Valuing the Impact of Forest Disturbances on the Climate Regulation Service of Western U.S. Forests

Abstract

The protection and expansion of forest carbon sinks are critical to achieving climate-change mitigation targets. Yet, the increasing frequency and severity of forest disturbances challenge the sustainable provision of forest services. We investigated patterns of forest disturbances’ impacts on carbon sinks by combining spatial datasets of forest carbon sequestration from biomass growth and emissions from fire and bark beetle damage in the western United States (U.S.) and valued the social costs of forest carbon losses. We also examined potential future trends of forest carbon sinks under two climate-change projections using a global vegetation model. We found that forest carbon losses from bark-beetle damage were larger than emissions from fires between 2003 and 2012. The cumulative social costs of forest carbon losses ranged from USD 7 billion to USD 72 billion, depending on the severity of global warming and the discount rate. Forest carbon stocks could increase around 5% under Representative Concentration Pathway (RCP) 4.5 or 7% under RCP 8.5 by 2091 relative to 2011 levels, mostly in forests with high net primary productivity. These results indicate that spatially explicit management of forest disturbances may increase forest carbon sinks, thereby improving opportunities to achieve critical climate-change mitigation goals.

Carbon stocks across different environments, disturbance regimes, and stand age in Fitzroya cupressoides forests, the longest-lived species of the southern hemisphere

“…In northwest Patagonia, forest landscapes are shaped by land use and disturbances influencing their composition, structure, and functional processes. Disturbances (such as fire, landslides, volcanism, or harvesting) play a significant role in the amount and distribution of carbon stocks and fluxes since they can release large amounts of carbon to the atmosphere (Keith et al, 2014;Thom and Seidl, 2016;Anderegg et al, 2020;Marcos-Martínez et al, 2022). However, key questions on the long-term influence of disturbance regimes mediated by physiographic location and environmental conditions (i.e., topography, climatic conditions, and soil fertility) on biomass and its allocation in living and dead biomass still remain largely unanswered (Pregitzer and Euskirchen, 2004;Hoover et al, 2012).…”

“…Moreover, there is no information on carbon allocated to live and dead pools in each of the studied conditions. Understanding the impact of forest disturbances on forest carbon sequestration from temperate ecosystems, which can contain trees older than 4,000 years (Lara et al, 2019), has the potential to provide unique information to address scientific issues that are globally relevant in the context of climate change (Luyssaert et al, 2008;Keith et al, 2009;Marcos-Martínez et al, 2022).…”