Alpha (α) and Beta (β) Biodiversity - Biodiversity is described by two parameters:

(i) point or α diversity represented by the number of species in a specified area and

(ii) β diversity represented by the turnover of species across space. The α diversity increases with the total number of individuals encompassed and thus with the increase in the area sampled and the productivity per unit area. We know that α -diversity is less on remote islands and increases as we move towards the equator.

β diversity depends on how large are species ranges and following two scenarios may be found:

(i) If the range is large, α -diversity is independent of the area sampled, so that a national park to protect diversity can be placed anywhere.

(ii) If α diversity is low with species ranges being small (despite high total diversity) and nonoverlapping, many parks will be needed to protect diversity.