Populations of wild bees are waning due to a loss of habitat in areas with heavy farming, a recently published article indicates.

Titled “Modeling the status, trends, and impacts of wild bee abundance in the United States,” the piece was published by a team of American researchers, and it points out that “Between 2008 and 2013, modeled bee abundance declined across 23 percent of U.S. land area. This decline was generally associated with conversion of natural habitats to row crops.” The researchers claim that despite the impact of pesticides, disease, and climate change, “habitat loss seems to contribute to most observed declines.”

The study identifies almost 140 U.S. counties where low bee counts parallel large areas of pollinator-dependent crops. These counties, according to the article’s figures, account for 39 percent of such pollinator-dependent growers across the United States—and that the agriculture which most crucially relies on wild bees for pollination actually sees the worst mismatching of bee count to need for natural pollinators.

Such trends not only threaten to increase farming costs, but could eventually destabilize crop production. The article states that the wild bees that need dedicated land for nesting and foraging contributed to an estimated 11 percent of the U.S.A.’s agricultural gross domestic product in 2009, about $3 billion.

Ecologist Taylor Ricketts of the University of Vermont, one of the project researchers, was quoted in a related write-up in Science News with advice: “Creating wild bee habitat on field edges could help maintain wild bee populations and sustain crop pollination…you grow more abundant bees of diverse kinds and they spill out into your fields.”