1. How do alien plants threaten native plants and animals?

2. What is a common name for "invasive aliens"?

3. What two characteristics do alien plant species have that allow them to spread quickly?

4. Define weed.

5. How are foreign plants introduced to local areas?

6. How do park managers fight the alien plant species? Decide if it is a mechanical, chemical or biological control method and place an X in the appropriate column.

7. Define biological control.

8. Why do park managers worry about using biological control methods?

Find 5 words that you did not know from the article. Write the sentence each was used in and underline the new word. On the back of this page, use each word in your own sentence.