(B) Abiotic components

These are the non - living components of an ecosystem. They are of two forms:
(i) Climatic. Temperature, humidity, precipitation, light etc.
(ii) Edaphic. Topography, pH, minerals, back-ground.

1. Temperature.
Maximum survival of organisms have been reported within a temperature range of 5⁰C - 35⁰C. However an exception always persists generally very high or very low temperature causes inactivity and death of an organism.
Poikilothermal animals/ ectothermal/Cold blooded animals. Animals which can regulate or maintain their functional with the varying external environment.

Homoeothermal / endothermal / warm blooded animals. Animals which cannot regulated themselves with the changing environment and are the most affected in case of any adverse condition. Some of the plant and animal adaptations to the varying temperature

High Temperature
Animal adaptations
(i) Aestivation - summer sleep
(ii) In maximum cases animals migrate to favourable region and then return to their homeland with the onset of favourable climate.
(iii) In desert, animals live in burrow during hot day and become active during-night (nocturnal), early morning (auroral), evening (vesperal)

2. Light.
Light is an important factor to determine the structure, growth and activities of organisms. For this the organisms possess photoreceptors. Light is essential for photosynthesis. Light intensity is greater at the equator than at the poles and hence maximum productivity lies in tropical forests and descends towards the poles. Light influences growth, increased light intensity produces short internodes, thick, small leaves, more mechanical tissue etc. reduction in intensity produces opposite effects.
Depending upon the particular period of the day animals are active at different intervals:
(i) Diurnal. Active during the day e.g. sparrow, crow, cattle, pigeon etc.
(ii) Noctrunal. Active during night e.g. owl, bat, cockroach
(iii) Auroral. Active at dawn only
(iv) Vesperalo. Active at dusk only e.g. Rabbit. Responding to light intensity some plants also show phototactic movements. In some cases even flowering is influenced by light.

3. Wind.
It affects ecosystem in many ways:
(i) Pollination
(ii) Dispersal of fruits, spores, seeds etc.
(iii) Increases transpiration
(iv) In dry areas wind causes soil erosion
(v) Areas frequented by unidirectional winds develop flag trees having branches on one side only.

4. Humidity.
It is amount of water vapours present in atmosphere. It controls, fog, dew, clouds etc. Epiphytes grow only in humid areas. Water lost through precipitation and transpiration is compensated by humidity.

5. Water.
No life can exist without water. Requirement of water varies from organism to organism and their distribution varies according to their needs e.g. xerophytes, Hydrophytes, Mesophytes. Actively swimming organisms can exist in rivers and streams while inactive ones live under stones or in burrow e.g. Neries. Animals with attaching devices survive in fast water e.g. Hydra. Plants found in fast flowing water have ribbon shaped leaves e.g. Laminaria.
Wave action affects organisms living in between high and low tide region (intertidal zone) as well as those that live in areas receiving breaking waves (spray zone). Deep sea organisms are consumers and do not possess air sac. Some of them are even luminescent.

6. pH.
There is a little change in pH is oceans. Terrestrial animals are also not much influenced by pH of soil. But distribution of land plants and soil organisms is determined by pH of soil. Snail and Earth worm do not occurs in acidic soils whereas Euglena and other flagellates are abundant. Animals having calcareous shells live in neutral medium.

7. Mineral Elements.
Availability and concentration of essential minerals control the distribution of microbes, plants and animals. Snail occurs in soil rich in calcium. Nitrogen fixing bacteria and cyanobacteria are abundant in nitrogen deficient soils. Areas having high salt content e.g. Dead Sea, Great Salt Lake are usually devoid of much vegetation. Salinity of ocean is removed by many animals though salt secreting glands.

8. Topography.
Also called surface configuration of an area and greatly influences the distribution of organisms. Topographical effects may be direct like - isolation, formation of new species. It also has indirect effects like temperature, air, pressure, light duration and intensity, rainfall, humidity etc. the centre and edge of a pond or a stream, top-side and under-side of a rock or a north and south face of a wall are generally inhabited by different species of organisms.

9. Background. Most animals have an adaptation to have colour pattern and general texture similar to the background where they operate and thus protect themselves by camouflaging e.g. lion and camel are sand - coloured. Most of jelly fishes, sea cucumbers are glassy, Chameleon can change its colour with the change in surroundings.