Ecology of Fungi

Free Response

Why does protection from light actually benefit the photosynthetic partner in lichens?

Hint:

Protection from excess light that may bleach photosynthetic pigments allows the photosynthetic partner to survive in environments unfavorable to plants.

Ambrosia bark beetles carry Ambrosiella fungal spores to trees, then bore holes and lay their eggs with the fungus. When the new larvae hatch, they eat the fungus that has germinated in the holes. Describe how this relationship can be classified as mutualistic.

Hint:

The bark beetles and the fungus have a mutualistic relationship since each partner benefits from interacting with the other. The beetle can provide food for its offspring, while the fungus can spread to new trees.

Ecologists often attempt to introduce new plants to restore degraded land. In an arid climate, scientists recommend introducing plants with arbuscular mycorrhizae. How would the mycorrhizae increase the plants’ survival compared to plants without mycorrhizae?

Hint:

Plants with arbuscular mycorrhizae are colonized by fungi that penetrate root cells, and exchange metabolites with the plant. The network of fungal hyphae extends from the root cells out into the environment, covering a larger area than the plant’s root system alone. This allows the plant to draw water from a larger area, increasing the likelihood that it can meet its daily needs.