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Trees in the Tundra

By Alix Morris, Earthwatch Institute Earthwatch scientists search for evidence of climate change in one of the most extraordinary places on the planet. Welcome to Churchill, Manitoba At the southern edge of the Arctic, in Canada’s Hudson Bay lowlands, lies Churchill, Manitoba – a small town that sits at the convergence of tundra, forest, freshwater,...

By Alix Morris, Earthwatch Institute

Earthwatch scientists search for evidence of climate change in one of the most extraordinary places on the planet.

Welcome to Churchill, Manitoba

At the southern edge of the Arctic, in Canada’s Hudson Bay lowlands, lies Churchill, Manitoba – a small town that sits at the convergence of tundra, forest, freshwater, and marine ecosystems. Churchill is perhaps best known for the roughly 1,000 polar bears that migrate to the region each year, earning it the nickname of “polar bear capital of the world.” These massive predators gather as they wait for the sea ice to freeze along the shores of the Hudson Bay before they begin their hunt for seals.

In the summer months, thousands of migrating beluga whales enter the Bay, just after breeding season. They stay in the river estuaries and along the coast throughout the summer to feed on capelin and give birth to their young before migrating back out into Hudson Strait and the North Atlantic. Churchill is also a bird lover’s paradise – more than 250 species of birds nest or fly through during their annual migrations.

For humans, however, the small town of Churchill is not for the faint of heart. In the winter months, the wind chill can drop to -50 degrees Fahrenheit. The cold is so severe that it threatens to seal eyelashes shut and freeze exposed skin. It can turn water to ice before it’s poured.

Why would anyone live in such a harsh, unforgiving climate? For Drs. LeeAnn Fishback and Steve Mamet, the question is – why not?

Credit: Matti Urlass

Arctic Fever

Drs. LeeAnn Fishback and Steve Mamet in Churchill, Manitoba

LeeAnn Fishback, lead scientist on the Earthwatch expedition Climate Change at the Arctic’s Edge, grew up on a dairy farm in Southern Ontario. Unlike most children her age who longed for the summer months, LeeAnn looked forward to the winter. Some of her earliest memories as a child involved racing after her Newfoundland dog as he bounded through the snow, carving a path for her to follow. Her parents, who had more time to spend with their children during the winter months, taught her to skate and toboggan. She quickly grew to love winter and the cold.

Years later, LeeAnn, who is now the Scientific Coordinator at the Churchill Northern Studies Centre, looked for opportunities to travel even further north. When the opportunity arose to spend a summer in Canada’s High Arctic, she jumped at it.

During her second year of field work, in 1993, LeeAnn experienced one of the warmest years in the High Arctic. She and her research team set up their camp on the glacier where they would spend the summer studying snow and ice melt.

On a glacier, there’s typically an “accumulation zone” at higher elevations where the snow is building up and doesn’t melt. The warmer “ablation zone” is at lower elevations – this is where melting occurs. LeeAnn and her team had set up their camp in the accumulation zone, expecting that they would be able to live in the snow for the whole summer. But by early-July it became apparent that the entire glacier was turning into an ablation zone. There was melting everywhere, and nothing they could do to prevent it.

“That was when climate change really hit home for me – when I was living on a piece of ice that was melting away, and it shouldn’t have been.” – Dr. LeeAnn Fishback


Credit: Shawn Brown

What Happens in the Arctic Doesn’t Stay in the Arctic

The Arctic and subarctic regions are critical to understanding the effects of climate change. But why are these regions so important? In part, it’s because changes in climate are amplified at the poles, and these regions are warming faster than elsewhere on the planet.

Dr. Bill Moomaw, Chair of Earthwatch’s Science Committee and Professor Emeritus of International Environmental Policy at Tufts University explains that change is happening more rapidly in the Arctic, so it’s easier to follow and to monitor.

“As ice and snow melt, a surface that reflects 90% of sunlight is replaced with a surface that absorbs 90% of sunlight. Since the Arctic is shifting most dramatically from a reflecting body to an absorbing body, it’s heating up faster than the rest of the earth. And that’s changing the dynamic of weather over the whole earth.” – Dr. Bill Moomaw

Churchill is located at the Arctic treeline, and is extremely sensitive to small environmental changes that have a huge impact on ecosystems. Warming temperatures have led to shrinking areas of polar sea ice, freshwater wetlands that are drying up, and less extensive winter snowpack that melts earlier.

One area of research scientists have been studying is the effect of warming temperatures on permafrost – a frozen layer of earth that starts within a meter of the surface. Permafrost, which covers 24% of the land mass in the northern hemisphere, is made up of dead plant matter that hold virtually all of the carbon stored by individual plants during their lives. Some of these deposits are more than 40,000 years old. When permafrost begins to thaw, it releases carbon in the form of carbon dioxide and methane – two of the most dangerous greenhouse gases.

Snowpack assessment | Credit: Jo-Anne Croft

In Churchill, LeeAnn and Steve have focused their research on the biological evidence of warming, specifically wetland dynamics and a shifting treeline.

Shallow wetlands make up approximately 40% of the tundra landscape in the region. Warming temperatures lead to more evaporation, which can alter these ecosystems that are susceptible to drying over the course of the summer. This has potential to adversely affect some of the species that depend on the wetlands for reproduction or food.

Warming also carries with it the possibility of an advancing treeline. Moving north towards the poles, the temperature drops. The point at which it becomes too cold for trees to grow is referred to as the treeline. With warming temperatures, trees advance into the tundra. Tree movement changes the entire ecosystem – everything from insects, to small mammals, to predators – the lemmings, the arctic fox, the snowy owl.

An advancing treeline could also lead to additional warming (dark trees absorb more sunlight) and release of additional greenhouse gases (more trees means more water vapor in the air). In Churchill today, islands of trees are emerging in a sea of tundra – islands that researchers believe may serve as a nucleus for further treeline expansion in the future.

In this subarctic climate, LeeAnn and Steve are working with Earthwatch volunteers and students to study these important research areas. Evidence collected in Churchill provides scientists with a first indication of climate change, and offers critical clues as to what the future might have in store for the environment. It’s a canary in the coal mine – a first warning of a large-scale challenge.

Vegetation Analysis at Edge of Tundra | Credit: Mark Stratton

The “So What?” Factor

LeeAnn and Steve would love to say that their research directly influences policy decisions. But it’s not quite as simple as that. Climate change is a political and economic minefield, and policy decisions are based on more than just science.

While the research from the Churchill project often feeds into policy assessments, it doesn’t always result in direct or immediate action. The timeline from data analysis to actual policy change can take years, if not decades.

So what drives these scientists in the meantime?

Steve believes field science is critical to understanding the effects of climate change. A lot of what we know about climate change is based on sophisticated computer models – models that make assumptions where data don’t exist. For Steve, field data are critical.

“We’re actually out there, we’re on the ground, we’re observing any changes that are occurring and we’re collecting data on them…The models are very important but the field data is there to make sure we’re on the right track.” – Steve Mamet

For LeeAnn, one incredibly important contribution they can make is training Earthwatch volunteers. As researchers and educators, LeeAnn and Steve aim to reach out to as many people as they can – to give them the opportunity to ask questions, to better understand climate change. These volunteers can then return home and better inform their own communities. Through education and awareness, she believes they can have a tangible impact.

In Churchill, volunteers have enabled scientists to paint one of the clearest pictures of climate change in the Arctic, so we can better understand the changes that will eventually take place in our own backyard. It’s evidence of the power of connecting citizens to science.

“We don’t want you to just believe in climate change. we want you to understand it.” – Dr. Steve Mamet

Earthwatch Institute is a non-profit organization dedicated to connecting citizens with scientists to conduct conservation research worldwide.

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Meet the Author

Alix Morris
Alix Morris is a science writer and the Director of Communications at Earthwatch Institute, with experience in science communications and global field research. Alix has a Masters in Science Writing from MIT and a Masters in Health Science from Johns Hopkins School of Public Health.