The interaction and interrelationship between the living community (plants, animals, and organisms) in relation to each other and the non-living community (soil, air, and water) is referred to as an ecosystem. Thus, an ecosystem is a structural and functional unit of biosphere. It is made up of living and non-living beings and their physical environment.
In other words, a natural ecosystem is defined as a network of interactions among the organisms and between organisms and their environment. Nutrient cycles and energy flows keep these living and non-living components connected in an ecosystem.
Ecosystem is a part of natural environment consisting of a community of living beings and the physical environment both constantly interchanging materials and energy between them. It is the sum total of the environment or a part of nature.
The environment consists of four segments as follows −
Atmosphere − The atmosphere refers to the protective blanket of gases, surrounding the earth. It sustains life on the earth. It saves the Earth from the hostile environment of the outer space. The atmosphere composed of nitrogen and oxygen in large quantity along with small percentage of other gases such as argon, carbon dioxide, and trace gases (the gases which makes up less than 1 percent by volume of the atmosphere.
Hydrosphere − Hydrosphere comprises all water resources such as ocean, seas, lakes, rivers, reservoirs, icecaps, glaciers, and ground water.
Lithosphere − It is the outer mantle of the solid earth. It contains minerals occurring in the earth’s crust and the soil.
Biosphere − It constitutes the realm of living organisms and their interactions with the environment (atmosphere, hydrosphere, and lithosphere).
The study of ecosystem or environmental studies has been seen to be multidisciplinary in nature, hence, it is considered to be a subject with great scope. It is no more confined only to the issues of sanitation and health; rather, it is now concerned with pollution control, biodiversity conservation, waste management and conservation of natural resources.