Who conducted long-term ecosystem experiments using outdoor plots?

What are the effects of biodiversity on ecosystem functioning?

As biodiversity increases in an ecosystem,its stability $...$

Which of the following statements are true?
$I$. Species diversity provides stability to the ecosystem.
$II$. Communities with more species tend to be more stable than those with fewer species.
$III$. Ecosystems with higher biodiversity are more productive than ecosystems with lower biodiversity.
$IV$. Biodiversity is not essential for the maintenance and health of the ecosystem.
Choose the correct option.

Give scientific reasons: Biodiversity is important in the maintenance of the biosphere and its ecosystem.

Outdoor plot experiments were conducted by