Biodiversity Flashcards
1
Q
Define biodiversity
A
- The variability within species, between species and between ecosystems
2
Q
Why is biodiversity important?
A
- all organisms depend on each other, interconnectedness
- where there is greater biodiversity there is a more stable ecosystem
- reduced biodiversity reduces connections between species
3
Q
What is an EIA and why is it necessary?
A
- Environmental impact assessment
- gives information about species present
- assesses positive and negative effects of a project on the biodiversity of an area
4
Q
What is habitat biodiversity?
A
- The range of different ecosystems or habitats within a particular region
- E.g it is low in the arctic but high in a rainforest
5
Q
What is species biodiversity?
A
- the number and variation of species within an area
- the number of species in an area is known as species richness
- measured using a combination of richness/ evenness
6
Q
What is genetic biodiversity?
A
- variation between individuals belonging to the same species
- this is the variation found within any species that ensures we do not look identical
- measured by allele frequencies
7
Q
What is sampling?
A
- An estimate no. of individuals without counting all of them
- gives us info on distribution of organisms
8
Q
Why do we use sampling?
A
- Look at the effect of disease
- indicator of climate change
- indicator of habitat change
- any time we want to know what there is and how many there are in an area
9
Q
Describe the procedure of random sampling
A
- Selecting by chance
- number tables or a computer can be used
- coordinates could be selected on a map before sampling
- lay out two tapes at right angles, use random numbers to select x+y coords
- use quadrat at each set of coords and repeat
10
Q
Describe the procedure of opportunistic sampling
A
- researcher makes sampling decisions based on prior knowledge or during sampling
- researcher may deliberately sample an area that is known to contain a particular species
11
Q
Describe the procedure of stratified sampling
A
- Populations divided into strata based on a characteristic
- a random sample is taken from each strata proportional to its size.
12
Q
Describe the procedure of systematic sampling (line)
A
- Line
- samples taken at fixed intervals across a habitat
- samples touching the line are counted
13
Q
Describe the procedure of systematic sampling (belt)
A
- samples taken at fixed intervals across a habitat
- provides more information than line as sampling it at intervals between two parallel lines
14
Q
What is sampling bias?
A
- Deliberately choosing an area which appeals to the researcher
- Reduced by using random sampling as the area being sampled will be as a result of chance not choice
15
Q
What is meant by chance and how does it affect reliability?
A
- Organisms being sampled are not as a result of human involvement
- Organisms selected may not be representative, reduced by large sample size
16
Q
What are three ways we can sample plant species?
A
- Using a point quadrat (pins pushed through at set intervals, species touching pins are counted, frame + horizon bar)
- Frame quadrats ( square frame divided into equal sized squares)
- Transect line
17
Q
How do we sample invertebrates?
A
- Pooters (sucking on a mouthpiece covered with a filter, draws insects up)
- Sweep nets for long grass
- Pitfall traps (deep enough to fall in and not crawl out, covered with waterproof tarp to stop rainfall, left overnight for nocturnal species)
18
Q
How do we sample small animals?
A
- Longworth trap= tunnel leads to a nest box with food and nesting material, when it enters it trips a lever and closes door, may be marked when it is released as part of mark-release-recapture
19
Q
Evaluate random sampling
A
- Unbiased
- chosen sample might not respresent the population due to random fluctuations
20
Q
Evaluate systematic sampling.
A
- does not involve random elements, performed quickly by a machine
- method could coincide with a pattern
21
Q
Evaluate opportunity sampling.
A
- Quick and easy
- very biased, no attempt to obtain representative sample has been made
22
Q
Evaluate stratified sampling.
A
- enables detailed analysis of sub-groups
- more complex and time consuming
