Rainforest-to-pasture conversion stimulates soil methanogenesis across the Brazilian Amazon

Author(s):Show less -

Kroeger, Marie E. ^{[1, 2]} ; Meredith, Laura K. ^{[3, 4]} ; Meyer, Kyle M. ^{[5, 6]} ; Webster, Kevin D. ^[7] ; de Camargo, Plinio Barbosa ^[8] ; de Souza, Leandro Fonseca ^[8] ; Tsai, Siu Mui ^[8] ; van Haren, Joost ^[9] ; Saleska, Scott ^[10] ; Bohannan, Brendan J. M. ^[5] ; Rodrigues, Jorge L. Mazza ^[11] ; Berenguer, Erika ^{[12, 13]} ; Barlow, Jos ^[12] ; Nusslein, Klaus ^[1]

Affiliation:Show less -

^[1] Univ Massachusetts, Dept Microbiol, Amherst, MA 01003 - USA

^[2] Los Alamos Natl Lab, Bioenergy & Biome Sci, Los Alamos, NM - USA

^[3] Univ Arizona, Sch Nat Resources & Environm, Tucson, AZ - USA

^[4] Univ Arizona, Biosphere 2, Tucson, AZ - USA

^[5] Univ Oregon, Inst Ecol & Evolut, Eugene, OR 97403 - USA

^[6] Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 - USA

^[7] Planetary Sci Inst, Tucson, AZ - USA

^[8] Univ Sao Paulo, Ctr Nucl Energy Agr, Sao Paulo, SP - Brazil

^[9] Univ Arizona, Honors Coll, Tucson, AZ - USA

^[10] Univ Arizona, Dept Ecol & Evolutionary Biol, Tucson, AZ - USA

^[11] Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 - USA

^[12] Univ Lancaster, Lancaster Environm Ctr, Lancaster - England

^[13] Univ Oxford, Environm Change Inst, Oxford - England

• Document type: Journal article
• Source: ISME Journal; v. 15, n. 3, p. 658-672, MAR 2021.
• Web of Science Citations: 1

Abstract

The Amazon rainforest is a biodiversity hotspot and large terrestrial carbon sink threatened by agricultural conversion. Rainforest-to-pasture conversion stimulates the release of methane, a potent greenhouse gas. The biotic methane cycle is driven by microorganisms; therefore, this study focused on active methane-cycling microorganisms and their functions across land-use types. We collected intact soil cores from three land use types (primary rainforest, pasture, and secondary rainforest) of two geographically distinct areas of the Brazilian Amazon (Santarem, Para and Ariquemes, Rondonia) and performed DNA stable-isotope probing coupled with metagenomics to identify the active methanotrophs and methanogens. At both locations, we observed a significant change in the composition of the isotope-labeled methane-cycling microbial community across land use types, specifically an increase in the abundance and diversity of active methanogens in pastures. We conclude that a significant increase in the abundance and activity of methanogens in pasture soils could drive increased soil methane emissions. Furthermore, we found that secondary rainforests had decreased methanogenic activity similar to primary rainforests, and thus a potential to recover as methane sinks, making it conceivable for forest restoration to offset greenhouse gas emissions in the tropics. These findings are critical for informing land management practices and global tropical rainforest conservation. (AU)

• 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