Pacific Northwest Invasive Plant Council

About Us

Invasive plants negatively impact native plants, wildlife and whole ecosystems. These invasives displace native plants, degrade habitat and recreation opportunities, as well as physically and chemically alter soil properties and fire frequencies. Additionally, invasive plants can jeopardize endangered plants, some of which are at risk due to invasive species, and further decrease biodiversity. Monetarily, in the United States, these damages and losses can cost up to $138 billion per year! Nearly 420,000 acres of National Forests and Grasslands in the PNW have been degraded by invasive plants.

Invasive plants are able to spread across urban, suburban, rural, and wild landscapes, they are not specific to the areas that they invade. These infested areas then provide seed sources for invasion of the neighboring areas.

Invasive plants are especially problematic when the impacted species are keystone species, causing disturbance of the food web structure and biodiversity functions. By removing the natural barriers between non-indigenous and native species as humans are doing at a phenomenal rate, we are altering the genetic diversity of the native species and native communities as well as homogenizing the biology of the region. Biological distinctiveness of regions should be protected and embraced. As Darwin observed, there is no doubt that our future world will be more homogenous than it is now.

We can slow the rate of change if each individual becomes more aware of the problem and what can be done to protect the native Pacific Northwest environment. The first line of defense is knowledge, as well as political action to slow the introduction and spread and finally, control of the invasive plants already established here. Knowing what species are problems and taking action against them are the best defenses against the spread of invasive species. Individually and collectively, we can make a meaningful difference in catching, stopping, and controlling invasive species to enrich and foster the diversity of the native species and habitats of the PNW.


The Pacific Northwest Exotic Pest Plant Council (PNW EPPC) was formed in December of 1993 and exemption status was granted by the IRS in late 1996. After several newsletters, meetings, a conference and other activities the PNW EPPC became inactive in late 1997 as the small group of initial founding members moved on.

In September of 2006, the PNW EPPC was revised at the “Meeting the Challenge: Invasive Plants in PNW Ecosystems” conference in Seattle, Washington. The group was re-formed and approved by those attending a discussion at the tail end of the conference. A survey was sent out in the summer of 2007 to over 1,000 researchers and land managers who work with invasive plants. Suggestions from this survey were used in developing the future objectives and roles of the PNW group. At this time the name was also changed to the PNW Invasive Plant Council (PNW IPC).

During this same time frame, the Northern Rockies EPPC began to come together as a formal EPPC as well. Therefore, the PNW IPC now includes the states of Oregon, Washington, and Alaska and the Provinces of British Columbia and Yukon.

All EPPC's / IPC's are a part of the National Association of Exotic Pest Plant Councils ( There are 13 state EPPC's / IPC's and now four regional EPPC's including the Pacific Northwest IPC.

Senecio jacobaea (Tansy ragwort)
Senecio jacobea
Carduus tenuiflorus
Carduus tenuiflorus
Isatis tinctoria
Isatis tinctoria