Dark green conifers invade and take over aspen groves, leading to a lack of diversity in the forest.
Any big fire, planned or unplanned, has an impact on the environment. Trees and plants die, smoke fills the air and greenhouse gases like carbon dioxide get into the atmosphere. At Tuesday's prescribed fire near Bruin Point, Division of Forestry, Fire and State Lands spokesman Jason Curry explained the differences and advantages of planned fires.
Most apparent for many miles is the plume of smoke and the haze of smoke. Yes, there are particulates released that pose problems for people with respiratory problems, he said. "But when - not if, but when - a forest fire happens, it won't be as severe," he added. The reason is that prescribed fires remove dead plant matter and underbrush that provide tinder for igniting major blazes.
Without a supply of dry fuel, natural or accidental fires don't travel as far or as fast and are more easily controlled.
Prescribed fires are also regulated by air quality standards. Fires that are likely to create a foggy blanket of smoke concentrated close to ground level are not permitted. Ideally, the smoke should rise high into the atmosphere, where winds aloft will scatter the particles.
Carbon dioxide, the greenhouse gas that results from all combustion, is a short term impact. (Remember the carbon cycle diagrams you had to draw in elementary school science?) New plant growth in the burnt out area absorbs carbon dioxide, generally faster than the older trees being replaced.
Habitat improvement, a principal reason for this fire, is a desirable impact on the environment. According to Curry, "Diversity is the objective." Conifers (fir, pine, spruce) are all fine, except when they invade and crowd out aspen groves. Aspen shoots are great browse for elk and deer, for example. The shoots, which sprout from roots of existing aspen, spread by the thousands in burned areas because ash provides a good source of plant nutrients.
Aspen propagation cannot happen in areas dominated by old-growth conifers.
The best forest, Curry explained, is one where the conifers and aspen each have their own turf. That's the diversity that will support a range of birds and beasts.