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Scientia Silvae Sinicae ›› 2025, Vol. 61 ›› Issue (5): 46-60.doi: 10.11707/j.1001-7488.LYKX20240239

• Research papers • Previous Articles     Next Articles

Effects of Simulated Nitrogen Deposition on Soil Microbial Community Structure and Enzyme Activities in Eucalyptus Plantations in Mid-subtropical Region

Yingjie Sun1,Denan Zhang1,Yuyi Shen2,Guangping Xu1,*(),Yang Cao3,Kechao Huang1,Yunshuang Chen4,Xinyue Mao5,Qiumei Teng1,Shihong Lü1,Junzhi Chu6   

  1. 1. Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain Guangxi Institute of Botany,Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences Guilin 541006
    2. Guangxi Key Laboratory of Functional Phytochemicals and Sustainable Utilization Guangxi Institute of Botany,Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences Guilin 541006
    3. The First Senior High School of Xinye County  Nanyang 473500
    4. The First Junior High School of Yudong New District in Yulin City Yulin 537000
    5. College of Life Sciences,Guangxi Normal University Guilin 541006
    6. College of Environmental Science and Engineering,Guilin University of Technology Guilin 541006
  • Received:2024-04-28 Online:2025-05-20 Published:2025-05-24
  • Contact: Guangping Xu E-mail:xugpgx@163.com

Abstract:

Objective: The central subtropical region is facing a challenge of increasing nitrogen deposition. Soil microorganisms are the link for maintaining terrestrial ecosystems and sensitive to global change. This study aims to explore the response of soil microorganisms and enzyme activities to the increased nitrogen deposition in Eucalyptus plantations in mid-subtropical region, so as to provide scientific basis for further research on the impact of nitrogen deposition on Eucalyptus plantation ecosystems under the background of global change. Method: A simulated nitrogen deposition experiment was established in Eucalyptus plantations in 2018, and four treatments were set up: CK (0 kg·hm?2a?1), low nitrogen (LN, 50 kg·hm?2a?1), medium nitrogen (MN, 100 kg·hm?2a?1) and high nitrogen (HN, 150 kg·hm?2a?1). After five years of simulated nitrogen deposition treatment, soil physical and chemical properties, microbial community structure, microbial diversity and soil enzyme activities were analyzed. Result: 1) Compared with the control, nitrogen deposition significantly increased soil cation exchange capacity, and the content of clay, soil organic carbon, total nitrogen, nitrate nitrogen, dissolved organic nitrogen, and microbial biomass nitrogen. As the level of nitrogen deposition increased, the content of total phosphorus, microbial biomass phosphorus, ammonium nitrogen and sand showed a trend of first increase and then decrease. The silt content showed a trend of first decrease and then slight increase, which was lower than that of the control. 2) Nitrogen deposition increased the total phospholipid fatty acids (PLFAs) of soil microorganisms. Low and medium nitrogen deposition treatments increased the content of soil bacteria, fungi, Gram-positive bacteria, actinomycetes, arbuscular mycorrhizal fungi and Gram-negative bacteria, and promoted the activities of soil β-glucosidase, cellulase, catalase, polyphenol oxidase, β-N-acetylglucosaminidase, urease and acid phosphatase. However, all the parameters tended to decrease under high nitrogen deposition. 3) The results of correlation and redundancy analysis showed that soil cation exchange capacity, microbial biomass nitrogen, silt, total nitrogen, dissolved organic nitrogen and total phosphorus contents were the key environmental factors affecting the changes of microbial community structure and soil enzyme activities. Conclusion: The short-term simulated nitrogen deposition of five years has improved the soil physico-chemical properties in Eucalyptus plantations, changed the soil microbial community structure and increased soil enzyme activities. Low and medium nitrogen deposition levels have a promoting effect on soil physicochemical properties, microbial community structure and soil enzyme activities, while high nitrogen deposition shows a certain inhibitory effect.

Key words: nitrogen deposition, microbial community structure, phospholipid fatty acid (PLFA), enzyme activities, Eucalyptus plantation

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