Question

Describe the components of an ecosystem.

Answer 1

An ecosystem has two types of components, biotic and abiotic.
Biotic Components. They are living organisms found in an ecosystem. Biotic components are of five types - producers, consumers, detrivores, decomposers and parasites.
(i) Producers. They are autotrophs which synthesize organic food from inorganic nutrients with the help of solar energy. The process is called photosynthesis. Solar energy is changed into chemical energy of food.
(ii) Consumers. They are animals which feed on other oranisms. Herbivores feed on plants. Carnivores prey upon other animals. Depending upon trophic level they are called primary carnivores (second order consumers), secondary carnivores (third order consumers) and top carnivores which are not preyed upon by others.
(iii) Detrivores. They feed on detritus causing its fragmentation and pulverisation, e.g., Earthworm, Vulture.
(iv) Decomposers. They are saprophytes which pour digestive enzymes over the organic matter for its solubilisation. It results in humification and mineralisation of organic matter.
(v) Parasites. They belong to different groups which obtain food from other living organisms called hosts.
Abiotic Components. They include climate, edaphic and topographic factors.
1. Temperature. There are four temperature zones - tropical, subtropical, temperate and arctic or alpine. Different types of organisms occur in different zones.
2. Light. Photosynthesis depends upon the availability of light which is maximum in tropical areas and decreases progressively towards poles. Plants growing under shade of large trees show less photosynthetic activity. In the form of photoperiods, light influences a number of activities including flowering, leaf fall, migration and breeding in many animals.
3. Wind. It influences transpiration, pollination, dissemination, tree growth and flight animals.
4. Humidity. It Influences luxuriance of biota.
5. Precipitation. Amount and periodicity of rainfall control forest type of the area. Water availability and humidity also depend upon rainfall.
6. Water. Depending upon its availability, plants are xerophytes, mesophytes, hydrophytes and hygrophytes.
7. Background. Most animals have colour, pattern and texture similar to background.
8. Topography. Topography or surface behaviour of earth influences other abiotic factors.
9. Gases. $CO$, concentration determines the rale of photosynthesis and warmth of the atmosphere. Oxygen concentration is supra optimum for $C_3$ plants and optimum for $C$, plants.
10. Soil. It determines vegetation growth and pattern.
11. $pH$. Tree growth is favoured by slightly acidic $pH$. Earthworms do not occur in acidic soils. Euglena and other flagellates are abundant.
12. Mineral Elements. Both excess and deficiency of minerals are harmful to biota. Optimum mineral elements are required for optimum growth.