Mountain Pine Beetle Infestation

Recently the Rocky Mountain West has witnessed the largest outbreak of mountain pine beetles in recorded history.  A tiny insect about the size of a grain of rice, the Mountain Pine Beetle is native to the North American forests.  Normally these insects attack small numbers of old or weakened trees thereby forcing faster development of younger, healthier forests.  However, unusually dry summers and mild winters in the beetles' range, combined with large forests filled with mature pine trees, have led to a full-fledged beetle epidemic.

Large patches of red-needled pine trees in the city’s forest backdrop provide visual evidence of the extensive mountain pine beetle activity.  Century-long fire exclusion in most of the surrounding forest lands has resulted in dense thickets of overstocked, stressed conifer trees and has proved ideal habitat for exploding mountain pine beetle populations.  Because natural parklands contain predominantly ponderosa pine, one of the mountain pine beetles preferred host species, the sudden and significant pine mortality has necessitated large-scale forest ecosystem health restoration and forest fuels treatment projects over the next decade. 

During the first phase of the city's open lands projects, the focus was on removing dead and dying pines.  Tree removal was combined with thinning of live Douglas fir and ponderosa pines to reduce public safety and infrastructure risks.  Eventually with the initial projects completed, the open lands management program will concentrate on restoring parkland forests to include trees of different species, ages, and stocking levels that may be more resilient to the stresses of climate change in the future.  While addressing the mountain pine beetle disturbance,  parks department staff will keep open lands enthusiasts informed of forest treatment strategies and schedules to increase scientific awareness and lessen the impact on open lands recreational usage.