July 1, 2010 | 2
Editor’s Note: Vienna, Austria-based science writer Chelsea Wald is taking part in a two-week Marine Biological Laboratory journalism fellowship at Toolik Field Station, an environmental research post inside the Arctic Circle. To see the current conditions in Toolik, check out the Webcam.
Walking over Eriophorum, Watch your step of you’ll fall off ‘em.
–Benjamin Shaw, 2010 MBL Polar Science Fellow, Ode to Eriophorum [excerpt]
It’s easy to hate the cottongrass tussock (officially Eriophorum vaginatum). Everyone from early Alaskan explorers to today’s cutting-edge scientists to intrepid journalists have cursed these clumpy arctic tundra sedges (don’t call them grasses!) for twisting ankles and taxing leg muscles.
Despite my own sore ankles and calves, I have found myself in an unlikely love affair with the lowly tussock. It started, as many great love stories do, with pity. Our first day at Toolik Field Station, associate science director and ecologist Syndonia Bret-Harte of the University of Alaska-Fairbanks told our journalist group that Arctic ground squirrels "eat the hearts out of tussocks" to survive the winter. At that point I had no idea what a tussock was, and I even considered that it might be some sort of animal, so I felt sorry for the poor thing, whatever it was.
Then we went out onto the tundra and ecologist Gus Shaver of the Marine Biological Laboratory cut open a tussock to show us just how tightly the stems and leaves inside a tussock weave together as they grow. As one of my colleagues put it, they look inside and out like "potted plants without the pots." He then told us the tussock he had just cut open could be older than 100 years. Everybody blinked back tears for the sacrifice that the wise, old tussock had made for our education.
But then pity turned to wonder as Shaver told us that the tussock would probably grow back together when he put the cut half back in the ground.
Soon I grew to admire the tussock’s ability to withstand insults. Something like 80 percent of them survived a major 2007 tundra wildfire thanks to their tight, moist bunching and minor height advantage. What’s more, fires fertilize the land that they burn by increasing nitrogen in the soil, biogeochemist Anne Giblin of the Marine Biological Laboratory told our group, and in fact the survivor tussocks have come back prettier than ever, sprouting beautiful cotton-ball flowers on long stems.
When I first saw a field of those truffula-tree-like flowers (pictured in the photo), admiration became full-fledged infatuation.
My crush finally turned to love, however, when I learned that the tussocks’ amazing resilience may help the landscape heal after a fire and especially after a critical failure of the permafrost, called a thermokarst (which you may remember from my last post http://www.scientificamerican.com/blog/post.cfm?id=adventures-in-alaskan-science-how-i-2010-06-26). On a trip to the Toolik River thermokarst, aquatic ecologist Breck Bowden of the University of Vermont told us that the tussocks may dig in and help prevent thermokarst ditches from growing and growing. Scientists are just starting to look into the thermokarst healing process, which will help them get a better hold on the future of the tundra.
Unfortunately, the future of the tundra may include fewer tussocks. Long-term experiments run here at Toolik show that a warmer future may favor woody shrubs, like the birches, willows, and alders that grow here. Tussocks will probably not disappear altogether, but they will almost certainly be losers in the climate-change game. That does not make me love them less, though. I’m now committed to the tussock, for better or for worse.
Images: Tussocks blooming by Horn Lake on Alaska’s North Slope, nearly three years after the area burned in a wildfire; courtesy of Chelsea Wald
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