Premium
Impacts of fire on sources of soil CO 2 efflux in a dry Amazon rain forest
Author(s) -
Metcalfe Daniel B.,
Rocha Wanderley,
Balch Jennifer K.,
Brando Paulo M.,
Doughty Christopher E.,
Malhi Yadvinder
Publication year - 2018
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.14305
Subject(s) - environmental science , soil respiration , ecosystem , litter , amazon rainforest , soil carbon , abiotic component , ecotone , carbon cycle , plant litter , dry season , rainforest , atmospheric sciences , ecology , soil water , soil science , biology , shrub , geology
Fire at the dry southern margin of the Amazon rainforest could have major consequences for regional soil carbon (C) storage and ecosystem carbon dioxide ( CO 2 ) emissions, but relatively little information exists about impacts of fire on soil C cycling within this sensitive ecotone. We measured CO 2 effluxes from different soil components (ground surface litter, roots, mycorrhizae, soil organic matter) at a large‐scale burn experiment designed to simulate a severe but realistic potential future scenario for the region (Fire plot) in Mato Grosso, Brazil, over 1 year, and compared these measurements to replicated data from a nearby, unmodified Control plot. After four burns over 5 years, soil CO 2 efflux ( R s ) was ~5.5 t C ha −1 year −1 lower on the Fire plot compared to the Control. Most of the Fire plot R s reduction was specifically due to lower ground surface litter and root respiration. Mycorrhizal respiration on both plots was around ~20% of R s . Soil surface temperature appeared to be more important than moisture as a driver of seasonal patterns in R s at the site. Regular fire events decreased the seasonality of R s at the study site, due to apparent differences in environmental sensitivities among biotic and abiotic soil components. These findings may contribute toward improved predictions of the amount and temporal pattern of C emissions across the large areas of tropical forest facing increasing fire disturbances associated with climate change and human activities.