 0 kg·hm-2), low N (N1, 25 kg·hm-2), and high N (N2, 50 kg·hm-2), with N being added as NH4NO3. The results showed that N addition had no significant effect on soil C mineralization rate, but significantly affected the accumulation of soil C minera-lization. The N2 treatment inhibited soil C mineralization. After the 40 d incubation, soil inorganic N content increased with increasing N addition. After the 80 d incubation, soil inorganic N content in the N2 and N1 was similar and significantly higher than that of CK. Those results indicated that N addition promoted soil N mineralization. The soil microbial biomass C and N in the N1 was higher than that in the N2 and CK, indicating that low N input had stronger effects on soil microbial activity. Increasing N deposition might accelerate C and N turnover in the tundra soils and enhance the soil inorganic N content. While it could provide more N for plants, it may increase the risk of N loss.