I Stock Analyst
Biofuel and bobwhites
By Spencer Hunt, The Columbus Dispatch, Ohio
The push to produce more corn and soybeans for biofuels might help lower gas prices and fight global warming, but it also could wipe out as many as two-thirds of the bird species that nest near farms.
On the flip side, if farmers grow grasses, the number of birds that nest near farms could double in parts of Ohio and other Midwestern states, researchers say.
Species that nest in the grassy "margins" around farms have the most to lose or gain, said Tim Meehan, a University of Wisconsin ecologist.
"I think the biggest concern is there are so many grassland birds that are already in danger," said Meehan, lead author for a study recently published in the Proceedings of the Natural Academy of Sciences.
"Take what you've seen so far over the last 100 years or so in bird trends and extend it," he said. "If you continue to annualize landscape, then expect more of the same and certain species to disappear."
Bird species that nest in prairies and fields of tall grasses can't compete with farming. Corn, soybean and wheat fields offer no shelter or food for grassland birds.
Habitat loss has been linked to significant declines in grassland bird populations tracked since 1966 by the North American Breeding Bird Survey.
"They all have been declining, more than any other group (of bird species)," said Paul Rodewald, an Ohio State University ornithologist.
In Ohio, the northern bobwhite and Henslow's sparrow, for example, each have seen their populations decline by more than 90 percent. The eastern meadowlark has declined more than 70 percent.
Those losses occurred without a push for biofuel. The U.S. energy bill of 2008 calls for 36 billion gallons of homegrown biofuels by 2022.
Now, about 11 billion gallons of ethanol are produced in the United States, largely from corn. Soybeans also are used to help make biodiesel. When demand increases and corn prices rise, farmers often plant on more "marginal" land to increase production.
Marginal farmland has poor soil or floods frequently. Farmers often take advantage of federal programs that pay them to plant tall grasses there. The grasses help keep fertilizers and chemicals from washing into steams, rivers and lakes.
When prices go up, growing corn or soybeans in the margins becomes more profitable. The U.S. Department of Agriculture estimates Ohio lost 16,300 acres of grassland to corn in 2008 after corn rose from $2 per bushel to $3.
To study the effects of corn grown in these areas, Meehan and other researchers used software to analyze land-use data and breeding-bird survey statistics for Ohio and six other Midwestern states
If an estimated 23.5 million acres of marginal grasslands were planted with corn or soybeans, the researchers predict that bird species that nest in those areas would decline by 7 percent to 65 percent.
But if an estimated 20.5 million acres of marginal land used to grow crops were planted with grasses for biofuels, the number of bird species would increase from 12 percent to as high as 207 percent.
Although the grass must be cut down for biofuel production, Meehan said most birds will have raised their young and left their nests before the harvest.
"In our model, we had a variety of grasslands, including things that might be pastures or managed perennial areas," said Claudio Gratton, a University of Wisconsin ecologist and study co-author. "It's the opposite of high-input row crops."
Although the idea of growing grass for biofuels looks more appealing, Gratton and other experts pointed out that there is no industrially proven method to convert these grasses into ethanol.
What farmers would plant to produce cellulosic ethanol also is unknown. Grassland nesting birds might be no better off in a field of switchgrass than in a field of corn, said Luke Miller, an Ohio Department of Natural Resources administrator who works with federal farmland conservation programs.
Birds such as grasshopper sparrows and Henslow's sparrows look for fields with diverse plants, including switchgrass, big bluestem, little bluestem and wildflowers. Those fields provide a variety of seeds and insects to eat, Miller said.
"A lot of folks in the wildlife community are looking for a happy medium for these marginal grounds where planting a diverse stand of native grasses could provide biofuels and more benefit to grassland nesting species," he said.