Water Resources Research Act Program

Details for Project ID 2012CA292B

Effect of forest management on water yields and other ecosystem services in Sierra Nevada forests

Institute: California
Year Established: 2012 Start Date: 2012-01-01 End Date: 2015-12-31
Total Federal Funds: $119,829 Total Non-Federal Funds: $169,455

Principal Investigators: Kevin O'Hara

Abstract: Water is arguably the highest-value ecosystem service associated with the conifer forests of Californias Sierra Nevada. Yet the provision of this essential service is vulnerable to changes in the energy and water balance associated with climate warming. To date, we have observed more precipitation falling as rain versus snow, earlier snowmelt, and greater summer water deficits. Such climate forcing will impact the water balance for the foreseeable future. However there is the potential to manage the water balance in forest ecosystems. The dominant vegetation (i.e., trees) is highly productive, forms dense canopies, and consequently, uses a great deal of water. There is a strong positive correlation between annual net primary productivity (the ultimate measure of the photosynthetic capacity of the ecosystem) and evapotranspiration (the primary cause of water loss). Any manipulation that reduces the productivity (i.e., removes trees) reduces evapotranspiration, shifts the balance of energy driving snowmelt, and thus may affect soil-water storage and streamflow. Water from the Sierra Nevada provides both hydropower and water supply to downstream users. Reducing and restructuring the forest vegetation density can also mitigate the negative impacts of wildfires as well as accomplishing some forest restoration objectives. Forest management that specializes in high value and long-lived forest products can produce the greatest amount of total carbon sequestration benefits when energy use in the consumer sector is considered. Recreation-, conservation-, and biodiversity-related ecosystem values often pose competing aims relative to forest management but there are few mechanisms to evaluate the tradeoffs and complements related to different strategies. Open space easements and hunting leases are two examples of ecosystem services that could provide a model for translating expressed value for other ecosystem services into real financial mechanisms. It is proposed to undertake a three-part, multi-year and multi-disciplinary research and assessment project that addresses issues related to climate warming, vegetation manipulation, and the forest water cycle. The three components are: i) measurements at sites of opportunity where fire or thinning treatments have taken place or are taking place, ii) meta-analysis and modeling using available data to interpret these results, and iii) evaluation of multiple ecosystem services and how multiple service providers (land and resource owners/managers) can effectively interact with service consumers (downstream and downhill residents).