Diversity Indices• Shannon Species Index• Species Richness • Pielou Index of Evenness• Margalef Species Richness

Objectives:

• Determine the importance of using Ecological indices in conducting ecological studies.

• Use the formula Shannon Species Index, Pielou Index of Evenness, Species Richness and Margalef Species Richness to solve an Ecological study simulation.

Ecology• Physiological Ecology Applications• Population Ecology• Community Ecology• Ecosystem Ecology

Why do we need to study Ecology?

Ecological Diversity

• Relates to the different forms of life which are present in a particular site.

Diversity Index

• A diversity index is a mathematical measure of species diversity in a community.

• Diversity indices provide more information about community composition than simply species richness (i.e., the number of species present); they also take the relative abundances of different species into account

Diversity Index

• Diversity indices provide important information about – rarity – commonness of species in a community.

The ability to quantify diversity in this way is an important tool for biologists trying to understand community structure.

Shannon Species Diversity Index

• The Shannon diversity index (H) is another index that is commonly used to characterize species diversity in a community.

• Shannon's index accounts for both abundance and evenness of the species present.

Practice: Determine species diversity using Shannon Species Diversity Index

Transfer your data in the tableSpecies #Individual Pi lnPi Pi (lnPi)

1

2

3

4

5

Total = H’=

Pielou’s Index of Evenness

• Refers to HOW close in numbers each species in an environment are.

Species Richness and Margalef Species Richness

• Species richness is a measure for the total number of the species in a community.

• This measure is strongly dependent on sampling size and effort.

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