Give an example of species diversity.

Species diversity refers specifically to the variety of different species within a given ecological or geographical area. The number of different species in a forest exemplifies species diversity because it directly counts the distinct organisms present in that area.

In a forest, higher species diversity means a greater variety of plants, animals, fungi, and microorganisms, which can lead to a more resilient ecosystem. This richness in species plays a crucial role in ecological interactions, such as predation, mutualism, and competition, which are vital for the overall health of the ecosystem.

While the other options touch on different concepts related to ecology and biodiversity, they do not specifically address species diversity. For example, the range of climates in different regions relates to environmental diversity rather than species diversity. The size of individual species populations pertains to population dynamics, while variation in diet among species can indicate functional diversity, but again does not quantify the number of different species. Hence, the answer correctly identifies the core concept of species diversity.