| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
|
|
|
|
|
Habitats Uncorking the Wild There's more than one way to grow a grape. Lou Preston, and an increasing number of other California vintners, are choosing better ways: better for their land, better for the plants and animals that rely on it, better for the creeks that course through it, and, Preston says, better for the quality of the grape itself, and the flavor and fragrance of the wine made there. "Ten years ago this would have just looked messy to me," says Preston, the proprietor of this 125-acre Sonoma County vineyard. "Now, I love it." We're driving along rows of vines in Preston's vegetable-oil-burning VW. The vines are interspersed with unruly rows of cover crop (mustard, clover, vetch, and other insect-attracting plants) and even among the vines, weeds grow here and there. It certainly does have a messier look than the monotonous, regimented rows of vines at nearby wineries. Preston, the proprietor of Preston of Dry Creek winery, has been growing grapes here for 30 years. For the first decade he used conventional methods, spraying pesticides to wipe out insects and inhibit weeds. "In those days we didn't need to spend so much time among the vines. It was a much less labor-intensive kind of farming," he says. "I was focused on getting the vines in and marketing the grapes. I didn't pay much attention to what was around me in terms of the natural world." But then the pests he was spraying began to develop resistance to the chemicals. His vines grew tired, run down, and easily sickened. The organic produce movement was just emerging as a farming model, and Preston began replacing chemical controls with biological ones. He and his employees began spending more time in the rows turning the ground and manually removing weeds. Instead of applying insecticides, they cultivated native plants to attract the pests' natural predators. "We had been turning this whole valley into a chemically sustained monoculture," he says. "Now, I'm doing whatever I can to resist that, to treat the farm like the complex ecosystem that it can be." How grape growers treat their land makes a huge difference to California wildlife. More than 500,000 acres of the state are planted in vineyards. And most of those are in rural counties bordering on wildlands. If vineyards were hospitable to wildlife, providing corridors for migration and some valuable habitat, they could contribute much toward preserving the state's biological diversity. On the other hand, vineyards that are hostile to wildlife (see "Habitats" Spring 2005) have major negative impacts. The biggest ecological impacts of vineyards come from pesticide use, erosion, damage to streamside riparian habitats, and their unfriendliness to wildlife. All of these effects can be reduced, and some of the methods employed to reduce them can even enhance the quality of the wine. The rows that Preston sows with native plants are good habitat for native birds, reptiles, and insects. They work as corridors for larger terrestrial mammals, too. "They contribute to the biological activity of the soil, releasing locked-up nutrients, and ultimately," Preston says, "encourage wine flavors that are indigenous to the property." Alongside Dry Creek, one of two creeks that nearly encircle Preston's vineyard, there is evidence of the way former growers tried to address erosion problems. The rounded hoods and tops of several 1940s cars stick out of the muck and are surrounded by exotic Bermuda grass and giant reed, a bamboo-like plant that quickly dominates native riparian habitat here. "They used to line the creek with old cars to keep the banks from washing away in a flood," says Preston. If degraded creeks are one tragic legacy of old farming practices, restoring and protecting them are ways for winegrowers to make huge contributions to the ecological health of their regions. Preston is working with the California Department of Fish and Game on restoring sections of his creeks where exotic plants are king and erosion is bleeding away his most precious resource: healthy soil. The restoration team has been anchoring boulders and logs in the creek to slow its flow and create a greater variety of flow types. Spawning fish and fry need both riffles and sanctuary. They've also been replacing the exotic plants with natives such as willow, alder, and cottonwood. The root structures of these natives are better suited to holding creek banks in place and provide much better habitat for hundreds of native species of mammals, fish, birds, insects, and amphibians. Preston hopes to help restore the salmon run that used to roil through here in the fall. But a more immediate challenge is trying to ward off Pierce's disease, a bacterial infection carried by a small bug called the blue-green sharpshooter. The sharpshooter lives part of its life cycle in the vegetation along the creek. By removing exotics such as giant reed and tamarisk that are attractive to the sharpshooter, and replacing them with more resistant natives, he has so far kept the pests to a minimum. Preston has taken out two rows of grapes along Pena Creek in order to make room for a barrier crop of perennial buckwheat, toyon, and ceanothus-host plants for native insects that prey on sharpshooters. The barrier will also keep the pests from reaching the crops in early spring, when sharpshooters usually abandon the creek for the vines. "I'm giving up about ten percent of my vineyard area-areas between blocks, around the vineyard, along creeks, and at my boundary with non-organic neighbors," Preston says. "I'm sure the neighbors are looking at me as if I'm crazy-but it's definitely worth it for me. The ecological and biological aspects of this approach are the most interesting, but it is the quality of the wines that are most validating." Preston's neighbors may think him eccentric, but 30 miles to the southeast, Benziger winery is taking land stewardship one step further. Biodynamics is a farming method developed by Austrian scientist-philosopher Rudolph Steiner in the 1920s. Its central tenet is that a farm should be as self-sufficient a system as possible. Eschewing the use of pesticides or outside fertilizers, biodynamic farmers use biological pest controls, make homegrown concoctions for nourishing their vines, and pay keen attention to the ecological forces in play at a specific site. The wines created by biodynamic methods are highly individualized, place-specific varietals, says Alan York, a biodynamic consultant to Benziger, near Glen Ellen in Sonoma Valley. "We're not trying to produce the best wine in the world. We're trying to produce wine that best reflects this place and the people who work here," says York. While Benziger makes deliciously complex and flavorful wines, it also looks and works something like a nature preserve. The creek corridor is broad and densely vegetated to allow wildlife safe passage. Islands of good habitat are distributed around the estate, including a constructed wetland that processes the vineyard's wastewater and attracts bluebirds, swallows, and dozens of other insect-eating birds. The farm has its own little fertilizer factories: two longhaired Scottish Highland cattle which graze on the vineyard's cover crops. It has a big herbaceous insectary that attracts the predatory wasps, pirate bugs, lacewings, and spiders that keep pests under control. "Instead of spending $12,000 a year on insecticides, we spend it on making habitats that benefit the environment. Multiply that by a decade and it is pretty significant," says York. Though well established in Europe, biodynamic winemaking is still small and young in California. But it's expanding here quickly. According to Demeter, the Oregon-based certifier for biodynamic farming, the number of certified grape farmers in California has grown to more than 20 in the past five years, and another twelve are being certified this year. Meanwhile, the conservation ethic is catching on at some big wineries, too. Down the road a ways from Preston's vineyard is Clos Du Bois, the maker of one of America's best-selling chardonnays. Keith Horn, the vineyard manager here, says he is always looking for ways to reduce the vineyard's impact on the landscape. Though Clos Du Bois uses insecticides and herbicides to control pests, "we try to keep them to a minimum," says Horn. He too has restored native plants to sections of creek passing through the vineyard, and has placed bird and owl boxes throughout the vineyard to attract gopher-killing raptors. Preston, Clos Du Bois, and Benziger are all part of a definite trend, says Karen Gaffney, an ecologist with Healdsburg-based Circuit Rider Productions. The nonprofit works on habitat restoration with several vineyards in the area. But there is an even more powerful counter trend, with vintners employing factory farming methods and taking them into new, previously wild lands. If sustainable grape growing is going to win this tug of war, it will be because consumers consider how their wine-buying habits affect California's wildlife. Some have already made changes. Jonathan Waters, the wine buyer at Berkeley's paragon of progressive taste, Chez Panisse, says that of the 250 wines on their list, 20 to 30 are certified organic, and 220 are "sustainably farmed." If the rest of us wine lovers considered these choices, the industry would take notice pretty fast. Gordy Slack is a science and nature writer and a California Wild contributing editor. |