The ecosystem consists of two major components:
(1) Abiotic or Non-living components:
The abiotic component comprises of:
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Physical factors: These include the climatic or environmental conditions of a given region such as air, water, soil, light, temperature, relative humidity, pH etc.
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Inorganic substances: Includes water, carbon, nitrogen, sulphur, phosphorous, all of which are involved in cycling of materials in the ecosystem
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Organic substances: These include carbohydrates, proteins, lipids, humic substances etc. present either in the biomass or in the environment.
(2) Biotic or living components:
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Autotrophic component: This component of the ecosystem comprises of the green plants (producers or energy transducers) which convert the solar energy into chemical energy with the help of organic substances such as enzymes and inorganic substances such as water and carbon dioxide by means of a process called photosynthesis. The autotrophs fall under two main groups:
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Photoautotrophs: These contain the green photosynthetic pigment chlorophyll to transduct the solar energy. E.g. grasses, trees, algae, phytoplanktons, photosynthetic bacteria, cyanobacteria.
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Chemoautotrophs: These include organisms that obtain energy by oxidizing inorganic compounds. The sole source of carbon is carbon dioxide. E.g. Microorganisms such as Beggiatoa, sulphur bacteria etc.
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Heterotrophic component: Heterotrophic organisms are also called as consumers, as they consume the matter built up by the autotrophs (producers). Consumers are of two types:
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Macroconsumers: Depending on their food habits, consumers can either be herbivores (plant eating) or carnivores (flesh eating).
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Herbivores: They are also known as Primary consumers and feed on green plants. E.g. insects, zooplanktons and animals such as cattle, deer, elephants etc.
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Secondary and Tertiary consumers: They are carnivores or omnivores. The secondary consumers are the carnivores which feed on herbivores. E.g. Insects like praying mantis, spiders, dragon flies and higher animals like lion, tiger, wolf, leopard etc.
Depending on their food habits, carnivores are recognized as carnivore of order-1 (C1), carnivore of order-2 (C2) and so on.
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Microconsumers: These include decomposers, reducers, saprotrophs, detritivores and scavengers which breakdown the dead complex organic matter into inorganic nutrients, thereby making them available for the autotrophs.
These include microorganisms such as bacteria, fungi and actinomycetes. They also include invertebrates such as protozoa and oligochaeta such as earthworms.
