Invasive Plants and Pests Overview

Download this page as an info sheet (includes Resources for Invasive Species content): WCSW Invasives Info Sheet

Invasive plants and insects pose serious risks to the biodiversity and functionality of our ecosystems as well as for producing lands including forests and agriculture. Many landowners have invasive plants on their land or nearby and want to understand how to control them or prevent infestation.

What are invasive plants?

In Maine a plant is considered invasive if it:

  1. Is not native to Maine
  2. Has spread (or has the potential to spread) into minimally managed plant communities (habitats)
  3. Causes economic or environmental harm by developing self-sustaining populations that are dominant or disruptive to native species

Invasive plants are a direct threat to what we value about Maine’s natural and working landscapes. The aggressive growth of invasive plants increases costs for agriculture, can affect forest regeneration, threatens our recreational experiences, and reduces the value of habitats for mammals, birds and pollinators. Species like Japanese barberry and multiflora rose can form thorny, impenetrable thickets in forests and agricultural fields.

Invasive species are the second-greatest threat to global biodiversity after loss of habitat. Invading plants out compete native species by hogging sunlight, water, nutrients, and space. They change animal habitat by eliminating native foods, altering cover, and destroying nesting opportunities. Some invaders are so aggressive they leave no room for our natives.

-from Maine DACF Horticulture Program

For Assistance with Invasive Plants and Insect Pests

The Maine Forest Service provides information and assistance with forest insect pests and other pathogens.

The Maine Natural Areas Program has information resources on invasive species and a program for mapping and managing invasive species called Imap Invasives.

See the section Resources for Invasive Species on this website for more information.

In addition, WCSWCD has expert assistance available to landowners wishing to manage invasive plants. See the section Conservation Assistance for more information.