Belowground changes to community structure alter methane-cycling dynamics in Amazonia

Author(s):Show less -

Meyer, Kyle M. ^{[1, 2]} ; Morris, Andrew H. ^[1] ; Webster, Kevin ^[3] ; Klein, Ann M. ^{[1, 4]} ; Kroeger, Marie E. ^[5] ; Meredith, Laura K. ^{[6, 7]} ; Braedholt, Andreas ^[8] ; Nakamura, Fernanda ^[9] ; Venturini, Andressa ^[9] ; de Souza, Leandro Fonseca ^[9] ; Shek, Katherine L. ^[1] ; Danielson, Rachel ^[10] ; van Haren, Joost ^{[7, 11]} ; de Camargo, Plinio Barbosa ^[9] ; Tsai, Siu Mui ^[9] ; Dini-Andreote, Fernando ^[12] ; de Mauro, Jose M. S. ^[13] ; Barlow, Jos ^[14] ; Berenguer, Erika ^{[14, 15]} ; Nusslein, Klaus ^[5] ; Saleska, Scott ^[8] ; Rodrigues, Jorge L. M. ^[10] ; Bohannan, Brendan J. M. ^[1]

Affiliation:Show less -

^[1] Univ Oregon, Inst Ecol & Evolut, Eugene, OR 97403 - USA

^[2] Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 - USA

^[3] Planetary Sci Inst, Tucson, AZ - USA

^[4] Coll Siskiyous, Weed, CA - USA

^[5] Univ Massachusetts, Dept Microbiol, Amherst, MA 01003 - USA

^[6] Sch Nat Resources & Environm, Tucson, AZ - USA

^[7] Univ Arizona, Biosphere 2, Tucson, AZ - USA

^[8] Univ Arizona, Dept Ecol & Evolutionary Biol, Tucson, AZ - USA

^[9] Univ Sao Paulo, Ctr Nucl Energy Agr, Piracicaba, SP - Brazil

^[10] Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA - USA

^[11] Univ Arizona, Honors Coll, Tucson, AZ - USA

^[12] Univ Sao Paulo, Dept Soil Sci Luiz de Queiroz, Coll Agr, Piracicaba, SP - Brazil

^[13] Univ Fed Oeste Para, Santarem Tapajos, Para - Brazil

^[14] Univ Lancaster, Lancaster Environm Ctr, Lancaster - England

^[15] Univ Oxford, Environm Change Inst, Oxford - England

• Document type: Journal article
• Source: Environment International; v. 145, DEC 2020.
• Web of Science Citations: 0

Abstract

Amazonian rainforest is undergoing increasing rates of deforestation, driven primarily by cattle pasture expansion. Forest-to-pasture conversion has been associated with increases in soil methane (CH4) emission. To better understand the drivers of this change, we measured soil CH4 flux, environmental conditions, and belowground microbial community structure across primary forests, cattle pastures, and secondary forests in two Amazonian regions. We show that pasture soils emit high levels of CH4 (mean: 3454.6 +/- 9482.3 mu g CH4 m(-2) d(-1)), consistent with previous reports, while forest soils on average emit CH4 at modest rates (mean: 9.8 +/- 120.5 mu g CH4 m(-2) d(-1)), but often act as CH4 sinks. We report that secondary forest soils tend to consume CH4 (mean: 10.2 +/- 35.7 mu g CH4 m(-2) d(-1)), demonstrating that pasture CH4 emissions can be reversed. We apply a novel computational approach to identify microbial community attributes associated with flux independent of soil chemistry. While this revealed taxa known to produce or consume CH4 directly (i.e. methanogens and methanotrophs, respectively), the vast majority of identified taxa are not known to cycle CH4. Each land use type had a unique subset of taxa associated with CH4 flux, suggesting that land use change alters CH4 cycling through shifts in microbial community composition. Taken together, we show that microbial composition is crucial for understanding the observed CH4 dynamics and that microorganisms provide explanatory power that cannot be captured by environmental variables. (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