STRUCTURE OF ECOSYSTEM

                   Ecology can be defined as the scientific study of the relations of living organisms  with respect to each other and their natural environment. In other words ecology is the study of the different types of  ecosystems.

ECOSYSTEM:
                    Biosphere is composed of smaller units called ecosystems. Ecosystem of a particular place includes all living and non living life forms including the natural habitat. It can be small or large in size. grassland, a multi-storeyed apartment, supermarkets, ocean(aquatic ecosystem),zoo,forest, etc. are all examples of ecosystems we find around us. 


                     In an ecosystem, there are various levels of organisation. The simplest form of ecosystem is an organism. Group of organisms form a population. Groups of population form a community. Different communities together makes an ecosystem.The place or the physical location where a community is present is called the habitat of the community.  


  
CLASSIFICATION OF ECO SYSTEM : 


                   An Eco system can be classified as follows:

  


STRUCTURE OF ECO SYSTEM:

ABIOTIC COMPONENTS:
                           The non living factors are called the abiotic component. They include the physical and chemical components. They are solar energy, water,CO2, temperature, humidity, pH, nitrogen, etc.


BIOTIC COMPONENTS:
                           The living components of the environment comprises the biotic components. Biotic components are classified as:

• PRODUCERS- These are the autotrophic organisms that are capable of photosynthesis. The are primarily the food producers.They make food for themselves and indirectly for other components directly or indirectly. Green plants are the primary producers. 
• CONSUMERS- They depend on producers for their food directly or indirectly. They are further classified as herbivores(feed only on plants), carnivores(feed only on animals) and omnivores(feed both on plants and animals). 
• DECOMPOSERS- They obtain food from the dead remains of other producers and consumers.They are very important to complete the food cycle.They include bacteria and fungi.

                  

                                The interactions between different components in the ecosystem happens through two processes:

1. Energy flow
2. Nutrient cycling

ENERGY FLOW:

                     Energy flow is an one-way process in an ecosystem. To the flow to persist there is a need of persistent input of energy into the system. Sun is the primary source of energy to most of the systems. Primary producers capture fracture of the sun's energy, convert it into chemical energy in the form of carbohydrates. Next the primary consumers and the secondary consumers derive energy when  the eat the tissues of producers containing carbohydrates.This process liberates heat as a by-product. This is an inefficient process as much of the energy is lost as heat.About 90%-95% of energy is lost during the transfer from to other. The food chain is one such example.Different food chain put together forms a food-web.

NUTRIENT CYCLING:

                              Nutrients are nothing but molecules required by living organisms. Eg. carbon, nitrogen, phosphorus,etc. Unlike energy the is no continuous supply of nutrients in any system, therefore there is a need to be used over and over again.Nutrients move through an ecosystem by the use of different biogeochemical  cycles( which includes biological, geological and chemical process).

                              Nutrients exist in either a reservoir or an exchange-pool. Reservoir is a store house of nutrients in an ecosystem. Nutrients here are not directly available to organisms. Examples are coral reefs, limestone, fossil fuels for carbon.

                              Exchange-pools are the place where nutrients are made available to the producers. Example-carbon in the form of carbon-di-oxide in the atmosphere. Nutrients released by decomposers get back into the exchange-pools.
                              One such example of a biogeochemical cycle is the carbon cycle.
CARBON CYCLE:

• Carbon is removed from the exchange pool by the producers through photosynthesis.
• Traverses through different tropic levels.
• Part of it is released back into the atmosphere by respiration and decomposition.
• Remaining part goes into the reservoir by carbonification.

                               This completes the carbon cycle. The below diagram depicts carbon cycle in detail.