Which one among the following is NOT a reason for low biodiversity?

Which one among the following is NOT a reason for low biodiversity?

Habitat stress
Abundance of ecological niches
Geographical isolation
Dominance by one species
This question was previously asked in
UPSC Geoscientist – 2021
The correct answer is Abundance of ecological niches.
Ecological niches are the roles and positions species occupy within an ecosystem. An abundance of ecological niches means there are many different ways for species to coexist and utilize resources without direct competition, which typically leads to higher biodiversity. Therefore, an abundance of ecological niches is a reason for *high* biodiversity, not low biodiversity.
Reasons for low biodiversity include habitat stress (harsh environmental conditions), geographical isolation (limits species migration and gene flow), and dominance by one or a few species (which outcompete or exclude others).