Invasive Grasses as Biofuel? Scientists Protest
October 25, 2012 | posted by The Institute
By JOANNA M. FOSTER
More than 200 scientists from across the country have sent a letter to the Obama administration urging the Environmental Protection Agency to reconsider a rule, in the final approval stages, that would allow two invasive grasses, Arundo donax and Pennisetum purpureum, to qualify as advanced biofuel feedstock under the nation’s renewable fuel standard.
“As scientists in the fields of ecology, wildlife biology, forestry and natural resources, we are writing to bring your attention to the importance of working proactively to prevent potential ecological and economic damages associated with the potential spread of invasive bioenergy feedstocks,” the scientists write.
“While we appreciate the steps that federal agencies have made to identify and promote renewable energy sources and to invest in second- and third-generation sources of bioenergy, we strongly encourage you to consider the invasive potential of all novel feedstock species, cultivars, and hybrids before providing incentives leading to their cultivation.”
Invasive species currently cost the nation $120 billion each year. Many of these invasive species were intentionally introduced by government-financed programs. Kudzu, or “the vine that ate the South,” for example, spread uncontrollably in the 1930s after farmers were paid to cultivate it in an attempt to curb erosion.
The scientists signing the letter fear that the kudzu story will be repeated if the E.P.A. rule goes into effect.
Pennisetum purpureum, known as napiergrass or elephant grass, is of African origin but has been introduced to many tropical areas around the world, where it multiplies rapidly. Arundo donax, or giant reed, is native to India and is considered particularly fearsome: it ranks as one of the world’s 100 worst invasive species.
Giant reed has shown promise as a biofuel source because it grows quickly and tolerates a variety of habitats, characteristics that simultaneously make it extremely threatening as an invasive species.
In Oregon, Florida and North Carolina, giant reed is already being cultivated for biofuel production, while in Texas, California, Colorado and Nevada it is classified as a noxious weed. When it invades an area, it chokes out nearly all other species, increasing wildfire risk and endangering birds, insects and other animals that depend on the native vegetation for their habitat and food. In California, it has been estimated that eradication of giant reed from a single acre of land can cost $5,000 to $25,000.
This month, 100 local and national groups including the California Invasive Plant Council and Tennessee Riverkeeper also sent the E.P.A. a letter (PDF) warning of the potential “serious unintended ecological and economic impacts” of the proposed rule.