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Corn Ethanol and Wildlife: How are Policy- and Market-Driven Increases in Corn Plantings Affecting Habitat and Wildlife?


Rebecca Brooke, Gregory Fogel, Aviva Glaser, Elizabeth Griffin, and Kristen Johnson

Advised by Professor Michael Moore and Professor Steven Yaffee


Project Overview


Government incentives have led to skyrocketing growth in the U.S. corn ethanol industry over
the past five years. This has contributed to major increases in corn prices and corn demand,
ultimately resulting in increased corn plantings across the country. Total corn acreage shot up
19% between 2006 and 2007, to a level not seen since the Dust Bowl. Though plantings
decreased slightly in 2008, they remain higher than at any point in the last fifty years. Farmers
have shifted land into corn production from other crops, idle agricultural land, and native prairie,
thereby causing wildlife habitat loss and degradation. Given that current legislative mandates
increase blending requirements for corn ethanol through 2015, these patterns are likely to

This study analyzes the current and potential impacts of increased corn ethanol production on
wildlife and habitat in four Midwestern states: Iowa, Minnesota, North Dakota, and South
Dakota. In addition to experiencing dramatic increases in corn plantings over the last five years,
these states all contain significant amounts of a unique wetland ecosystem known as the Prairie
Pothole Region (PPR). This region contains important native prairie and wetland habitat, and
thus holds special importance for wildlife. The goal of this report is to provide policymakers and
practitioners with both an assessment of the wildlife and habitat impacts of corn ethanol
expansion and a series of recommendations on ways to mitigate these impacts.




We used several methods for our analysis. First, we used GIS to construct a series of maps
indicating “hotspots” where increased corn plantings are coinciding with habitat loss. These
maps then informed a statistical analysis quantifying changes in grassland bird populations
associated with increases in corn plantings. Through a review of current legislation and market
data, we identified drivers of growth in the corn ethanol industry. Finally, we interviewed more
than 30 conservation practitioners to assess the potential of federal and state conservation
policies and programs to mitigate the impacts on wildlife.


Key Findings


Numerous federal and state laws, incentives, and programs drive growth in the corn ethanol
industry. Chief among these is the Renewable Fuel Standard (RFS), which sets a floor for corn
ethanol demand, and the Volumetric Ethanol Excise Tax Credit (VEETC), which pays blenders
to blend ethanol with gasoline. States also support corn ethanol through various channels,
ranging from incentives for ethanol refiners to high blending requirements. Furthermore,
domestic ethanol is protected from foreign competition by high tariffs. This substantial support
for corn ethanol production guarantees demand and easy financing, which are driving growth in
the industry.

Dramatic increases in corn plantings and loss of grassland habitat have been concentrated within
the Prairie Pothole Region. This region has lost alarming amounts of native prairie and
Conservation Reserve Program (CRP) land to crop production since 2006. In addition to this
direct habitat loss, increased corn plantings have led to increased erosion, sedimentation, and
pesticide and fertilizer pollution—all of which degrade remaining habitat.

Grassland-breeding bird populations have declined in areas experiencing high increases in corn
plantings. As demonstrated by our analysis of grassland-breeding birds, areas of high corn
increases have shown significant declines in both the number of grassland species and the
number of individual grassland birds. Our analysis found that populations of sensitive grassland
birds declined by almost 30% between 2005 and 2008 in areas of high corn increase. The loss
and degradation of grassland habitat in the region, driven by increased corn plantings, is further
imperiling these already threatened species. All but one of the five species we analyzed in our
wildlife analysis are listed as species of conservation concern in Iowa, Minnesota, North Dakota,
and/or South Dakota. Beyond the effects of increased corn plantings on specific grassland bird
populations, loss of habitat in the PPR due to increased corn plantings may threaten North
American waterfowl from across the continent, 70% of which breed in this ecologically unique

Conservation practitioners in Iowa, Minnesota, North Dakota, and South Dakota presently
conserve valuable habitat through a suite of federal and state programs. However, these
programs are not equipped to mitigate the additional threats posed by corn ethanol expansion.
Practitioners explained that demand for biofuels, high commodity prices, new genetically
modified varieties of crops, and insurance payments that make marginal land more suitable for
crop production incentivize the conversion of grassland into cropland. Funding and resources for
conservation programs have not kept pace with these increasing pressures. If this trend is not
reversed, expanding corn ethanol production will have an irreversible impact on habitat and
wildlife across the Prairie Pothole Region.



We recommend the following actions be taken to prevent further losses of valuable habitat and
declines in wildlife populations:

• Decrease government incentives for corn ethanol
• Prioritize conservation of native prairie
• Invest in CRP to maximize its potential for land conservation
• Increase the capacity of agencies to more effectively implement existing programs
• Collect and make publicly available data measuring conversion of grassland to cropland



The Renewable Fuel Standard requires that corn ethanol production increase from 10.57 billion
gallons in 2009 to 15 billion gallons in 2015. This 4.47 billion gallon increase in corn ethanol
production will create demand for an additional 10.7 million acres of corn plantings a year at
present corn yield levels. Such increases in corn production have serious implications for wildlife
and habitat.
If corn ethanol demand continues to contribute to high corn prices and CRP rental rates remain
too low to incentivize farmers to keep their acres enrolled in the program, CRP land will
continue to be converted into cropland to accommodate increased corn plantings. Moreover,
there is currently no state or federal legislation that discourages conversion of native prairie into
cropland. Without changes to ethanol incentives, CRP, and prairie protection policies, loss of
habitat and wildlife in the PPR will continue.


The full report is also available in a single document (note that this is a large file). A PDF version of the group's powerpoint presentation with accompanying notes is available here.


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