ECOSYSTEM (COMPONENTS, SIZE AND TYPES OF ECOSYSTEM).

F.Y.B.A. (ENG)                                                   

SEM : 1                                                               

MDC 101 - A                                            

ECOSYSTEM

 

A complex, interrelated system of living species and their physical environment is referred to as an ecosystem. It includes species' relationships, their habitats, and the numerous biotic (living) and abiotic (non-living) factors that influence their existence. Plants, animals, and people all cohabit with a wide variety of other plants and creatures. 

These organism communities are more than just irregular collections of individuals or populations; they are a highly organised, dynamic, and sophisticated organisation. Technically, such complex natural organisations with their living and non-living environments that control them and supply food to living organisms are referred to as a "ecosystem" or a "ecological system."

Sir Arthur Tansley

The relationship between living beings and their environment is a two-way street, organisms affect and are affected by their surroundings. Professor Arthur Tansley, a British botanist, introduced the word ecosystem in 1935 and defined it as the "system resulting from the integration of all living and non-living factors of the environment."

The concept of this interacting system has proven tremendously useful, and the ecosystem is now considered as a fundamental unit for ecological research.

Components of Ecosystem.

The components of the ecosystem can be categorised into abiotic or non-living and biotic or living components;

Abiotic components

The non-living elements of an ecosystem or environment are referred to as abiotic components or abiotic factors. These elements are critical in shaping and affecting ecosystem abilities and activities. Abiotic factors are physical and chemical factors that can have an impact on the living creatures in an environment.

The important abiotic components are

      a)Energy : Basically, sunlight is required for life to exist. In the case of plants, the sun provides all of the necessary energy. Because animals cannot directly consume sun energy, they receive it indirectly by consuming plants, animals, or both. The distribution-prganisms in the environment are determined by energy.

       b)Materials: (a) organic compounds such as proteins, carbohydrates, lipids, and humic substances that are produced from inorganic material and then decomposed into them.

      (b) inorganic compounds - oxygen, nitrogen, carbon, carbon dioxide, water, sulphur, nitrates, phosphates, and different ions are required for life to survive.

      c) Climatic factors: light, heat, temperature, wind, humidity, rainfall, snowfall etc.

      d) Edaphic factors (structure and composition of soil along with its physical and chemical characteristics) : also exert significant influence on the organisms.

Biotic components 

Biotic components include living organisms comprising plants, animals and decomposers and are classified according to their functional attributes into producers and consumers. Biotic components, also known as biotic factors, are the living organisms and the interactions among them within an ecosystem.

These living organisms play a vital role in shaping and influencing the characteristics and dynamics of their environment.

      a)  Producers (Plants)

   Autotrophs (self-sustaining) are green plants that create carbohydrates from simple inorganic raw materials such as carbon dioxide and water in the presence of sunshine for themselves and, indirectly, for other non-producers. Producers in terrestrial ecosystems are primarily herbaceous and woody plants, whereas producers in marine and fresh water ecosystems are numerous species of microscopic algae. Chemosynthetic bacteria produce as well. However, unlike plants, which are the primary producers, these bacteria, which are found in deep ocean trenches where sunlight is rare, receive energy from hydrogen sulphide seeping through breaks in the sea floor through the process of chemosynthesis.

      b) Consumers (Animals)

      

    Heterotrophs(other nourishing) are incapable of photosynthesis and depend on organic food derived from animals, plants or both.

      

Consumers can be divided into two broad groups namely macro and micro consumers.

(i)              Macro consumers

          Macro consumers or Phagotrophs feed on plants or animals or both and are categorised on the basis of their food' sources.

Herbivores are primary consumers which feed mainly on plants e.g. cow, rabbit.

Carnivores feed only on animals. Secondary consumers feed on primary consumers e.g. wolves. 

            

Carnivores which feed on secondary consumers are called Tertiary consumers e.g. lions which can eat wolves. 

            

Organisms which consume both plants and animals are called Omnivores e.g. men.

            

OMNIVORES

(ii)            Micro consumer

            Decomposer (Micro-organisms)

        Saprotrophs (decomposers) are chiefly bacteria and fungi which obtain energy and nutrients by decomposing dead organic substances (detritus) of plant and animal origin. Some of the products of decomposition such as inorganic nutrients released in the ecosystem are reused by producers and thus recycled. 

Earthworm and certain soil organisms such as Nematodes. 

            

 

Arthropods are also detritus feeders and help in the decomposition of organic matter.

            

 

Size of Ecosystem.

An ecosystem can be as little and basic as a cow dung or as complicated and huge as an ocean or the biosphere itself, with a diverse range of species. It's worth noting that ecosystems can exist within ecosystems. For instance, a cow dung ecosystem may be contained within a forest ecosystem, which is contained within the biosphere.

In some circumstances, such as a pond ecosystem, the boundaries are clear. There are no distinct boundaries in forests, meadows, or deserts. These habitats are frequently separated from neighbouring ecosystems by a transition zone or a diffused boundary zone known as an ecotone. In the ecotone zone, organisms from nearby habitats mix; as a result, they may have a larger diversity of species than the neighbouring ecosystems.

 

Types of Ecosystem.

 

 

Ecosystems can also be grouped into two categories, namely natural and artificial or manmade as shown below:

A natural ecosystem has a diverse amount of species and plants, whereas artificial ecosystems are limited. Natural ecosystems are self-sustaining and result from spontaneous natural reaction, while artificial ecosystems require the assistance of humans.

Basically  Natural ecosystems are of two types : terrestrial and aquatic. If you travel from plains to the mountains in the Himalayas, you notice significant changes in the landscape. Deserts, grasslands, crop fields, forests and glaciers represent different terrestrial ecosystems. Oceans, estuaries, mangroves, coastal marshes, rivers, lakes, ponds and swamps are examples of aquatic ecosystem.

Natural ecosystems are those which are mostly free from human disturbances, such as tropical forests, grasslands, oceans, lakes and deserts

Artificial or man-modified ecosystems are formed as a result of human modification of the natural ecosystems. For example, man has transformed natural forests and grasslands into crop fields. An extreme example of an artificial ecosystem is a city. Increasing human interference has destroyed many natural ecosystems and replaced them with artificial ecosystems,'such as crop fields, urban centres and industrial estates.