Effects of nitrogen deposition on soil microbial communities in temperate and subtropical forests in China

• Published in: The Science of the total environment Vol. 607-608; pp. 1367 - 1375
• Main Authors: Tian, Di, Jiang, Lai, Ma, Suhui, Fang, Wenjing, Schmid, Bernhard, Xu, Longchao, Zhu, Jianxiao, Li, Peng, Losapio, Gianalberto, Jing, Xin, Zheng, Chengyang, Shen, Haihua, Xu, Xiaoniu, Zhu, Biao, Fang, Jingyun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 31.12.2017
• Subjects: Forest ecosystem; Microbial biomass; Microbial community; N deposition; PLFA; PLFA; N deposition; Microbial biomass; Forest ecosystem; Microbial community
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2017.06.057

Increasing nitrogen (N) deposition has aroused large concerns because of its potential negative effects on forest ecosystems. Although microorganisms play a vital role in ecosystem carbon (C) and nutrient cycling, the effect of N deposition on soil microbiota still remains unclear. In this study, we investigated the responses of microbial biomass C (MBC) and N (MBN) and microbial community composition to 4–5years of experimentally simulated N deposition in temperate needle-leaf forests and subtropical evergreen broadleaf forests in eastern China, using chloroform fumigation extraction and phospholipid fatty acid (PLFA) methods. We found idiosyncratic effects of N addition on microbial biomass in these two types of forest ecosystems. In the subtropical forests, N addition showed a significant negative effect on microbial biomass and community composition, while the effect of N addition was not significant in the temperate forests. The N addition decreased MBC, MBN, arbuscular mycorrhizal fungi, and the F/B ratio (ratio of fungi to bacteria biomass) in the subtropical forests, likely due to a decreased soil pH and changes in the plant community composition. These results showed that microbial biomass and community composition in subtropical forests, compared with the temperate forests, were sensitive to N deposition. Our findings suggest that N deposition may have negative influence on soil microorganisms and potentially alter carbon and nutrient cycling in subtropical forests, rather than in temperate forests. [Display omitted] •Simulations of N deposition in natural subtropical and temperate forests are conducted.•Microbial community structures respond differently to N deposition in two forests.•N deposition may exhibit an overall negative influence on microorganisms in forests.