Scientists explore forest adaptation, mitigation at forest pow-wow in Aspen
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By Bob Berwyn
SUMMIT COUNTY — Given the importance of forest ecosystems worldwide as carbon-absorbing areas, as wildlife habitat and sources of water, leading scientists this week called on policy makers to start considering how to address the impacts of climate change, which is killing trees on every continent at a distressing pace.
While there aren’t many clear answers on what can be done, some of the researchers speaking at the Feb. 18 For the Forest symposium in Aspen suggested at the very least that managed fire must play a role in trying to avert more destructive and deadly uncontrolled wildfires.
Others suggested starting to explore the idea of assisted species migration — which basically means planting trees in new areas to make forests more adaptable and resilient in the face of climate change. Read a story about a whitebark pine restoration here.
Until recently, it was a given that forests absorb more carbon dioxide than they emit, but as massive forest die-backs spread around the world, that equation has become more fuzzy, said Werner Kurz, a senior research scientist with the Canadian Forest Service.
Because of the massive pine beetle infestation in western Canada, Kurz said researchers have seen some data suggesting that Canada’s forests have become net producers of greenhouse gases in some years during the past decade. For one, the dead and dying trees release significant amounts of greenhouse gases as they decompose. And wildfires, growing in size, frequency and intensity as the world grows warmer, have the potential to release huge pulses of CO2 into the air.
It’s not clear how the trend will play out globally in the long run, as new forests growing in some parts of the world could balance those effects, he said, explaining that vacated agricultural land in Russia is being reclaimed by trees — to the tune of tens of millions of acres in the past two to three decades. Still, some of the recent data includes troubling warning signs that we can’t the role of forests as carbon sinks for granted in the face of climate change, he concluded.
It’s the threat of those wildfires that prompted the University of Arizona dendroecologist Tom Swetnam to advocate for more active management of forests, especially with the purposeful use of fire in the landscape.
Swetnam maintains one of the world’s most extensive records of tree-ring research, and that incontrovertible evidence suggests that, even without climate change, severe cycles of drought and wildfire are inevitable. Warming global temperatures will only exacerbate those events, he explained.
Swetnam said climate change calls for humans to combine the conservationist philosophy of John Muir with the more activist approach of Gifford Pinchot — “It’s up to us now as stewards. What will happen if we see 30-year droughts worse than any we’ve ever seen,” he said, suggesting that that climate change could help fuel forest fires of almost unimaginable magnitude and that controlled burns could help thin out the fuels before those massive fires burn uncontrolled.
“we’re heading into uncharted territory with climate change … Forests have evolved under very variable conditions and there have been long, extreme droughts … We must reintroduce fires. We have to use fire as a tool, Fire will happen regardless, but will it be on our terms?” he concluded.
To do that will require greater collaboration between the research community and the planning community within public land agencies, said Linda Joyce, a quantitative ecologist with the U.S. Forest Service. Joyce said, that given the critical importance of forest ecosystems, land managers must at least explore the options for making them less vulnerable to risks associated with climate change.
A new national planning rule released in draft form last week could help the Forest Service do just that, said Undersecretary of Agriculture for Natural Resources and Environment Harris Sherman. The new rule directs forest managers to emphasize restoration and on on making forests more resilient with adaptive management and careful monitoring, but it’s too early to say how that directive will play out on the ground.