Werner A. Kurz talks with
ScienceWatch.com and answers a few questions about
this month's New Hot Paper in the field of Environment
& Ecology.
Article Title: Mountain pine beetle and forest
carbon feedback to climate change
Authors: Kurz,
WA;Dymond, CC;Stinson, G;Rampley, GJ;Neilson,
ET;Carroll, AL;Ebata, T;Safranyik, L
Journal: NATURE
Volume: 452
Issue: 7190
Page: 987-990
Year: APR 24 2008
* Nat Resources Canada, Canadian Forest Serv, Pacific
Forestry Ctr, Victoria, BC V8Z 1M5, Canada.
* Nat Resources Canada, Canadian Forest Serv, Pacific
Forestry Ctr, Victoria, BC V8Z 1M5, Canada.
(addresses have been truncated)
Why do you think your paper is highly
cited?
Our team's publication on the impacts of a mountain pine beetle outbreak on
the carbon balance of the forests of British Columbia has received
international attention because it highlights the magnitude of the impact
and the feedbacks to climate change of a natural disturbance type that is
not considered in other models of the forest carbon cycle.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
To estimate the net greenhouse gas balance of the study area, we combined
detailed data on the scale and impacts of a forest insect outbreak that
covers over 13 million hectares, with data on forest inventory, growth and
yield, wildfires, and harvesting. We used the Carbon Budget Model of the
Canadian Forest Sector (CBM-CFS3) to simulate forest dynamics and the
impacts of the beetle. We conducted analyses of the likely course of the
insect outbreak to 2020, and compared the greenhouse gas balance with
and without the beetle impacts.
Would you summarize the significance of your paper
in layman's terms?
"Understanding and quantifying the
response of natural systems to global climate
change is therefore essential for the
development of climate change mitigation
strategies."
The mountain pine beetle rapidly kills its host trees, reduces the uptake
of carbon from the atmosphere and increases the release of carbon as
beetle-killed trees decompose. Our analyses demonstrate that, compared to a
model run without the impacts of the bark beetle, nearly one billon tons of
carbon dioxide (CO2) are added to the atmosphere over the
21-year analysis period.
The current mountain pine beetle outbreak is unprecedented in its
geographic range and scale and is in part a response to climate change.
Because the beetle contributes to additional increases of atmospheric
carbon dioxide, the insect disturbance provides feedback between future
climate change and the carbon cycle.
How did you become involved in this research, and
were there any problems along the way?
Over the past twenty years we have developed the CBM-CFS3 and applied the
tool to analyses that advance the understanding of the contribution of
Canada's forests to the global carbon cycle. The team for this paper
brought together expertise on the carbon cycle, forest dynamics, and the
mountain pine beetle. This interdisciplinary approach allowed us to
overcome several scientific challenges, to synthesize existing data, and to
develop projections for the near future.
Where do you see your research leading in the
future?
Our team continues to research the impacts of forest management and natural
disturbances on the carbon balance of Canada's forests. A second large
insect outbreak (eastern spruce budworm) is just starting in central Canada
and it too will have impacts on the carbon balance.
Our research also seeks to identify mitigation options in the forest
sector. For example, can we improve the greenhouse gas balance by salvage
logging of trees killed by insects or wildfire and using the biomass for
bioenergy to offset fossil fuel emissions? Can we identify mitigation
options with the greatest benefits to the atmosphere? And how can we
facilitate and accelerate the rates of carbon uptake in forests affected by
natural disturbances?
Do you foresee any social or political implications
for your research?
Our analyses documented one example in which early impacts of global
climate change on Canada's forests increased the extent of a natural
disturbance. Higher temperatures and more frequent droughts are predicted
to increase the area annually burned by wildfires more than three-fold in
Western Canada and Alaska in the course of this century.
Large-scale natural disturbances, tree mortality from drought and other
extreme events, and the increased release of soil carbon due to higher
temperatures are all examples of ecosystem responses that contribute to
higher atmospheric greenhouse gas concentrations.
Such ecosystem responses would greatly increase the level of human efforts
required to meet atmospheric greenhouse gas stabilization targets.
Understanding and quantifying the response of natural systems to global
climate change is therefore essential for the development of climate change
mitigation strategies.
Werner Kurz, Ph.D.
Senior Research Scientist
Global Change and Landscape Ecology
Natural Resources Canada
Canadian Forest Service
Victoria, BC, Canada Web |
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