Why species loss destabilises an ecosystem — practice questions

Question 1 · difficulty L1 · recall

What does the rivet popper hypothesis illustrate about biodiversity loss?

• A. Species loss can progressively weaken ecosystem function
• B. Every species can be removed because ecological roles are completely interchangeable
• C. Species loss always improves stability
• D. Only large animals affect ecosystems

Question 2 · difficulty L2 · understanding

Which feature is generally associated with a more stable ecosystem?

• A. Large year-to-year fluctuations in productivity despite otherwise unchanged conditions
• B. Lower variation in productivity between years
• C. Complete absence of consumers
• D. No response to environmental change

Question 3 · difficulty L3 · application

A plant community loses several pollinator species, and seed production then falls in many plants. What does this best demonstrate?

• A. Pollinators are unrelated to plant reproduction
• B. Only plants are affected by biodiversity loss
• C. Species loss can propagate through ecological interactions
• D. Ecosystem species function independently, so losses cannot affect interacting partners

Question 4 · difficulty L5 · analysis

Two grasslands experience the same drought. The more species-rich grassland shows smaller changes in total biomass and recovers faster. Which inference best fits biodiversity-stability ideas?

• A. Drought has no measurable ecological effect once a community contains many species
• B. Higher diversity guarantees no species ever declines
• C. Lower diversity always produces more biomass
• D. Greater diversity can buffer ecosystem function