Valuing the impacts of forest disturbances on ecosystem services: An examination of recreation and climate regulation services in U.S. national forests

The increasing frequency and severity of forest disturbances challenge the sustainable provision of ecosystem services by forests, and this is true even in regions with net forest growth. The combination of ecosystem service losses from forest disturbances that are immediate as well as the slower post-disturbance process of forest regrowth could result in long-lasting social, economic, and environmental costs. Using economic and geospatial analysis, we estimate the value of recreational services losses due to drought and quantify the social cost of carbon emissions due to wildfires and bark beetle damage in three National Forests in the Sierra Nevada region, California (Inyo National Forest, Tahoe National Forest, and Lake Tahoe Basin Management Unit). Our findings indicate that recent droughts resulted in an annual reduction of about 73 million, 36 million, and 15 million for Lake Tahoe Basin Management Unit, Tahoe, and Inyo National Forests, respectively. Tree biomass loss due to wildfires and bark beetle damage generated around 10 Mt CO2 of total emissions from 2003 and 2012. The estimated cumulative social costs of such emissions were around 0. 8 million for fire and 2. 4 million for bark beetle (using a 3% discount rate for related climate change damage). The social costs almost tripled under extreme climate damage projections. Our analysis could inform adaptation and management strategies to conserve or enhance the health and function of publicly managed forests, and to protect their flow of ecosystem services for present and future generations.