Dispatches from the River: Pine Beetles and the Watershed

“…the dynamics in the forest have changed dramatically.”

The headwaters of the Colorado River begin in the Rocky Mountain National Park. Here the stunning landscape is dotted with dull brown trees…remnants of the almost 20 year Pine Beetle epidemic which ravaged the forests in Colorado between 1996 and 2013. The 2015 aerial survey conducted by The U.S. Forest Service and Colorado State Forest Service showed that in many parts of the state, the epidemic has ended due to the depletion of mature pine trees.

*Jeff Deems with CIRES at one of the SNOTEL (snow pack monitoring) sites in the RMNP in Colorado.*

More than 3.4 million-acres of forests in Colorado were impacted by the Pine Beetle. That has resulted in a complex set of repercussions for the watershed says Jeff Deems, a research scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES) in Boulder.

“The beetle infestations are changing the forest cover canopy by killing trees and when we remove trees from the forest or reduce the amount of forest cover canopy, it changes a numbers of things with the snow pack.”

Less tree canopy means that more snow is falling on the ground, snow that would have been intercepted by the forest canopy and potentially blown away. In addition, more wind and more sun hits the snow-pack on the ground. “So what we see is more snow accumulation during the winter but we get a faster snow melt in the spring time.”

In addition to the snow, the dead trees no longer take in water from the soil through their roots “so what we end up with is a series of off-setting impacts and it’s really difficult to tell down at the stream gauge exactly how much impact is being experienced on any given river basin, so the short answer is we don’t know how much impact is there, we don’t know going forward what to look for but we do know that the dynamics in the forest have changed dramatically.”

Dispatches from the River: Pine Beetles and the Watershed KGNU News

KGNU News Director Maeve Conran was on the Colorado River last week with the Institute for Journalism and Natural Resources, meeting people impacted by changes in water flows due to water diversions to the Front Range and climate change. We’re featuring these stories in this series Dispatches From The River.