Forests

Old Growth Forest that has not been disturbed by humans or disaster for 200 years or more Russia, Canada, Brazil, Indonesia & Papua New Guinea have more than 75% of the world’s Old Growth forests

Second Growth Forest Forest resulting from secondary succession

Benefits of Forests Remove CO2 from the atmosphere Provide habitat for many species Plants found in forests may be used for pharmaceutical purposes Reduce erosion Purify water Recreation Jobs Fuel wood & lumber

Harm from deforestation Erosion Habitat fragmentation Sediment runoff

Forest Fires Surface fires – burn the forest floor Benefits: – Burn away flammable material making the forest less susceptible to more damaging fires – Free up mineral nutrients in the litter and undergrowth – Release seeds from lodge pole pines – Stimulate germination of certain tree seeds – Control disease and insects

Crown Fires Very hot, leaping tree-to-tree, engulfing entire trees in flame Usually occur when areas have not had surface fires for several decades – Dead wood, leaf litter accumulate – Fires destroy vegetation – Kill wildlife – Increase vegetation – Burn/damage structures

Forest Fire in Colorado We have had an increasing number of forest fires in Colorado Forest fires are fought and suppressed as soon as possible Is this the right thing to do?

Suppression Benefits Saves homes Saves trees Keeps forests aesthetically pleasing (do we really want to see Summit County burned?)

Suppression Drawbacks Species adapted to periodic fires cannot adapt (lodge pole pine) Overcrowding in the forests – More, weaker trees – Susceptible to disease (pine beetle) Crown fires more likely

Pine Beetles Pine beetles attack stressed trees – Overcrowded – Old age – Drought – Disease

Pine Beetle Prevention Natural Controls: – Predators such as woodpeckers and insects that feed on the pine beetle – Extreme cold (severe freeze in the fall, temperatures below -30 F for 5 days in the winter) – Peeling the bark

Are beetle kill areas timber waiting to burn? This seems like an obvious answer with so much dead wood, however…. Recent research suggests that the dead fall left behind makes the forest less vunerable to forest fires because: – Live trees have flammable oil in the needles, dead trees do not – Crown forest fires jump from tree-to-tree

What is best for the forest may not be what is best for us

Other Forest issues Rainforest Destruction Boreal Forest Destruction