Investivating Populations Flashcards
1
Q
What is a population?
A
- all individuals of a given species living together in the same area at the same time
2
Q
What is carrying capacity?
A
- maximum, equilibrium number of organisms of a particular species that can be supported indefinitely in each stable environment
3
Q
What is community?
A
- all individuals of all the species living together in the same area at the same time
4
Q
What is a habitat?
A
- place where and organism lives within an ecosystem
5
Q
What is a niche?
A
- where an organisms lives and its roles, e.g what it feed son and how it interacts with other organisms
6
Q
What is the difference between intra specific and inter specific competition?
A
- intraspecific = competition within a species
- interspecific = competition in between species
7
Q
When to use percentage cover?
A
- too many individuals to count
- organism is too small
- hard to identify
- overlap with other species
8
Q
Data must be…
A
- reliable
- representative
- not biased
- random
9
Q
Random quadrating can be used to…
A
- find relative abundance
- compare species abundance in two different areas
- compare species abundance at one site
10
Q
Method for random quadrating…
A
- use a grid to split area
- random number generator for random coordinates
- find frequency in each quadrant
- calculate mean/average
11
Q
How many quadrats should you use in the sample?
A
- calculate running mean
- stop sampling when there is little change
- enough to carry out statistical test
- large number to make sure it is reliableNeed to make sure work can be carried out in the time available
12
Q
Systematic sampling used for…
A
- changes across an area
13
Q
Describe how you would investigate the distribution of marram grass from one side of the dune to another.
A
- transect from one side to the other
- place quadrants at regular intervals along the line
- count plants/percentage cover/ abundance scale
14
Q
Population size =
A
N1 x N2 / Nm
(Number caught first time x number caught second time / number caught second time that were marked)
15
Q
Mark release re-capture method…
A
- capture sample, mark, release
- appropriate method of marking
- allow time for releases organism to redistribute back into population
- take second sample and count marked organisms
- no’ in population = N1 x N2 / Nm
16
Q
Biotic factors affecting the distribution of a species…
A
- competition between organisms
- predation
- disease
17
Q
Abiotic factors affecting the distribution of species…
A
- temperature
- light intensity
- pH
- wind speed
- water availability and humidity
