The environment of our earth has a number of life zones that support birth and development of all types of organisms.
All the life zones of the earth are collectively called as Biosphere.
The biosphere vertically extends into the atmosphere up to about 10 km and downwards into the oceans up to a depth of about6.9 km.
Each life zone of the biosphere is made up of several small and interdependent units comprising plants, animals, microorganisms, soil, water and climatic factors. Each one of these units is called an ECOSYSTEM.
Thus, an Ecosystem can be defined as- the unit of biosphere comprising different types of life forms interfacing closely among themselves and with their physical environment is called as Ecosystem.
Ecosystem comprises plants, animals, microorganisms, rocks, soils, water, air, sunlight etc. These may be categorized as Living beings and non-living things.
An ecosystem is a dynamic unit of biosphere. In this dynamic unit, there remains a continuous interaction between plants, animals, microorganisms etc. among themselves and with the non- living environment.
Human beings derive lots of benefits from ecosystems of the environment. The benefits are cumulatively called Ecosystem Services. Services from ecosystems are regularly involved in many ways like provisioning of clean drinking water, and the decomposition of waste materials.
The services of ecosystems were popularized in 2000s by the Millennium Ecosystem Assessment (MEA). A report of it was released in 2005. It is a group of over 1000 of leading biological scientists of the world who analyse the state of the Earth’s Ecosystems and provide guidelines for decision making authorities across the globe.
The report from MEA refers to natural ecosystems as “life-support systems”. The MEA has grouped ecosystem services into four broad categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and crop pollination; and cultural, such as spiritual and recreational benefits.
Ecosystem Services and Ecosystem functions are different terms. Ecosystem services refer to what benefits ecosystems provide to human beings whereas ecosystem functions relate to roles of ecosystems in the biosphere like transfer of food and energy in cyclic pathways and the decomposition of wastes.
Ecosystem functions incorporate biological, geo-chemical and physical processes and components that exist within an ecosystem.
In other words, ecosystem functions relate to the structural components of an ecosystem like vegetation, animals, microorganisms, water, soil, atmosphere; and how they interact with each other within ecosystem and across ecosystems. Maintaining ecosystem functions is important to maintaining the capacity of the region to supply ecosystem services.
