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Newsletter - Spring 2009

Current Research - Landscape Processes

Landscape analysis of agriculture and climate change

LAWR soil ecology Professor and CE Specialist Louise Jackson led an interdisciplinary research team to conduct a case study for Yolo County assessing how climate change will impact California’s agricultural landscapes. A wide range of issues related to crop productivity, greenhouse gas mitigation potential, and land use change were addressed. This project was part of the larger analysis of climate change scenarios by the California Climate Change Center, in accordance with Assembly Bill 32, the Global Warming Solutions Act. The full set of reports is available at

Planning for both mitigation of greenhouse gases and adaptation to new climate regimes was the main objective, rather than definitive predictions. The study utilized historical data, models, GIS analysis, and storylines for potential responses to climate change during the period 2010–2050. Storylines were developed in response to a series of scenarios identified by the Intergovernmental Panel for Climate Change.

Under a global scenario of high greenhouse gas emissions and loss of agricultural land, county population would expand rapidly and urban land would nearly double, with large decreases in farmland, and some changes in crop mix emphasizing higher value monocultures. With little planning for climate change, soil, water and land management could risk large yearly variation in production due to climate change-induced water shortages and flooding risks.

Under a global scenario with lower greenhouse gas emissions, and more sustainable land-use scenarios, agricultural land would be preserved. Due to research and extension, growers would be prepared to diversify their crop mix for resilience, reduce intensity of nitrogen-based fertilizer use and tillage, and use more efficient water management. Mitigation strategies will be employed, e.g. orchard crops, elimination of fossil fuel inputs, and extensive conservation practices to sequester carbon in wetlands and woodlands along waterways, using practices that minimize nitrous oxide and methane emissions. Novel food systems would encourage reduction of greenhouse gas emissions, as well as greater resilience and sustainability.

Yolo County’s water supply may see little change under either scenario, based on current models for 2010–2050, but agricultural water would decrease with urban demand. Reduced Sierra snowpack will increase flooding along the Sacramento River, presenting serious economic and ecological tradeoffs for ecosystem restoration versus farming.

Of the ten UC Davis faculty members on the project, three are from LAWR (Louise Jackson, Toby O’Geen, and Will Horwath). They worked with county agencies, and a statewide steering committee. The Yolo County Agricultural Commissioner, Rick Landon, and the UCCE farm advisors, provided important guidance. The main outcome of the project was the need for vigorous planning strategies to reduce vulnerabilities and to simultaneously increase mitigation and adaptation potential, so that preservation of Yolo County’s agricultural lands will continue.

In Yolo County, the eastern boundary near the sacramento River, has the greatest frequency of flooding. The lands of the Yolo Bypass will become more prone to flooding as the climate warms, since Sierra snowpack will be reduced, and snowmelt will occure earlier in spring.