What is the Difference Between Noxious and Invasive Weeds

The main difference between noxious and invasive weeds is that noxious weeds grow out of places and they are competitive, persistent, and pernicious, whereas invasive weeds are plants that are not native to a particular environment.

Noxious and invasive weeds are two types of unwanted plants that grow in a particular environment. Since they are weeds, they cause economical losses, and ecological damage, and create health problems in humans and animals.

Key Areas Covered

1. What are Noxious Weeds
   • Definition, Characteristics, Importance
2. What are Invasive Weeds
   • Definition, Characteristics, Importance
3. Similarities Between Noxious and Invasive Weeds
   • Outline of Common Features
4. Difference Between Noxious and Invasive Weeds
   • Comparison of Key Differences

Key Terms

Invasive Weeds, Noxious Weeds

What are Noxious Weeds

Noxious weeds are weeds that are harmful and injurious weeds in a particular ecosystem. Generally, weeds are plants that grow where they are not wanted to grow. However, weeds can be native or non-native, invasive or non-invasive, and noxious or not-noxious. Moreover, noxious weeds are injurious to public health, agriculture, recreation, wildlife, or property. In addition, noxious weeds are defined as plants that grow out of place. In general, they are competitive, persistent, and pernicious.

Figure 1: Noxious Weeds

Furthermore, weed plants cause economic losses, or ecological damage, creating health problems for humans and animals. Noxious weeds are undesirable. With the identification of a plant as a noxious weed, authorities tend to destroy it and limit its spread.

What are Invasive Weeds

Invasive weeds are weeds that are not native to the ecosystem where they are growing. They establish, persist, and spread widely in natural ecosystems outside the plant’s native range. Normally, many noxious weeds are invasive. In addition to noxious weeds, invasive plants include plants that are not native to the country or to the area where they grow. In other words, invasive plants grow in places where they do not evolve. These plants do not have competitive plant species in the ecosystem to limit their growth.

Figure 2: Invasive Weeds

Since invasive weeds do not have enemies in their new ecosystem, their growth and reproduction are not limited. Therefore, they spread without limits. Unfortunately, the major drawback of invasive weeds is that they produce significant changes in the ecosystem by changing vegetation, composition, structure, or ecosystem function.

Similarities Between Noxious and Invasive Weeds

• Noxious and invasive weeds are unwanted plants for a particular ecosystem.
• These plants can cause economical losses and ecological damage, and create health problems in humans or animals.
• Both are not typically native to the ecosystem where they grow.

Difference Between Noxious and Invasive Weeds

Definition

Noxious weeds refer to a weed that is considered to be harmful to the environment or animals, especially one which may be the subject of regulations governing attempts to control it, while invasive weeds refer to non-native species that show a tendency to spread out of control.

Significance

Noxious weeds grow out of places and they are competitive, persistent, and pernicious while invasive weeds are plants that are introduced to a particular environment rather than evolving in that place.

Effect

Noxious weeds are harmful to the animals and environment while invasive weeds cause economical losses.

Examples

Examples of noxious weeds are purple loosestrife, Hydrilla, and witchweed while examples of invasive weeds include tree of heaven, tamarisk, and downy brome.

Conclusion

In brief, noxious weeds and invasive weeds are two types of unwanted plants in a particular ecosystem. Noxious weeds are harmful to humans, animals, and to other plants, while invasive plants do not belong to the ecosystem where they are. Therefore, the main difference between noxious and invasive weeds is their effect on a particular ecosystem. Both types of weeds cause economical losses, and damage to the ecosystem and create health problems in animals, plants, and humans. 

References:

1. “Programs: Natural Resources: Weeds and Invasives: About Weeds and Invasive Species: Bureau of Land Management.” Home.

Image Courtesy:

1. “Noxious Weed?” By born1945 – Own work (CC BY 2.0) via Flickr
2. “Cotton Thistle, Galong, New South Wales ” By Johnscotaus – Own Work (CC BY-SA 4.0) via Commons Wikimedia