Increasing wildfires threaten historic carbon sink of boreal forest soils

@article{Walker2019IncreasingWT,
  title={Increasing wildfires threaten historic carbon sink of boreal forest soils},
  author={Xanthe J. Walker and Jennifer L. Baltzer and Steven G. Cumming and Nicola J. Day and Christopher Ebert and S. Goetz and Jill F. Johnstone and Stefano Potter and Brendan M. Rogers and Edward. A.G. Schuur and Merritt R. Turetsky and Michelle C. Mack},
  journal={Nature},
  year={2019},
  volume={572},
  pages={520-523}
}
Boreal forest fires emit large amounts of carbon into the atmosphere primarily through the combustion of soil organic matter1–3. During each fire, a portion of this soil beneath the burned layer can escape combustion, leading to a net accumulation of carbon in forests over multiple fire events4. Climate warming and drying has led to more severe and frequent forest fires5–7, which threaten to shift the carbon balance of the boreal ecosystem from net accumulation to net loss1, resulting in a… 
Carbon loss from boreal forest wildfires offset by increased dominance of deciduous trees
TLDR
In Alaskan boreal forests, it was found that shifts in dominant plant species catalyzed by severe fire compensated for greater combustion of soil carbon over decadal time scales, pointing to a potential mitigation of the feedback effect of boreal forest fire to climate warming.
Wildfire combustion and carbon stocks in the southern Canadian boreal forest: Implications for a warming world
TLDR
This work sampled 79 stands throughout central Saskatchewan to characterize above- and belowground carbon stocks and combustion rates in relation to historical land use, vegetation characteristics, and geophysical attributes, and reinforces previous studies showing that northern boreal stands are at a high risk of holding less carbon under changing disturbance conditions.
Decadal‐Scale Recovery of Carbon Stocks After Wildfires Throughout the Boreal Forests
Boreal forests store 30% of the world's terrestrial carbon (C). Consequently, climate change mediated alterations in the boreal forest fire regime can have a significant impact on the global C
Using a natural experiment to foresee the fate of boreal carbon stores
  • D. Bowman
  • Environmental Science
    Global change biology
  • 2020
TLDR
A natural experiment design was used to show that legacy effects of past logging and fire distrubance have strongly contrasting effects on above ground and below ground carbon losses associated with major wildfires that occurred in 2015 in southern boreal forests in central Saskatchewan, Canada.
Australian forests, megafires and the risk of dwindling carbon stocks.
TLDR
Research involving empirical measurements, modelling and a mix of large-scale management intervention is urgently required to determine what interventions can maximise carbon storage in the face of climate change driven fires.
Low‐intensity frequent fires in coniferous forests transform soil organic matter in ways that may offset ecosystem carbon losses
TLDR
The relative increase in forms of soil organic matter that are resistant to decay or stabilized onto mineral surfaces, and the associated decline in decomposition suggest that low-intensity fire can potentially promote mineral soil C storage in pools with long mean residence times in coniferous forests.
Escalating carbon emissions from North American boreal forest wildfires and the climate mitigation potential of fire management
Wildfires in boreal forests release large quantities of greenhouse gases to the atmosphere, exacerbating climate change. Here, we characterize the magnitude of recent and projected gross and net
Patterns of Ecosystem Structure and Wildfire Carbon Combustion Across Six Ecoregions of the North American Boreal Forest
Increases in fire frequency, extent, and severity are expected to strongly impact the structure and function of boreal forest ecosystems. An important function of the boreal forest is its ability to
...
...

References

SHOWING 1-10 OF 45 REFERENCES
Cross‐scale controls on carbon emissions from boreal forest megafires
TLDR
The results indicate that black spruce stands located at landscape positions with intermediate drainage contribute the most to C emissions, which offsets almost 50% of mean annual net ecosystem production in terrestrial ecosystems of Canada.
Fire as the dominant driver of central Canadian boreal forest carbon balance
TLDR
The carbon balance of this region was driven by changes in fire disturbance from 1948 to 2005, and poor soil drainage decreased the variability of the landscape carbon balance, which suggests that increased climate and hydrological changes have the potential to affect disproportionately the carbon dynamics of these areas.
The role of fire in the boreal carbon budget
To reconcile observations of decomposition rates, carbon inventories, and net primary production (NPP), we estimated long‐term averages for C exchange in boreal forests near Thompson, Manitoba. Soil
Carbon loss from an unprecedented Arctic tundra wildfire
TLDR
The magnitude of ecosystem C lost by fire, relative to both ecosystem and biome-scale fluxes, demonstrates that a climate-driven increase in tundra fire disturbance may represent a positive feedback, potentially offsetting Arctic greening and influencing the net C balance of the tundRA biome.
Recent burning of boreal forests exceeds fire regime limits of the past 10,000 years
TLDR
It is suggested that boreal forests can sustain high-severity fire regimes for centuries under warm and dry conditions, with vegetation feedbacks modulating climate–fire linkages.
Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity
TLDR
Analysis of data from 48 sites in savanna grasslands, broadleaf forests and needleleaf forests spanning up to 65 years finds that frequently burned plots experienced a decline in surface soil carbon and nitrogen that was non-saturating through time, and predicts that the long-term losses of soil nitrogen that result from more frequent burning may in turn decrease the carbon that is sequestered by net primary productivity.
Influence of tree species on continental differences in boreal fires and climate feedbacks
© 2015 Macmillan Publishers Limited. Wildfires are common in boreal forests around the globe and strongly influence ecosystem processes. However, North American forests support more high-intensity
Quantifying fire severity, carbon, and nitrogen emissions in Alaska's boreal forest.
TLDR
It is concluded that using postfire measurements of adventitious roots on black spruce trees in combination with soils and tree data can be used to reconstruct prefire organic soil depths and biomass pools, providing accurate estimates of fire severity and emissions.
Soil organic layer combustion in boreal black spruce and jack pine stands of the Northwest Territories, Canada
Increased fire frequency, extent and severity are expected to strongly affect the structure and function of boreal forest ecosystems. In this study, we examined 213 plots in boreal forests dominated
Climatic thresholds shape northern high‐latitude fire regimes and imply vulnerability to future climate change
Boreal forests and arctic tundra cover 33% of global land area and store an estimated 50% of total soil carbon. Because wildfire is a key driver of terrestrial carbon cycling, increasing fire
...
...