How cli­mate change leaves Arc­tic cari­bou out in the cold

Com­peti­tors move in when shrubs start to grow in habi­tat: re­searchers

Edmonton Journal - - FRONT PAGE - Ed Struzik Jour­nal Staff Writer ED­MON­TON

Univer­sity of Al­berta bi­ol­o­gist Isla My­ers-smith and her col­league were tak­ing down their re­search camp in the Ruby Moun­tain Range when a snow­storm with winds of near hur­ri­cane force blew down their tent and sent their elec­tric gen­er­a­tor tum­bling down a hill­side.

For nearly three days, My­ers-smith and He­len Wheeler hun­kered down, eat­ing what lit­tle food they had and watch­ing ner­vously as the bat­ter­ies of their satel­lite phone got weaker and weaker.

Hun­gry and un­com­fort­able, they couldn’t even sleep be­cause their bat­tered tent was con­stantly flap­ping in the wind.

Re­al­iz­ing from ex­pe­ri­ence that such snow­storms can last for weeks in the Yukon, My­ers-smith be­gan won­der­ing what their fate would be af­ter spend­ing sev­eral months in the wilder­ness.

“I was never so re­lieved when the weather cleared up long enough for the he­li­copter to come in and get us,” says My­ers-smith. “It was nice to get out of there be­fore win­ter set in.”

This was My­ers-smith’s first year on a long-term study that Univer­sity of Al­berta sci­en­tist David Hik is con­duct­ing on the rapidly chang­ing land­scape of the alpine and tun­dra en­vi­ron­ment in the Yukon.

Up un­til then, most ev­ery­one knew that snow cover, cold tem­per­a­tures and high winds come early and of­ten to the Yukon, which is why much of the Arc­tic and sub-arc­tic world is cov­ered with lichens, mosses and other small plants that tend to grow low or hor­i­zon­tally along the frozen ground.

It’s also why these alpine and tun­dra en­vi­ron­ments tra­di­tion­ally favour cari­bou over deer and Arc­tic hares, Arc­tic fox, pikas, ground squir­rels and mar­mots over other smaller mam­mals that can’t han­dle the ex­treme cold.

But the lat­est work by My­ers-smith, Hik and 30 other re­searchers from 10 coun­tries in the world sug­gests that siz­able chunks of this alpine/ tun­dra world are be­ing taken over by shrub cover that is in­creas­ingly crowd­ing out those plants that many Arc­tic an­i­mals de­pend on.

“Cli­mate warm­ing may well be a rea­son why this is hap­pen­ing,” said My­ers-smith, who is the lead au­thor of a pa­per pub­lished re­cently in the sci­en­tific jour­nal En­vi­ron­men­tal

Re­search Let­ters. “But snow cover, nu­tri­ent avail­abil­ity and in­ter­ac­tions with other plant species may also be im­por­tant.”

An in­crease in shrub growth may not sound se­ri­ous when com­pared to the ad­vance of trees such as spruce, which some sci­en­tists be­lieve are mov­ing higher up in the alpine coun­try and closer to the Arc­tic coast as the cli­mate warms.

But shrubs such as alder, wil­low, dwarf birch and creep­ing ju­niper grow a lot faster than trees and they shade out sun­shine that lichens, mosses and other alpine and tun­dra plants need to thrive dur­ing a grow­ing sea­son that is of­ten mea­sured in weeks rather than months.

“Shrubs also trap snow, which in­su­lates soils in the win­ter, and shades soils in the sum­mer,” says My­ers-smith.

“Re­search has shown that soil in shrub-free zones can be al­most a cold as the air above it. But that same soil that lies be­neath shrubs in win­ter can be up to 30 de­grees warmer than the air tem­per­a­ture. This in­su­lat­ing and cool­ing can al­ter soil tem­per­a­tures, nu­tri­ent cy­cling and per­mafrost thaw.”

“Shrubs also seem to do best in a land­scape that is in­creas­ingly be­com­ing more dis­turbed,” she says. “The dark­en­ing of the sur­face as­so­ci­ated with shrubs grow­ing above snow could also ac­cel­er­ate snowmelt and cause re­gional warm­ing.”

For­est fire ex­perts and cli­ma­tol­o­gists such as Mike Flan­ni­gan of the Univer­sity of Al­berta are in­creas­ingly turn­ing their at­ten­tion to this world where there are no trees. The pro­lif­er­a­tion of woody shrubs could con­ceiv­ably in­crease the po­ten­tial for fu­ture tun­dra fires such as the one that burned 600 square kilo­me­tres of tun­dra in Alaska in 2007, putting as much car­bon into the at­mos­phere as the en­tire tun­dra world can store in a year. Woody shrubs can pro­duce a lot more fuel for wild­fires than most tun­dra plants.

The re­search that My­ers-smith and her col­leagues are do­ing can be painstak­ingly slow, of­ten con­ducted over sev­eral years in a world that is not al­ways wel­com­ing to hu­mans. Mos­qui­toes and wild weather make the field­work work ex­tremely try­ing and oc­ca­sion­ally dan­ger­ous.

While snow and wind storms are com­mon, there are also griz­zly bears, po­lar bears and even thun­der­storms to worry about.

Sev­eral years ago, My­ers-smith was work­ing with col­leagues in Alaska when a vi­o­lent thun­der­storm moved in. They knew they were in se­ri­ous trou­ble when their hair stood on end from the static electricit­y pro­duced by the light­ning.

“It got to the point where I could feel this in­tense pres­sure be­hind my eyes,” says My­ers-smith. “Then I started hear­ing what I thought was the sound of a cricket. ‘What kind of cricket lives up here in Alaska I thought?’ ”

My­ers-smith took off her sun­glasses and saw sparks from static electricit­y bounc­ing from one arm of the glasses to the other.

For some young Arc­tic sci­en­tists, field­work in re­mote ar­eas can be over­whelm­ing. More than one grad stu­dent from a Cana­dian univer­sity has had to be flown out from a re­mote camp, or given time off to deal with the stress that comes with the job.

Be­ing the daugh­ter of two univer­sity sci­en­tists may be the rea­son why My­ers-smith is more melan­choly than re­lieved when the field sea­son ends. Her mother is a pro­fes­sor emer­i­tus at the Univer­sity of Bri­tish Columbia and her fa­ther, who died in 2005, was an or­nithol­o­gist with a good deal of field ex­pe­ri­ence in the Far North. He worked in the Yukon with Hik, My­ers-smith’s PHD su­per­vi­sor.

“I made my first trip north to the Yukon with my dad when I was just nine years old,” she re­calls. “That’s when I first fell in love with this part of the world.”

As much as the cli­mate change de­bate has fiz­zled in re­cent years, My­ers-smith is ab­so­lutely cer­tain that in­vest­ment in the kind of re­search she does will pay div­i­dends.

“Cli­mate change re­search in the North will help us to un­der­stand how our world is chang­ing,” she says.

“It will also help us un­der­stand where the change is hap­pen­ing most rapidly. Ecol­o­gists can help us to iden­tify when we can in­ter­vene to bet­ter man­age a wildlife species or re­store a dis­turbed area, and how ecosys­tems will change in the fu­ture so that we can adapt to the new con­di­tions.

“Some­times a small study at one lo­ca­tion can iden­tify an un­con­sid­ered fac­tor that will go on to have big reper­cus­sions for our un­der­stand­ing of how ecosys­tems work.

“You can’t al­ways pre­dict when or where the ex­cit­ing find­ings will hap­pen, so we need to keep sup­port­ing the ba­sic re­search and we also need to get to­gether and share our data from dif­fer­ent sites and dif­fer­ent species to start build a more com­plete picture of the ecosys­tems we are study­ing.”

Cath er­ine Henry, Spe­cial to The Jour­nal

Univer­sity of Al­berta bi­ol­o­gist Isla My­ers-smith ex­am­ines the spread of sum­mer shrub cover above the Kaskawalsh Glacier in the Yukon.

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