Many Routt County residents have been thrilled to have a snowy start to the winter. We foresters are especially excited.

In addition to great ski conditions, a deep snowpack provides water to our forests and watersheds. When spring arrives, the winter’s snowpack acts as a store of water that promotes forest health by reducing drought stress and wildfire risk, benefits that can last well into the summer. Spring snowmelt also feeds our rivers, and is critical to sustaining water resources. With 80% of Colorado’s streamflow originating as snowmelt, and with Colorado rivers supplying water to 19 states, what can foresters do to sustain and improve our water yield?

While we have been fortunate with snowfall this year, Colorado has had less persistent snowpack in recent decades. Both forest health and water supplies have suffered as a result of sustained drought conditions. Trees that are drought stressed are more susceptible to insect attacks, which has led to multiple major outbreaks since the turn of the century. Drier forests are also more likely to burn. 

Climate change is expected to elevate these threats in the future. Although its effects on precipitation are difficult to predict, warmer temperatures alone substantially increase drought stress on trees and increase evaporation rates in our reservoirs. At the same time, the growing population is demanding more of our water supplies in both local and regional watersheds.

The Colorado State Forest Service uses the latest science to adapt management strategies to the changing conditions in forest ecosystems. A recent publication from Colorado State University compiled numerous studies on snowpack in forests and provided actionable suggestions for management. The combined results of these studies indicate that an effective method to maximize snowpack in our area is to focus on high elevation forests and create small openings scattered across the landscape. Small openings, 1-5 acres in area, can both increase the rate of snow accumulation and limit the rate of snowmelt. 

Forest openings lead to greater snow accumulation because trees “intercept” snow before it reaches the ground. Snow that accumulates on trees evaporates relatively quickly. Snow falling in larger openings piles up on the ground, but tends to melt in the sun. Researchers have found that small openings allow snow to accumulate on the ground, but remain largely shaded by surrounding trees. 

This finding is encouraging because small scattered openings can benefit forest health in other ways. Such openings reduce wildfire risk by breaking up fuel continuity and create habitat for wildlife. They also provide opportunities for younger trees to grow in the newly opened spaces. Younger trees tend to be more resistant to pathogens such as bark beetles. Forests composed of trees of varying ages are more resilient and are well situated to recover from disturbances. 

The Colorado State Forest Service uses accepted, peer-reviewed science to inform our forest management strategies. Drought is one of the greatest challenges for our forest ecosystems and our water supplies. Using ecologically sound forest management practices, we can deliver more water to our forests, rivers, and homes.

Justin Minott is a forester with the Colorado State Forest Service.