What is species richness?

Tropical regions exhibits species richness as compared to polar regions. Justify?

"Stability of a community depends on its species richness." Write how did David Tilman show this experimentally.

"Stability of a community depends on its species richness." Write how did David Tilman show this experimentally.

A graph of species richness vs area on log-log axes is

In the above graph, which slope represents more species richness ?

In mollusks of New York state, which of these experiences gives you a value between 0.1 to 0.2? ( S = log of species richness, A = log of Area, C = log of Y- intercept in the species richness area curve)

Which of the statement are in accordance with the observation of geographer Alexander von Humboldt ? I. Within a region species, richness increases with increasing explored area but within a limit. II. The relation between species richness and area is a rectangular hyperbole. III. The richness of species decreases with the increasing explored area. IV. There is no relation between the explored area and species richness .

Which of the statement are in accordance with the observation of geographer Alexander von Humboldt ? I. Within a region species, richness increases with increasing explored area but within a limit. II. The relation between species richness and area is a rectangular hyperbola. III. The richness of species decreases with the increasing explored area. IV. There is no relation between the explored area and species richness .