Search this site:

Walk on the Wild Side Explore Your Public Lands Activity Book

FCIC: Walk on the Wild Side: Explore Your Public Lands Activity Book
Walk on the Wild Side:
Explore Your Public Lands

Silent Invaders
(.pdf version)

BLM works to keep the land as healthy as it can be. Sometimes it's not easy. Human activities often create problems, and natural forces can add to the challenge of protecting public lands. We'll look at a few of the challenges, one at a time. Let's look at a problem with "aliens" first.

Image of a tiny plant with very long rootsDid you know that aliens have invaded many areas of the United States? No, not aliens from outer space, but alien plant species, also known as invasive weeds. Invasive weeds usually come from other countries or regions. They spread rapidly and they can do a lot of damage, especially to native plants - those plants that grow naturally in the area.

Scientists estimate that invasive weeds are spreading at a rate of about 1,900 hectares (4,600 acres) each day on public lands in the West. That would cover an area larger than the state of Delaware in just one year! Invasive weeds can spread easily because most often there are no natural controls on their growth. Their enemies, such as disease and predators, were left behind.

Invasive weeds also have special characteristics that help them get a head start on native plants. Many have a long root system (see illustration at right), which makes it easier for the plant to get water. (Especially in dry areas, much of the water supply is located deep underground.) Many weeds are tall and bushy and have hundreds of seeds. The seeds can travel great distances by wind or water, or they can "hitchhike" on wildlife, horses, livestock, and people - and on people's cars and trucks, too. Some invasive weeds grow tall quickly and keep the sun from reaching smaller, slow-growing native plants. Still others grow in dense patches, crowding out native plants.

Help Wanted!

Invading plants are costly to remove or control. That's why land managers need your help to prevent them from getting started in the first place. Check with a local naturalist or extension agent to find out which invasive weeds are a threat in your area. To help:

  • leave the plants alone and report all sightings to local extension agents, land managers, rangers, or conservationists;
  • remove all weed seeds from clothing, shoes, pets, camping gear, and tire treads; and
  • don't pick "wildflowers" or any plants. They could be invasive weeds.

Invasive plants not only damage native plants, but they can also:

  • endanger wildlife and livestock that depend on native plants for food and shelter;
  • increase soil run-off into streams, damaging fish;
  • absorb more water, leaving less for native plants and wildlife;
  • increase the problem of wildfire because they burn better and faster; and
  • cause problems for hikers and animals who come into contact with thorny or poisonous plant parts.

Activity

Where's Weedo?
(.pdf version)

Botany is the study of plants. Scientists who study plants are called botanists. They are specially trained to identify plants, and they can tell which plant is a weed and which is a native plant. They have to pay close attention when they work, so that they can find invasive plants before those plants get to be a problem.

Now you can work like a botanist does and find the invasive plants in the woods. Look for the four invasive plants pictured in the big picture, and circle them. Want an extra challenge? Use a field guide to try to identify the native plants shown in the picture.

Table of Contents
Search this site:

Get the Savvy Consumer Newsletter! (FREE)