The poplar tree has entered the crowded field of sustainable biofuel crops, and now it seems that China, Israel and the U.S. are racing to tap into its potential. Poplars have a couple of big advantages over conventional biofuel crops, especially food crops like soy and corn. For one thing, raising poplars is potentially more fuel efficient and generates a lower carbon footprint than annual food crops. Depending on the growing conditions poplars don’t need as much pest control or soil enhancement, and they don’t necessarily need to be harvested each year – cut them back and they just keep growing. Also, a properly managed biofuel woodland can be part of a viable wildlife habitat, and could potentially coexist with human populations or recreation areas.
One roadblock is the slow growth rate of poplars relative to nonfood biofuel darlings like crambe and camlina. That may not be a factor much longer. Last fall an Israel-China research partnership was formed to develop new poplar variants for biofuel production in China. And here in the U.S., the National Science Foundation has just announced a $3.2 million grant for the University of Maryland and Bowie State University to create new high-yield poplars for biofuel.
Poplar Trees and Biofuel
Though poplars are slowpokes when compared to annual biofuel crops, they are actually fast-growing compared to other trees. They’ve been a subject of intense interest among biofuel researchers for several years now. Researchers have already solved one conundrum by developing cost effective ways to break down cellulose. That means woody crops like trees or weeds like switchgrass can compete with “soft” biofuel crops like corn or soy. The U.S. team will focus its NSF grant on studying the poplar’s nitrogen cycle in order to speed up growth. Meanwhile, FuturaGene of Israel has partnered with the Chinese Academy of Forestry to develop strains of drought resistant, salt tolerant poplars.
Poplars and Brownfields
The development of nonfood biofuel crops dovetails with the EPA’s new program to reclaim brownfields for renewable energy production, called RE-Powering America’s Land. The program builds on the success of existing reclamation projects, some of which use “green remediation” methods that deploy low cost, on site processes rather than digging out contaminated soil and dumping it elsewhere. One of these methods is phytoremediation, in which plants are used to clean up pollution, and the EPA has found that poplars can not only neutralize contaminants but even thrive on polluted sites.
Image: Poplar trees by Sids 1 on flickr.com.
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.