Keystone Species and Foundation Species Are Sometimes Also Ecosystem Engineers

question 26

Multiple Choice

Keystone species and foundation species are sometimes also ecosystem engineers, which change the environment and provide habitat for a variety of species.In the process, they have a profound effect on community structure.Which of the following would be considered members of keystone or foundation species but not ecosystem engineers?

• A) Beavers that cut down trees and dam streams, changing flowing water into ponds
• B) Porcupines that, while digging for food, create soil pits that persist and create plant habitats
• C) Termites that build mounds, increasing soil fertility and plant density in the area
• D) Woodpeckers that excavate holes in dead trees, creating habitats for a variety of species
• E) Sea otters that act as top predators and start trophic cascades in kelp ecosystems

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Definitions:

Finite

Something that has limits or bounds; having a definite end or duration.

Profit Rate

The ratio of profits generated to the amount of capital or investment, indicative of the financial health and efficiency of an entity.

Demand And Supply

Fundamental economic concepts that describe the amount of a product or service available for sale (supply) and the desire of buyers for it (demand), influencing its price.

GDP

Gross Domestic Product; the total value of all goods and services produced over a specific time period within a country's borders, used as a broad measure of economic performance.