Non-Native Invasive Species (NNIS)

• Overview and
  Background
• Controlling
  Invasive Species
• Southern Region
  NNIS List
• Non-Native
  Invasive Plants
• Partnerships
  & Collaboration

Introduction

Non-native invasive species have been identified by the USDA Forest Service as one of four critical threats to our nation’s ecosystems.  It is estimated that non-native invasive species cost an estimated $138 billion each year in environmental damage and other losses.   

Mission Statement

The goal of the USDA Forest Service Southern Region is to reduce, minimize, or eliminate the potential for the introduction, establishment, spread, and impact of non-native invasive species across all landscapes and ownerships. 

What is a non-native invasive species?

According to Executive Order 13112 on invasive species, released February 2, 1999, a non-native invasive species meets two criteria:

• it is not native to the ecosystem under consideration, and
• its introduction causes or is likely to cause economic or environmental harm or harm to human health.

Introduction of non-native invasive species can occur intentionally or accidentally, and once established, can aggressively spread.  Thousands of non-native invasive species have infested hundreds of millions of acres of land and water throughout the United States; disrupting ecosystem function, reducing biodiversity, and degrading the health of forests, prairies, mountains, wetlands, rivers and oceans.

The Invasive Species Threat

Why Are Non-Native Invasive Species So Successful?

Non-native invasive species often out-compete native organisms, including threatened, endangered and sensitive species for water, sunlight, nutrients, and space.  Non-native invasive species typically:

• flourish in habitats where population control mechanisms, such as defoliators, pathogens or predators, are absent;
• thrive in a variety of habitats; and
• reproduce successfully.

Non-Native Invasive Species Impacts

Non-native invasive species have significant economic and environmental impacts in the United States.  Studies by Pimental et al (2000) show that economic losses caused by non-native invasive species exceed $138 billion annually.  In addition, 400 of the 958 (42%) species listed by the Federal Government as threatened or endangered have been negatively affected by non-native invasive species.