UMass Amherst Researcher Explores Fighting Weeds With Sawdust to Help Native Species

July 8, 1998

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AMHERST, Mass. - Peter Alpert, associate professor of biology at the University of Massachusetts, is spending the summer investigating whether sawdust might be used to help native plant species recover from invasions by weeds.

"Throughout America, native plant species are being replaced by non-native invaders, imported intentionally or accidentally by people," he explained. For example, more than half of the nation’s grasslands are now dominated by invasive species, according to Alpert. He is exploring how remaining native plant species can be protected, and whether it is possible to help native plants re-take lands occupied by weeds. Alpert is conducting the research at the University of California Bodega Marine Lab, in the highly invaded coastal grasslands of northern California.

The weapon of choice may be sawdust, Alpert said. Sawdust is rich in carbon; adding carbon to soil can temporarily tie up the nutrients that weeds rely on to thrive. "We hope that temporary soil de-fertilization with the cheap, safe carbon in sawdust may restore the native grasses and wildflowers," he said.

"Oddly, relict patches of native grassland often seem to be found where growing conditions are poorest. We suspect that invasive plants out-compete natives when conditions are good, but that natives are ‘tougher’ and better adapted to tolerate local stresses such as low soil fertility," he said. "If so, temporary soil ‘de-fertilization’ might tip the balance of competition in favor of natives long enough for the natives to flourish." Working with Alpert on the project are biology graduate student Annette Kolb, undergraduate Jennifer Benson, and University of Washington faculty member John Maron.