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Valley Grapes Crushing Critters?
Just a few years ago, a driver on the Central Valley's highways and byways would pass field after field of rice, corn, tomatoes and other row corps, interspersed with open pastures. Today, acre after acre of vineyards line many of those roads, a shift that is creating new challenges for those attempting to protect what's left of the Valley's native fauna.
Vineyards are being planted so swiftly that "you can hardly keep track of it," says Cliff Ohmart of the Lodi-Woodbridge Winegrape Commission. According to state Department of Agriculture statistics, San Joaquin County had 48,545 acres of fruit-bearing vines in 1998, and 11,930 acres of non-bearing vines-those planted within the previous three years. In Sacramento County, the acreage planted with vines has more than doubled within the last three years, to 6,560 acres of bearing vines and 6,827 non-bearing. Grapes are now the county's number one crop.
The conversions are being driven strictly by economics, say observers. "The price of land for new vineyards in the traditional growing areas of Napa and Sonoma is so high that it is difficult to make money there," says Ohmart. On the other hand, "vineyards are the most profitable use you can put land to, outside of developing it," according to Pete Schmidt of Ducks Unlimited.
These conversions-which mirror a statewide trend-are not good news for the numerous species, particularly raptors such as the endangered Swainson's hawk, that managed to adapt to life on the farm even as the grasslands that were their native habitat disappeared. "Raptors can hunt in the pasturelands and row crop fields that replaced the natural environment, and small animals can shelter in the uncultivated margins of fields," says Wendy Halverson Martin of the CALFED Restoration Program, adding that winter-flooded rice and corn fields also offer habitat to birds using the Pacific Flyway. " But when you convert those fields and pastures to permanent cover crops, such as grapes or orchard fruit, you destroy what little habitat values they still had." Even birds that can hunt among the vines have a hard time of it. "Vineyards and orchards are pretty sterile environments for wildlife," says the Audubon Society's Waldo Holt. "There are no rodents and pesticides eliminate insects, so the prey base is essentially removed."
Not necessarily, says Ohmart, who maintains that the grape industry has taken the lead in promoting environmentally sustainable agricultural practices. Ohmart's commission operates a biologically integrated farmingprogram designed to encourage members to switch to drip irrigation systems, reduce fertilizer and pesticide use, plant cover crops and install owl boxes and raptor perches to help control the resulting populations of rodents. "Cover crops help with water penetration, prevent surface erosion and encourage microbial growth, which is important for healthy soil," he says. "Healthy soil means healthier, more disease resistant vines and better quality grapes."
For some, the environmental impacts of vineyards themselves are less troubling than the potential long-term implications."It seems likely that in many cases the conversions are merely a steppingstone to further development," says CALFED's Martin. However, not everyone shares this concern. "I think the capital outlay to put in grapes is large enough that people won't turn around and develop it," says Holt. "It takes a while to recoup your investment."
To be on the safe side, CALFED is buying agricultural easements to make sure that land is not converted to vineyard. "We can't afford to buy land that has been converted to vineyard. We're buying it now to ensure that beneficial agricultural practices are preserved and the option for future restoration is maintained," says Martin.
Contact: Wendy Halverson Martin (916)657-2666, Cliff Ohmart (209)367-4727
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