May 10, 2008
The mountain pine beetle epidemic devastating Colorado’s lodgepole pine forests is one of many issues influencing the health of Colorado’s forests, according to a report released by the Colorado State Forest Service.
Wildfire suppression, climate change and rural property development will also impact the state’s forests over the next several decades.
Insect infestations continue
Colorado’s forests in recent years have experienced large-scale insect infestations, from ips beetles in the pinyon forests of southwestern Colorado to mountain pine beetles in northern lodgepole pine forests. Both infestations have or will result in tree mortality rates that exceed 90 percent. Spruce beetles likely will be Colorado’s next forest insect challenge, and outbreaks are expanding in many locations throughout Colorado.
The presence of western balsam bark beetle and root diseases, which are native to subalpine fir forests, has increased during the past decade or two.
Additionally, Sudden Aspen Decline (SAD) more than doubled in Colorado from 2006 to 2007, increasing from 139,000 to 334,000 acres, according to the CSFS, a division of Colorado State University.
Urban forest at risk
Threats to urban and community forests also are on the rise. Salts used to de-ice roads continue to weaken roadside trees such as maples, lindens, and elms. Black walnut mortality is killing urban walnut trees in several Colorado cities and towns.
Tamarisk and invasive trees such as Russian olive also threaten Colorado’s riparian forests. Although this represents only about 1 percent of the state’s total forested area, these forests provide essential benefits disproportionate to their size and are critical to the livelihood of Colorado’s agricultural communities, the report noted.
Colorado forests in decline
Several factors have contributed to the decline of Colorado’s forests. For example, wildfire suppression has led to expansive areas of forests that are either the same age or overcrowded. This makes them more prone to widespread and intense wildfires, and predisposes them to forest insect and disease epidemics that result in high mortality rates. Warming temperatures from climate change also increase the likelihood of more wildfires, according to the service.
Residential development in fire-prone areas, the wildland-urban interface, reduces forest cover and increases demand for wildfire protection, fractures wildlife habitats and increases forest management costs.
“In the past, wildfire was an agent that actively helped our forests stay healthy,” said Jeff Jahnke, state forester and director of the Colorado State Forest Service. “But without wildfires to regenerate forests and introduce a beneficial mix of ages, forest management may be necessary to create and maintain forests that Coloradans rely on,” said Jahnke.
Communities that are proliferating in fire-prone areas increase the need for wildfire suppression, and the lack of wildfire may mean more intense fires in the future, according to the report.
A Colorado State University analysis found more than 300,000 homes in Colorado’s wildland-urban interface in 2000. More than 720,000 homes are projected in 2030.
Colorado Gov. Bill Ritter recently created the Colorado Forest Health Advisory Council, bringing together forestry experts and stakeholders to identify short- and long-term actions to sustain Colorado’s forests. The council also will build on the successes of local forest partnerships that already exist across the state, many of which have developed strategies to address their specific areas of concern.
By consulting with these groups, the council will determine how best to support them and incorporate their findings into a statewide plan.
The Colorado forest health report — 2007 Report on the Health of Colorado’s Forests, Special Issue: Forest Challenges, Today and Tomorrow — may be viewed on the Colorado State Forest Service Web site.
Source: Colorado State University.