Land use change alters carbon and nitrogen dynamics mediated by fungal functional guilds within soil aggregates

Chenggang Liu; Yanqiang Jin; Fangmei Lin; Chuan Jiang; Xiaoling Zeng; Defeng Feng; Fuzhao Huang; Jianwei Tang

doi:10.1016/j.scitotenv.2023.166080

Land use change alters carbon and nitrogen dynamics mediated by fungal functional guilds within soil aggregates

Sci Total Environ. 2023 Dec 1:902:166080. doi: 10.1016/j.scitotenv.2023.166080. Epub 2023 Aug 5.

Authors

Chenggang Liu¹, Yanqiang Jin², Fangmei Lin³, Chuan Jiang³, Xiaoling Zeng³, Defeng Feng⁴, Fuzhao Huang⁵, Jianwei Tang²

Affiliations

¹ CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, China. Electronic address: liuchenggang@xtbg.ac.cn.
² CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, China.
³ CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Institute of Highland Forest Science, Chinese Academy of Forestry, Kunming 650233, China.
⁵ 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, China.

PMID: 37544435
DOI: 10.1016/j.scitotenv.2023.166080

Abstract

Land use change is one of the greatest threats to soil biodiversity and ecological functions; however, how such a transition affects soil carbon (C) and nitrogen (N) dynamics driven by fungal communities at the aggregate level remains unclear. Here, we explored the variation in soil C and N pools, specific enzyme activities and fungal communities and functional guilds within three aggregate sizes (megaaggregates, > 2 mm; macroaggregates, 0.25-2 mm; microaggregates, < 0.25 mm) in a natural forest, 12- and 24-year-old rubber monocultures and corresponding agroforestry systems in tropical China. Tropical forest conversion to rubber monocultures generally reduced C and N pools in all aggregates, while agroforestry systems decreased microbial biomass C and N. Carbon- and N-degrading enzyme activities responded differently to forest conversion and were enhanced in agroforestry systems. The levels of C and N pools and their related enzyme activities increased as the aggregate size decreased. Moreover, fungal compositional shifts in dominance from copiotrophic Ascomycota and Basidiomycota (r-strategists) into oligotrophic Zygomycota (K-strategists) were noted following forest conversion, resulting in more pathogenic fungi at the expense of saprotrophic and arbuscular mycorrhizal fungi. Pathogenic fungi were greatly inhibited due to abundant Mortierella after the establishment of 12-year-old agroforestry systems. The diversity of saprotrophic fungi was the highest in microaggregates. Regardless of land use type, aggregate-associated C and N pools, especially DOC, MBC, NO₃^--N and DON in microaggregates, were interactively mediated by functional guilds of fungi, which was primarily driven by soil pH. These results highlight the importance of fungal functional guilds in determining C and N dynamics at the aggregate level and provide insights into the sustainable management of cash tree plantations.

Keywords: Agroforestry system; Fungal guilds; Pathogenic fungi; Specific enzyme activity; Tropical forest conversion.

MeSH terms

Ascomycota*
Carbon
Forests
Fungi
Nitrogen / analysis
Rubber
Soil Microbiology
Soil*

Substances

Soil
Carbon
Nitrogen
Rubber