Climate change continues to challenge long time positions on how to manage natural processes.
Among grizzly bear advocates, the loss of whitebark pine in Yellowstone and surrounding forests, due to the climb up mountains by pine beetles enhanced by global warming, is one of the greatest threats to long-term survival. They rightfully worry that the loss of this critical late summer and early fall food source presents a long term threat to grizzly bears.
Now, biologists are seeing how climate change has helped an alien, invasive species, take hold in the park and actually provide additional food to Yellowstone. The Canada thistle, the bane of every farm boy who ever had to pull weeds along a roadside, thrived in the park in the absence of control and due to the warming climate, Montana writer Jim Robbins reports in the New York Times.
Park officials say the growing season in Yellowstone has expanded 20 days, aiding the thistle. Bears are now eating more of it, especially in the years when the whitebark pine nut crops fails.
Ever since a panel of scientists in the 1960s led by biologist Starker Leopold recommended restoring national parks to their pre-Columbian “natural state,” the philosophy of the Park Service has been clear.
“A reasonable illusion of primitive America could be recreated, using the utmost in skill, judgment, and ecologic sensitivity.” the Leopold panel concluded. “This in our opinion should be the objective of every national park and monument.”
Going backwards’ wisdom was based on the idea that human alteration of the ecosystem had inherently made it less resilient. The policy was the basis for the policy of returning fire to national parks forests and reintroducing wolves to Yellowstone.
But now, with climate change altering entire ecosystems, the goal of going backwards does not fit. Climate change is creating ecosystems where they never were.
Instead of managing for a “reasonable illusion of primitive America,” scientists are calling for managing for change.
The debate over when to intervene won’t necessarily change. Whether we let nature take its course or actively manage a place will begin as an ideological debate steered by science.
But the decision either way will clearly be a human decision that leaves effects on the environment either way.