For species-area relationships among very large areas like entire continents,the $Z$ values are in the range of:

$A$: Taxonomic diversity represents the maximum level of species diversity.
$R$: It represents species of taxonomically different groups occurring in equal balance.

The forests play an important role in the well-being of seven billion inhabitants of the world,of which ........... people directly depend on forests for their livelihood.

Which part of the world has a high density of organisms?

Given below is the representation of the extent of global diversity of vertebrates. What groups do the portions represent?

$A$: Tropics have more biodiversity.
$R$: Climate of tropical region is more seasonal.