Forest fires and the fire threat of conifers killed by beetles have been in the news. Earlier this year, when Colorado had a number of forest fires, a newscast said that of all the thousands of acres Colorado has lost to fires this year, 10 times as many have been lost to bark beetles, for which there is no control. What are bark beetles, should we care, and are they a problem here?
The ravages of these insects in the West are a problem of our own creation. Fire is a constant in the ecosystems of these pine woodlands, and for decades fires have been suppressed. Before fire suppression, Western forests were naturally very thin stands of trees that were widely spaced. The trees in them represented a great variety of age categories because they were really the few survivors of one or more fires.
Fire suppression changed all that. Now many of the forests are dominated by trees of a very narrow age range. They grow much closer together. They compete with each other for water.
When drought is a factor, as it has been for the past several years, trees are stressed beyond their limits. Enter the mountain pine beetle, Dendroctonus ponderosae. It attacks many species of pine under stress but is particularly fond of ponderosa pine, which happens to be the most widespread and adaptable pine in the West. The result is widespread death of huge areas of pine forest.
Horticulturist Scott Aker answers your gardening questions.
