Question

What leads to a decrease in biodiversity?

Answer 1

Anything that removes a particular biological species from an ecology.

Explanation:

"Diversity" is the measure of different types of species in an ecology. Decreasing it means that there are fewer 'different' types. This can be a result of over-use (hunting, agriculture) of a resource or displacement of several species by a particular (usually invasive) species.

Generally, biodiversity is to be preferred. Lack of biodiversity creates risks of disease epidemics, unfavorable genetic legacies and a potential further decrease in biodiversity.