Ecosystem Dynamics and Succession Concepts

The video covers ecological succession, focusing on primary and secondary types. Primary succession occurs in lifeless areas, starting with pioneer species like lichens, leading to a climax community. Secondary succession happens in areas with existing soil, following disturbances. Key factors include keystone species, which shape ecosystems, and indicator species like amphibians, which signal ecosystem health. Amphibians are declining due to chytrid fungus and habitat loss, indicating ecosystem distress.

What is the main difference between primary and secondary succession?

• Secondary succession starts on bare rock.

• Secondary succession does not involve pioneer species.

• Primary succession occurs in areas with existing soil.

• Primary succession begins in lifeless areas without soil.

Which species are typically the first to colonize an area during primary succession?

• Lichens and small plants

• Shrubs

• Large trees

• Grasses

In primary succession, what follows the establishment of pioneer species?

• Aquatic plants

• Climax community

• Intermediate species like shrubs and small trees

• Large mammals

What is a characteristic of secondary succession?

• It does not involve any pioneer species.

• It starts in areas with no previous life.

• It begins on bare rock.

• It occurs in areas where a previous community was disrupted.

Which species are considered keystone species due to their role in creating habitats?

• Lichens

• Woodpeckers

• Grasses

• Fungi

What role do beavers play in their ecosystems?

• They are indicator species.

• They are primary producers.

• They create dams that alter ecosystems.

• They are top predators.

How can indicator species help in assessing the health of an ecosystem?

• By indicating the presence of predators

• By showing the level of pollution and disturbances

• By reducing the number of invasive species

• By increasing biodiversity

Why are amphibians considered good indicator species?

• They are top predators in their ecosystems.

• They have a life cycle that involves both land and water.

• They are resistant to habitat changes.

• They are immune to pollution.

What is one of the main threats to amphibian populations globally?

• Increased biodiversity

• Chytrid fungus

• Excessive rainfall

• Overpopulation of predators

What is the significance of species richness in an ecosystem?

• It indicates the number of predators.

• It shows the variety of species present.

• It determines the water quality.

• It measures the amount of soil available.