Functionality of methane cycling microbiome during methane flux hot moments from riparian buffer systems

Author(s)

Obregon, Dasiel ; Mafa-Attoye, Tolulope G. ; Baskerville, Megan ; Mitter, Eduardo K. ; de Souza, Leandro Fonseca ; Oelbermann, Maren ; Thevathasan, Naresh V. ; Tsai, Siu Mui ; Dunfield, Kari E.

• Document type: Journal article
• Source: Science of The Total Environment; v. 870, p. 12-pg., 2023-02-09.

Abstract

Riparian buffer systems (RBS) are a common agroforestry practice that involves maintaining a forested boundary adja-cent to water bodies to protect the aquatic ecosystems in agricultural landscapes. While RBS have potential for carbon sequestration, they also can be sources of methane emissions. Our study site at Washington Creek in Southern Ontario, includes a rehabilitated tree buffer (RH), a grassed buffer (GRB), an undisturbed deciduous forest (UNF), an undisturbed coniferous forest (CF), and an adjacent agricultural field (AGR). The objective of this study was to assess the diversity and activity of CH4 cycling microbial communities in soils sampled during hot moments of methane fluxes (July 04 and August 15). We used qPCR and high-throughput amplicon sequencing from both DNA and cDNA to target methanogen and methanotroph communities. Methanogens, including the archaeal genera Methanosaeta, Methanosarcina, Methanomassiliicoccus, and Methanoreggula, were abundant in all RBSs, but they were significantly more active in UNF soils, where CH4 emissions were highest. Methylocystis was the most prevalent taxon among methanotrophs in all the ri-parian sites, except for AGR soils where the methanotrophs community was composed primarily of members of rice paddy clusters (RPCs and RPC-1) and upland soil clusters (TUSC and USC alpha). The main factors influencing the composi-tion and assembly of methane-cycling microbiomes were soil carbon and moisture content. We concluded that the differ-ences in CH4 fluxes observed between RBSs were primarily caused by differences in the presence and activity of methanogens, which were influenced by total soil carbon and water content. Overall, this study emphasizes the impor-tance of understanding the microbial drivers of CH4 fluxes in RBSs in order to maximize RBS environmental benefits. (AU)

• FAPESP's process: 18/09117-1 - ACTIVE MICROBIOTA IN METHANE SEQUESTRY IN FOREST AND PASTURE SOILS REVEALED BY STABLE ISOTOPE PROBING AND METAGENOMICS
• Grantee: Leandro Fonseca de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/50320-4 - Dimensions US-BIOTA - São Paulo: collaborative research: integrating dimensions of microbial biodiversity across land use change in tropical forests
• Grantee: Tsai Siu Mui
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 18/05223-1 - Linking methane flux and microbial diversity in Amazon soils across forests-to-pasture conversion: a multidisciplinary approach
• Grantee: Dasiel Obregón Alvarez
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 16/24695-6 - Spatio-temporal dynamics of the active microbiota on the methane cycling in an Amazonian soil after forest-to-pasture conversion
• Grantee: Dasiel Obregón Alvarez
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)