The National Park Service has as a goal the maintenance and restoration of not only individual species but all the components and processes of naturally evolving ecosystems. Therefore, controlling exotic species that have substantial impacts on park resources is a high priority. Low priority is given to species that cause little damage or are virtually impossible to control.

Exotic plants are especially common in areas where construction, road building, or other human activity disturbs the soil. They often have a competitive edge over indigenous plants when they invade an altered site. Therefore, most of the exotic plants at Craters of the Moon are concentrated along the highway, and the dirt road and streams in the northern part of the monument.

The following are the most widespread exotic plants that occur within the monument:

Most of these plants are in isolated pockets and are not currently a threat to native ecosystems. Others, like cheatgrass and field pennycress, are so widespread that control efforts would have little success.

Common mullein is one of the most conspicuous exotic plants at Craters of the Moon. The plant was originally imported from Europe for its ornamental qualities, but soon escaped the confines of the home garden. Mullein quickly expanded its range over most of the temperate areas of North America. Common mullein is an example of how difficult it can be to eradicate a non-native species once it has become established.

In the 1980s the monument staff, faced with extensive stands of these plants, decided to fight back.

Round 1. Staff pulls mullein out by the roots. Mullein expands even more rapidly because it grows well in the disturbed site left behind.

Round 2. Staff clips seed heads from plants. Mullein quickly grows two new seed heads to replace each lost one.

Round 3. Staff cuts the plant's stalk where it joins the root with a spade or applies a herbicide directly to the mullein. Mullein sprouts the following year from seeds that remain viable for up to fifty years.

Round 4. Staff analyzes the results of their efforts for the last three years. No headway has been made in eradicating the mullein. The National Park Service is still trying to prevent the spread of mullein into new areas, but it is a daunting task which will require concerted effort over a long period of time. Although complete eradication is likely impossible, the monument is having some success eliminating mullein along the highway corridor.

Exotic Animals

Exotic animal species have also invaded the monument and upset the natural balance of the ecosystem: the European house sparrow, European starling, chukar, grey partridge, and domestic pigeon. The starling and sparrow, both introduced from Europe, compete aggressively with native birds for the limited nesting holes in trees. If the number of starlings and house sparrows continues to grow, native cavity nesters like the bluebird may be severely affected.

Game managers introduced chukars into Idaho from Asia to provide another upland game bird for hunting. Because harsh winters greatly reduced the population, it has not become a threat to native species. There is anecdotal evidence that the number of domestic pigeons in Indian Tunnel is rapidly increasing, and that the nesting pigeons are displacing native violet-green swallows. Resource managers at the monument hope to establish a system to monitor the domestic pigeons and assess what impact they are having. If the impact on the violet-green swallows is serious, the monument will explore options for their removal.

1. Contact the National Park Service to set up a date when a member of the staff can accompany your group and lead the exotic species eradication section of this exercise.

2. As preparation in the classroom, discuss what exotic plants are, the threat they may pose to native ecosystems, and why the National Park Service seeks to eradicate them.

3. Upon arrival at the monument you will travel by dirt road into the "North End" of the monument, where exotic species are most heavily concentrated. The Park Service has marked a permanent location for the monitoring grid. Mark off one square meter at the marked location.

4. Complete the "Exotic Species Grid Work Sheet." They may refer to the plant identification materials and field guides available in the support kit at the Visitor Center to assist in identifying plants. Your school may want to consider using the same grid location from year to year to assess whether any change in plant community composition is occurring through time.

5. If time permits, the park ranger can guide your group in removing exotic plants in a small area.

6. Upon your return to school, have the students complete the questions on the back of the "Exotic Species Grid Work Sheet."

This project has real value to the monument, both in terms of providing data on trends in exotic species populations through monitoring, and through assisting with eradication efforts. Please emphasize to your students that this is not just an exercise, but a real project of benefit to the park and we appreciate their assistance.