Connecting habitat in the Central Valley could help save California’s pollinators
University teams with Xerces Society in study of agricultural fields, urban interface
Mike Wolterbeek

Native plants on a farm’s border provide habitat for pollinators in California’s San Joaquin Valley. Photo by Cameron Newell, Xerces Society.
A study published in the science journal PLoSOne finds that planting the margins of agricultural fields with pollinator-friendly plants and minimizing pesticide use in the Central Valley of California could help pollinators there to survive. Pollinators, vital for food production, are rapidly declining, often most severely in agricultural areas.
“Insects populations and the pollinating services that they provide are decreasing at alarming rates across the globe,” the study’s lead author Tom Dilts, a research scientist in the College, said.
The Central Valley produces 25% of the country’s food and 40% of its fruits and nuts. The value of pollination services from wild pollinators to California agriculture is up to $2.4 billion per year.
Dilts collaborated with the University's College of Science and the Xerces Society on the study. The team developed a tool for modeling landscape connectivity for insects that uses land-use information, lethality of pesticides and expert opinion on insect movement.
“We looked at three different agricultural margin scenarios combined with three different pesticide use scenarios,” Dilts said, “We found that agricultural margins have the potential to greatly enhance habitat connectivity for pollinating insects.”
They also found that reducing pesticide loads can further increase connectivity for pollinators.
Farmers who plant hedgerows at their field edges see more benefits than just returning pollinators. The field borders can also attract pest-controlling insects, provide habitat for birds and other wildlife, and minimize soil erosion. USDA offers programs that allow farmers a quicker return on investment for habitat planting.