4.2.1 Biodiversity COMPLETE Flashcards
DEFINITION- Species
A group of organisms that can breed together and produce fertile offspring
DEFINITION- Organism
An individual
DEFINITION- Population
All individuals of the same species
DEFINITION- Community
All different species that live in an area
DEFINITION- Habitat
Where species live
DEFINITION- Ecosystem
A community and its non living (Abiotic) environment make an ecosystem
DEFINITION- Niche
Ecological role the animal plays in the environment
DEFINITION- Habitat Diversity
The number of different habits found within an area
DEFINITION- Species Diversity
A measure of diversity within the community, takes into account both species richness and species evenness
DEFINITION- Genetic Diversity
Variety of genes that make up a species
DEFINITION- Species Richness
No of species living in a particular area
DEFINITION- Species Evenness
The number of each species living in a community
Why take samples
- More cost effective
- Less time consuming
DEFINITION- Sampling
To measure diversity of a habitat you need to identify and observe all the individuals of all the species in the area, instead you select a small portion of the habitat and study that carefully.
Two estimates made using information from samples
- Estimate the number of organisms in an area
2. Gain an estimated measurement of a particular characteristic of an organism
Random Sampling
Ensures data is not biased but may not cover all areas of a habitat equally. Species with a low presence may be missed leading to underestimates of biodiversity
Opportunistic Sampling
Uses the organisms that are conveniently available. Its easy and quick but data may be biased.
Stratified Sampling
Divides population into sub groups based on particular characteristics, random samples are then then from it.
Ensures that no species are underestimated but may lead to overestimation of biodiversity.
Systematic Sampling
Different areas in an overall habitat are identified and then sampled separately, Belt and Line transects.
Useful when habitat shows a clear gradient however only species on the line are recorded so some species may be underestimated.
Ensuring Reliability
Repeat and test if results are similar
Avoid sampling bias (eliminate human involvement)
Minimise impact of chance (use large sample)
Sampling plants
Frame quadrat- Gives more accurate and consistent estimates of % cover
Point quadrat- Allows a choice of size based on the habitat