Alaska - climate change causing ancient lakes and wetlands to be replaced by forest
James E. Kloeppel, Physical Sciences Editor
National Research Council of Canada press release
September 28, 2005
Ottawa, September 28, 2005 - Lakes and wetlands in the Kenai Peninsula of south-central Alaska are drying at a significant rate. The shift seems to be driven by climate change, and could endanger waterfowl habitats and hasten the spread of wildfires.
The trend fits within a global picture of drying wetlands in northern latitudes, with similar changes already appearing in lower latitudes. Klein, a biologist who did his graduate research with Alaska Pacific University, says the transformation of Alaska's landscape corresponds with an increase in temperatures over the past 100 years. "When you look at the climatologic data, it shows a warming trend. This is just one of the physical manifestations of that trend that is hard to refute."
The researchers compared aerial photos of the Kenai Peninsula taken in 1950 and 1996. Combined with extensive field study and analysis of vegetation, the research confirms that the Kenai Peninsula is becoming woodier and dryer. In the areas studied, wooded areas increased from 57 percent to 73 percent from 1950 to 1996, while wetland areas decreased from 5 percent to 1 percent.
The results confirm what the researchers could see for themselves. "It's very clear when you fly over closed basin lakes, many of which are the kettle ponds left after the glaciers receded," says Klein. "They have a kind of apron, or area between the water and mature forest, and you can see it getting larger as the water goes down."
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Wetlands are hotspots for biodiversity. The shift to woodland and forest means loss of many types of wetland vegetation and fewer habitats for migratory birds. The greater forest cover also creates a continuous swath of vegetation that helps wildfires to spread more quickly.
Similar drying is happening outside the Kenai Peninsula. "It's certainly happening in Alaska on a very broad scale," says Dr. Berg. "Much of the interior is showing the same kind of drying pattern."
If the warming trend continues, Alaska's lakes and wetlands will continue to disappear, creating a dryer landscape in the long term.
Klein says that Alaska's transformation is another piece of evidence in the climate change puzzle. "The bottom line is that a change is happening," he says. "There is an overall environment shift occurring in Alaska, and especially in the northern hemisphere. I think it's a bioindicator of climate change and what is happening to the planet as a whole."
The Canadian Journal of Forest Research is a scientific peer-reviewed journal published by the NRC Research Press, the publishing arm of the Canada Institute for Scientific and Technical Information (CISTI).
For the complete article, see http://pubs.nrc-cnrc.gc.ca/cgi-bin/rp/rp2_abst_e?cjfr_x05-129_35_ns_nf_cjfr8-05.
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This is a modified press release from the National Research Council of Canada. The original version is found at Climate change transforming Alaska's landscape