WARMING, WILDFIRE, WATER, AND THE SURVIVAL OF MOUNTAIN FORESTS IN THE WESTERN US

In a warming climate, mountain forests can expect longer growing seasons, experience higher water demand, and suffer hotter dry periods. This can bring greater drought stress and more-severe wildfires, leading to loss of our iconic conifer forests. More-frequent management interventions to control live biomass and fuel loads can partially mitigate these potentially stand-replacing events and return a beneficial wildfire regime to the forests. Using an ecosystem-services framework we find that in California’s Sierra Nevada fuels treatments to reduce the severity of wildfire provide fire protection, while also enhancing water supply, reducing smoke-related health concerns, improving habitat, and providing other secondary benefits. Given and the urgency of increasing the pace and scale of restoring severely overstocked forests to more-sustainable conditions, regional stakeholder partnerships are forming to help plan, finance, and carry out fuels treatments on public lands. In some cases, monetizing just the water-related benefits of restoration can finance partnership costs. The aim is to transform these overstocked forests, which are the result of past management practices that suppressed wildfires and prioritized timber harvesting, to multi-benefit ecosystems that can be managed using low-severity fire. With treatment costs exceeding $1000 or even $2000 per acre in the Sierra Nevada, and millions of acres needing immediate restoration, this is a multi-billion-dollar challenge. Recent data and findings confirm the effectiveness of fuels treatments in reducing wildfire severity, providing more water for downstream hydropower and water supply, reducing drought stress, increasing carbon storage, mitigating wildfire-related erosion risk, and lowering wildfire risks to other forest ecosystem services. These new data and tools are particularly important in facilitating partnerships formed to increase the capacity to manage public lands, and in encouraging greater public investments in landscape restoration. This research is supported through the Center for Ecosystem Climate Solutions, https://california-ecosystem-climate.solutions.