The same characteristics that make a good biofuel stock also make successful weeds. The next generation of biofuels won’t come from corn, but from cellulose-rich plants—grasses, algae, and reeds—and those most suited for biofuel production might be those that are “fast-growing, highly productive, highly competitive, self-propagating or able to regrow rapidly,” a report from the National Wildlife Federation suggests.
“Unfortunately, many invasive species, by their very nature, exhibit these qualities as well,” researchers Aviva Glaser and Patty Glick write in the report.
So far, biofuel production hasn’t been good for biodiversity. Expansive fields of corns do provide particularly good habitats for a wide variety of species, and expanding biofuel production has transformed tracts of grassland and forest into monocultures. But as the industry moves away from corn, there could be an opportunity to cultivate a more biodiversity-friendly brand of biofuel production—if the plants chosen for the purpose aren’t expansion-minded invasive species that threaten the natives.
The NWF report highlights a slew of invasive species that are grown as biofuel crops or could be soon. Reed canarygrass, which has overtaken wetlands and lakes, could be planted in Michigan’s Upper Peninsula. One algae under consideration has choked bodies of water in the Great Lakes region with toxic algae blooms. BP is developing a variety of elephant grass, which can grow 10 feet tall and which the NWF report calls “one of the most problematic weeds in the world,” for cultivation all along the Gulf Coast. “We have a lot of scientists that we work with,” says Glaser. “They were hearing about these crops being grown and they have concerns about them.”
Hardy plants like these might be grown with the best intentions, but the plants have an agenda of their own: to spread and multiply. Invasive plants can push out native species and threaten the livelihoods of people who depend on them. And once in place, they’re almost impossible to eradicate.
In fact, the tenacity of invasive species already thriving has made them potential targets for biofuel production. If the masses of kudzu that have taken over the southeastern United States could be turned into biofuel, there’d be a financial incentive to start dealing with it. The ideal model for turning existing invasive species into biofuels could be to use mobile units to process the plants. (Otherwise, the owner of a kudzu field could have a perverse reincentive to replant the problematic plant.)
But the NWF report also highlights biofuel projects that are moving beyond corn without using invasive species. The Show Me Energy Cooperative in Missouri, for instance, is using a mix of native plants as biofuel stocks. Projects like these can improve biodiversity, instead of destroying it as invasives could—not only in fields feeding biofuel production but in the surrounding areas.
“With any of our energy choices, we have to be aware of the risks that are involved in those choices,“ says Glaser. “There's really great potential for bioenergy… if it's done right. Once a species becomes invasive, it's often too late. We have unique opportunity right now to prevent a problem.”
Photo courtesy of the National Renewable Energy Laboratory