Dr. Vidhin Kamble Dept. of Zoology. Sangola College, Sangola

09 December 2020

Temperature as Abiotic component of Environment

 

Abiotic factor/ components of ecosystem

Temperature as ecological/ abiotic factor of environment

Explain the temperature as ecological / abiotic/ physical factor of environment.

The physical or abiotic factors such as temperature, light, soil, water, PH, atmospheric gases etc are much important which influences  various activities of biotic components (Plants and animals)

Temperature is most familiar environmental abiotic factor having multisided effect on plants and animal.  Temperature regulates all chemical process of metabolism and much physical process. It controls feeding, respiration, growth, survival, reproduction, migration, geographical distribution of plants and animals.

1.     Variation in temperature

The range of temperature variation in different environment is different such as fresh water, marine water, terrestrial environment varies vary greatly.  There is variation in temperature during day and night is called as diurnal variation.

2.     Range of temperature tolerance

Whatever necessary metabolic process are occurs in plants and are always in certain limit of temperature range.  The metabolic processes for life begins at certain minimum temperature and increases with increases temperature until it reaches the maximum level of temperature, which is called as optimum temperature.

The temperature at which the organism can live in an active state is termed as minimum survival temperature.

The temperature at which the physiological processes or activities of animals and plants are maximum is called optimum temperature.

The maximum temperature at which rate of reaction stops is called maximum temperature.

On the basis of temperature regulation animals are classified as Homoeothermic and poikilothermic  All animals are classified into two groups.

1.     Cold blooded animal

2.     Warm blooded animal

The cold blooded animals are also called as poikilothermic.  These includes fishes, amphibians and  reptiles. In  poikilotherms are the animal which body temperature changes according to the environment

 Eg. Body temperature of fishes will be same as that of water in which they found.

Warm blooded animals are also called as homiothermic animals.  These animals are able to maintain their constant body temperature. 

Eg. In human being body temperature at constant level at 37 0C.

Effect of temperature on plants and animals

Temperature plays an important role in shaping the structure and guiding physiological process, behavior, distribution of plants and animals.

Effect of temperature on biotic factor of organisms are as follows.

a.      Effect on metabolism

b.     Effect on cell

c.      Effect on development

d.     Effect on reproduction

e.      Effect on development

f.       Effect on sex ratio

g.     Effect on growth

h.     Effect on crossing over

i.       Effect on coloration

j.       Effect on distribution

k.     Migration

 

a.     Effect of temperature on metabolism:

In every organism metabolic activities are regulated by different enzymes.  The activity of enzymes are influenced by temperature.  The activities of enzymes increase with increase in temperature but at certain temperature activity is stops.  For ex. activity of arginase enzyme is found increase gradually with the increase in temperature from 170 C to 480 C. but beyond 480 C and below 170 C  the enzyme activity decrease rapidly .

Optimum Temperature

 


Minimum Temperature

 


 

 Graph: Showing effect of temperature on physiological activities of animal

Effect of temperature on Cell:

The minimum and maximum temperatures have adverse effect on the cells.  At very low temperature cell protein get destroyed.  While at higher temperature coagulation of protein is takes place in the cell.

Effect of temperature on Reproduction:

Temperature plays an important role in the maturation of gonads, gametogenesi and release of gametes. As compare to colder region maximum reproductive activities are observed in tropical areas. 

Eg. In Blow fly the number of laying increases with increase in temperature up to 32.50C.

Effect of temperature on Development:

Temperature influence the speed and success of development of plants and animals.  For the development certain limit of temperature is required. 

Eg. In Ground beetle Plerostichus oblongpunctatus  entire development from egg to mature beetle at 150 C takes 82 days.  while at 250 C it takes 45 days for the complete development.

 

Effect of temperature on growth:

The growth rates of different animals and plants are also influenced by temperature. 

Eg. In Oyster the length of body increases from 1.4 to 10.3 mm when temperature is increased from 10 0c to 20 0 c. Corals are also do not flourish well when water temperature drops below 21 0 c.

In plants lower and higher temperature have adverse effect. Low temperature cause cold injury while extremely high temperature causing and finally death of plant is occur called as heat injury.

Effect of temperature on sex ratio:

In some species environmental temperature determines sex ratio. 

Eg. In Copepod Macrocyclopes albidus number of male significantly increases with increase in temperature. 

Effect of temperature on Colouration:

Temperature influenced on body color and color pattern in animal. In warm and humid climate, many animals like insects, birds and mammals have shows darker color or pigmentation than the races of same species found in cool and dry climate.  This phenomenon is known as Gloger’s rule. In Hyla (Tree frog), Phrynosoma low temperature causes dark pigmentation (Coloration).

Effect of temperature on Crossing over:

Crossing over and somatic expression of gene character  influenced by lower and higher temperature in some animals.

Eg. In drosophila the development of wing, eyes and other characters are influenced when larvae and pupae are exposed to low or higher temperature.

Effect of temperature on animal Distribution:

For the distribution and survival of animal,  range of  favorable temperature  is very much important.  Temperature influences the distribution of animals and plants. 

Eg. Coral reef requires minimum temperature of 210 c for their survival and existence.  The coral reefs are completely absent in colder region oceans

Rotifers found in ponds when temperature is below 240 c and disappear when temperature increases above 240c.

Thermal adaptations due to temperature

Animals and plants during the course of time develops several methods to overcome harmful effect of extreme temperature.  Which are as follows.

1.        Formation of heat resistant spores, cysts, seeds coat. etc.

2.        Dormancy (It includes hibernation (Winter sleep) Aestivation (Summer sleep)

3.        Thermal migration

Formation of heat resistant spores, cysts, seeds etc.

To withstand at higher temperature some animals and plants produces heat resistant cysts, eggs, pupae seeds spores etc which can tolerate extremes environmental temperature.

Dormancy

To avoid extreme hot and cold temperature animals and plants have develops certain adaptations Called dormancy.

Or

 For certain period plants and animals are remain in inactive state which is called as dormancy.

Some animals pass winter in dormant condition is called winter sleep or hibernation.

Dormancy of animal during summer is called summer sleep or Aestivation.  Eg. Some invertebrates, lung fishes, amphibians some mammals and plants.

Thermal migration: To avoid extreme condition of environment (High temperature and cold) some animals moves from one place to another place is called as Thermal Migration.

 

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