https://www.nationalobserver.com/2018/04/20/news/worst-case-scenario-trees-big-parts-canadas-boreal-forest-will-probably-die-says
[links and images in on-line article]
In worst case scenario, the trees in big parts of Canada's boreal forest
'will probably die,' says federal scientist
By Carl Meyer in News | April 20th 2018
Large portions of Canada’s vast boreal forest could be at risk of dying
off by the end of the century, as climate change will dramatically
aggravate the risk of wildfires, drought and insect infestations, say
government scientists in a groundbreaking new study.
Even by mid-century, parts of Canada’s 270-million hectares of boreal
forest that purifies water and air, regulates the climate and stores
carbon will already be at heightened risk of devastating fires like the
ones seen in Fort McMurray, Alberta in 2016, the Northwest Territories
in 2014 and the James Bay area in 2013, according to scientists in the
Canadian Forest Service.
“The conditions that are driving those kinds of big fires...will be much
more prevalent in the future, and they will occur much more often,” said
Yan Boulanger, a research scientist in forest ecology at the service’s
Laurentian Forestry Centre, and one of seven authors of a peer-reviewed
study published April 12 in the scientific journal Ecological Applications.
The lethal wildfire that swept through Fort McMurray in 2016 forced
88,000 people to evacuate, the largest in Alberta history, and ravaged
$3.8 billion worth of property. It raged for 15 months and burned down
close to 6,000 square kilometres. Canada lost around one per cent of its
entire GDP in the second quarter that year due to the fire.
“We have a problem in big parts of Canada, when you see 100 per cent of
the volume (of trees), in the worst case scenario, will probably die,”
said forest ecology biologist Dominique Boucher, another author of the
study. National Observer spoke with both scientists on April 18 to
discuss their findings.
The worst case scenario that she was referring to would be a model that
has been studied by climate scientists in which humans failed to scale
back consumption of fossil fuels, leading to a global temperature rise
of up to 4.8 C before the end of the 21st century.
Climate to be more 'suitable' for mountain pine beetle
The study used recent nationwide data compiled by the forest service
that estimated the volume of trees across Canada in 2001. The scientists
then combined this information with detailed climate projection
scenarios designed by the Intergovernmental Panel on Climate Change to
factor in anticipated changes in emissions, population and economic growth.
They then used these models to estimate how the boreal forest might
respond to the four most critical natural disturbances it currently
faces: wildfires, droughts, and two insect outbreaks — in the east, the
spruce budworm, and in the west, the mountain pine beetle.
Fires and infestations are currently major issues, while drought is
expected to play an increased role as climate change intensifies. "It is
becoming warmer in the future, and drier," said Boulanger.
The four disturbances are driven by temperature and precipitation, both
significant components of climate change. Scientists say carbon
pollution in the atmosphere is warming the planet and changing the water
cycle. The climate will be much more suitable for the mountain pine
beetle, said Boulanger, and more suitable for large and frequent fires.
“If those natural disturbances are increasing in future, there will be a
great impact on the trees themselves, on the mortality potential,” said
Boulanger.
“What we found is that there is an increase in those disturbances.
Timber volume will be much more at risk to mortality in the future, in
some specific areas. Some places will be more affected by fire, other
places will be more affected by certain insect outbreaks,” he said.
Tree risk changing in coming decades
Effectively managing Canada's boreal forest is crucial for the planet,
as the country holds almost a third of Earth's boreal zone. The forests
and the earth under them also support jobs and communities, provide food
and resources and are home to 70 per cent of Indigenous communities.
A high risk of fire and resulting risk of tree death appears in central
Quebec as early as 2040, according to the paper, titled “Current and
projected cumulative impacts of fire, drought and insects on timber
volumes across Canada.”
“When disturbance effects are cumulated, important changes in volumes at
risk are projected to occur as early as 2011-2041, particularly in
central and eastern Canada,” the paper reads.
“In our last simulation period covering 2071 to 2100, nearly all timber
volumes in most of Canada’s forest regions could be at risk of being
affected by at least one of the four natural disturbances considered in
our analysis, a six-fold increase relative to the baseline period
(1981-2010).”
Boucher said she took the models designed by Boulanger and others and
studied their overlap. The scientists had to account for the interaction
between the disturbances, to make sure they don’t count trees dying off
twice. This is part of the novelty of the study, as earlier research
looked at the threats more in isolation, they said.
As well, they had to account for dynamic factors, as climate change
continues to alter the face of the planet through the century. For
example, scientists already know that climate change is significantly
stunting the growth of black spruce — the iconic boreal tree in Canada,
stretching from one end of the country to the other — and it’s expected
to stunt the growth of other trees over time.
Another dynamic factor is that the probability of tree death is affected
by the frequency of wildfires in unpredictable ways. Increased fires
could lead to less trees, for example, which might also mean less fuel
for other fires. “We are not projecting, for example, in the future,
what will be the (timber) harvest..we’re just saying...what would happen
to this volume if we made it experience the climate of the future?” said
Boulanger.
Safe trees could be lower than current harvests
What’s clear is that the provinces and territories, which have
jurisdiction over most forests in Canada, will have to take research
like this into account when planning future laws and regulations. That's
because at some point during the century, the amount of timber being
regularly harvested will become greater than what is beyond the reach of
the disturbances studied.
“By 2100, estimated wood volumes not considered to be at risk could be
lower than current annual timber harvests in central and eastern
Canada,” states the paper. “Current level of harvesting could thus be
difficult to maintain without the implementation of adaptation measures
to cope with these disturbances.”
The study was carried out in parallel with other research by the forest
service that aims to map the probability of wildfires in most permanent
settlements in the boreal forest of Canada. That work, when completed,
will bring more precision to this study, said Boulanger, allowing the
scientists to better define particular areas where the probability of
fire is greater.
Two other authors of the paper, remote sensing and spatial modeling
research scientist André Beaudoin and remote sensing project manager Luc
Guindon, have also been working on turning a large amount of satellite
data into forest maps.
Large portions of Canada’s vast boreal forest could be at risk of dying
off by the end of the century, as climate change will dramatically
aggravate the risk of wildfires, drought and insect infestations, say
government scientists in a groundbreaking new study.
Even by mid-century, parts of Canada’s 270-million hectares of boreal
forest that purifies water and air, regulates the climate and stores
carbon will already be at heightened risk of devastating fires like the
ones seen in Fort McMurray, Alberta in 2016, the Northwest Territories
in 2014 and the James Bay area in 2013, according to scientists in the
Canadian Forest Service.
“We have a problem in big parts of Canada, when you see 100 per
cent of the volume (of trees), in the worst case scenario, will probably
die,” said federal forest ecology biologist Dominique Boucher.
“The conditions that are driving those kinds of big fires...will be much
more prevalent in the future, and they will occur much more often,” said
Yan Boulanger, a research scientist in forest ecology at the service’s
Laurentian Forestry Centre, and one of seven authors of a peer-reviewed
study published April 12 in the scientific journal Ecological Applications.
The lethal wildfire that swept through Fort McMurray in 2016 forced
88,000 people to evacuate, the largest in Alberta history, and ravaged
$3.8 billion worth of property. It raged for 15 months and burned down
close to 6,000 square kilometres. Canada lost around one per cent of its
entire GDP in the second quarter that year due to the fire.
“We have a problem in big parts of Canada, when you see 100 per cent of
the volume (of trees), in the worst case scenario, will probably die,”
said forest ecology biologist Dominique Boucher, another author of the
study. National Observer spoke with both scientists on April 18 to
discuss their findings.
The worst case scenario that she was referring to would be a model that
has been studied by climate scientists in which humans failed to scale
back consumption of fossil fuels, leading to a global temperature rise
of up to 4.8 C before the end of the 21st century.
File photo of forest ecology research scientist Yan Boulanger and forest
ecology biologist Dominique Boucher, two of the seven authors behind a
new study on the impact of fire, drought and insects on Canada's boreal
forest. Photo courtesy Boulanger
Climate to be more 'suitable' for mountain pine beetle
The study used recent nationwide data compiled by the forest service
that estimated the volume of trees across Canada in 2001. The scientists
then combined this information with detailed climate projection
scenarios designed by the Intergovernmental Panel on Climate Change to
factor in anticipated changes in emissions, population and economic growth.
They then used these models to estimate how the boreal forest might
respond to the four most critical natural disturbances it currently
faces: wildfires, droughts, and two insect outbreaks — in the east, the
spruce budworm, and in the west, the mountain pine beetle.
Fires and infestations are currently major issues, while drought is
expected to play an increased role as climate change intensifies. "It is
becoming warmer in the future, and drier," said Boulanger.
The four disturbances are driven by temperature and precipitation, both
significant components of climate change. Scientists say carbon
pollution in the atmosphere is warming the planet and changing the water
cycle. The climate will be much more suitable for the mountain pine
beetle, said Boulanger, and more suitable for large and frequent fires.
“If those natural disturbances are increasing in future, there will be a
great impact on the trees themselves, on the mortality potential,” said
Boulanger.
“What we found is that there is an increase in those disturbances.
Timber volume will be much more at risk to mortality in the future, in
some specific areas. Some places will be more affected by fire, other
places will be more affected by certain insect outbreaks,” he said.
A map from the new study by seven Canadian federal scientists that shows
the volume of boreal forest at risk in four time periods. The map shows
that by the final period, 2071-2100, a large portion of the boreal
forest is at risk of death. Screenshot of study
Tree risk changing in coming decades
Effectively managing Canada's boreal forest is crucial for the planet,
as the country holds almost a third of Earth's boreal zone. The forests
and the earth under them also support jobs and communities, provide food
and resources and are home to 70 per cent of Indigenous communities.
A high risk of fire and resulting risk of tree death appears in central
Quebec as early as 2040, according to the paper, titled “Current and
projected cumulative impacts of fire, drought and insects on timber
volumes across Canada.”
“When disturbance effects are cumulated, important changes in volumes at
risk are projected to occur as early as 2011-2041, particularly in
central and eastern Canada,” the paper reads.
“In our last simulation period covering 2071 to 2100, nearly all timber
volumes in most of Canada’s forest regions could be at risk of being
affected by at least one of the four natural disturbances considered in
our analysis, a six-fold increase relative to the baseline period
(1981-2010).”
Boucher said she took the models designed by Boulanger and others and
studied their overlap. The scientists had to account for the interaction
between the disturbances, to make sure they don’t count trees dying off
twice. This is part of the novelty of the study, as earlier research
looked at the threats more in isolation, they said.
As well, they had to account for dynamic factors, as climate change
continues to alter the face of the planet through the century. For
example, scientists already know that climate change is significantly
stunting the growth of black spruce — the iconic boreal tree in Canada,
stretching from one end of the country to the other — and it’s expected
to stunt the growth of other trees over time.
Another dynamic factor is that the probability of tree death is affected
by the frequency of wildfires in unpredictable ways. Increased fires
could lead to less trees, for example, which might also mean less fuel
for other fires. “We are not projecting, for example, in the future,
what will be the (timber) harvest..we’re just saying...what would happen
to this volume if we made it experience the climate of the future?” said
Boulanger.
Centre Foresterie Laurentides, insects, forestry, scientist
Laurentian Forestry Centre scientist André Beaudoin, one of the authors
of the study, demonstrates data used to create maps of Canada's forests
on Sept. 27, 2017. Photo by Clothilde Goujard
Safe trees could be lower than current harvests
What’s clear is that the provinces and territories, which have
jurisdiction over most forests in Canada, will have to take research
like this into account when planning future laws and regulations. That's
because at some point during the century, the amount of timber being
regularly harvested will become greater than what is beyond the reach of
the disturbances studied.
“By 2100, estimated wood volumes not considered to be at risk could be
lower than current annual timber harvests in central and eastern
Canada,” states the paper. “Current level of harvesting could thus be
difficult to maintain without the implementation of adaptation measures
to cope with these disturbances.”
The study was carried out in parallel with other research by the forest
service that aims to map the probability of wildfires in most permanent
settlements in the boreal forest of Canada. That work, when completed,
will bring more precision to this study, said Boulanger, allowing the
scientists to better define particular areas where the probability of
fire is greater.
Two other authors of the paper, remote sensing and spatial modeling
research scientist André Beaudoin and remote sensing project manager Luc
Guindon, have also been working on turning a large amount of satellite
data into forest maps.
In addition to Boucher, Boulanger, Beaudoin and Guindon, the other
authors are: forest vegetation ecologist Isabelle Aubin; forest
productivity research scientist Pierre Bernier and forest succession
research scientist Sylvie Gauthier.
