Menu Bar

Like Box

Total Pageviews

My Pages On Different Subjects which Hyperlinked to all my Blog Posts

Friday, 27 April 2012

Ecosystem & Food Web : Biological Relationship among the Organisms in terms of Food

3D Picture Of Forest Ecosystem

A community and its physical and chemical environment. An ecosystem has living (biotic) and nonliving (abiotic) components.Soils , temperatures, rainfall , even organic matter are examples of Abiotic component.The classes of organisms detailed above from the biotic component.

3D Picture of Marine Ecosystem

The " Self Feeding" (auto trophic) organisms which include most plants and some micro-organisms.The producer synthesize their own organic compounds from simple inorganic substances with the aid of energy from the Sun (Photosynthetic autotrophs) or from the inorganic substances themselves (chemo synthetic auto trophs).

Picture of Photosynthetic Green Plants (Producers)
Plant Leaf produces Oxygen and Glucose by taking Sunlight, Water and Carbon-di-oxide through Photosynthesis

All organisms that are " not self feeding" (heterotrophic) and that ingest other (usually) living organisms in whole or in part obtain organic nutrients.Thus the consumers called herbivores eat plants, carnivores eat animals and parasites take blood sap, and other tissues from living hosts.

Lion : Top Consumer(Carnivore)  Of African Forest
Cheetah : Consumer (Carnivore) After Lion In the African Forest
Deers: Secondery Consumers (Herbivore) In the Forest

Mostly heterotrophic bacteria and fungi that obtain organic nutrients by breaking down the remains or products of organisms. The activity of decomposers allows simple compounds to be recycled back to autotrophs.


Each system runs on the energy of sun.Plants and other photosynthetic autotrophs, which are the most common "Self feeder," capture sunlight energy and convert it to forms they can use to synthesize organic compounds from from simple inorganic substances. By doing so, autotrophs secure the energy used by the entire system.

Energy stored in their self-assembled organic compounds is transferred through a number of heterotrophs before being lost as heat to the surroundings.The heterotrphs, recall include consumers (herbivore, carnivores, scavengers, and parasites), decomposers (bacteria and fungi that degrade organic remains or products), and detritivores (invertebrates thatfeed on partially decomposed particles of organic matter). In addition, autotrophs secure nutrients for the entire system.

Elephants: Top Herbivores in the forest

During growth, they take up water and carbon-di-oxide (as sources of hydrogen, carbon and hydrogen) along with dissolved minerals, including ionized forms of nitrogen and phosphorus. Such nutrients are essential for the synthesis of carbohydrates,lipids proteins and nucleic acids--- which autotrophs as well as heterotrophs use in biosynthesis and other cell activities.

Autotrophs and Heterotrophs

When decomposers and detritivores get their turn at this organic matter,they break it down completely to inorganic bits.If those bits are not washed away or otherwise removed from system, they can be used again as nutrients by the autotrophs. What we have just described in broad outline is an ecosystem, which includes all those organisms in a defined region as well as their physical environment.

Trophic Levels:

Trophic Levels Within Different Animals of Different Ecosystem

For all ecosystem, the feeding relationships among its component members are structured in much the same way.Each member fits into a hierarchy of energy transfer called trophic levels (from troph, meaning nourishment). "Who eats whom?",we can ask.When organism B eats A, energy is transferred from A to B. All organisms that are the same number of transfer steps away from the energy input into an ecosystem are said to be at the same trophic level.

Food Web & Food Pyramid:

Food Web and Chain Within Arctic Marine Animals, Sea-shore Birds (Penguin Sea-Gull)

Food Web:
The general sequence of who eats whom is sometimes called a food chain. However, the term implies a simple, isolated relationship that seldom occurs in ecosystems.More typically, the  same food resource is at one of the low trophic levels.Such interconnected feeding relationships take the form of food webs.To gain insight into the difference between a food web and a food chain, think about a fishermen netting some fish that were feeding an algae near the ocean`s surface.Come lunchtime, he cooks some of his catch.Should he later slip on the deck and fall into the water, where others carnivores lurk, the "chain" might be portrayed as:
       Algae-----> Fish------->Fisherman---------->Shark.

This chain would be oversimplification of feeding relationships, however for it exclude a number of alternatives.Most likely crustaceans also were grazing on the algae.Small squid and assorted medium sizedfishes might have been feeding on the  crustaceans; some larger fishes were probably feeding on smaller ones.Sharks may heve been moving into feed on the large and medium sized fishes.The fisherman might have cooked his fish in wine and herbs, shifting back and forth between herbivore and carnivore.He would have been even more omnivorous in consuming the alcoholic product of decomposers (Yeasts whose fermentation activities yield wine from crushed grapes).

Primary Productivity among the Different Ecosystems

Primary Productivity:
In terrestrial ecosystems, plants capture solar energy and convert it to the chemical energy of organic compounds. The rate at which those primary producers capture and store a given amount of energy in a given interval is called the ecosystem`s
primary productivity.

The gross primary productivity is the total rate of photosynthesis for the ecosystem during a specified interval.

The net primary productivity is the rate of energy storage in plant tissues in excess of the rate of respiration by the plants themselves.

The net community productivity is the rate of energy storage in excess of heterotrophic consumption.

Energy Flow:
1) Energy flows into ecosystems from an outside source (The sun, in most cases).

2) Energy flows through ecosystems by way of grazing food webs (based on the consumption of living tissues of photosynthesizes) and detrital food webs (based on the use of organic waste products and remains of photosynthesizes and consumers).

3) Energy leaves ecosystems through heat losses from each organism.

Ecological Pyramid:

Ecological Pyramid or Food Pyramid

The trophic structure of an ecosystem is influenced by the different numbers and sizes of its component organisms, their different metabolic rates,and the amount of energy lost at each transfer.often the trophic structure is diagrammed as one or another type of "Ecological pyramids," in which producers form a base for successive tiers of consumer above them.

Pyramids of Numbers:  A pyramids of number is based on an actual "head count" of all the individuals in an ecosystem. The lowest tier represents the food production base for higher trophic levels of a bluegrass field.

Pyramids of Biomass:  Weighing the individuals at each trophic level instead of counting them allows us to construct the pyramid of biomass (the total dry weight of all the organisms at a given level).

Pyramid of Energy:  A pyramid of energy represents energy losses at each transfer to another trophic level in an ecosystem.It is probably the most informative way to potray the functional roles of trophic levels.

No comments:

Post a Comment


My Animated 3D Clips

http___makeagifcom_media_1-25-2013_yjncdu_zpsf08430e5.gif http___makeagifcom_media_1-25-2013_dcZIsS_zps45443cec.gif http___makeagifcom_media_1-26-2013_yzv3o4_zpsc6d6967d.gif http___makeagifcom_media_1-26-2013_ILE5z7_zps464ce4a1.gif