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Invasive weeds

Spring 2003

Mounting a defense against biological invaders

Whatever its impact on trade, the World Trade Organization has opened the doors to biological invasion, says Dick Mack. A professor of botany at Washington State University, Mack is a leading authority on invasive species and lead author of Predicting Invasions of Nonindigenous Plants and Plant Pests, a report recently published by the National Research Council.

Invasive species are those that are introduced, whether deliberately or not, only to find their new home much too accommodating. Whereas a plant might be an inconspicuous face in its home crowd, it could become the ubiquitous bully in a new ecological crowd with no defense against its aggressiveness. … » More …

Fall 2009

Foiling an invasive

Sometimes, figuring something out only deepens the overall mystery.

Take Pseudomonas fluorescens D7, for example.

Ann Kennedy, a USDA-Agricultural Research Service soil microbiologist at Washington State University, has isolated these native bacteria as a perfectly natural way to fight cheatgrass, also known as downy brome, scientific name Bromus tectorum. Recently, she and her colleagues were awarded a large grant to test the effectiveness of Pseudomonas fluorescens D7 for controlling cheatgrass in rangeland.

Cheatgrass, which was introduced in the late 19th century as a forage crop, is an aggressive invader, a grass that has, according to WSU botanist Richard Mack, changed … » More …

Summer 2009

1200 Weeds—of the 48 States & Adjacent Canada

Richard Old ’77, ’81
XID Services, Inc., 2008

When you don’t know what you’re dealing with, weedy plants may be hard to handle. Richard Old, a longtime Pullman resident and weed identification expert, has put together this comprehensive database of weeds for both public and private use.

The DVD, a sequel to Old’s CD 1,000 Weeds, contains more than 6,000 images of weeds found throughout North America. With details like the color of the plant juice, height, flower traits, leaf shape, … » More …

Sparingly introduced in waste places

Although scientists have been aware of biological invasions at least since the mid-1800s, when Charles Darwin noted the rampant spread of European species in South America, only recently has the scientific community recognized the broader threat invaders pose to biodiversity and environmental quality. Richard Mack of Washington State University recalls that when he first started talking about the cheatgrass invasion at annual meetings of the Ecological Society of America (ESA), his presentations would be scheduled for the “Miscellaneous” session on the meeting’s last day.

“Thirty years ago, it wasn’t on the radar screen as an academic topic worthy of investigation,” he says. “It felt … » More …

Fall 2008

Let the invasions begin

As Beijing prepared to welcome athletes and spectators to the Olympic Games, a quieter and much less welcome influx was already under way.

According to a new study by Washington State University ecologist Richard Mack and four Chinese colleagues, China’s explosive economic growth and ambitious public-works projects have allowed non-native species of plants, insects, and other organisms to spread throughout the country and inflict more than $14 billion of damage on the nation’s economy—and the Olympic Games could provide an opportunity for even more biological invaders.

Mack and his co-authors combed through trade and economic data to discover that China’s economic boom has been accompanied … » More …

Summer 2002

An English import invades Puget Sound

A classic case of good intention gone bad, English cordgrass (Spartina anglica) was introduced to Washington around 1962 to stabilize dikes and provide forage for cattle. The U.S. Department of Agriculture imported seeds from England, and a WSU extension agent planted the seeds near Stanwood in the Stillaguamish Estuary.

English cordgrass has since infested large areas around Stanwood, particularly Port Susan Bay, Skagit Bay, Admiralty Inlet, and Saratoga Passage. It has also spread, with disastrous environmental effect, to other parts of Puget Sound, including Camano Island, Whidbey Island, and the San Juan Islands.

Due to its tenacity, its rapid growth rate, and its ability to … » More …