Ecosystem PPT Biology Class 12

 Page 1


ECOSYSTEM
Page 2


ECOSYSTEM
ECOSYSTEMS
? The interaction between the living organism and the non-living  
environment is called ecosystem.
? ECOSYSTEM –STUCTURE AND FUNCTION:
? Interaction of biotic and abiotic components results in a physical  
structure that is characteristic of each type of ecosystem.
? Identification and description of plant and animal species of an  
ecosystem gives its species composition.
? V ertical distribution of different species occupying different levels is
called stratification.
? The components of the ecosystem are seen to function as a unit:
? Productivity.
? Decomposition.
? Energy flow and
? Nutrient cycle
Page 3


ECOSYSTEM
ECOSYSTEMS
? The interaction between the living organism and the non-living  
environment is called ecosystem.
? ECOSYSTEM –STUCTURE AND FUNCTION:
? Interaction of biotic and abiotic components results in a physical  
structure that is characteristic of each type of ecosystem.
? Identification and description of plant and animal species of an  
ecosystem gives its species composition.
? V ertical distribution of different species occupying different levels is
called stratification.
? The components of the ecosystem are seen to function as a unit:
? Productivity.
? Decomposition.
? Energy flow and
? Nutrient cycle
? Description of pond as an ecosystem:
? The abiotic components include all dissolved inorganic and organic substances and  
the rich soil deposit at the bottom of the pond.
? The solar input, cycle of temperature, day length, regulates the rater of function of  
the entire pond.
?       
         
? The consumers are represented by zooplankton, free swimming and bottom  
dwelling animals.
? The decomposers are the fungi, bacteria especially abundant at the bottom of the  
pond.
? Basic events (in terms of function) in an ecosystem:
? Conversion of inorganic into organic material (photosynthesis) by producers.
? Consumption of the autotrophs by heterotrophs.
? Decomposition and mineralization of the dead organic matter to release them back  
for reuse by the autotrophs
? There is unidirectional flow of energy towards the higher trophic levels and its  
dissipation and loss as heat to the environment.
Page 4


ECOSYSTEM
ECOSYSTEMS
? The interaction between the living organism and the non-living  
environment is called ecosystem.
? ECOSYSTEM –STUCTURE AND FUNCTION:
? Interaction of biotic and abiotic components results in a physical  
structure that is characteristic of each type of ecosystem.
? Identification and description of plant and animal species of an  
ecosystem gives its species composition.
? V ertical distribution of different species occupying different levels is
called stratification.
? The components of the ecosystem are seen to function as a unit:
? Productivity.
? Decomposition.
? Energy flow and
? Nutrient cycle
? Description of pond as an ecosystem:
? The abiotic components include all dissolved inorganic and organic substances and  
the rich soil deposit at the bottom of the pond.
? The solar input, cycle of temperature, day length, regulates the rater of function of  
the entire pond.
?       
         
? The consumers are represented by zooplankton, free swimming and bottom  
dwelling animals.
? The decomposers are the fungi, bacteria especially abundant at the bottom of the  
pond.
? Basic events (in terms of function) in an ecosystem:
? Conversion of inorganic into organic material (photosynthesis) by producers.
? Consumption of the autotrophs by heterotrophs.
? Decomposition and mineralization of the dead organic matter to release them back  
for reuse by the autotrophs
? There is unidirectional flow of energy towards the higher trophic levels and its  
dissipation and loss as heat to the environment.
PRODUCTIVITY:
? Primary productivity:
? The amount of biomass or organic matter produced per unit area over a time period by plants  
during photosynthesis.
? It is expressed in terms of weight (g-2) or energy (kcal m-2)
? The rate of biomass production is called productivity.
? Gross primary productivity: (GPP) is the rate of production of organic matter during  
photosynthesis.
? Net primary productivity:
? A considerable amount of energy is utilized by plants in respiration.
? Gross primary productivity minus respiration losses (R) is the net primary productivity.
? GPP – R = NPP .
? Net primary productivity is the available biomass for the consumption to heterotrophs  
(herbivore and decomposers.
? Secondary productivity: is defined as the rate of formation of new organic matter by the
consumer.
Page 5


ECOSYSTEM
ECOSYSTEMS
? The interaction between the living organism and the non-living  
environment is called ecosystem.
? ECOSYSTEM –STUCTURE AND FUNCTION:
? Interaction of biotic and abiotic components results in a physical  
structure that is characteristic of each type of ecosystem.
? Identification and description of plant and animal species of an  
ecosystem gives its species composition.
? V ertical distribution of different species occupying different levels is
called stratification.
? The components of the ecosystem are seen to function as a unit:
? Productivity.
? Decomposition.
? Energy flow and
? Nutrient cycle
? Description of pond as an ecosystem:
? The abiotic components include all dissolved inorganic and organic substances and  
the rich soil deposit at the bottom of the pond.
? The solar input, cycle of temperature, day length, regulates the rater of function of  
the entire pond.
?       
         
? The consumers are represented by zooplankton, free swimming and bottom  
dwelling animals.
? The decomposers are the fungi, bacteria especially abundant at the bottom of the  
pond.
? Basic events (in terms of function) in an ecosystem:
? Conversion of inorganic into organic material (photosynthesis) by producers.
? Consumption of the autotrophs by heterotrophs.
? Decomposition and mineralization of the dead organic matter to release them back  
for reuse by the autotrophs
? There is unidirectional flow of energy towards the higher trophic levels and its  
dissipation and loss as heat to the environment.
PRODUCTIVITY:
? Primary productivity:
? The amount of biomass or organic matter produced per unit area over a time period by plants  
during photosynthesis.
? It is expressed in terms of weight (g-2) or energy (kcal m-2)
? The rate of biomass production is called productivity.
? Gross primary productivity: (GPP) is the rate of production of organic matter during  
photosynthesis.
? Net primary productivity:
? A considerable amount of energy is utilized by plants in respiration.
? Gross primary productivity minus respiration losses (R) is the net primary productivity.
? GPP – R = NPP .
? Net primary productivity is the available biomass for the consumption to heterotrophs  
(herbivore and decomposers.
? Secondary productivity: is defined as the rate of formation of new organic matter by the
consumer.
DECOMPOSITION:
? Earthworm is said to be ‘friends’ of farmer:
? Breakdown the complex organic matter.
? Loosening of the soil helps in aeration and entry of root.
? The decomposers break down complex organic matter into inorganic substances like  
carbon dioxide, water and nutrients, called decomposition.
? Dead plant remains such as leaves, bark, flowers and dead remains of animals,  
including fecal matter, constitute the detritus.
? The process of decomposition completed in following steps:
? Fragmentation : Break down of detritus into smaller particles by detritivore  
(earthworm).
? Leaching: Water soluble inorganic nutrients go down into the soil horizon and get  
precipitated as unavailable salts.
? Catabolism : Bacterial and fungal enzymes degrade detritus into simple inorga  nic
substances.
? Humification: Accumulation of dark coloured amorphous substances called humus.