April 23, 2015
Lincoln, Neb. — A University of Nebraska-Lincoln rangeland ecologist is among the co-authors of a study published in Science that has quantified land use change and the reduction of ecosystem and cropland productivity stemming from large-scale expansion of oil and gas development.
Dirac Twidwell, an assistant professor in UNL's Department of Agronomy and Horticulture, is among the authors of the paper, which was published April 24 in the journal.
The research concludes that oil and hydraulic fracturing operations have contributed to significant vegetation loss across broad swaths of central North America. The increasing footprint of such development in the Great Plains, researchers said, also signals what is likely to occur in other regions of the world.
"Land use is changing in the Great Plains, and there is considerable momentum for further conversion of our nation's rangelands to support energy demand," Twidwell said. "Whether we are talking about advances in oil and gas development, wind or biofuels, we should be aware of our growing energy footprint and how it might influence some of our last remaining iconic rangeland ecosystems, like the Nebraska Sandhills."
The research team, led by Brady Allred of the University of Montana, examined all of central North America, from the southern coast of Texas to northern Alberta. By looking at developments on a continental scale, the team found impacts and degradation that were not apparent when focusing more locally. They also noted how their analysis could be incorporated into land use planning and policy to avoid compromising future ecosystem integrity.
The study estimated that from 2000 to 2012, oil and gas development removed large amounts of rangeland vegetation, culminating at a rate-per-year equivalent to more than half of the annual grazing available on U.S. public lands. Vegetation removed from this development on croplands is equivalent to 120.2 million bushels of wheat, about 13 percent of all wheat exported by the United States in 2013.
In addition, the researchers said, nearly half of drilled wells are in extreme or high water stress regions. High-volume hydraulic fracturing uses two to 13 million gallons of water per well, which intensifies competition for water among agriculture, aquatic ecosystems and municipalities.
"This research adds to increasing calls for a better understanding, and awareness of, the potential trade-offs of regional-scale energy growth to other needs in a global society, like environmental and food security," Twidwell said. "Rangeland ecology students have a real opportunity to step into the workforce, work with the energy industry, and provide leadership in landscape planning and restoration."
The authors assessed the lost ecosystem resources by analyzing high-resolution satellite measurements of vegetation growth.
In addition to Allred and Twidwell, co-authors include W. Kolby Smith from the Institute on the Environment at the University of Minnesota; Julia Haggerty from Montana State University; Steve Running and Dave Naugle from the University of Montana; and Samuel Fuhlendorf from Oklahoma State University.
Agronomy and Horticulture