Guest Author - Alegra M. Bartzat
Recent studies released by the University of Minnesota Initiative for Renewable Energy and the Environment indicate that biodiversity and energy independence may be growing hand in hand.
In a recent issue of Science (Dec. 8, 2006), UM published findings that show that pasture lands that are let loose to grow a diverse array of prairie grass and other native plants grow more efficiently than single-crop fields of corn or switch grass. While switch grass has long been touted as the answer to America’s fuel independence, it turns out that this weedy mono-crop loses to America’s amber waves of grain. The native prairie grasses produce 238 percent more energy than the monocrop competitors.
This is good news for soil conservation and biodiversity. Growing native prairie grasses require essentially no pesticides nor fertilizers, and very little irrigated water. Compared to the labor-intensive fields of single crops, this means that the land and water are free from chemical additives; the plants can actually do their job of cleaning the land, water, and air by absorbing chemicals including carbon dioxide. Retaining native biodiversity allows migrating birds places to rest, and invites smaller animals back into the prairies to feed the animals up on the food chain, providing a base for a healthy ecosystem.
As the United States looks for a the silver bullet to solve out energy crisis, many people are looking towards monocrops like corn or switch grass to provide the biomass needed to make fuel such as ethanol. Though these options fare better for the environment than fossil fuels, they don’t improve our ecological impact very much. Monocrops like corn and switch grass require a great amount of fertilizer (often, and ironically, made from petroleum), as well as imported water. Though all plants absorb and hold carbon dioxide, the growing, processing, and burning of the monocrops studied still yield to an overall increase in carbon dioxide in the environment.
In contrast, the native prairie grasses that are grown and processed into fuel are considered carbon negative. This means they were the only crop in University of Minnesota’s study that still capture more carbon dioxide from the atmosphere than they release into it, when all is said and done and the crops have been grown, processed, and burned.
This information does still pose some risks. The potential for abuse could result in over harvesting of prairie grass; harvesting that occurs in pristine meadow will destroy he little “old growth” prairie that is left in North America. However, the opportunity to restore massive amounts of prairie land, from Texas to Canada, that have previously been destroyed to create marginal agriculture land is a great chance to restore America’s natural history. Restoring tallgrass prairie would improve seed banks and restore our natural heritage by rehabilitating this grassland ecosystem, providing habitat for birds, butterflies, insects, and other grassland wildlife.
