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Open Access Publications from the University of California

Volume 66, Issue 4, 2012

Issue cover
Cover Caption: State budget cuts have dramatically reduced funding for the Williamson Act, the conservation law that provides property tax relief for the owners of 15 million acres of farms and rangeland. In a survey of Central Valley ranchers, researchers found that landowners planned to sell 20% of their total acres if Williamson Act contracts were eliminated (page 131); 76% of those owners predicted buyers would develop the land for nonagricultural uses. Shown is an Angus cow grazing in Mission Peak Regional Preserve, which overlooks the City of Fremont and the San Francisco Bay. Photo by Sheila Barry
Williamson Act cuts: Survey finds ranch land at risk

Research and Review Articles

Analysis reveals potential rangeland impacts if Williamson Act eliminated

California budget cuts have resulted in dramatic reductions in state funding for the Williamson Act, a land protection program that reduces property taxes for the owners of 15 million acres of California farms and rangeland. With state reimbursements to counties eliminated, the decision to continue Williamson Act contracts lies with individual counties. We investigated the consequences of eliminating the Williamson Act, using a geospatial analysis and a mail questionnaire asking ranchers for plans under a hypothetical elimination scenario. The geospatial analysis revealed that 72% of rangeland parcels enrolled in Williamson Act contracts contained habitat important for statewide conservation goals. Presented with the elimination scenario, survey respondents reported an intention to sell 20% of their total 496,889 acres. The tendency of survey participants to respond that they would sell land was highest among full-time ranchers with low household incomes and without off-ranch employment. A majority (76%) of the ranchers who reported that they would sell land predicted that the buyers would develop it for nonagricultural uses, suggesting substantial changes to California's landscape in a future without the Williamson Act.

Clean Development Mechanism agricultural methodologies could help California to achieve AB 32 goals

California Assembly Bill 32 (AB 32), passed in 2006, mandates reductions in California's greenhouse gas emissions to 1990 levels by 2020. Charged with implementing the bill, the California Air Resources Board has identified emission reduction strategies, including nine for agriculture. The goals set for agriculture are voluntary, but because the agricultural sector represents a significant portion of both the state's economy and its greenhouse gas emissions, it offers considerable opportunities for mitigation activities. To reduce compliance costs, the Board's plan includes a cap-and-trade program that allows for offsets to be purchased from nonregulated firms that undertake mitigation in or outside the state. However, methodologies are needed to assess the impact of mitigating activities. Without them, emission reductions are expected to fall far short of potential. We review an existing international mechanism — the Kyoto Protocol's Clean Development Mechanism (CDM) — that offers a framework for evaluating offset projects and advanced methodologies that could facilitate AB 32 implementation in California.

Converting oak woodland or savanna to vineyards may stress groundwater supply in summer

Water resources are important to land-use planning, especially in regions where converting native oak woodlands or savannas to wine grape vineyards may affect the amount of water available for restoring salmon runs. Research has shown that woodland conversion to grasslands (for possible rangeland grazing) leads to greater and more sustained stream flow and groundwater recharge; however, little information is available about woodland conversion to vineyards. To inform resource managers and planners, we developed a water balance model for soil and applied it to vineyards, native oak woodlands and annual grasslands to evaluate their relative use of groundwater. We applied the model to Sonoma County, using climate data from 1999 to 2011, and determined that oak tree canopy coverage of 40% to 60% results in annual groundwater extraction equivalent to that of an established irrigated vineyard. However, vineyard groundwater use far exceeded that of oak woodlands in late summer to early fall, which could further stress already affected groundwater resources. We also evaluated the prediction sensitivity of the model to key parameters associated with rain levels, soil water-holding capacity and irrigation management.

Turnover rates are decreasing in California dairies

Dairy employees in the San Joaquin Valley are staying longer in their jobs. Our study in 2009 showed that the average length of employment has increased 250% since 1953 and 40% since 1984. However, tenures among non-Hispanic employees were twice as long as among Hispanic employees, suggesting there are opportunities to further increase workforce stability. The reasons why workers leave dairies are mostly the same as they were 30 and 60 years ago. We also compared our 2009 California interview results with recent studies in the eastern United States, where trends were similar.

4-H boosts youth scientific literacy with ANR water education curriculum

Scientific literacy among K-12 youth in the United States needs to be improved, and UC Agriculture and Natural Resources has identified this as a key area for research and extension. In 2010, ANR developed a water education curriculum for implementation by 4-H, which has a record of successful, nonformal science education programming that complements classroom-based instruction. The development of the new curriculum, There's No New Water!, is described, and preliminary results from a pilot test with high school youth are provided. Preliminary outcomes showed gains in both science knowledge and life skills.

Editorial, News, Letters and Science Briefs