Short essay on the Structure and Function of Ecosystem

Structure and function, are the two major aspects of an ecosystem. In all ecosystems, living organisms interact with the non-living substances to produce an exchange of materials.

Structure Means

(i) The composition of biological community including distribution in space sped number, biomass and life history etc.

(ii) The distribution and quantity of non-living materials.

(iii) Gradient of conditions of existence.

Function Means

(i) The rate of biological energy flow.

(ii) Rate of material or nutrient cycles and

(iii) Regulation of environment by the organism and regulation of organisms by environment.

Structure of Ecosystem

An ecosystem has two major components:

(a) Abiotic Component

1. Components, those are non-living are called abiotic components.

2. They have a strong influence on the structure, distribution, behaviour and interrelationship of organisms.

Abiotic components are mainly of two types:

(i) Climatic factors: which include rain, temperature, light, wind, humidity pH, organic inorganic components, minerals etc?

(ii) Edaphic factors: Which includes pH, organic, inorganic components, minerals etc?

(b) Biotic Component

1. The living organisms including plants, animals and microorganisms (Bacteria and fungi)! that are present in an ecosystem form the biotic components.

2. On the basis of their role in the ecosystem the biotic component can be classified into three main groups.

(i) Producers

(ii) Consumers

(iii) Decomposers or Reducers

(i) Producers:

1. Autotrophic plants are main producers.

2. These are capable of synthesize food from non-living components.

3. In this chemosynthesis bacteria also included.

4. As the green plants manufacture their own food they are known as Autotrophs.

(ii) Consumers

1. The animals lack chlorophyll and are unable to synthesise their own food.

2. Therefore, they depend on the producer, for their food. They are known as heterotrophs. The consumer’s are of four types, namely:

(a) Primary Consumers (Herbivores)

1. These are the animals, which feed on plants or the producers. They are called herbivores. Examples: Rabbit, dear, goat, cattle, grasshopper etc.

(b) Secondary Consumers or Primary Carnivores

2. The animals, which feed on the herbivores, are called the primary carnivores. Examples: Cats, dogs, fox, snakes etc.

(c) Tertiary Consumers or Secondary Carnivores

1. These are the large carnivores which feed on the secondary consumers. Examples: Wolves.

(d) Quaternary Consumers or Omnivores

2. These are the largest carnivores, which feed on the tertiary consumers and are not eaten up by any other animal.

Examples: Lions and tigers.

(iii) Decomposers or Reducers

1. Bacteria and fungi belong to this category. They breakdown the dead organic materials of producers and Consumers for their food and release to the environment the simple inorganic and organic substances product as byproducts of their metabolisms

2. The producers resulting in a cycling exchange of materials between the biotic community and the abiotic environment of the ecosystem reuse these simple substances.

3. The decomposers are known as saprophytes.

On the nourishment standpoint, biotic components may be divided into two groups:

1. Autotrophic Components or Producers

The producers, which are mainly autotrophic green plants and certain photosynthetic or chemosynthetic bacteria, which can convert the light energy of sun into potential chemical energy in the form of organic compounds, needed by plant for their development.

Thus producers stand as intermediaries between the inorganic and organic world. They obtain C0₂ from the atmosphere and release 0₂ instead. About 99 percent of living mantle of earth is a producer. They produce oxygen as a byproduct of photosynthesis, needed by all living organisms for respiration.

2. Heterotroph Components or Consumers

These are mainly animals, including man, which have an intake of organic material as food, which is provided in the first instance by autotrophs. In heterotrophic components, utilisation, rearrangement and decomposition of complex materials predominate. The consumers are further subdivided into two groups:

(A) Macroconsumers:

These consist of relatively larger consumers. They all phagotrophs which include chiefly animals that ingest other organic and particulate organic they are of two types:

(i) Herbivores:

They are primary consumers and feed on the plants. Depending upo nature of plant part eaten by them, they can be of different types like root f’ sucking animals, bark feeders and eaters etc. They may be large cattle, goats etc.

(ii) Carnivores:

They are secondary and tertiary consumers. They feed on flesh of animals. The carnivores, which feed on secondary consumers, are known as consumers and so on. The carnivores, which are not further preyed upon are c top carnivores, e.g., tiger.

(B) Micro Consumers:

These are minute to small and microscopic animals. They three types:

(i) Parasites:

A parasite is an organism that lives on or in the body of another deriving benefit at the expense of the latter. The organism, which harbours the is called the “host.” The parasite is always benefitted in this association and then injured or harmed.

(ii) Detervores and scavengers:

Detervores like earthworms feed on organic whereas, scavengers like vultures feed on dead bodies.

(iii) Decomposers:

These are saprotrophs and include chiefly bacteria, actinomycetes fungi.