Stability & Change 1

Which of the following best illustrates the concept of ecosystem stability over long periods?

• The rapid regeneration of grasslands after a wildfire

• The presence of fossilized plant species in unchanged wetland environments for millions of years

• The extinction of species due to natural selection

• The ability of invasive species to dominate an ecosystem over time

Which of the following is NOT a key requirement for ecosystem stability?

• Continuous supply of energy

• Genetic diversity among populations

• Unlimited nutrient availability

• Climatic variables remaining within tolerance levels

Why is large-scale deforestation of the Amazon considered a potential tipping point for ecosystem stability?

• It reduces the generation of atmospheric water vapor, affecting rainfall and cooling

• It directly increases the genetic diversity of the region

• It prevents solar energy from entering the ecosystem

• It ensures more efficient carbon sequestration in the soil

Why are keystone species critical for maintaining ecosystem stability?

• They are the most abundant species in an ecosystem

• They have a disproportionately large impact on community structure and interactions

• They prevent all ecological changes from occurring

• They contribute to ecosystem instability by limiting biodiversity

Which of the following best explains why sealed glass mesocosms are preferred over open tanks for studying ecosystem stability?

• They replicate natural ecosystems more accurately than open systems

• They allow for unlimited nutrient cycling without external influences

• They completely block both energy and matter transfer, ensuring a perfectly isolated system

• They allow energy transfer but prevent matter from entering or leaving, making it easier to control variables