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

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.

Aditional Resources

McCauleyetal 2022 Appendix 1

Citation

McCauley, L.A., Bradford, J.B., Robles, M.D., Shriver, R.K., Woolley, T.J. and Andrews, C.A., 2022. Landscape-scale forest restoration decreases vulnerability to drought mortality under climate change in southwest USA ponderosa forest. Forest Ecology and Management, 509, p.120088. https://www.sciencedirect.com/science/article/pii/S0378112722000822