Trees of knowledge – and benefit

While Curtis Beutler and Austin Shirley dig snow pits measuring the snow’s density and temperature to predict how much water it will deliver to streams and soil in the East River basin, they’re also active in another study in the Taylor River basin. There, scientists and land managers are looking at how to help forests adapt to climate change. RMBL researchers led by Ken Williams, PhD, of the Lawrence Berkeley National Laboratory, are working alongside the forest-focused group but training their sights on preserving water resources.

The Adaptive Silviculture for Climate Change (ASCC) is a network of experimental forest sites in the U.S. and Canada. At these 14 sites, scientists and land managers, in partnership with the U.S. Forest Service, are testing several treatments to see whether scientifically informed management can boost certain species’ chances of adapting to a warming climate. Focusing on lodgepole pine, a keystone species at the Taylor River site, researchers are comparing three silviculture treatments: resistance, resilience, and transition.

The resilience treatment is designed to strengthen the lodgepole’s defenses against a changing climate and insect-borne diseases by removing small, spindly trees to free up water and nutrients for the older, established ones. In the transition treatment, which assumes that lodgepole pines won’t survive the warming climate, managers clear-cut the pines and replant seedlings of trees like ponderosa pine or blue spruce, which are better adapted to a hotter, drier environment.

Extracting even more knowledge from the Taylor River site, Dr. Williams’ team is looking at how forests can be managed to not just address issues of forest health but also optimize water resources in a hotter and drier future. Trees are major players in the hydrologic cycle, with their water use coming from both snowmelt and summer rains. While a dense and lush canopy of green lodgepole pine needles is emblematic of a healthy forest, that thick canopy can act counterintuitively to intercept snow and rain, thereby preventing it from reaching the soil and root zone. In a snow- or rain-scare future, it’s essential to manage Western forests in a way that finds a “sweet spot” in the forest composition to preserve forest health against threats like wildfire and insects while optimizing precipitation inputs.

Dr. Williams’ team wants to identify that sweet spot in forest management where we can move toward more resilience not only for forests but also for water resources. He expects to be working on this study over the next five to ten years. With such important work, science is already thirsting for answers.

Kenneth Williams holds a Ph.D. in Environmental Science, Policy & Management from the University of California, Berkeley. He is a staff geological scientist in the Climate and Ecosystem Sciences Division of the Lawrence Berkeley National Laboratory. He’s also the Program Lead for Environmental Remediation and Water Resources at Berkeley Lab and the Deputy Lead of Berkeley Lab’s Watershed Function Scientific Focus Area at RMBL. He is focused on understanding how mountainous systems retain and release water, nutrients, carbon, and metals in response to climate change. A pioneer in biogeophysics, he brings a unique perspective as a biogeochemist, with interests spanning geology, geochemistry, hydrology, and microbiology.