Ecosystems

Ecosystems

• Habitat - the place where an organism lives
• Population - All the organisms of a species in a habitat
• Community - All the different species in a habitat
• Ecosystem - All the organisms living in a particular area and all the non-living conditions 

Quadrats

Quadrats can be used to find an estimate for the population size of a certain area.

1. Place a 1m²  quadrat at a random point in the area that you're testing
2. Count all the organisms within the quadrat
3. Multiply the number of organisms by the total area of the habitat

NB - the placing of the quadrat must be random. To do this divide the area under investigation up into a grid and use a random number generator to find random coordinates. Place the quadrat there.

The sample may not be representative of the population as you're only testing a small section so to increase the accuracy (the value closest to the truth) do repeats to test a larger area.

Using Quadrats to find the Distribution of Organisms

You can investigate how the distribution of organisms change as you move from one area to another:

1. Mark out a line in the area you want to study
2. Collect data in metre intervals with the quadrats by placing them next to each other.