Components of the Ecosystem
An ecosystem has two basic components
i) Abiotic components
ii) Biotic components
The relationship between the abiotic components and the biotic components of the ecosystem is termed 'holocoenosis'.
Those include the non-living or physico-chemical factors like air, soil, water and the basic compounds and elements of the environment.Abiotic factors are classified broadly under three categories: Climatic factors, including the climatic regime with physical factors in the environment such as light, atmospheric temperature, wind, humidity, etc; Edaphic factors, which relate to the composition and structure of the soil like its chemical and physical properties – like the soil type, soil profile, organic matter, minerals, soil water, and soil organisms. Inorganic substances like water, carbon, sulphur, nitrogen, phosphorus and so on. Organic substances like proteins, lipids, carbohydrates, humic substances etc.
It consists of the living parts of the environment, including the association of a lot of interrelated populations that belong to different species inhabiting a common environment. The populations are those of the animal community, the plant community and the microbial community. The biotic community is divided into autotrophs, saprotrophs and heterotrophs. Autotrophs (from Greek : auto - self, trophos - feeder) are called producers, transducers or convertors, as well. Those are photosynthetic plants, normallu chlorophyll bearing, which synthesize a high-energy complex organic compound ( or food) from the inorganic raw materials utilizing the aid of the sunt, and this process is called photosynthesis. Autortophs form the core of all biotic systems.
In terrestrial ecosystems, autotrophs are usually rooted plants. In the aquatic ecosystems, the floating plants referred to as phytoplankton and the shallow water rooted plants – macrophytes - are the main producers.
Heterotrophs (from Greek: heteros - other; trophs - feeder) are the consumers, normally animals that feed on the other organisms. Consumers are also referred to as phagotrophs (phago - to swallow or ingest) while macroconsumers are normally herbivores and carnivores. Herbivores are called First order or primary consumers, for they feed directly on green plants. For example, Terrestrial ecosystem consumers are cattle, deer, grass hopper, rabbit, etc. Aquatic ecosystem consumers are protozoans, crustaceans, etc.
Carnivores are animals that prey or feed on other animals. Second order consumers or Primary carnivores include those animals that feed on herbivorous animals. For example, fox, frog, smaller fishes, predatory birds, snakes, etc.
Third order consumers or Secondary carnivores are the animals that feed on primary carnivores. For example, wolf, owl, peacock, etc. Some larger carnivores prey on Secondary carnivores. Quaternary consumers or Tertiary carnivores include those animals which feed upon secondary carnivores. For example, the lion, the tiger, etc. Those are not eated by any other animal. The larger carnivores which cannot be preyed on further are also called the top carnivores.
Saprotrophs (from Greek again: sapros - rotten; trophos - feeder) are called the reducers or decomposers. They break the complex organic compounds in dead matter down (dead plants and animals). Decomposers don’t ingest the food. Instead they secrete a digestive enzyme into the dead, decaying plant or animal remains and digest this organic material. The enzymes act on the complex organic compounds in the dead matter. Decomposers absorb a bit of the decomposition products to provide themselves with nourishment. The remaining substance is added as minerals in the process of mineralisation to the substratum. Released minerals are utilised or reused as nutrients by plants - the producers.