Large-Scale Forest Restoration Stabilizes Carbon Under Climate Change in the Southwest U.S.
Lisa A McCauley, Marcos D Robles, Travis Woolley, Robert M Marshall, Alec Kretchun, and David F Gori
Climate Change, Fire
A century of fire suppression along with a warmer climate have increased the size, frequency and severity of wildfires, which has increased risk to communities, water supplies, wildlife, forest cover and carbon stocks. The Four Forest Restoration Initiative (4FRI), a collaboration between the U.S. Forest Service and stakeholders to accelerate forest thinning, was formed in response to the large fires. We examined the fate of forest carbon with different rates of forest thinning across 1 million acres of 4FRI in northern AZ by simulating carbon sequestration and emissions between 2010 and 2100 under four climate change scenarios and different rates of mechanical thinning followed by prescribed fire. We examined how forest thinning and prescribed fire will affect wildfire severity and forest growth under a changing climate. We found that accelerated forest thinning followed by prescribed fire resulted in a 9-16% increase in carbon, stabilizing forest carbon stocks for decades and buying considerable time to better understand the effects of climate change on forests. In the accelerated forest thinning scenarios, 70% of the gains in carbon were due to a decrease in wildfire severity and 30% were due to an increase in forest productivity. Fire-adapted forests comprise more than 40% of the total forest cover in the western U.S., the majority of those forests are at risk of catastrophic fire. This study suggests that accelerated forest thinning can sustain forest cover and mitigate greenhouse gas emissions by reducing catastrophic wildfire.
Aerial view of the Parks West restoration site overseen by TNC. Taken March 16, 2020.
Conservancy staffers, Dale Turner and Amanda Rebore, helping to map the Sabn Pedro River in Arizona. They use a GPS unit to denote the end of the water flow on the LowerSan Pedro River. They hiked through the Conservancy’s San Pedro Preserve.
Our Approach to Science
The Nature Conservancy’s conservation science program in Arizona engages stakeholders and expertise in applied science and policy to develop new information, ideas, and tools that can help solve some of our most pressing challenges affecting people and nature
Explore Our Science
We are working with partners and stakeholders to accelerate the pace and scale of forest restoration for a healthy Arizona
Mapping the Status of River Streams
Wet/dry mapping provides a low-cost, river-wide snapshot of hydrologic conditions for rivers with interrupted perennial surface flows.
The Nature Conservancy, in collaboration with the Western Water Assessment and the USDA-Agricultural Research Service, has produced a snowtography handbook to support resource managers, researchers, and practitioners seeking to understand how the arrangement and density of trees, or the size and sev[…]
John. B. Bradford, Robert K. Shriver, Marcos D. Robles, Lisa A. McCauley, Travis J. Woolley, Caitlin A. Andrews, Michael Crimmins, David M. Bell
Tree mortality response to drought-density interactions suggests opportunities to enhance drought resistance
A future of hotter temperatures and less precipitation under climate change could increase tree mortality under drought conditions in dry forests across the western U.S., causing large-scale tree die offs. Restoration projects that reduce densities of overgrown forests can result in lower competit[…]
San Pedro River
Dale Turner, Holly Richter, Brooke Bushman
Wet/Dry Mapping Instructions and Data Forms
Example wet/dry mapping instructions and data forms used for the San Pedro wet/dry mapping effort. For more information, see our wet/dry mapping page.[…]