The Impact of Keystone Species on Ecosystem Balance

Keystone species are vital for ecosystem stability, having a large impact relative to their abundance. They maintain biodiversity and include categories like predators, modifiers, prey, mutualists, and hosts. Examples include the purple sea star, gray wolf, and quaking aspen. Protecting these species supports ecosystem health, aiding in nutrient cycling, pollution control, and resilience to environmental changes.

What is the primary role of keystone species in an ecosystem?

• To play a unique and crucial role in ecosystem function

• To eliminate predators

• To decrease biodiversity

• To increase the population of a single species

Who coined the term 'keystone species'?

• Charles Darwin

• Dr. Robert Payne

• E.O. Wilson

• Jane Goodall

Which of the following is NOT a category of keystone species?

• Keystone predators

• Keystone modifiers

• Keystone competitors

• Keystone hosts

What happens if a keystone predator like the gray wolf is removed from an ecosystem?

• Prey populations decrease

• Prey populations increase exponentially

• New predators take over

• The ecosystem remains unchanged

How do alligators act as keystone modifiers?

• By preying on large mammals

• By creating depressions that provide water refuges

• By increasing the number of fish

• By reducing plant diversity

Which species is an example of keystone prey in the Pacific Northwest?

• Black-tailed prairie dog

• Gray wolf

• Pacific salmon

• American alligator

What is a significant effect of keystone prey on ecosystems?

• They increase plant diversity

• They eliminate other prey species

• They cause significant fluctuations in predator densities

• They reduce predator densities

What role do hummingbirds play as keystone mutualists?

• They create habitats for other species

• They are a major food source for mammals

• They are primary predators

• They pollinate specialized plants

Which tree species acts as a keystone host by creating an open canopy?

• Oak

• Pine

• Quaking aspen

• Maple

What is one benefit of maintaining keystone species in an ecosystem?

• Increased pollution

• Decreased biodiversity

• Better recovery from environmental events

• Reduced water resources