Investigating abundance and distribution

Question 1

What does abundance refer to?

Answer 1

• How many organisms there are

Question 2

What does distribution refer to?

Answer 2

• Where the organisms are

Question 3

Why do scientists use sampling and what is it?

Answer 3

• It is very time consuming and difficult to measure the determination and abundance . Instead scientists use sampling
• Sampling is when we measure a subset of organisms and use that to make predictions about the whole populations

Question 4

What are quadrats and transects used for?

Answer 4

• Quadrats: used to measure abundance
• Transects: used to measure how distribution changes

Question 5

Steps of using a quadrat

Answer 5

• Place tape measures along the width and length of the field
• Use random number generator to generate 10 pairs of random numbers
• Use these pairs as X and Y coordinates on the tape measures
• At each point, place a quadrat and count the number of organsims (e.g: dandellions)
• Find the average for the number of dandellions per m2 (each quadrat is 1 m2)
• Estimate the total population size on the field

Question 6

Steps of using a transect

Answer 6

• A transect line is laid out in a straight line between the lake and woodland
• Quadrats are placed in regular intervals along the transect lines
• The abundance of dandellions is measured by counting the number of organisms in each quadrat
• Steps 1-3 are repeated using new transect lines which are parallel to the first

Question 7

What is a transect?

Answer 7

• A line through a habitat along which organisms are sampled