As Climate Changes, So Do Fire Strategies
As warmer temperatures and drier conditions in much of the United States have led to earlier and longer-lasting fires, some wildland fire managers have modified firefighting tactics, taken steps to reduce public health hazards and adjusted the timing of seasonal hiring.
“In the words of hockey player Wayne Gretzky, we skate to where the puck is going to be, not to where it has been,” said Refuge System fire ecologist Lou Ballard. “In addition to planning for climate change, even when managing an ongoing fire, we must anticipate what the weather and [vegetation] fuel loading will allow us to do and where those points of control or protection exist.”
In the Southeast, firefighters on forested wetlands have faced several large wildfires in recent years – including two each at Virginia’s Great Dismal Swamp National Wildlife Refuge and Georgia’s Okefenokee Refuge, and one each at Pocosin Lakes Refuge and Alligator River Refuge in North Carolina. These fires produced sustained smoke and embers smoldering as deep as eight feet into organic peat soils.
To address the challenges, U.S. Fish and Wildlife Service fire specialists Sue Wilder and Kelley Van Druten gathered 50 experts for a 2½-day symposium at the Coastal North Carolina National Wildlife Refuges Gateway Visitor Center in Manteo late last year.
The symposium covered priority wildlife needs, hydrology and sea-level rise resiliency projects, fire danger rating for organic soils, mineral cycling/subsidence and accretion as well as management concerns, challenges and best management practices related to fire.
A key symposium finding was the need to continue work with partners and neighbors to install more water control structures at refuges. Such devices allow refuges to reduce saltwater intrusion into wetlands, specifically at Alligator River Refuge, and move in fresh water during drought conditions. That keeps peat from drying out and becoming flammable at refuges like Pocosin Lakes and Great Dismal Swamp.
Additionally, as sea-level rise increases salinity in soil, forested wetlands are dying and being replaced by salt-tolerant shrubs and then marsh. During this transition, standing or fallen dead trees increase fuel for wildfires. Land managers are experimenting with ways to decrease saltwater intrusion and slow these changes, including planting salt-tolerant tree species and installing special water control structures.
Furthermore, managers are focused on soil subsidence and accretion studies to help identify the right frequency and extent to use prescribed fire to stimulate plant productivity and biomass accumulation in peat soils. The resultant soils may help combat rising sea level. However, if burns are conducted too frequently or burn too hot, then biomass will not accumulate. Because peat soils are major source of carbon sequestration, if prescribed burns go too deeply into the soils, carbon is released into the atmosphere, contributing to climate change.
“Alligator River was established to protect forested wetlands, so we want to hold onto them as long as we can,” said Van Druten, a wildlife refuge specialist for North Carolina Coastal Plain Refuge Complex. “We are really struggling to find that balance between burning for either [reduced] fuels or habitat management, without adding that additional stressor that is going to tip the scales and push the habitat irreversibly towards shrub and then marsh.”
The 2011 Pains Bay fire at Alligator River National Wildlife Refuge in North Carolina is one of several fires in the Southeast in recent years that have produced sustained smoke and embers smoldering as deep as eight feet into organic peat soils. (USFWS)
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