What are Pyrophytic Plants?

NGSS Phenomena: A video of a car driving through a forest that's on fire.

Forest fires can be terrifying and very destructive. Fires destroy many living things, but not all. In the table below, researchers looked at 6 types of trees and how much area those trees covered before a fire and a year after a fire.

Most of these types of trees have existed in ecosystems that have fires for thousands to millions of years. Think about what kinds of adaptations would help some of these tree populations survive after a fire.

References:

Apfelbaum, S., Haney, A., 1981. Bird populations before and after wildfire in a Great Lakes pine
forest. Condor 83, 347–354.

1. Which of the following traits would best help a tree to survive over time in an ecosystem with frequent fires?

Having thicker bark on the outside to protect against predators.
Having longer leaves that can capture more sunlight faster
Having seeds that release when they pass through the digestive system of an animal.
Having longer branches that fall off when there’s a fire.

2. Explain how your model shows the way a trait might help a tree to survive over time in an environment where there are fires.

3. Based on the information presented here, explain what populations of trees that you expect to grow over time and which populations of trees will not grow over time.

4. Draw a model in the space below to show how a trait might help a tree to survive over time in an environment where there are fires.

Color

Width

5. Explain why we can or cannot say that the changes in the population of Balsam Fir are only due to the fire.

6. These researchers also traveled to a different ecosystem, where there are never fires. Predict how the populations of trees in this new ecosystem would react if it caught on fire.

Make sure to consider the fact that these organisms are not used to fires. (hide hints)

7. In the space below, draw a graph to show the changes in Black Spruce and Jack Pine before and after the fire.

Color

Width

8. Explain how your graph shows the changes in the area covered by Black Spruce and Jack Pine before and after the fire.

9. One of your classmates make the following claim:

“In other forests where there are fires, I would expect to see less and less Paper Birch. This data shows that Paper Birch can’t survive in a fire.”

Evaluate this statement and explain why you think they are right or wrong. Discuss which tree you would most expect to see after a fire.