Biodiversity Measurements: Species Diversity

Definition

• Species diversity is a key component of biodiversity, comprising two factors: the number of different species present in an ecosystem and the proportion or relative abundance of each species within that ecosystem.

Species Richness

• Species richness represents the count of the total number of different species in an ecosystem.
• It indicates how diverse an ecosystem is in terms of the variety of species it contains.
• For example, an ecosystem with 10 different species has higher species richness than one with only 5 species.

Relative Abundance

• Relative abundance refers to the proportion of each species in an ecosystem's community.
• It reveals how common or rare each species is within the ecosystem.
• Communities with even proportions of each species exhibit higher species diversity in terms of relative abundance.

Dominant Species

• In some ecosystems, a dominant species may be present, which is exceptionally common and widespread.
• Dominant species can influence species diversity by reducing the relative abundance of other species.
• Ecosystems with dominant species may have lower species diversity in terms of relative abundance.

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Biodiversity Measurements: Species Diversity

Biology

Comparison

• Two ecosystems with the same species richness but different dominant species can exhibit varying species diversity.
• Ecosystem A: 10 species with even proportions (higher species diversity)
• Ecosystem B: 10 species with one dominant species (lower species diversity)

Summary

• Species diversity includes species richness (number of different species) and relative abundance (proportion of each species).
• High species diversity indicates a more varied and balanced ecosystem.
• Dominant species can impact species diversity, reducing the relative abundance of other species in an ecosystem.