Populations and succession

Define population

All of the organisms of one species in one area at one time

Define Community

All of the organisms of all species at one time

Define habitat

The place that an organism lives

Define niche

The role of an organism in its ecosystem

Define ecosystem

The interaction between all the biotic and abiotic factors

When is random sampling used

When you want to work out the average population of an area

Compare the average of two areas

When is systematic sampling usually used

When you want to investigate the change in a population over a distance

Describe how you would randomly sample an area to estimate the population

Create a grid on the field

Use calculator to generate random number used as coordinates

Place quadrant at the intersection of coordinates

Estimate the abundance of —— in the quadrat-%cover

Repeat many times so the mean abundance is reliable

Multiply the number of plants per quadrat by the number of times the quadrat fits into the total area of the field in order to work out the population in the whole field