Lincoln Index

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Estimating population size of mobile organisms

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Biological Diversity : 

2 factors are considered when measuring diversity: richness - the number of different kinds of species present. evenness – the similarity of the population sizes (relative abundance of species). Biological Diversity

Slide 2: 

Both fields have the same richness (3 species) and the same total number of individuals (1000). However, Field 1 sample has more evenness than Field 2. Field 2 is less diverse than Field 1.

Diversity : 

Diversity A community dominated by 1 or 2 species is less diverse than one in which several different species have a similar abundance. As species richness and evenness increase, so diversity increases.

Calculating Diversity : 

Calculating Diversity The number of individuals of each species is counted e.g. by sampling random quadrats. (There is no need to identify the species, provided they can be distinguished from each other)

Diversity index : 

Diversity index Where: D = diversity index N = total number of organisms of all species n = number of individuals of a particular species

Diversity Index : 

Diversity Index The index is used to quantify the biodiversity of habitats. The diversity index takes into account the number of species present (richness) and the relative abundance of each species (evenness).

Slide 7: 

Worked example: Calculating the Diversity index( D) for ground vegetation in a woodland. Mean values per quadrat

Slide 8: 

Worked example: Calculating the Diversity index( D) for ground vegetation in a woodland. Mean values per quadrat

Slide 9: 

Worked example: Calculating the Diversity index( D) for ground vegetation in a woodland. Mean values per quadrat

Slide 10: 

The higher the value of D, the greater the diversity.

What is Biodiversity? : 

What is Biodiversity? ‘Biodiversity is the full range of living things on earth and their surroundings and their heritage (genes)’. ‘Everything from genes to ecosystems’ ‘The millions of plants, animals, fungi and microbes that inhabit earth; the genes they contain; and the ecosystems they help build’

Biodiversity is reflected in: : 

Biodiversity is reflected in: Ecosystem Diversity - community composition and environmental conditions. Species Diversity - species richness (number of species) and relative abundance of each species (species evenness). Genetic Diversity - DNA comparisons.

SPECIES RICHNESS : 

SPECIES RICHNESS How many species on earth? Only 1.5 million have been classified. Best estimate places number of species at 10 million. Birds, mammals and butterflies are mostly named and described by science.

Global Distribution of Species Richness : 

Global Distribution of Species Richness Highest species richness is found in tropical forests. Mammals and butterflies are often used as indicators of species richness.