Forest thinning underway to protect watersheds

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By Arin McKenna

The devastation brought on by the Cerro Grande and Las Conchas wildfires is something no one wants to see repeated. Not only were thousands of acres of forests devastated, watersheds were choked with ash and debris for months afterwards, effecting municipal water supplies as far away as Albuquerque.
The Nature Conservancy-led Rio Grande Water Fund is an ambitious 20-year program aimed at protecting forests from those high-intensity fires and, by extension, the state’s watersheds. Their efforts are directed at the entire northern Rio Grande watershed.
The program is modeled after the Jemez Mountains/Valles Caldera National Preserve Collaborative Forest Landscape Restoration Program, which was established by Congress in 2010.
Bob Parmenter, the preserve’s division chief for science and resource stewardship, has been involved with that project from the start and now sits on the RGWF board.
The foundation of both efforts is restoring healthy forests.
“The overall goal of the (CFLRP) program is to reduce the risk of uncharacteristic wildfire in forested watersheds,” Parmenter said. “And that is being accomplished by thinning some of the overgrown second-growth stands that have been logged in the 20th century and have come back as what we refer to as ‘dog hair forests.’ The trees are as dense as the hairs on the back of a dog, basically. We refer to them as ‘dog hair thickets’ or ‘dog hair forests.’”
In second-growth forests that have not been subject natural fires from lightning or the managed fires set by American Indian people, young trees are not naturally thinned out. They compete for light, water and nutrients and form and form an unbroken forest across the landscape.
A healthy forest has only 40 to 60 trees per acre. Fires would regularly move through the understory, burning off debris and vegetation and leaving nutrient-rich soil that encouraged new growth. Those ground fires could burn weeks or months, but rarely result in a stand replacement fire where the entire forest is decimated.
Today’s forests average 200 to 2,000 trees per acre. When a fire comes through, that dense thicket of fuel allows fire to leap to the tree crowns (a crown fire).
“So we have something like the Cerro Grande or Las Conchas fire, which travel a long, long way uninterrupted because they find continuous fuel resources,” Parmenter said.
The CFLRP and the RGWF programs both start with forest thinning.
“By thinning those forests, we seek to make it difficult for fire to get into the canopy of these forests,” Parmenter said. “And even if it does, like from a lightning strike or something, it won’t go tree to tree for very long. It may go through a patch of trees, but it can’t go through a large area.  We’re trying to get forest conditions back to where natural fires can just do their business as part of the natural ecosystem process.”
Restoration efforts include manual thinning, managed fires and prescribed fires.
Managed fires are natural lightning fires that are managed by National Forest Service (NFS) and National Park Service (NPS) personnel, who direct make sure they remain in the areas they want burned and do not threaten habituated areas.
Prescribed burns are planned and set in particular areas.
“These fires will function like a natural fire but in areas that we’ve already thinned and are suitable for burning under these conditions,” Parmenter said.
Thinning efforts are actually helping the local economy by using companies such as Jemez Pueblo’s Walatowa Timber Industries.
Restoration of riparian areas is accomplished through volunteer groups and nonprofit organizations. Efforts range from planting willows to redirecting runoff.
Both programs also do extensive monitoring to measure the results of their efforts. Parmenter sits on the RGWF committee responsible for designing monitoring efforts.
“Because every time you’re asking citizens of the state to contribute funds or resources or volunteer days in the mountains to do things, you want to be able to actually show that effort is bearing fruit,” Parmenter said.
 “So the only way to do that is to actually take measurements, monitor the volume of water and the quality of water and the fisheries and wildlife stability and all these things. And in the long run you’ll start seeing these trends of reduced severe fire frequencies and improved water quality and stabile flows and increased flows in some cases.”
Network organizations are a significant part of both efforts. Valles Caldera was the first entity to sign on to the RGWF project, and the preserve has taken an active part in their efforts.
“So it’s through this very large collaborative network of groups of people that we restore all the contributing watersheds going into the Rio Grande,” Parmenter said. “Then we can ensure a much safer water supply well into the future, without the floods and the devastation that comes with landscape high severity fires.”
RGWF is focusing its current efforts on the Southwest Mountains, with more than 32,000 acres authorized for thinning. At current funding levels, they anticipate thinning between 2,000 and 3,000 acres a year for the 10-year contract period.
For more information on the RGWF, visit nature.org.