The pond ecosystem

A pond is a shallow water body and a fairly self-sustaining, simple example that shows all four basic functions of an ecosystem.

Abiotic component: the water, the inorganic and organic matter dissolved in it, and the nutrient-rich soil on the pond floor.

Solar input, the temperature cycle, day length and other climatic conditions regulate how fast the whole pond functions.

Autotrophs (producers): phytoplankton, some algae, and plants that float, stay submerged or grow along the margins.

Consumers: zooplankton, and free-swimming and bottom-dwelling forms.

Decomposers: fungi, bacteria and flagellates, most abundant at the bottom of the pond.

The pond does what every ecosystem does: autotrophs turn inorganic into organic matter using solar energy, heterotrophs consume the autotrophs, and dead matter is decomposed and mineralised for the autotrophs to reuse.

Energy moves in one direction towards higher trophic levels and is lost as heat to the surroundings.