Ecosystem Dynamics and Biodiversity Concepts

The video explores biodiversity and ecosystems, focusing on stability and change. It defines biodiversity, explaining species richness and abundance. The role of dominant and keystone species is discussed, highlighting their impact on ecosystem stability. The video also covers scientific studies on food webs and the effects of human actions on ecosystems.

What is one of the general features of ecosystems mentioned in the video?

• They never change.

• They are always changing.

• They are stable over long periods but can change dramatically.

• They are unstable and change frequently.

How is biodiversity defined in the video?

• The size of an ecosystem.

• The number of different organisms interacting in an ecosystem.

• The variety of terrains in an ecosystem.

• The number of plants in an ecosystem.

What does species richness refer to?

• The total number of different species in an ecosystem.

• The number of plants in an ecosystem.

• The number of animals in an ecosystem.

• The total number of organisms in an ecosystem.

What is species abundance?

• The number of different species in an ecosystem.

• The number of individuals in each species and their proportion in the ecosystem.

• The number of plants in an ecosystem.

• The number of animals in an ecosystem.

What is an example of an ecosystem with an uneven distribution of species?

• An ecosystem dominated by elephants and one type of grass.

• An ecosystem with equal numbers of all species.

• An ecosystem with no dominant species.

• An ecosystem with only plants.

Why do complex food webs contribute to ecosystem stability?

• They have fewer interactions.

• They have more interactions and competition, preventing dominance.

• They have no competition.

• They are simple and easy to manage.

What happens if a single organism is removed from a complex food web?

• The ecosystem collapses.

• The ecosystem remains stable due to other interactions.

• The ecosystem stops functioning.

• The ecosystem becomes unstable.

What is a dominant species?

• A species that is rare in the ecosystem.

• A species that has no impact on the ecosystem.

• A species that makes up the majority of the biomass in an ecosystem.

• A species with a small population but a strong impact.

What is a keystone species?

• A species with a large population and a strong impact.

• A species with a small population but a significant role in the ecosystem.

• A species that is dominant in the ecosystem.

• A species that has no impact on the ecosystem.

How do elephants act as a keystone species in some African ecosystems?

• By being the only species in the ecosystem.

• By having no impact on the ecosystem.

• By being the most numerous species.

• By eating acacia trees and preventing them from dominating.