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Impacts of fire on sources of soil CO2 efflux in a dry Amazon rain forest

Metcalfe, Daniel B. LU ; Rocha, Wanderley ; Balch, Jennifer K. ; Brando, Paulo M. ; Doughty, Christopher E. and Malhi, Yadvinder (2018) In Global Change Biology 24(8). p.3629-3641
Abstract

Fire at the dry southern margin of the Amazon rainforest could have major consequences for regional soil carbon (C) storage and ecosystem carbon dioxide (CO2) emissions, but relatively little information exists about impacts of fire on soil C cycling within this sensitive ecotone. We measured CO2 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 CO2 efflux... (More)

Fire at the dry southern margin of the Amazon rainforest could have major consequences for regional soil carbon (C) storage and ecosystem carbon dioxide (CO2) emissions, but relatively little information exists about impacts of fire on soil C cycling within this sensitive ecotone. We measured CO2 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 CO2 efflux (Rs) was ~5.5 t C ha-1 year-1 lower on the Fire plot compared to the Control. Most of the Fire plot Rs reduction was specifically due to lower ground surface litter and root respiration. Mycorrhizal respiration on both plots was around ~20% of Rs. Soil surface temperature appeared to be more important than moisture as a driver of seasonal patterns in Rs at the site. Regular fire events decreased the seasonality of Rs 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.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Amazon tropical rain forest, Burn experiment, Carbon dioxide, Climate change, Fire, Mycorrhizae, Soil respiration partitioning
in
Global Change Biology
volume
24
issue
8
pages
3629 - 3641
publisher
Wiley-Blackwell
external identifiers
  • pmid:29748988
  • scopus:85047797011
ISSN
1354-1013
DOI
10.1111/gcb.14305
language
English
LU publication?
yes
id
3b358ced-834b-4433-9e7d-9c031a1fda97
date added to LUP
2018-06-15 15:45:32
date last changed
2019-12-10 07:34:20
@article{3b358ced-834b-4433-9e7d-9c031a1fda97,
  abstract     = {<p>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<sub>2</sub>) emissions, but relatively little information exists about impacts of fire on soil C cycling within this sensitive ecotone. We measured CO<sub>2</sub> 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<sub>2</sub> efflux (R<sub>s</sub>) was ~5.5 t C ha<sup>-1</sup> year<sup>-1</sup> lower on the Fire plot compared to the Control. Most of the Fire plot R<sub>s</sub> reduction was specifically due to lower ground surface litter and root respiration. Mycorrhizal respiration on both plots was around ~20% of R<sub>s</sub>. Soil surface temperature appeared to be more important than moisture as a driver of seasonal patterns in R<sub>s</sub> at the site. Regular fire events decreased the seasonality of R<sub>s</sub> 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.</p>},
  author       = {Metcalfe, Daniel B. and Rocha, Wanderley and Balch, Jennifer K. and Brando, Paulo M. and Doughty, Christopher E. and Malhi, Yadvinder},
  issn         = {1354-1013},
  language     = {eng},
  number       = {8},
  pages        = {3629--3641},
  publisher    = {Wiley-Blackwell},
  series       = {Global Change Biology},
  title        = {Impacts of fire on sources of soil CO<sub>2</sub> efflux in a dry Amazon rain forest},
  url          = {http://dx.doi.org/10.1111/gcb.14305},
  doi          = {10.1111/gcb.14305},
  volume       = {24},
  year         = {2018},
}