Hydrologic Systems and Forest Restoration

forest restoration
Hydrogeologist Abe Springer and student researcher Karissa Ramstead working in the field. Photo: Ecological Restoration Institute

Many scientists say intense wildfires, like the Slide Fire in Oak Creek Canyon, underscore the urgency for forest restoration. Hydrogeologist Abe Springer studies how forest treatments, like thinning and prescribed burns, are impacting natural water systems. He says 80-85% of precipitation evaporates or transpires in northern Arizona's overcrowded forests. Most of the rest runs off with very little left to recharge the aquifers.

Springer says, "Studies have shown that when you do restoration treatment on typical forests in this region, you reduce the amount of evaporation and transportation by about 15%."

According to Springer, improved technology is helping Northern Arizona University researchers better understand the current and restored forest structure as it relates to hydrologic processes. One new tool is a remotely controlled drone, soon to be hovering in the forest around Flagstaff. "It's small," Springer explains, "but it will carry some instruments with which we can do low-elevation observation of the topography, forest structure, forest canopy, leaf area. So, we do types of measurements on intermediate scales that we've never done before."

What's really important for forest restoration and water yield, he adds, is not just the overall treatment of trees, but also a very careful design of where there are clumps and openings. Springer says identifying forest-health treatments that decrease the size and intensity of future wildfires, and also improve surface and ground water systems, is critical now and into the future as Earth's climate warms and evaporation rates increase.

—Bonnie Stevens