Plenty of websites offer definitions of invasive plant terms. We recommend “Native, Invasive, and Other Plant-Related Definitions” on the U.S. Department of Agriculture website.
So why did MoIP create another page?
We needed a reference guide for our internal communication. Several different industries and agencies are represented in our task force, and we encountered communication challenges despite our shared passion for invasive species control. We each come from a slightly different culture with slightly different meanings for terms such as “invasive,” “aggressive,” and “non-native,” so we have agreed on definitions when engaging as a group.
We are providing these definitions here for new MoIP members, stakeholders and visitors to get on the same page regarding how we talk about invasive plants at our meetings and on our website.
Native plants originally occur within a region as the result of natural processes and are adapted to local climate and soils. They have co-evolved with native insects and wildlife and are critical to ecosystem functions. For MoIP’s purposes, native plants are those species present prior to wide-spread European settlement. (Modified from GrowNative.org.)
Non-native plants are those introduced (intentionally or accidentally) to a new place or new type of habitat. Historically, most of these introductions have resulted from human activities. Since they did not evolve locally over thousands of years, their presence can often have negative impacts on endemic ecosystems. The words “exotic,” “alien,” and “introduced” are synonyms for “non-native.” Note: not all non-native plants are invasive and these generally are not the focus of MoIP’s attention.
Aggressive plants are species that, usually because of human-caused disturbances, spread rapidly and can outcompete other plant species. Aggressive plants can be native or non-native, and they may be aggressive in some situations, but not others.
An invasive plant species is an aggressive, non-native species whose presence causes or is likely to cause economic harm, environmental harm, or harm to human health. These species grow and reproduce rapidly. (Modified from.)
MoIP is most concerned with invasive species because of their direct negative ecological impacts.