Question

(a) Taking an example of a small pond, explain how the four components of an ecosystem function as a unit.
(b) Name the type of food chain that exists in a pond.

Answer 1

The pond ecosystem is a unit of ecosystem that can sustain on its own. A pond is known to exhibit all the functions of an ecosystem, say, nutrient recycling, energy flow, decomposition and productivity in a shallow water body via the food chain. In ponds, the lowest energy trophic level attains its energy through photosynthesis.

Complete answer:
In the pond ecosystem, the following four components of an ecosystem namely the productivity, decomposition, flow of energy and recycling of nutrients functions as a unit.
a) Pond is a freshwater aquatic ecosystem. Producers form the first trophic level in any food chain. In the pond ecosystem, it may be phytoplanktons which utilize solar energy and prepare their own food. These are then eaten up by zooplanktons (primary consumers) which are further eaten up by the small fishes (secondary consumers). Finally big fishes (tertiary consumers) eat these small fishes. In this way, all the four components of the pond ecosystem function as a unit.
b) In the pond ecosystem, a grazing food chain exists which is initiated when producers undergo photosynthesis and thus are eaten by consumers thereby transferring energies to various trophic levels.

Note: In a pond ecosystem, various dissolved organic and inorganic substances and the deposited soil in the bed of the pond serves as the abiotic component. Moreover algae, phytoplanktons and several other aquatic plants contribute to the productivity of the ecosystem under the influence of temperature, solar radiations and various climatic factors. Producers are then consumed by fishes, zooplanktons and various other water-dwelling animals which are represented as consumers. These consumers regulate flow of energy among various trophic levels. Further nutrient cycling is carried out through decomposition which occurs via bacteria, fungi and other decomposers.