Biotic And Abiotic Factors Organisation or Structural aspect

Biotic And Abiotic Factors

Organisation or Structural aspect of an ecosystem) An ecosystem comprises of two basic components • ii) Biotic • i) Abiotic components

The relationship between the biotic components And abiotic components of an ecosystem is called 'holocoenosis'.

• Abiotic Components • These include the non-living, physico - chemical factors such as air, water, soil and the basic elements and compounds of the environment.

Abiotic factors are broadly classified under three categories. 1) Climatic factors which include the climatic regime 2) Physical factors , light, temperature, wind, etc. 3) Edaphic factors which are related to the structure and composition of soil including its physical and chemical properties, like soil and its types, soil profile, minerals, organic matter, soil water, soil organisms. Inorganic substances like water, carbon, sulphur, nitrogen, phosphorus and so on. Organic substances like proteins, lipids, carbohydrates, humic substances etc.

physical factors of the environment like Light Temperature

Biotic Components It comprises the living part of the environment, which includes the association of a number of interrelated populations belonging to different species in a common environment. The populations : one species Community, diff. living organisms, Animals, plant and microbial.

• Biotic community is distinguished into: 1)Autotrophs, (Plants) 2) heterotrophs and (Animals) 3) Saprotrophs (Decomposers)

• In aquatic ecosystems, a- floating plants called phytoplankton and shallow water macrophytes rooted are plants the called dominant producers. b- Consumers like protozoans, crustaceans, etc.

Autotrophs: (Gr: auto - self, trophos transducers. - feeder) are also called producers, convertors or # These are photosynthetic plants, generally chlorophyll bearing, which synthesize high-energy complex organic compounds (food) from inorganic raw materials with the help of sunlight, and the process is referred as photosynthesis. Autortophs form the basis of any biotic system.

Heterotrophs (Gr: heteros - other; trophs - feeder) are called consumers

In terrestrial ecosystems Autotrophs are mainly the rooted plants, Consumer's also referred as phagotrophs (phago - to ingest or swallow) or macroconsumers are mainly herbivores and carnivores. Herbivores are referred as First order consumers or primary consumers, as they feed directly on plants. • For e. g. , Terrestrial ecosystem consumers like cattle, deer, rabbit, grass hopper, etc. Carnivores are animals, which feed or prey upon other animals

• Primary carnivores or Second order consumers include the animals which feed on the herbivorous animals. (e. g. , fox, frog, predatory birds, smaller fishes, snakes, etc. ) • Secondary carnivores or Third order consumers include the animals, which feed on the primary carnivores. (e. g. , wolf, peacock, owl, etc. ) • Tertiary carnivores or Quaternary consumers include the animals, which feed on the secondary carnivores. (e. g. , lion, tiger, etc. ) Top Carnivores, are not eaten by any other animals.

Saprotrophs • • (Gr: sapros - rotten; • trophos - feeder) • are also called Decomposers or reducers. • They break down the complex • organic compounds of dead matter (of plants and animals). to the substratum (mineralisation). •

Decomposers do not ingest their food. Instead they secrete digestive enzymes into the dead and decaying plant and animal remains to digest the organic material. Enzymes act upon the complex organic compounds of the dead matter. Decomposers absorb a part of the decomposition products for their own nourishment. The remaining substances are added as minerals (producers).

“Big question” Discuss to what extent do the transfer of energy through the food chain fulfill the laws of thermodynamics ?