Read the passage carefully and give the answers to the next five questions:

Does the number of species in a community really matter to the functioning of the ecosystem? This is a question for which ecologists have not been able to give a definitive answer. For many decades, ecologists believed that communities with more species, generally, tend to be more stable than those with less species. According to the International Union for Conservation of Nature and Natural Resources (IUCN) (2004), the total number of plant and animal species described so far is more than 1.5 million.

The scientist who proved that species richness directly correlates with the stability of a community, was _____________.

David Tilman

The correct answer is Option (2) – David Tilman

David Tilman, an ecologist, conducted extensive research on biodiversity and ecosystem functioning. His experiments demonstrated that higher species diversity in ecological communities often contributes to greater stability and resilience against fluctuations in biomass production across different years. This phenomenon, known as the biodiversity-stability relationship, suggests that ecosystems with greater species richness tend to exhibit more consistent and stable productivity over time. Tilman found that plots with more species showed less year-to-year variation in total biomass. He also showed that in his experiments, increased diversity contributed to higher productivity.