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Mar 2022

Landscape-scale forest restoration decreases vulnerability to drought mortality under climate change in southwest USA ponderosa forest

Lisa A. McCauley, John. B. Bradford, Marcos D. Robles, Robert K. Shriver, Travis J. Woolley, Caitlin A. Andrews
Arizona
Climate Change, Fire, Forest Restoration Benefits
Forest
USGS
Abstract

Drought is projected to increase tree mortality in many western US forests due to climate change and could result in large-scale tree die-offs, altering forest composition and ecosystem services. Tree mortality has also been found to be higher in forests with greater tree density. Southwestern US forests are particularly susceptible to increased tree mortality due to the predicted temperature increases, drier soils, and forests with high tree density. The goal of this study was to examine how the Four Forests Restoration Initiative (4FRI), a large-scale forest restoration currently being implemented to reduce the risk of severe wildfire, will affect ponderosa pine mortality under climate change. We found that without thinning, mid-century changes in climate could increase annual ponderosa pine mortality rates by 45–57% over contemporary rates. However, with 4FRI thinning, mid-century mortality was predicted to remain near or below contemporary rates and these rates are 31–35% less than the mid-century scenarios without thinning. Our study shows that while climate change is likely to increase tree mortality rates, large-scale forest restoration projects, such as 4FRI, have the potential to ameliorate the effects of climate change and keep mortality rates near contemporary levels for decades.

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(ALL RIGHTS GRANTED TNC) View of Escudilla Mountain. Fall colors heighten the natural beauty of forest and meadow in the White Mountains, one of Arizona’s last wide-open spaces and where TNC works to protect the headwaters of three major Arizona rivers: the Salt, Gila, and Little Colorado and their greenbelts – riparian habitats critical for wildlife and water quality – as well as restore healthy forests within the largest ponderosa pine community in the world, save rare and unique wildlife and plant species, and control non-native, invasive species, such as crayfish, Arizona. © Betsy D. Warner/TNC
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.

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Mar 2022
Papers
Arizona
Climate Change, Fire, Forest Restoration Benefits
Forest
USGS
Lisa A. McCauley, John. B. Bradford, Marcos D. Robles, Robert K. Shriver, Travis J. Woolley, Caitlin A. Andrews
Landscape-scale forest restoration decreases vulnerability to drought mortality under climate change in southwest USA ponderosa forest
Drought is projected to increase tree mortality in many western US forests due to climate change and could result in large-scale tree die-offs, altering forest composition and ecosystem services. Tree mortality has also been found to be higher in forests with greater tree density. Southwestern US fo[…]
Nov 2021
Papers
Arizona, Colorado River Basin, Western U.S.
Forest
USDA ARS, Western Water Assessment
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Nov 2021
Papers
Arizona
Climate Change, Forest Restoration Benefits
Forest
USGS
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
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