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

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

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 (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.

Detaljer

Författare
  • Daniel B. Metcalfe
  • Wanderley Rocha
  • Jennifer K. Balch
  • Paulo M. Brando
  • Christopher E. Doughty
  • Yadvinder Malhi
Enheter & grupper
Externa organisationer
  • Umeå University
  • Amazon Environmental Research Institute
  • University of Colorado
  • Northern Arizona University
  • University of Oxford
  • Woods Hole Research Center
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Klimatforskning

Nyckelord

Originalspråkengelska
Sidor (från-till)3629-3641
TidskriftGlobal Change Biology
Volym24
Utgåva nummer8
Tidigt onlinedatum2018 jan 1
StatusPublished - 2018 aug
PublikationskategoriForskning
Peer review utfördJa