Required Practical 12 - Investigation into the effect of a named environmental factor of the distribution of a givent species.

Question 1

List some abiotic factors.

Answer 1

• Humidity
• Wind speed
• Day length
• Water supply
• Nutrient supply
• Light intensity
• Temperature

Question 2

List three biotic factors.

Answer 2

• Competition for resources.
• Predation
• Disease

Question 3

How is percentage cover calculated.

Answer 3

• Use a quadrant with squares.
• count how many squared the required species in present in.
• Only count a square if more than half of the square is covered.
• Calculate the percentage of squared the species is present in.

Question 4

State the formula for the mark-release-recapture method.

Answer 4

• Population size = no in 1st sample x no. in 2nd sample / no. marked in 2nd sample.

Question 5

State some assumptions for the mark-release-recapture method.

Answer 5

• No births, deaths or immigrations.
• Random mixing of marked individuals with population.
• Marking doesn’t not affect behaviour of individuals or make them more vulnerable to predators.