Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Biodiversity: The term popularized by sociobiologist Edward Wilson to describe the combined diversity at all levels of biological organization, ranging from macromolecules within cells to biomes.
Genetic Diversity: A single species might show high diversity at the genetic level over its distributional range. Example: growing in different Himalayan ranges produces different concentrations of the active chemical reserpine.
Species Diversity: The variety in the number and richness of species within a region. For instance, the Western Ghats have a greater amphibian species diversity than the Eastern Ghats.
Ecological Diversity: Diversity at the ecosystem level. India has greater ecosystem diversity (deserts, rain forests, mangroves, coral reefs, etc.) than a Scandinavian country like Norway.
Latitudinal Gradients: Species richness generally decreases as we move away from the equator towards the poles. Tropical latitudes ( to ) harbor more species than temperate or polar areas.
Species-Area Relationship: Described by Alexander von Humboldt, who observed that within a region, species richness increases with increasing explored area, but only up to a limit. On a logarithmic scale, this relationship is a straight line.
Importance of Tropical Regions: Tropics have remained relatively undisturbed for millions of years, allowing for species specialization, and they receive more solar energy, which contributes to higher productivity and greater diversity.
📐Formulae
💡Examples
Problem 1:
Explain the variables in the Species-Area relationship equation and provide the value of for frugivorous birds in tropical forests.
Solution:
, , , and . For frugivorous birds and mammals in tropical forests across continents, the slope is .
Explanation:
The value of indicates the steepness of the slope. While usually ranges from to for small areas, it becomes much steeper (ranging from to ) when analyzing very large areas like entire continents.
Problem 2:
Compare the bird species richness of Colombia, New York, and Greenland to illustrate latitudinal gradients.
Solution:
Colombia (located near the equator) has nearly species; New York (at ) has species; Greenland (at ) has only species.
Explanation:
This demonstrates that species richness decreases as one moves from the equator () toward the poles, showing the impact of latitudinal gradients on biodiversity.