The report describes the habitat in question as follows:
Prairie pothole habitat consists of tallgrass prairie, shortgrass prairie, and mixed prairie interspersed with temporary and semi-permanent wetlands. These prairies and associated wetlands support an array of treasured wildlife including waterfowl, shorebirds, and grassland birds.
This habitat is an important breeding ground for 75 percent of all North American waterfowl and 300 species of migratory birds (over 1/3 of those that live in North America). Furthermore, this area is important for carbon sequestration. The report says:
When the region's undisturbed soil is put into cultivation, it releases up to half of its carbon over 50 years of cultivation, exacerbating climate change. One 2008 study estimated that this conversion releases approximately 59.8 tons of CO2 per acre over this time span.
Prairie pothole habitat exists in Iowa, Minnesota, North and South Dakota, Nebraska, and Montana. And, as it happens, Iowa is the nation's #1 corn producer. Nebraska's #3, Minnesota's #4, and South Dakota is #7.
I recently reported that just over 30 percent of America's corn goes to ethanol for fuel. The USDA began tracking how much ethanol we used for fuel in 1980/81 and we've increased the number of bushels used for ethanol in most years since then. In 1980/81, we used only 35 million bushels of corn for ethanol. In 2009/10 we will use a projected 4.2 billion (with a B) bushels of corn for ethanol.
It appears to me that the big jump in ethanol use really began around 2002/03... and even more so in 2004/05. Historically, corn used for ethanol production jumped from 1% of our total corn harvest in 1980/81 to 7% in 2001/02, rarely increasing more than 1% or so per year. Here are the numbers since then:
Percent of Total Corn Harvest Used for Ethanol
2002/03: 11%
2003/04: 12%
2004/05: 11%
2005/06: 14%
2006/07: 20%
2007/08: 23%
2008/09: 30%
2009/10: 32%
In that time, we more than quadrupled the amount of corn used for ethanol, and we increased the amount of corn grown in the U.S. by nearly half (47%). A major year was 2007/08, in which ethanol production increased by 44% and corn production increased by 24%.
But as far as the birds are concerned, this is only part of the story. What really matters to wildlife is the acreage devoted to corn production, not the number of bushels harvested. (After all, some of the increases in production come from increased yield.) In 2007/08, the U.S. increased the number of acres where corn was planted by 19.4% from 78.33 million acres to 93.53 million acres. The last time we devoted that many acres to corn was the Dust Bowl. Since 2007/08, we've relaxed a bit, decreasing to about 86 million acres of corn planted in each year since then, but these are still historic highs compared to each of the past fifty years, excluding 2007/08.
Data Source: USDA ERS Feed Grains Database
When we increased corn production between 2005 and 2007, according to the report, we put an additional 3.2 million acres into corn in the Prairie Pothole region. Some of these were switched from other crops to corn, which isn't such a big deal for existing bird habitat. But other areas were switched from native grassland to corn or they were removed from conservation programs to grow corn. In areas where corn acreage was significantly increased between 2005 and 2008, there was a significant drop in birds of grassland species sighted. |
