Organisms within an ecosystem are organised into levels ... of all species remain relatively constant over time. In the example above the amount of grass, and the numbers of rabbits and foxes ...

Primary consumers Usually eat plant material - they are herbivores. For example rabbits, caterpillars, cows and sheep. Secondary consumers Usually eat animal material - they are carnivores.

Take, for example, Water User Associations ... Such an appreciation about the interdependence of water with other constituents of the ecosystem is key to effective water management and conservation.

A primary example of this involves the energy currency in ecosystems, which is carbon. The amount and form of carbon present in different ecosystem pools — such as plants, animals, air ...