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Bulletin of Botanical Research ›› 2023, Vol. 43 ›› Issue (2): 194-206.doi: 10.7525/j.issn.1673-5102.2023.02.005

• Physiology and Ecology • Previous Articles     Next Articles

Effects of N addition on Root Exudates and Their Mediated Nutrient Rransformation Processes in a Betula albosinensis Burk Forest in Southwest China

Zhenggang XU1, Hang XU1, Xiutao PENG1, Shijun LIANG2, Rong LIU1, Shanghua LUO1, Juan XIAO1()   

  1. 1.School of Environmental Science and Engineering,West China Normal University,Nanchong 637000
    2.Sichuan Nanchong Ecological Environment Monitoring Center Station,Nanchong 637000
  • Received:2022-05-27 Online:2023-03-20 Published:2023-03-07
  • Contact: Juan XIAO E-mail:xiaojuanhj@163.com
  • About author:XU Zhenggang(1996—),male,postgraduate student,mainly engaged in underground ecology research.
  • Supported by:
    National Natural Science Youth Fund Project(31700387);Planned project of Sichuan Provincial Department of science and technology(2021YJ0283);Innovation training program of West China Normal University(cxcy2021201)


At present, we still lack a deep understanding of the response direction and amplitude of root exudate flux and related ecological consequences to different nitrogen(N) deposition levels. In order to reveal the difference in the effects of different N addition treatments on root exudate C flux and its mediated soil nutrient transformation process, the typical Betula albosinensis Burk forest in the mountainous area of southwest China was used as materials, and different nitrogen deposition levels were simulated by in-situ N addition experiment(control group, 0 kg·hm-2?a-1); low nitrogen treatment, 25 kg·hm-2?a-1; High nitrogen treatment, 50 kg·hm-2?a-1 respectively. The results showed that: (1)N addition significantly reduced the C input rate(the average root exudation rate per unit root biomass decreased by 14.87% under low nitrogen(N25))and annual C input flux of root exudates(about 45.01% reduction under low nitrogen condition)(P<0.05), and high N treatment had stronger inhibition effect on root exudates C input. (2)N addition significantly inhibited soil N mineralization rate and related microbial extracellular enzyme activities(P<0.05), and significantly reduced its rhizosphere effect. In conclusion, N deposition significantly inhibited the root exudates C flux and its mediated soil nutrient transformation process, and this inhibition effect increased with the increase of N deposition level. The results could enrich the understanding of carbon-nutrient cycling in forest under global climate change.

Key words: Betula albosinensis Burk forest, root exudates, soil N transformation, rhizosphere effect, nitrogen deposition

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