March 12th, 2013 by

By Tacy Lambiase

More intense wildfires, drought and drier soil — these are just some of the negative consequences of climate change that can seriously affect the health of trees. But what happens when warmer temperatures actually make certain ecosystems more hospitable for trees? According to a new study, the arctic tundra is one environment that won’t be treeless for much longer.

The tundra in Kobuk Valley National Park in Alaska

The tundra in Kobuk Valley National Park in Alaska. Credit: Western Arctic National Parklands

The arctic tundra, an ecosystem traditionally known for its lack of trees and shrubs, is undergoing a transformation. Over the past few decades, pine trees and large shrubs have begun to cover this once sparsely vegetated region. Using advanced climate models and satellite data, the authors of the new study in Nature Climate Change have concluded that Earth’s northernmost treeline is infringing on the arctic tundra.

“As a result of the enhanced warming … the total amount of heat available for plant growth in these northern latitudes is increasing,” Compton Tucker, an author on the study and a climate scientist at NASA’s Goddard Space Flight Center, tells Discovery News. “This created, during the past 30 years, large patches of vigorously productive vegetation, totaling more than a third of the northern landscape — over nine million square kilometers, which is roughly about the area of the USA — resembling the vegetation that occurs further to the south.”

Although many species of trees do not seem to be able to migrate fast enough to keep up with a changing climate, clearly some plants are successfully moving northward and thriving. But will this migration be ultimately beneficial for these trees? What about the landscape they’re changing?

Canada’s Sirmilik National Park, which is situated within the Arctic Cordillera

Canada’s Sirmilik National Park, which is situated within the Arctic Cordillera. Credit: Mike Beauregard

As Discovery News points out, warmer temperatures do not necessarily mean more rainfall, especially in North America. If the arctic tundra becomes simultaneously warmer and drier, then some trees might not be able to survive there after all. The native vegetation and wildlife of the arctic tundra can also be negatively impacted by climate change. Since its small plants and mosses need cool temperatures and a wetter climate to survive, the arctic tundra may not be able to continue to support these species. Although it may seem like more trees in any part of the world is a positive development, broader effects of climate change could ultimately spell disaster for the natural ecosystems of our northern climates.

In addition, the arctic tundra might even contribute to exacerbating climate change. Much of the arctic tundra is covered in permafrost, or frozen soil, which releases carbon and methane into the air when it melts. If temperatures become too high for the permafrost to remain frozen, the amount of carbon released by melting permafrost will have a significant effect on the atmosphere, climate change and the ecological make-up of the tundra.

The arctic tundra is a beautiful, but complex ecosystem. As scientists continue to study the effects of climate change, it will be important to keep this particular habitat on our radars.