Forest Changes in Alaska Reveal Changing Climate
Evidence is mounting that climate change is transforming Alaska’s boreal forest, an expert said yesterday.
“A biome shift is now occurring,” University of Alaska, Fairbanks, forest ecologist Glenn Juday said. “You don’t have to wait for the effects. They’re happening.”
The state’s white spruce stands, which according to one recent study contain half of the genetic diversity of all white spruce in North America, are suffering.
Empirical studies of forests across Alaska show that North America’s white spruce require at least 280 millimeters (11 inches) of precipitation each year, a number that rises if mean summer temperatures are higher than 15.5 degrees Celsius (roughly 60 degrees Fahrenheit).
When the mercury hits a mean temperature of 21.1 degrees Celsius, or just shy of 70 degrees Fahrenheit, the trees can’t survive.
In Fairbanks, conditions are hovering right on that edge. Annual precipitation is about 280 millimeters, and July temperatures have exceeded 15.5 degrees Celsius several times in the last couple of decades.
White spruce that grow around Fairbanks are “probably not viable on a long-term basis under such conditions,” Juday said. “With each additional degree of warming, their growth goes down.”
Part of the problem is that the region is drying, the scientist said. The growing season in Fairbanks now stands at 120 days, 50 percent longer in 2007 than it was in 1905.
Climate changes in the Arctic region are happening more dramatically than in many other parts of the world.
There have been numerous reports and studies addressing the changes in the Arctic, and this is just the latest bit of news to strengthen the conclusion - without a doubt, climate change is happening and right before our eyes.
Well, if one has eyes to see, that is.
Looking at another species of tree:
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Meanwhile, the birch trees that scientists once suspected would “pick up the slack” when climatic conditions began to overwhelm white spruce appear to be similarly susceptible to the environmental changes.
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It is hard to think that in this day there would still be those who want to deny the effects that humans have had, especially since the beginning of the Industrial Revolution.
However, one of those people looks to win the GOP nomination for Senator - from Alaska - Joe Miller.