Differentiation of fungal trophic guilds to long-term nitrogen addition in a poplar plantation

• Published in: Forest ecology and management 2024-03, Vol.555, p.121699, Article 121699
• Main Authors: Yang, Nan, Zhang, Jiangbao, Hua, Jiani, Song, Baohan, Wang, Tianyi, Xing, Wei, Wang, Guobing, Mao, Lingfeng, Ruan, Honghua
• Format: Article
• Language: English
• Subjects: administrative management; Ascomycota; Basidiomycota; biomarkers; ecosystems; Forest ecology; forests; Fungal trophic guild; genes; ITS sequencing; land management; nitrates; nitrogen; Nitrogen management; Populus; saprotrophs; social identification; soil; soil fungi; Soil microbial diversity
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2024.121699

Continuous increase of nitrogen (N) deposition induces deleterious environmental changes in forest ecosystems, affecting biotic diversity and ecosystem functions. However, inconsistent responses of soil fungal community to N addition were reported by previous studies, which prevent a further understanding of potential influences on the structure and ecological functions of forest ecosystems under accumulative N-addition. Therefore, this study investigated the differentiation of fungal trophic guilds to N-addition in a poplar (Populous deltoids) plantation. Illumina sequencing of fungal biomarker ITS gene was carried out to determine fungal communities, while functional group identification in terms of trophic levels (saprotrophic, symbiotic and pathogenic fungi) was conducted based on FUNGuild predictions. The results showed that in irrespective of N treatment levels, the core phyla of fungi were affiliated to Ascomycota > Mortierellomycota > Rozellomycota > Basidiomycota in terms of their relative abundance. Interestingly, the higher soil N availability induced by N-addition significantly declined the relative abundance of saprotrophic and symbiotic fungi, but promoted the growth of pathogenic fungi. The decreasing saprotrophic and pathogenic fungal diversity resulted in an ultimate decrease in Shannon diversity of overall fungal communities under N-addition, and was apparently closely associated with soil nitrate concentrations. Taking together, these findings highlighted the ecology and functions of fungal groups in long-term N managed soils, and advanced the current understanding on the importance of microbial management in contemporary land management practices. •N-addition declined the proportion of saprotrophic and symbiotic fungi.•N-addition enhanced the growth of pathogenic fungi.•Overall fungal diversity was mediated by saprotrophic and pathogenic fungi.•Soil NO3− regulated soil fungal diversity under N-addition.•Fungal trophic mode potentially determined fungal response to N-addition.