Biodiversity in Ecosystems

These flashcards cover the key concepts of biodiversity, types of diversity, sampling techniques, and measurement indices like Simpson's Index based on the lecture notes.

What is the definition of a monoculture?

A single species in an area, often referred to in the context of crop farming.

How is species richness defined?

The number of different species present in a specific area.

What is species diversity?

The number of species in an area compared to the number of individuals.

What is the Simpson’s Diversity Index?

The probability that two individuals randomly selected from a sample belong to different groups, such as species or family.

What are the three levels at which biodiversity can be considered?

Habitat Diversity, Species Diversity, and Genetic Diversity.

What does a high biodiversity level indicate about a habitat?

It indicates that the habitat is healthier.

Define habitat diversity.

The number of different habitats found within a specific area.

What factors are included in a habitat?

Physical factors like soil and temperature (abiotic factors) as well as living organisms (biotic factors).

What is the biological definition of a species?

A group of similar organisms that can reproduce and produce fertile offspring.

What is genetic diversity?

The variation of alleles within a species or a population of a species.

What is an allele?

A version of the same gene, such as different coat colors (black, brown, white).

Why is sampling used to collect biodiversity data instead of counting every individual?

Because it would take too long to count every individual in a habitat, samples are used to estimate the whole population.

How is random sampling conducted to ensure it is not biased?

By using grids and random number generators to ensure each sample site has the same probability of being chosen.

What is systematic sampling?

A type of non-random sampling where samples are taken at fixed intervals, often along a line such as a belt transect.

What is opportunistic sampling?

A non-random sampling technique where samples are chosen by the investigator; it is simple but the data will be biased.

What is stratified sampling?

A non-random sampling method where different areas in a habitat are identified and sampled separately in proportion to their part of the habitat as a whole.

Name three pieces of equipment mentioned for recording species in a sample site.

Sweep net, Pitfall trap, and Quadrats.

How is the total number of organisms for a whole habitat estimated from sample data?

By calculating the mean for the data collected and then multiplying by the size of the whole habitat.

How is species evenness defined?

The measure of the relative abundance of each species in an area.

How do species richness and species evenness relate to biodiversity?

The greater the species richness and evenness in an area, the higher the biodiversity.

What is the formula for calculating percentage frequency of a species?

\text{% frequency} = \frac{\text{# of individuals in a given species}}{\text{Total # of species in the study}}

How is percentage cover calculated in quadrats?

\text{% cover} = \frac{\text{# of squares which contain cover}}{\text{Total # of squares}}

In Simpson's Index of Diversity, what does a value close to 1 represent?

A more diverse habitat with a greater ability to cope with change, such as the introduction of a new predator.

In Simpson's Index of Diversity, what does a value close to 0 represent?

A less diverse habitat that is likely to be easily damaged by change.