Lake Tahoe West Science Summary of Findings Report

As part of the Lake Tahoe West Restoration Partnership, a science team worked with resource managers to evaluate effects of forest dynamics and management strategies on social and ecological values within a 59,000-acre landscape in the western part of the Lake Tahoe basin in California. Forest growth and fire dynamics were modeled across the landscape using the LANDIS-II platform over 100 years; interconnected models were used to evaluate changes in wildlife habitat, water quality, and economics. Additional modeling and some field monitoring were conducted to evaluate how treatments would affect fire behavior, fuels, and snow hydrology within forest stands. These investigations evaluated how different management strategies would affect outcomes important to stakeholders, including abundance of old trees, wildlife habitat, fine sediment, water quantity, implementation costs, fire characteristics and threats, air quality, cultural resource quality, and carbon sequestration. The scenarios spanned a wide range of management approaches, from wildfire-suppression only, fuels reduction near communities, moderate and extensive restorative thinning and/or prescribed burning. The results indicated that moderate and extensive thinning or burning treatments would promote overall objectives better than no treatment or thinning only near communities, except for carbon sequestration and treatment costs. Over the long-term, more treatment would reduce the wildfire threat to communities, the risk of unnaturally large patches of high intensity burns, and days of extreme emission of smoke into downwind communities. More extensive treatments were projected to increase water yield and promote the growth and occurrence of pine and aspen trees. Increased treatments, especially burning, may promote cultural resources important to the Washoe Tribe of Nevada and California (hereafter the “Washoe Tribe”), who consider Lake Tahoe the center of their ancestral homelands. On the other hand, greatly ramping up prescribed burning may pose a challenge in terms of avoiding near-term impacts of treatments on air quality and water quality, even though such a strategy may yield long-term net benefits.