Photosynthetic organisms are the producers of biomass for life on earth
feeding relationships within a community can be presented by food chains
All food chains begin with a producer which synthesises molecules
The start of a food chain is usually a green plant or alga which makes glucose by photosynthesis
A range of experimental methods using transects and quadrants are used by scientists to determine the distribution and abundance of species in an ecosystem
Producers are eaten by primary consumers, which in turn may be eaten by secondary consumers and then tertiary consumers.
Using quadrats:
place a 1m^2 quadrat on the ground at a random point within the first sample area
you could do this by dividing the area into a grid and using a random number generator to pick coordinates
count all organisms within the quadrat
repeat steps 1-3 as many times as possible
work out the mean number of organisms in the first sample area