What Occurs in an Ecosystem?

Ecosystem is a term that is used to describe a biological environment, all the organisms living there, their relationship with one another and the nonliving components of the environment. The living components of an ecosystem are referred to as the biotic factors while the nonliving components are referred to as the abiotic factors.

Basic Concepts

• The interaction of organisms with each other and with their environment leads to the exchange of energy. The abiotic components of an ecosystem include the chemical and physical factors in the environment, such as radiation, temperature, soil, light, sound waves, pressure and water. The biotic factors include the plants, animals, fungi and bacteria. All of these factors are interconnected and balanced in such a way that makes the system work. If there is any alteration, like the introduction of pollutants, the ecosystem will no longer be balanced and this imbalance will lead to a chain of unpleasant consequences like acid rain and its effects.

Biotic and Abiotic Factors

• Abiotic factors are a crucial part of the ecosystem. Consider this cycle: the soil provides nutrients to plants like grass, the sun helps the plants grow, and they provide nourishment to herbivores like goats, which are a source of food to carnivores like lions or omnivores like man, who will eventually be decomposed by bacteria and fungi. This is known as energy transfer and there are different categories: the primary producers, like the plants; the primary consumers, like herbivores; secondary consumers, like carnivores and omnivores; and decomposers like bacteria and fungi. This system of grading energetic processes is known as trophic levels. The flow of energy from the sun is completed when the decomposers, like bacteria and fungi, break down the fixed carbon, derived from the plants by the consumers, into lower forms of energy, in order to release the carbon fixed by photosynthesis back into the atmosphere.

Biotic Interactions

• There are many forms of interactions between the biotic components, or organisms in an ecosystem. Competition is a type of interaction between two species or organisms where both are competing for the same limited resources. Symbiosis describes the interaction between organisms of different species where both organisms benefit. Predation is an interaction where one organism captures biomass from another (like primary consumers and secondary consumers), and neutralism is where the presence of one organism in an ecosystem does not affect the other.

Aquatic Ecosystems

• The aquatic ecosystems are water-based ecosystems. They include the marine ecosystem, which is made up of the saltwater bodies like the seas and oceans. The freshwater aquatic ecosystem is made up of bodies of water with limited salt content, like lakes and streams. The flow of energy in the aquatic ecosystem is similar to the terrestrial or land-based ecosystem. The sun helps the algae growand the algae produce oxygen for fish and food for small organisms like planktons. The fish eat the planktons, absorb oxygen with their gills and expel carbon dioxide, which the marine plants use to grow.