Historic ponderosa pine forests used to be much more open, with many less tress per acre than most ponderosa forests today. Such open, “park-like” forests were created through frequent lightning-caused fires. Every ten years or so, a dry stretch of weather would allow a lightning strike to ignite a fire. The openness of the forest, with grasses and small amounts of low-growing fuel, would generally keep the fire on the ground, consuming many of the younger trees. The relative coolness of the fire would scorch the thick lower bark but not kill most of the more mature trees. These forests had healthier trees, more grasses and open habitat for diverse plant and animal species, and were much less prone to stand-clearing wildfires.
Many decades of fire suppression have led to overly dense forests in Pueblo Mountain Park that our efforts are to remedying. We are actively engaged in an on-going process of thinning the trees and removing ladder fuels (medium height vegetation that can take a ground fire up into the tops of the trees, known as the canopy). The results are beginning to manifest – a park with forests that are healthier, less prone to catastrophic fire (such as the 2005 Mason Gulch Fire), and fuel for the biomass boilers that heat the Horseshoe Lodge. The trees that we have removed from the sides of the scenic highway (the park’s upper road) allow more snow onto the road for better ski and snowshoe conditions.
Note that we approach this work holistically with overall ecosystem health foremost in mind. Most of the trees coming out are smaller diameter (very few larger than 12” in diameter), we avoid dropping trees during bird-breeding season, and we have no plans of building any additional roads to access the forests. Our approach to dealing with the slash includes burning of slash piles (during wet times) and, when possible, chipping.
We feel this tree-thinning project is a win-win effort on many levels – a healthier forest with more diverse wildlife habitat, less inclination for big burns, better winter recreation, and locally-sourced, more carbon-neutral, and less expensive fuel for the boilers.