Any organic material present on this earth is used and reused, again and again. Therefore, organic matter or nutrients are never lost from an ecosystem but are recycled over and again indefinitely. This cyclic movement of nutrient elements between organisms and the environment is known as nutrient cycling or biogeochemical cycles.
Nutrient cycles are of two types – gaseous and sedimentary. In gaseous cycles, the atmosphere is the main reservoir of nutrients whereas in sedimentary cycles, soil, rocks and minerals of the earth’s crust are the main reservoir of nutrients. The rate of release of nutrients into the atmosphere in both gaseous and sedimentary cycles is regulated by biotic factors as well as abiotic factors such as soil, temperature, moisture and pH. At any given time, the amount of nutrients, such as nitrogen, phosphorous, calcium and carbon in soil is known as standing state. There are several important nutrient cycles that sustain life on earth such as nitrogen, carbon are some of the important gaseous cycles while phosphorous, calcium and are some of the important sedimentary cycles.
The carbon cycle is an important gaseous cycle. In fact, carbon is the principal constituent of all living organisms on earth. It constitutes forty nine per cent of dry weight of organisms. The carbon cycle describes the movement of carbon.
Phosphorous is a major constituent of the cell membrane, nucleic acid, teeth, bones and cellular energy transfer systems in all living organisms. The phosphorous cycle along with other nutrient cycles play a very important role in maintaining healthy ecosystems.
Healthy and functioning ecosystems offer us a wide range of products and services known as ecosystem services. Some of the products provided by a healthy ecosystem include fruit, pure drinking water, food crops, spices, fibre, energy and medicinal plants, among other things.
Researchers like Robert Constanza and his colleagues have found that the value of fundamental ecosystems is an average thirty three trillion US dollars a year. Thus, our ecosystems are of great value. However, their services and products are limited and so efforts must be taken to preserve natural ecosystems for the sustenance of human life.