Tuesday, May 10, 2011

4.3) Quadrats sample

Quadrats sample means to use quadrats as sample to find out the distribution of a population in a certain habitat.

Quadrats sample must be...
- random (so no bias would be introduce)
- representative (large/ as close to the true number of population as possible) the bigger the number the better... about 10% of the actual field area would be appropriate

How to make a quadrat sample?
- Set up a grid system across the field (which work like the x, y coordinate on graph)
- Select random numbers (generated online or from the talbe) that gives the (x,y) coordinate so you'll know where to place your quadrats
- Calculate the area of your quadrat, then count the number of organism in it

Recording your data...
- Make a table (right column = number of quadrats, left coloum = number of organism found in the quadrat)
- Find the mean (average). This would give you the number of organism per square metre.

What can you do with the sample collected by quadrating?
- Calculate the estimate number of organisms in an ecosystem or given field
- Compare the number of a populations between two different areas

No comments:

Post a Comment