The Dolores District of the San Juan National Forest is proposing a robust plan for prescribed fires to reduce overgrown forests brought on by a century of ill-advised fire-suppression management.
The Dolores Prescribed Fire Pine Ecosystem Restoration Project would use low- to moderate-intensity surface fires in ponderosa pine and gambel oak forests for ecological benefits. An initial scoping plan has been released and is accepting public comment until July 2.
The 240,000-acre project area stretches from the northwest corner of The Glade to the southeast corner of Haycamp Mesa.
The goal is to burn 2,000 to 10,000 acres of forest annually to reduce ground litter, dense oak and ladder fuels, which can lead to catastrophic fires.
The plan would streamline the forest’s prescribed burn program by providing environmental clearances upfront for a larger area.
“It is a more programmatic, landscapewide environmental analysis for prescribed burns,” said Derek Padilla, district ranger of the Dolores Ranger District. “We want to clear out fuels, so in the future if there is a wildfire, it would not be as intense.”
Prescribed fires for pine have been limited to boundaries in timber sale areas. But there is a need to expand the treatment areas because the beneficial effects of fire are still largely missing, Padilla said.
Forest officials are trying to mimic a more natural, historical fire regime from pre-1880. Back then, before major Euro-American settlement, surface fires on the San Juan National Forest were more frequent, occurring in ponderosa pines every six to 10 years. Larger fires historically occurred every 13 to 30 years, less frequently than today, according to a 2004 study.
In the early 1900s, the Forest Service established a policy of suppressing all wildfires, which led to fuel overloading. Heavy logging then led to proliferation of even-aged stands of ponderosa and gambel oak understory seen today, which has ecological consequences.
For example, dense pine stands have diminished nutrient cycling to forest soils, and support fewer plant varieties. This leads to a prevalence of non-native weeds such as Russian thistle and cheatgrass. Deep-rooted native bunchgrass is more resilient during dry years and has evolved to recover from fire. They provide food for small mammals, birds, elk and domestic livestock.
“In fire-deprived ponderosa pine forests, large accumulations of litter have reduced the amount of Arizona fescue and other native grasses,” according to plan documents.
Vast gambel oak thickets are familiar to local forest visitors. The plan proposes mechanical mowing and prescribed burns to open up areas between oak stands to allow more sunlight to reach the forest floor.
“When left unchecked, the oak chokes out the herbaceous resource relied on by wildlife,” Padilla said. “By burning, we create a mosaic of open spaces interspersed throughout the forest.”
When oak brush becomes too thick, there is also more competition for water, which leads to less acorn production, especially during dry years.
While recent forest management such as thinning and timber harvesting has opened up some forest canopies, the fire component is still missing.
“Ponderosa pine forests are dependent on fire for regeneration,” Padilla said, because reducing the duff layer exposes a soil bed for new ponderosa seedlings.
In the Dolores Ranger District, some stands have not been treated with prescribed fire in 10 to 30 years. Others have never been treated.
Since 2002, there have been 10,852 acres of prescribed burns within the Dolores Ranger District, representing 5 percent of the ponderosa forests. Before European settlement, natural fires in the district burned 5 to 17 percent of the ponderosa forest – 10,000 to 36,000 acres – every six to 20 years.
The proposal’s 240,000 acres have been divided into seven implementation areas at 7,000 to 8,900 feet in elevation. They are Lake Canyon, The Glade, Benchmark, Salter, Trimble/Carlyle, Boggy and Haycamp Mesa.
Prescribed burns under the project would avoid major canyons, piñon-juniper and mixed conifer forests. They must meet strict conditions for fuel loads, smoke, temperature, humidity, wind speed and other factors. To mimic a natural fire regime, prescribed burned areas should be revisited with fire every six to 20 years.
The Dolores Ranger District is conducting a scoping comment period on the burn plan from June 2 to July 2. For more information, visit the project’s scoping plan.
This article was reposted on June 7 to correct the misconception that pine cones require fire to open up and release their seeds.jmimiaga@the-journal.com