Species Distribution

Question 1

What two ways can you measure the distribution of a species?

Answer 1

> use a quadrat to measure how common a species is in two sample areas

> investigate how the distribution of a species changes by placing a quadrat along a transect

Question 2

How can you compare the distribution of an organism in two different sample areas?

Answer 2

> use the quadrat sampling method

1. ) divide sample area 1 into a grid
2. ) use a random number generator to determine a coordinate, place the 1m2 quadrat on this coordinate and count the number of the target organism present
3. ) repeat as many times as possible
4. ) find a mean number of organisms per m2 for this sample area
5. ) repeat all step for second sample area and compare the means of the two areas

Question 3

How can you study the change in distribution of an organism along a line?

Answer 3

> Mark a line using a tape measure or string

> use quadrats (either consecutively or intermittently eg. Every 2m) to measure the presence of the organism

> observe how this distribution changes

Question 4

How do you ensure reliability of a distribution of organisms investigation?

Answer 4

> large sample size with lots of quadrats/transects

> random sampling as is more reproducible

Question 5

How can you ensure validity of the experiment?

Answer 5

> by making sure it is reliable

> by answering the original question of whether a specific environmental factor has an affect on the distribution of an organism.

Question 6

Why must all of the variables be controlled?

Answer 6

Because otherwise the study will give no indication as to whether the variable you are supposed to be investigating has any affect on the distribution

Question 7

What 5 environmental factors affect the distribution of species?

Answer 7

> light

> water

> CO2 and O2

> temperature

> availability of nutrients

Question 8

What is a habitat?

Answer 8

An environment where an organism lives