欢迎访问《应用生态学报》官方网站,今天是 分享到:

应用生态学报 ›› 2022, Vol. 33 ›› Issue (9): 2388-2396.doi: 10.13287/j.1001-9332.202209.016

• • 上一篇    下一篇

杉木人工林土壤微生物生物量和碳源利用能力对模拟氮沉降和干旱的响应

宋鸽1,2, 李晓杰1,2, 王全成1,2, 吕茂奎1,2, 谢锦升1,2,3, 贺纪正1,2,3, 郑勇1,2*   

  1. 1福建师范大学湿润亚热带生态地理过程教育部重点实验室, 福州 350007;
    2福建师范大学地理科学学院, 福州 350007;
    3福建三明森林生态系统国家野外科学观测研究站, 福建三明 365002
  • 收稿日期:2022-01-29 接受日期:2022-07-14 出版日期:2022-09-15 发布日期:2023-03-15
  • 通讯作者: * E-mail: zhengy@fjnu.edu.cn
  • 作者简介:宋 鸽, 女, 1997年生, 硕士研究生。主要从事土壤微生物生态学研究。E-mail: sg13156235062@163.com
  • 基金资助:
    国家自然科学基金项目(31971447)资助。

Responses of soil microbial biomass and carbon source utilization to simulated nitrogen deposition and drought in a Cunninghamia lanceolata plantation

SONG Ge1,2, LI Xiao-jie1,2, WANG Quan-cheng1,2, LYU Mao-kui1,2, XIE Jin-sheng1,2,3, HE Ji-zheng1,2,3, ZHENG Yong1,2*   

  1. 1Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China;
    2School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China;
    3Fujian Sanming Forest Ecosystem National Observation and Research Station, Sanming 365002, Fujian, China
  • Received:2022-01-29 Accepted:2022-07-14 Online:2022-09-15 Published:2023-03-15

摘要: 杉木林是我国亚热带地区最主要的人工林和重要的碳汇。本研究以杉木人工林为对象,通过设置氮素添加(40 kg N·hm-2·a-1)和隔离降雨(-50%)试验分别模拟氮沉降和干旱,在夏季(7月)和冬季(1月)采集表层土壤,通过磷脂脂肪酸、平板计数、Biolog等方法综合分析土壤微生物生物量、数量及碳源利用能力。结果表明: 土壤微生物生物量及微生物组成在两季节间存在显著差异;氮添加和隔离降雨可在一定程度上减少可培养细菌和真菌的数量,细菌数量较真菌数量对氮添加和隔离降雨的响应更敏感。隔离降雨显著抑制了土壤中微生物的碳源利用能力,而氮添加无显著影响。土壤细菌数量与微生物碳源利用能力呈显著正相关,表明可培养细菌是介导微生物碳转化的关键组分。本研究强调了氮沉降和干旱对亚热带杉木人工林表层土壤微生物的影响,可为评估未来全球变化情景下亚热带森林生态系统的土壤微生物生态功能提供科学依据。

关键词: Biolog, CFUs, 碳源利用能力, 模拟氮沉降, 干旱, 磷脂脂肪酸

Abstract: Chinese fir (Cunninghamia lanceolata) plantation is a dominant forest type and carbon sink in the subtropical region in China. An experiment with simulated nitrogen deposition (addition of 40 kg N·hm-2·a-1) and drought (50% of precipitation exclusion, PE) was established in Chinese fir plantation in 2018. Soil samples (0-15 cm) were collected in summer (July 2020) and winter (January 2021). Soil microbial biomass, colony forming units (CFUs) and carbon source utilization were determined through phospholipid fatty acids (PLFAs), plate count, and Biolog methods, respectively. The results showed significant seasonal variations of PLFAs-related microbial biomass and composition. Soil bacterial and fungal CFUs tended to be decreased by nitrogen addition or precipitation exclusion treatment, and bacterial CFUs were more sensitive to the two treatments than fungal CFUs. Soil microbial function (i.e. carbon source utilization) was not affected by nitrogen addition, but significantly decreased by precipitation exclusion. There was a significant positive correlation between bacterial CFUs and microbial function, indicating the crucial roles of culturable bacteria in microbial carbon transformation. Our results highlight the critical effects of nitrogen deposition and 50% reduced precipitation on microbes in topsoil of fir plantation, with implications for unraveling soil microbial ecological function of subtropical forest ecosystem under global changes in future.

Key words: Biolog, CFUs, carbon source utilization, simulated nitrogen deposition, drought, PLFAs