Lynn Huntsinger, a professor of rangeland management at UC Berkeley who is not affiliated with the study, said that the findings are significant because the study is the first to discover that conserving rangelands enhances crop production.

“This evidence of economic symbiosis makes it clear that rangeland conservation cannot be separated from the needs of agriculture, whether it is farming or ranching,” Huntsinger said.

She said that precisely because rangelands have been used for ranching – livestock grazing – ranchers have kept the land conserved and stewarded it in ways that result in habitat that sustains wild bee species as well as other wildlife.

“Studies in some ecosystems have shown that well-managed grazing can keep invasive grasses from shading out the flowering herbs that native pollinators rely on,” Huntsinger said.

The state’s rangelands have been decreasing steadily, as the foothills and oak-dotted grasslands can be highly desirable for residential development, Huntsinger said. California lost 105,000 acres of grazing lands to urbanization between 1990 and 2004, according to the state Department of Conservation. The California Oak Foundation projects that the state could lose another 750,000 acres by 2040.

She said the vast majority of rangelands are privately owned, and income from ranching is usually small compared to the price the land can command in the real estate market, so when cash is needed for college, retirement or other major expenses, ranchers face strong pressure to sell.

“This new finding about pollinators is important because not only does it tell us something we need to know to maintain our ability to grow food, it also provides a statewide value for the service of providing pollinator habitat. Ranchers need to get that value and other rangeland values recognized in order to sustain their ranches,” Huntsinger said.

The finding comes at a time when there is growing interest within the ranching community in providing ecosystem services, Huntsinger said. For example, as part of conservation efforts, California ranchers have been asked to maintain flowers for endangered butterflies and to keep small spring wetlands known as vernal pools healthy – using grazing as a tool to manipulate the grassland.

Darrel Sweet, a fifth generation cattle rancher from Livermore and a former president of the California Cattlemen’s Association, said that placing a dollar value on rangelands pollination services lends powerful support to these efforts.

“The value of grazing and other land stewardship practices of California’s ranchers is being increasingly acknowledged as not only a preferred land use, but also as an essential resource management tool,” said Sweet. “I hope this study is just the beginning of comparable findings that show how ranching is a critical – and multifaceted – element of California agriculture.”

Calling to mind the classic “Oklahoma!” song “The Farmer and Cowman Should Be Friends,” the study’s findings suggest a host of ways farmers might work with ranchers to their mutual benefit, Kremen said.

While the study issues the caveat that the exact value of pollination services from natural habitats is difficult to pin down using currently available data, Kremen said the findings highlight from a biophysical perspective how important this value is.