The end of the Ice Age in coastal British Columbia may indicate what will happen to shrinking ice sheets in Greenland, study indicates

If some travellers, perhaps about 12,000 years ago, had headed up what is now called Douglas Channel, around the north end of Hawkesbury Island they likely would have seen a glacial retreat driven by a warming planet, something very familiar to the television viewers of 2017, video of 21st century coastal Greenland, where massive glaciers are calving ice bergs into the ocean.

The history of rapid glacial retreat over several thousand years from the interior and coastal British Columbia at the end of the last Ice Age is now becoming a crucial indicator of what may happen to both Greenland and the Antarctica. Under the current ice sheets both Greenland and parts of Antarctica are mountain ranges similar to those here in British Columbia. According to new research published to today in Science, that may indicate what could happen as those ice sheets melt and how that will affect  volatile climate change.

The paper written by Brian Menounos of the University of Northern British Columbia and co-authors indicates that the glacial retreat  in BC was faster than previously believed, beginning about 14,000 years ago. That left some parts of  coastal and western  BC ice free, rather than beginning 12,500 years ago as previously estimated. The last Ice Age probably reached its maximum coverage about 20,000 years ago.

One of the cirque moraines at the end of a glacier studied by Brian Menounos and his team. It is in northern British Columbia just south of the Yukon border. ( Brian Menounos/Science plus Google Earth)

The decay of the ice sheet was complex, partly due to presence of mountainous terrain and also because Earth’s climate rapidly switched between cold and warm conditions during the end of the last Ice Age.
One of the factors that may have triggered a climate change back to colder conditions was a massive outflow of cold, fresh water from coastal British Columbia, which may have affected ocean currents.

What geologists call the Cordilleran ice sheet once covered all of present-day British Columbia, Alaska and the north Pacific United States. How the Cordilleran ice sheet responded to climate change was different from the Laurentide ice sheet which covered the flatter terrain (prairie and the Canadian Shield) of central North America. The Cordilleran ice sheet is about the same size as the current Greenland ice sheet.

“Our work builds upon a rich history of collaborative research that seeks to understand when and how quickly the Cordilleran ice sheet disappeared from Western Canada,” Menounos says. “Projected sea level rise in a warming climate represents one of the greatest threats to humans living in coastal regions. Our findings are consistent with previous modeling studies that show that abrupt warming can quickly melt ice sheets and cause rapid sea level rise.”

Menounos, the Canada Research Chair in Glacier Change, teamed up with 14 co-authors from Canada, the United States, Sweden, Switzerland and Norway to produce the paper titled Cordilleran Ice Sheet mass loss preceded climate reversals near the Pleistocene Termination.

One of the co-authors of the paper is John Clague, now a professor emeritus of Earth Science at Simon Fraser University who studied the glaciation patterns in the Kitimat valley and Terrace in the 1970s when he worked for the Geological Survey of Canada.

Earlier researchers, including Clague, relied on radiocarbon dating to establish when the ice sheets disappeared from the landscape. The problem is that radiocarbon dating may not work in higher alpine regions where fossil organic matter is rare (above the tree line).

Menounos and the researchers used surface exposure dating – a technique that measures the concentration of rare beryllium isotopes that accumulate in quartz-bearing rocks exposed to cosmic rays – to determine when rocks first emerged from beneath the ice. If the rocks are under an ice sheet that means they are not exposed to cosmic rays, and thus measuring the beryllium isotopes can indicate when the retreating ice exposed the rocks to the cosmic rays.

The scientists studied small “cirque moraines” found only beyond the edge of modern glaciers high in the mountains, and valley moraines.

The alpine cirque moraines could not have formed until after the Cordilleran ice sheet had retreated. Menounos and his team show that several alpine areas emerged from beneath the ice sooner than previously believed. Then once the mountain peaks emerged from the thinning ice, new, smaller glaciers grew back over the high-elevation cirques at the same time that remnants of the ice sheet “reinvigorated” in the valleys during subsequent climate reversals

Most of the work of the team was done in the interior of British Columbia, the Yukon and Northwest Territories. Menounos says that new, similar work is being done on the mountains of the coastal region which will be published when the research is complete.

At its maximum, the Cordilleran ice sheet likely extended from what is now the mainland coast across Hecate Strait to the east coast of Haida Gwaii.

Starting about 14,500 years ago, the planet entered a phase of warming, with the average temperature rising about 4 degrees Celsius over about a thousand years. The Cordilleran ice began to thin rapidly leaving what the paper calls a “labyrinth of valley glaciers,” which then allowed the alpine glaciers to re-advance.

Diagram from Science shows how the glaciers retreated at the end of the last Ice Age, with the mountainous Cordilleran ice sheet behaving differently from the central North American Laurentide ice sheet (Science)

The scientists have suggested the rapid ice loss, beginning 14,500 years ago, came relatively quickly in geological time, perhaps just 500 years. That may have then contributed to subsequent Northern Hemisphere cooling through freshwater rushing into the ocean. That melt water disrupted the overturning ocean circulation of cold and warm water. That led to a new cooling period that lasted from about 14,000 to 13,000 years ago. (Similar to the completely fictional scenario in the movie The Day After Tomorrow,  where the cooling happens in days not centuries).

That same outflow could have raised then existing sea levels by two and half to three metres, Menounos says. (The overall sea level on Earth rose about 14 metres by the end of the Ice Age)

Then the climate reversed again, first briefly warming and then in a period that saw another abrupt change back to cooler conditions which geologists call the Younger Dryas,   The Younger Dryas occurred beginning about 12, 900 years ago to about 11,700 years ago, when warming began again. The Dryas is named after a wildflower that grows in arctic tundras.

The study indicates that the First Peoples could not have settled the interior of what is now British Columbia prior to the Younger Dryas, but it is likely as was explored in a paper last week in Science that the First Peoples were able to come down the “kelp highway” on the coast by at least 14,000 years ago.

Map of British Columbia showing the extent of the glaciation during the last Ice Age and now the ice retreated. The coloured graphics are where the study was done mostly in the interior of BC and the age of the deposits. KA means kilo-years or thousand years ago. (Science)

So what happened in Douglas Channel?

So what does the new study of glacial retreat mean for the history of Douglas Channel?

John Clague studied the Douglas Channel, the Kitimat Valley and the Terrace area in the 1970s and was one of the co-authors of the current study that provides a new timeline for the retreat of the glaciers on the British Columbia coast.

He says that the timeline from his work in the 1970s with radio carbon dating of fossilized organic material is fairly consistent with the new work by Brian Menounos of the University of Northern British Columbia using the beryllium isotope technique.

The paper, Clague says, is more of a general commentary on the last stages of the decay of the Cordilleran ice sheet.

“At the time we’re taking about in the paper, there was ice in the corridor between Kitimat and Terrace.

“What we see in detail based on the work I did ages ago, is the retreat of the glacier from the Kitimat Arm back to the north towards Terrace [in the Young Dryas ]. It occasionally stabilized and the melting ice discharged a lot of sediment into that marine embayment.

Based on his original work and the new study Clague says at the time, the mountains are beginning to become ice free but there was still ice in the major valleys such as the Skeena Valley and the corridor south of Terrace towards Kitimat.

“They’re overlapping stories.” Clague says.

“The ice sheet hadn’t completely disappeared at the time Brian is focusing on,” Clague says. “His point is that a lot of the mass of the ice sheet appeared to be thinning and through marginal retreat from Haida Gwaii and some of the islands off the mainland back toward the mainland itself. So we’re trying to put a chronology on it, as to the various steps in the glacial decay.”

The work seems to indicate that the final ice sheet retreat happened in four stages around 12,000 to 11,000 years ago. “I was interested in the detailed reconstruction of the ice front tracked north from Kitimat you see a number of periods when it stabilized long enough to build up very large deltas and braided melt water plains,” Clague says.

The first moraine is Haisla Hill in Kitimat, where the glaciers discharged large amounts of sediment into what is now Douglas Channel. The second is the hill leading to what is called Onion Flats, the third is the flat area where the Terrace Kitimat Regional Airport now is and the final stage of glacial retreat created the “terraces’ around Terrace and Thornhill.

“It’s interesting that in this area there was so much sediment discharged into the sea remarkably for the time over which the ice was retreating through the area. It had to have been a major kind of discharge point of water from the ice sheet south from Terrace towards Kitimat otherwise you wouldn’t get that huge amount of sediment deposited probably over a period of a thousand years. Then it retreated again to just north of the airport and anchored there for a while and we found evidence for a final last gasp upstream around Thornhill and that kind of near Terrace.”

“At that time some of the high elevation glaciers were re-energized and readvanced, but it probably didn’t affect the overall health of the ice sheet itself It’s such a big mass of ice that it doesn’t respond quickly to such a brief cooling so what we’ve done in many places is these glaciers actually advanced up against ‘the dead ice’ an ice sheet that was lower in elevation.”

At the times the oceans rose at the end of the Ice Age, there were “sea corridors” between Kitimat and Terrace and also in the Skeena Valley. “So you can imagine there were arms of the sea extending to Terrace from two directions almost making that area which is now part of the mainland an island.” But the region likely never did become a true island, Clague says because as the ice sheets retreated,, they were also shedding large amounts of sediment that would become land area at the same time as the earth’s crust was rebounding once it was freed from the weight of the ice sheet.

 

 

 

 

Photo op or engagement? How the Harper government failed in the northwest

Bear totem at UNBC
The bear totem at the University of Northern British Columbia, one of the backdrops considered by Natural Resources for an announcement by Joe Oliver. (UNBC)

If anyone wanted a snapshot (or for younger folks a selfie) of why the Harper government grounded out at home, never even getting to first base  with northwestern British Columbia on Northern Gateway and other resource projects, it can be found in about sixty pages of  documents, obtained by Northwest Coast Energy News under the Access to Information Act, documents that outline the planning for former Natural Resources Minister Joe Oliver’s first visit to Terrace in March 2013

  • The documents reveal the priority for Natural Resources communications staff was mainly finding an appropriate First Nations visual backdrop for Oliver’s speech announcing the appointment of Douglas Eyford as special representative to First Nations, the Harper government’s attempt to smooth relations as it dawned on the government that opposition to Northern Gateway wasn’t just going to disappear.
  • Despite years of media coverage from both those opposed to and even those who support the Northern Gateway project that highest priority issue was preventing oil spills whether from tankers or pipelines, the Ottawa-based communications planners in Natural Resources Canada were talking about how aboriginal and non-aboriginal communities could respond to oil spills.
  • For an event that was supposed to engage the First Nations of coastal British Columbia and gain their support for resource projects, all the economic examples are about Alberta First Nations who are working the extraction of bitumen in Alberta, there are no example of how BC First Nations might profit from Northern Gateway (that is if any BC First Nations actually wanted to do so)
  • A visit to Kitimat, the centre of the debate, wasn’t even on the radar in March, 2013, as Joe Oliver, then Minister of Natural Resources, even though Kitimat is just a 40 minute drive from the site of the announcement at the Terrace campus of Northwest Community College.

When Natural Resources Canada started planning Joe Oliver’s announcement they created what was called a “Message Event Proposal” which even in its title shows how the government and the communications staff think. The message is more important than the event.

Northwest Coast Energy News
Finding a background with a First Nations focus was a high priority for Natural Resources Canada in choosing Northwest Community College in Terrace for an announcement by Minister Joe Oliver on March 19, 2013. (Robin Rowland/Northwest Coast Energy News)

The planning documents from Natural Resources, starting on March 5, 2013, indicate that from the beginning the announcement was being treated as a photo op. Invitations to or participation by “stakeholders” are listed as N/A “not applicable,” which meant that meetings, even private meetings, with representatives of northwestern First Nations and other communities either weren’t considered or the communications staff weren’t informed. (If there were such plans they were not part of the access documents released and as far as Northwest Coast Energy News can find out no meetings took place since Oliver left for Ottawa immediately after the announcement)

The documents show that there were no plans to involve "stakeholders" in Joe Oliver's announcement.
The documents show that there were no plans to involve “stakeholders” in Joe Oliver’s announcement.

The Natural Resources communications staff were working on multiple angles in March, as part of what the planning documents call “a suite of events in Vancouver on marine and pipeline safety.”

The first set of those events would eventually take place on March 18, 2013, in Vancouver, and included the announcement, without consulting either Rio Tinto Alcan or the District, that Kitimat’s private port run by Alcan since it was first built would be turned in a federal public port.

The announcement of Eyford’s appointment  would eventually take place at the Waap Galts’ap community long house at Northwest Community College in Terrace on the morning of March 19.

That location certainly wasn’t clear at first. The first documents suggested the announcement take place in Vancouver, and then a day later on March 6, the proposed venue, according to the staff, was in either Prince Rupert or Prince George.

According to the internal e-mails, sometime that week what Ottawa bureaucrats call MINO — the minister’s office– decided that the venue should be Terrace. On March 11, e-mails among Natural Resources staff show that the choice had changed to either Terrace or Prince George.

Since the “special representative” whom we now know would be Douglas Eyford, would report directly to Prime Minister Stephen Harper, the political level was involved.  MINO took over writing Oliver’s speech and the arrangements were copied to the Privy Council Office, the civil service branch that has overall supervision of the federal bureaucrats and works directly with the Prime Minister. So the speech that the communications branch had drafted for Oliver became “can please turn the one we had done for him into the remarks for the new guy?”

Plan B in Prince George

The choice of Terrace left the Natural Resources Ottawa staff hedging their bets, looking for a “potential plan B” in Prince George. The e-mails indicate that Ottawa asked  Natural Resources west coast communications officer for a list of suitable locations in Prince George.

The communications officer replied with three locations at the University of Northern British Columbia “a moving bear totem on campus” the main administration building which the e-mail said “ has a strong First Nations focus,” adding  “Environment Canada has done…events there. Strong FN visuals.” The third choice was “a new bio energy facility that looks industrial.”

Backups were The College of New Caledonia trade centre and the Prince George industrial park.

UNBC adminstration building
Natural Resources Canada also considered the “strong First Nations visuals” at the University of Northern British Columbia administration building. (UNBC)

NRCan email

 

UNBC bioenergy lab
The University of Northern British Columbia’s bioenergy facility. (UNBC)

E-mails from the staff on Wednesday, March 14 and Thursday, March 15, showed while they were now aware the event would be in Terrace, and probably at Northwest Community College, there was still a lot of uncertainty. “We haven’t been able to contact them to confirm, but as soon as we do, we will let you know the exact details as well as what is required in terms of logistics.”

Remembering that Natural Resources and Transport Canada were also planning the Vancouver event on Monday, March 18, it appears that even as Oliver arrived on the morning of March 19, the minister’s staff both political and bureaucratic were still scrambling.

On March 19, the NWCC staff on site were complaining that as soon as the Ottawa delegation saw the standard arrangements for an event at the Waap Galts’ap community long house they ordered the NWCC staff to immediately rearrange the room, so that the podium was in front of one wall with what Oliver’s staff thought was a better First Nations painting. That rearranging was still going on when I arrived to cover the announcement.

Joe Oliver
Joe Oliver tries out a heavy equipment simulator at Northwest Community College on March 19, 2013, prior to his speech. (Robin Rowland/Northwest Coast Energy News)

Even after the furniture was rearranged, the start was delayed as Oliver and his staff disappeared into an upstairs room for a meeting before the news conference began, and Oliver announced Eyford’s appointment.

During the question and answer session with the media during the news conference, the students that had essentially been brought in as props for the photo op and to help promote Northwest Community College’s industrial training program, began to ask questions.

news conference
Joe Oliver listens to a question from a student at the Northwest Community College news conference. (Robin Rowland/Northwest Coast Energy News)

One student asked Oliver if Eyford’s appointment was going to replace “all talks” with First Nations about resource projects. The Natural Resources public relations staff tried to cut off one student, since the national media were waiting on a telephone conference call. To his credit, Oliver did answer the student’s question, saying Eyford’s appointment was not intended to “replace the independent, regulatory review.” He went on to explain the Northern Gateway Joint Review would continue its work and report at the end of 2013.

What was Ottawa thinking? You too, can respond to an oil spill.

If the aim was to engage the First Nations and other residents of northwestern BC, it is clear that the concerns of this region hadn’t reached out Ottawa.

It appears from the planning documents for Joe Oliver’s trip to Terrace, that a main concern of everyone in the northwest, aboriginal and non-aboriginal, opponents and supporters of the Northern Gateway pipeline, preventing oil spills also wasn’t on the government radar, rather it was preparing and responding to oil spills.

Guess who would respond?

As part of the measures to strengthen Canada’s Marine Oil Spill Preparedness and Response Regime, the Government of Canada will strengthen the engagement and involvement of Aboriginal and non-aboriginal communities in preparing for and responding to oil spills.

oilspill

When it comes to a key section on benefits from the Northern Gateway and other resource projects, there is no mention of benefits to British Columbia; rather it appears all the examples of benefits for aboriginal communities come from Alberta, including $1.3 billion in contract work for oil sands companies not including construction, for the year 2010, and $5 billion since 2001. The Message Event Proposal also cites a joint venture between the Bigstone Cree and Bronco Energy, “the biggest oil sands project every undertaken on First Nations reserve lands.”

economicbenefit

Overall the plan was to “Promote Canada’s commitment to achieving its goals under its plan for Responsible Resource Development, including increased consultations with Aboriginal peoples.”

The “media lines’ issued by Natural Resources also outlined the Harper government’s attitude to the Northern Gateway, noting that Eyford’s appointment was independent of the Northern Gateway Joint Review, and went to indicate that the JRP was “conducting a rigorous, extensive, open, science-based assessment.” It adds that “we will continue to rely on the integrity of this process,” again showing how out of touch Natural Resources was (at least in talking points) since by March 2013, there was growing consensus in the northwest that the JRP had lost its credibility.gateway1
gateway2

The media lines also show that the Harper government believed that “Aboriginal consultations are fully integrated into the review process to ensure meaningful consultation occurs,” a position that most First Nations in British Columbia reject, insisting on meaningful consultations between the Crown and the First Nation.

consultation1

When Eyford presented his report to the Prime Minister in December, 2013, Eyford called for stronger action to engage First Nations opposed to new oil and gas pipelines.

“It’s never too late to engage and do so in a process of good faith negotiations… “This won’t be an easy process. I hope my report is perceived as providing objective and blunt advice to all the parties engaged in this process.’’

The 53 page report contained dozens of recommendations mainly concerned with a more open and principled dialogue with First Nations.

“The development of West Coast energy infrastructure provides an opportunity to forge partnerships and build relationships. There is a strong interest and real opportunity for Canada and aboriginal Canadians to more effectively collaborate to address their respective interests.’’

Editor’s note:  On the port issue, an RTA spokesperson noted that talks with the federal government are continuing. He noted that all the Kitimat port facilities are privately owned, by Rio Tinto Alcan or by LNG Canada and there are “multiple stakeholders” involved.

Documents

Natural Resources Media Lines  (pdf)

Natural Resources Message Event Proposal  (pdf)

Forging Trust Douglas Eyford’s final report  (pdf)

Related Links

Joe Oliver makes flying visit, meets Haisla, snubs Kitimat (almost)

Harper government to District of Kitmat Drop Dead

Genetics show stronger pine beetle evolving; stream flow increases in infected forests: studies

A new study, based at the University of Alberta, released this week, indicates that natural selection may be making the mountain pine beetle more tolerant of colder temperatures and that the beetle may be evolving the ability to fly longer distances.

A second study, from the Colorado School of Mines, also released this week, is tracking how the extent of pine beetle infected or killed trees in forests is changing ground water and stream flows.

The mountain pine beetle infestation has wreaked havoc in North America, across forests from the American Southwest to British Columbia and Alberta. Millions of hectares of forest have been lost, with severe economic and ecological impacts from a beetle outbreak ten times larger than previous ones.

Dust from beetle killed wood is believed partially responsible for the explosions at the Lakeland Mill in Prince George and the Babine Forest Products mill in Burns Lake. The explosion in early 2012 at the Babine Forest Products mill killed two workers and injured another twenty. The Lakeland Mill explosion killed two workers and injured twenty four others.

As part of the fight to contain the mountain pine beetle, scientists recently sequenced the pine beetle genome.

Using that genome, Jasmine Janes and colleagues at the University of Alberta, with assistance from the University of British Columbia and the University of Northern British Columbia, used genetics to track how the pine beetle was able to expand its range so rapidly. The study was published in Molecular Biology and Evolution.

Studied at molecular level

While teams of researchers have tracked the path of the pine beetle across BC on the ground, how the beetle spread so easily “is only beginning to be understood at the molecular level,” the study says.

Pine beetles were collected from 27 sites in Alberta and British Columbia. The University of Alberta scientists were especially interested in how the pine beetle was able to jump across the Rockies, something that earlier researchers believed would not happen.

By looking at the genetic markers, the team concluded that the pine beetle may have been able to spread by adjusting its cellular and metabolic functions to better withstand cooler climates and facilitate a larger geographic dispersal area.

In an e-mail to Northwest Coast Energy News, Janes said the research looked at genomic signatures to find out how the beetle had been able to spread into Alberta – where did it come from, what route did it take and how did it overcome the physical and climatic barriers that we had always assumed?

The research discovered that there are two genetically different populations of pine beetles, one from the south of British Columbia and Alberta and one in the north. Another group of pine beetles, found near Valemount, “were harder to classify as being from either north or south genetically. The beetles in this area were showing higher genetic diversity.”

The pine beetle has always been around and killed older trees (called “low quality hosts”), helping to renew the ecosystem. There were also larger five-year infestations that occurred on a 20 to 40 year cycle. The current pine beetle “epidemic” in BC has gone on now for more than 20 years, with the pine beetle “observed in previously unrecorded numbers” over a much wider area

It is generally believed that climate change has help the pine beetle survive milder winters.

The study notes:

Successful establishment of mountain pine beetle on pure jack pine in northern Alberta has raised concerns that the mountain pine beetle will continue to expand its range into the vast boreal forest of jack pine that extends across North America from the Northwest Territories to the Atlantic Coast.

The teams concludes that one group of the beetles originated in southwestern BC perhaps from Whistler or Manning Park. Then the beetles spread north up the west coast of BC toward Houston “with rapid population size increases in central and northern BC and then dispersed long distances with prevailing winds toward the east and Alberta.”

Some of the beetles from southwestern BC appear to have taken a different route, moving more slowly eastward in the south of BC toward Crowsnest Pass area and then moving northward along the base of the Rockies, Janes said, adding. “Our research suggests that these two routes have then met in the middle again, around Valemount and that is why we see the genetic patterns across the landscape that we observed.”

Selective pressure

The second part of the research was answering the question of how the beetles were able to do this. How could they withstand the colder temperatures to spread further north and east?

To answer the scientists used the same genetic markers (single nucleotide polymorphisms) to conduct “selective sweeps” of the beetle genome. The sweeps look for unusual genetic markers that could indicate the beetles are under “selective pressure.”

The study looked at specific functions in the beetle: the genes that govern “actin filaments” that “control muscle contractions like shivering and moving wings”; “the synthesis of cholesterol that provides energy for metabolic activities” and transport of ions across cell membranes.

Normally, female pine beetles can only fly short distances to find a new host tree to lay eggs. They can travel longer distances if they are up in the tree canopy and are then carried by the wind. Stronger pine beetles that can fly longer distances show the threat is likely evolving.

The study concludes that Canadian Mountain Pine Beetle range expansion:

may continue as populations are currently exhibiting signals of selection. These signals suggest ongoing adaptation of metabolic and cellular processes that could potentially allow them to withstand colder temperatures, shift developmental timing and facilitate longer dispersal flights.

Janes said further research is required to fully validate and understand these signatures of selection, but it does suggest that the beetle is adapting and that is why it “may have been able to breach the Rocky Mountains”

Water and trees

Precipitation samples
Colorado scientists collected precipitation samples to determine their unique chemical fingerprints. ( Lindsay Bearup/Colorado School of Mines)
In Colorado alone, the mountain pine beetle has caused the deaths of more than 3.4 million acres of pine trees. The new research findings show the consequences of an obvious observation: Dead trees don’t drink water

The Colorado study asked how all those dead trees are changing stream flow and water quality?

“The unprecedented tree deaths caused by these beetles provided a new approach to estimating the interaction of trees with the water cycle in mountain headwaters like those of the Colorado and Platte Rivers,” said Reed Maxwell a hydrologist at the Colorado School of Mines.

Maxwell and colleagues have published results of their study of beetle effects on stream flows in this week’s issue of the journal Nature Climate Change.

As the trees die, they stop taking up water from the soil, known as transpiration. Transpiration is the process of water movement through a plant and its evaporation from leaves, stems and flowers.

The “unused” water then becomes part of the local groundwater and leads to increased water flows in nearby streams.

“Large-scale tree death due to pine beetles has many negative effects,” says Tom Torgersen of the US National Science Foundation’s Directorate for Geosciences and program director for the NSF’s Water, Sustainability and Climate program.

“This loss of trees increases groundwater flow and water availability, seemingly a positive,” Torgersen says.

“The total effect, however, of the extensive tree death and increased water flow has to be evaluated for how much of an increase, when does such an increase occur, and what’s the water quality of the resulting flow?”

Under normal circumstances, green trees use shallow groundwater in late summer for transpiration.

Red- and gray-phase trees–those affected by beetle infestations–stop transpiring, leading to higher water tables and greater water availability for groundwater flow to streams.

The Colorado study shows that the fraction of late-summer groundwater flows from affected watersheds is about 30 per cent higher after beetles have infested an area, compared with watersheds with less severe beetle attacks.

“Water budget analysis confirms that transpiration loss resulting from beetle kill can account for the increase in groundwater contributions to streams,” write Maxwell and scientists Lindsay Bearup and John McCray of the Colorado School of Mines, and David Clow of the U.S. Geological Survey, in their paper.

Dead trees create changes in water quality

“Using ‘fingerprints’ of different water sources, defined by the sources’ water chemistry, we found that a higher fraction of late-summer stream flow in affected watersheds comes from groundwater rather than surface flows,” says Bearup.

“Increases in stream flow and groundwater levels are very hard to detect because of fluctuations from changes in climate and in topography. Our approach using water chemistry allows us to ‘dissect’ the water in streams and better understand its source.”

With millions of dead trees, adds Maxwell, “we asked: What’s the potential effect if the trees stop using water? Our findings not only identify this change, but quantify how much water trees use.”

An important implication of the research, Bearup says, is that the change can alter water quality.

The new results, she says, help explain earlier work by Colorado School of Mines scientists. “That research found an unexpected spike in carcinogenic disinfection by-products in late summer in water treatment plants.”

Where were those water treatment plants located? In bark beetle-infested watersheds.

 

The TRIA project (a collaboration of researchers at the University of Alberta, University of British Columbia, University of Montreal, University of Northern British Columbia). The TRIA project investigates the physiology, genetics and ecology of all three players in the mountain pine beetle system – the pines (lodgepole and jack pine, and their hybrids), the beetle and the fungus (several types).

The Colorado study is funded by the National Science Foundation’s (NSF) Water, Sustainability and Climate (WSC) Program. WSC is part of NSF’s Science, Engineering and Education for Sustainability initiative.