BFE - Biodiversity Patterns (Lesson)

Biodiversity Patterns

Species richness generally increases as one approaches the equator. This pattern of variation with latitude, called the latitudinal gradient, is one the most obvious patterns in ecology, yet one of the most difficult ones for scientists to explain. Greater amounts of solar energy, heat, and humidity at tropical latitudes lead to more plant growth, making areas nearer the equator more productive and able to support larger numbers of animals. Additionally, polar and temperate regions may be relatively species-poor because glaciation events repeatedly force organisms from these regions toward more tropical latitudes.

The latitudinal gradient influences the species diversity of Earth's biomes. Tropical dry forests and rain forests tend to support far more species than tundra and boreal forests. Tropical biomes typically show more evenness as well, whereas, in high latitude biomes with low species richness, particular species greatly outnumber others.

For any given area, species diversity tends to increase with a diversity of habitats, because each habitat supports a somewhat different set of organisms. Thus, ecotones, transition zones where two or more habitats intersect, often support high biodiversity. Human disturbance (such as when we clear open patches within a forested landscape) can sometimes create ecotones or patchwork combinations of habitats.

 

Terrestrial Biome Distribution 

Biodiversity and Speciation Self-Assessment

Click here to watch "How Did Life Emerge Here?" Links to an external site.

 

Use the following flashcards to complete a self-assessment.

 

 

 

RESOURCES IN THIS MODULE ARE OPEN EDUCATIONAL RESOURCES (OER) OR CREATED BY GAVS UNLESS OTHERWISE NOTED. SOME IMAGES USED UNDER SUBSCRIPTION.