Extensive work in environmental sciences and ecology involves sampling populations of organisms.

When conducting environmental sampling, research questions that are often asked include is the organism present, and how many organisms are there. The technique of random sampling is a statistically sound procedure that is used to answer these types of questions. For your knowledge we will discuss two types of random sampling techniques, abundance and presence/absence.

If you want to determine the abundance of organism in an environment, you could count all the organisms one by one.  As you might imagine, it is often impossible for a scientist to count all the organisms present in an environment, regardless if it is a small amoeba or a large elephant. 

As such the abundance random sampling technique is used to get an estimate of the numbers of organism in a given location. This procedure involves creating an imaginary grid over the land mass you wish to check for the organism.

After creating this grid chose a random number of squares in the grid, as illustrated by the blue highlighted boxes. Then count only the organisms in those squares.  Next determine the average number of organisms in a single square, then multiply this number by the total number of squares in your grid.  By doing this you will obtain an estimate of the abundance of that organism.