Community Dynamics and Invasive Species

The video tutorial discusses community ecology, focusing on invasive species and their impact on ecosystems. It explains how species can become invasive in one community but not another, depending on factors like predators and competition. The tutorial also examines the effects of removing primary producers and how toxins can alter community structures, leading to reduced species diversity.

What do the models of Community A and Community B assume about their initial conditions?

• Community A has more species than Community B.

• They have different initial biomasses.

• Community B has more species than Community A.

• They have the same initial biomass.

What factor does NOT contribute to a species becoming invasive in a community?

• Lack of natural predators

• Abundance of diseases

• Lack of competition

• Favorable environmental conditions

Why does removing pp1 have a greater effect on Community B than on Community A?

• Community B has more primary producers.

• Community A has alternative food sources for PC2.

• Community B has more secondary consumers.

• Community A has fewer tertiary consumers.

In Community B, what happens to SC2 if pp1 is removed?

• SC2 population increases.

• SC2 finds a new food source.

• SC2 population remains stable.

• SC2 population decreases.

Where should the invasive species I andv be placed in Community B?

• At the primary producer level

• At the primary consumer level

• At the secondary consumer level

• At the tertiary consumer level

What is the role of the arrow in the diagram for the invasive species I andv?

• Indicates the species is being consumed

• Indicates the species is consuming SC2

• Indicates the species is a secondary consumer

• Indicates the species is a primary producer

How can human activities that add toxins to the soil affect community structure?

• Increase species diversity

• Decrease species diversity

• Have no effect on species diversity

• Only affect primary producers

What is biomagnification?

• The increase in species diversity

• The decrease in species diversity

• The buildup of toxins in higher trophic levels

• The reduction of toxins in lower trophic levels

What happens to primary consumers if primary producers are reduced due to toxins?

• Their population remains stable

• Their population increases

• Their population decreases

• They become primary producers

What is a likely outcome for species at each trophic level when resources become scarce?

• Species will become primary producers

• Species will thrive

• Species will compete more

• Species will migrate to other communities