Saturday, October 1, 2011

Arundo Power, Part 2

Last March I posted an article on growing giant reed grass (Arundo donax) in Oregon for biofuel, Today, I want to give you an update.

Arundo donax in Arizona.
Just last month, the State Weed Board and the Oregon Invasive Species Council met in Boardman for a joint meeting focused on Arundo. Included was a tour of Arundo fields, Experiment Station test plots, and Portland General Electric’s (PGE) power plant. Fifty-eight people participated, and most of them stayed until almost 6:00 PM to participate in the interesting discussion that followed.

Oregon's only coal-producing power plant is in Boardman.
If you live in Oregon and use electricity, you are a player in a giant experiment. PGE needs to replace coal as the fuel for their Boardman powerplant by 2020 or shut the plant down. They could build new natural gas-fired power plants, but they prefer to keep the “already paid for” Boardman plant operating with a renewable fuel—thus their interest in a fast growing source of biomass that could be produced in huge quantifies within 50 miles of the powerplant. The power plant consumes 350 tons of coal per hour and operates around the clock! That’s four long trains-worth of Wyoming open pit-mined coal every week.

PGE is proposing to replace all that coal with torrefied biomass (the plant is dried with heat until it almost turns to charcoal) from about 50,000 to 90,000 acres of Arundo. Other sources of biomass, such as torrefied wood waste, could be incorporated with the Arundo. Theoretically, the powerplant would need very little modification for this conversion. Interestingly, because of laws mandating use of renewable energy sources in Oregon, energy produced from biomass would not have to compete with fossil fuel-produced power. We were told it could be five times more expensive to produce, yet it might still be economic. Biomass would be a good complement to wind turbines, because it can provide power when the wind isn’t blowing.

Unfortunatly, Arundo is a weed. In fact, it is considered one of the worst weeds in the world. Arundo is invasive in warm climates, especially in riparian areas. Up until now, it hasn’t been invasive in Oregon, but it will definitely grow here. Some of the fields and test plots that were planted last March and April now have 10-ft. tall plants. It is too early to say how well it will overwinter, but previous test plots in Prosser, Washington persisted for six years.

At this point, the Arundo in Oregon looks like a crop. It has not spread beyond the field borders. It hasn’t produced any flowers or seeds. PGE recently cut and swathed four of the 85 acres currently in the ground. It looks like it will be easy to bale. The canes were pretty well shattered by the mower/conditioner. Pieces of cane and rhizomes left on the ground were dried out and showed no signs of taking root. Oregon State University, PGE, and the first Arundo farmers deserve credit for being careful while sticking their neck out and trying something new.

None of this convinced the people in the group with first-hand Arundo-fighting experience. In fact, they looked at the first year, 10-ft tall plants and shuddered to think how well Arundo would do in our natural riparian areas. After the tour, some of them were less concerned with PGE’s plans to grow Arundo under irrigation circles than they were with Arundo being sold in the nursery trade. Wayne Lei, PGE’s chief engineer on the Arundo project, highlighted this issue by buying a pot of Arundo at a Portland nursery and planting it right beside the front door of the Boardman powerplant!

It seems clear that Oregon Department of Agriculture (ODA) needs to maintain regulations to prevent Arundo from establishing in riparian areas. This means we need to consider phasing it out of the nursery industry. If we don’t, sooner or later, someone will plant it on a river bank, and we’ll have a weed worse than Japanese knotweed on our hands. Assuming growing Arundo for biomass goes beyond the test phase, we also need to find a mechanism to pay for riparian area surveys. An assessment based on acres planted or tons produced was suggested. I like that idea. Just a dollar or two per acre would pay for a pretty robust survey and maybe some research as well.

Everyone loves the idea of renewable biofuels, and no one wants to introduce new weeds. Can we have it both ways? Planting huge quantities of Arundo involves risk, but maybe if we’re smart about how we do it, we can have our green electricity and our Arundo-free environment, too. What do you think?  ODA will begin crafting Arundo regulations to replace the expiring temporary rule soon. We could use your input.

Dan Hilburn


  1. As ever, very well put and an excellent blog.

    One of the other considerations (and the great economic unknown) is whether enough farmers will be willing to lock themselves into a long term contract, especially over so many acres, to grow Arundo.

    Vern Holm
    Northwest Weed Management Partnership

  2. Most troubling to me is why this species not flowering or setting seed in Oregon or at "this latitude" is an issue or indicative of some inability to be invasive here. I keep reading and hearing this "fact" and still don't understand why this would be cited for a species which only reproduces asexually in Californian (and likely all non-native) populations. I'm not sure what this indicates. I am all for experimentation but if this basic tenet of the biology of this species is disregarded, then I am unfortunately reminded of the Alyssum biomining fiasco in SW Oregon. See an earlier comment on "Part 1" for a citation.

  3. I'd like to second Dominic's previous post. I have experience with this weed in the Central Valley of California. Flowers and seeds are irrelevant. Floods carry large rootwads downstream where they establish. ODA (and all PNW states)should prohibit the sale of this species by nurseries. If it gets loose in the watershed, it will be difficult and expensive to control.

  4. This plant is already in Oregon--and most other places. It's planted ornamentally in people's yards and tracked all over the place in the treads of bulldozers. It forms small clumps here and there, and doesn't spread much because its rhizomes are globular and, as said, it doesn't drop seed (although it _will_ flower--it's just thoroughly sterile). Any ecological threat Oregon is facing from this grass, it's already facing it, so why not make use of an environmentally friendly replacement for coal? I've done research in invasive species for years and it always amazes me how some relatively harmless exotics get huge attention while serious invaders go completely ignored. In the Southeast, people would have you believe that Kudzu is some kind of land devouring monster. But it really grows mostly by roadsides, where it's quite visible. Privet, which no one talks about, invades deep into the forests and assimilates entire groves, destroying the ecosystem there. Infamy is just not a good metric of ecological hazard. Arundo is everywhere and has been everywhere for a while. It's only caused problems after purposeful large-scale riparian plantings in California. Oregon is not California, and I guarantee you that stem fragments of Arundo have found their way into the Oregon watershed at some point years ago. It'll be allright as long as no one tries to use it for large scale riverbank erosion control.