Hypothesis/Concept Experiment/Concept A. Rivet Popper Hypothesis 1. High species richness leads to less variation in total biomass B. Tilman’s Ecosystem Experiments 2. Essential species are crucial for ecosystem stability C. Ecosystem Stability 3. Higher biodiversity contributes to higher productivity D. Productivity and Biodiversity 4. The loss of key species is more detrimental to ecosystem health

Step-by-step solution

A - 4: The Rivet Popper Hypothesis suggests that the loss of key species (rivets) is more critical to ecosystem health. B - 1: Tilman’s experiments found that high species richness leads to less year-to-year variation in total biomass. C - 2: Ecosystem stability is maintained by having a diverse set of species, some of which play crucial roles. D - 3: Increased biodiversity generally leads to higher productivity in ecosystems.