PULLMAN, Wash. English ivy, cheat grass and other weeds are recognized pests, but bamboo can be troublesome as well. The plants are extending their ranges and showing up in new areas.
“Bamboo is not on the radar as an invasive plant,” said Richard Mack
, an ecology professor at WSU in the School of Biological Sciences. But it is nearly impossible to eliminate once established, he said: a multi-year campaign of cutting, chopping and herbicide is required to get rid of it.
“Bamboo has the ability to take over entire sites and can cause significant harm to other species,” he said.
Resource for researchers, agencies
Mack and WSU post-doctoral researcher Melissa Smith are collaborating to research temperate bamboo naturalizations. Non-native bamboo naturalizations in North America have been little studied, so the range and extent of the plant species is largely unknown.
Mack and Smith are developing a database that will allow other researchers and government agencies to become familiar with non-native bamboo species. The database will include pictures, measurements and species identification. It will be an open-access resource that can be actively updated by researchers and agencies.
Smith with bamboo in WSU greenhouse.
The project will look at temperate running bamboo naturalizations in the Pacific Northwest, Hawaii, California and the Carolinas. Mack and Smith expect it will be completed in June 2012.
The work is funded by $30,000 from the U.S. Department of Agriculture to the WSU School of Biological Sciences.
Reconsidering bamboo imports
“The purpose of this project is to monitor and control the spread of these invasive plants,” Smith said. “The project aims to provide a preliminary, but accurate, survey of the extent of the bamboo naturalizations in the U.S.”
“The point of doing this is to provide managers and policy makers with a clearer picture of bamboo’s status in order for them to make informed decisions regarding temperate running bamboo’s continued sale and importation,” she said.
Ultimately, the project is a step in limiting bamboo invasions to current levels and preventing future invasions by inhibiting the import and sale of invasive bamboo species.
Unwelcome garden additions
Smith in a bamboo grove in Hawaii.
According to Mack, there are only three native bamboos in North America; all the other species have been brought here for mainly gardening purposes.
A lot of people who plant bamboo are unaware that the species has wide ecological tolerance to shade and drought as well as resistance to plant pathogens, he said. Additionally, “running” bamboos have rapid vegetative growth and can hinder other species’ growth.
Examining DNA, photos, more
Mack and Smith will employ a variety of research methods to obtain their data. One method described by Smith is hemispherical photography. This estimates leaf area index (LAI), or photosynthetic area in a given region of vegetation.
If LAI is very high, then most light is intercepted before it reaches the forest or garden floor. Bamboo has very high LAI values and blocks growth of other species through competition for light.
Another method is collecting leaf samples for DNA extraction in order to look at relatedness of bamboos. Genetic information can provide clues to a bamboo’s mode of transport into a new area and also its origin.
The researchers also plan to look at aerial photos to estimate spread of bamboo over time and total land area of invasions.