TY - JOUR
T1 - Belowground changes to community structure alter methane-cycling dynamics in Amazonia
AU - Meyer, Kyle M.
AU - Morris, Andrew H.
AU - Webster, Kevin
AU - Klein, Ann M.
AU - Kroeger, Marie E.
AU - Meredith, Laura K.
AU - Brændholt, Andreas
AU - Nakamura, Fernanda
AU - Venturini, Andressa
AU - Fonseca de Souza, Leandro
AU - Shek, Katherine L.
AU - Danielson, Rachel
AU - van Haren, Joost
AU - Barbosa de Camargo, Plinio
AU - Tsai, Siu Mui
AU - Dini-Andreote, Fernando
AU - de Mauro, José M.S.
AU - Barlow, Jos
AU - Berenguer, Erika
AU - Nüsslein, Klaus
AU - Saleska, Scott
AU - Rodrigues, Jorge L.M.
AU - Bohannan, Brendan J.M.
N1 - Publisher Copyright:
© 2020 The Authors
PY - 2020/12
Y1 - 2020/12
N2 - 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 μg CH4 m−2 d−1), consistent with previous reports, while forest soils on average emit CH4 at modest rates (mean: 9.8 ± 120.5 μg 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 μg 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.
AB - 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 μg CH4 m−2 d−1), consistent with previous reports, while forest soils on average emit CH4 at modest rates (mean: 9.8 ± 120.5 μg 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 μg 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.
KW - Amazon basin
KW - Biodiversity-ecosystem function
KW - Land use change
KW - Methane
KW - Methanogen
KW - Methanotroph
KW - Microbial ecology
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U2 - 10.1016/j.envint.2020.106131
DO - 10.1016/j.envint.2020.106131
M3 - Article
C2 - 32979812
AN - SCOPUS:85091515280
SN - 0160-4120
VL - 145
JO - Environment international
JF - Environment international
M1 - 106131
ER -