Biodiversity - Module 4 Flashcards
What is species abundance?
The amount of organisms in a species
What are the 2 types of sampling?
- Random sampling
- Non - random sampling
Describe how random sampling could be carried out
Measure a grid using 2 tape measures at right angles and using a random number generator, make coordinates and take temples using quadrant
What are the 3 methods of non random sampling?
- Opportunistic
- Stratified
- Systematic
What is opportunistic sampling?
The weakest form of sampling that uses organisms readily available
What is stratified sampling?
When populations are divided into subgroups based on characteristics
What are the 2 methods of systematic sample and describe them?
- Line transect
Samples are taken at regular intervals along a line of organisms touching or within a distance of the line - Belt transect
2 transects are set out parallel and samples are taken at intervals form the space between he two lines
Give 2 reasons why samples are never fully representative?
- Sampling bias - remove this by removing human involvement
- Chance - organisms sampled may not be representative of the population
How do you obtain more reliable sampling results?
Use a larger sample size
What are 5 methods of sampling insects?
- Pooter
- Sweep nets (insects in long grass)
- Pitfall traps
- Tree beating (insects in trees)
- Kick sampling (organisms in riverbed)
What is a point quadrant?
A bar with long push pins, and whatever the pin lands on is recorded
What is a frame quadrant?
A square frame divided into equal sections
What is species richness?
Number of different species in an area
What is species evenness?
How many individuals in each species compared to other species in the area
How are abiotic factors in an area measured?
Using sensors that can hold information on computers
How are animal population sizes estimated?
Using capture mark release recapture method
What are the components of the Simpson index of biodiversity calculation?
D = 1 - (sum of) (n/N)^2
N = total number of organisms in a species n = total number of organisms in individual species
Why is genetic biodiversity so important?
It allows organisms to adapt to their environment as some individuals may have advantageous alleles preventing extinction
How does gene flow occur? And what does it affect?
Gene flow occurs through interbreeding of different populations resulting in an impact on genetic biodiversity
What is the genetic bottleneck and what does this impact?
When few individuals survive an event so gene pool is low and genetic biodiversity is impacted
What is the founder effect?
A small number of individuals start a new colony resulting in a smaller gene pool
What is genetic drift and what does it affect?
The random nature of alleles to be passed onto offspring affects the genetic biodiversity of a population
How is genetic biodiversity measured?
The frequency of polymorphic genes
What are the main 3 factors affecting biodiversity?
- Agriculture
- Deforestation
- Climate change
What is a keystone species?
A species that plays a key role in balancing and maintaining ecological community in an area
What are the 3 reasons e would maintain biodiversity?
- Aesthetics
- Economic
- Ecological (interdependence of species)
