CHAPTER-12
ECOSYSTEM
ECOSYSTEM
Class-12th... 100% NCERT based
For CBSE,ICSE and State Boards
•Ecosystem:
- The interaction between biotic and abiotic components is known as Ecosystem
-Term was coined by Tansley
-Structural and Functional unit of nature
•Types of Ecosystem
i) On the basis of area
Terrestrial Aquatic
Ecosystem Ecosystem
ii) On the basis of Nature
Natural
NOTE:
Man made
Eg: Aquarium
Eg:Forest,Pond
etc
Earth is
Global
Ecosystem
,• Ecosystem- Structure and Function
✓ Ecosystem Structure
i) Species composition: Identification or counting of plant and
animals species found in an ecosystem
ii)Stratification: Vertical distribution of different species in
different levels in an ecosystem
Ex-Herbs---->Shurbs---->Trees
iii)Trophic Level: Each successive level in a food chain is known as
trophic level
iv)Standing crop: Amount of biomass of living organism present at
particular time. Measured by dry and wet weight
v)Standing state: Amount of inorganic nutrients present in a
particular time in ecosystem
✓ Ecosystem Functions
1.Productivity
2.Decomposition
3.Energy flow
4.Nutrient Cycle
•Productivity
-Rate of biomass production is called productivity
-Expressed in gm^-²yr^-¹ or Kcalm^-²yr^-1
✓ Types of Productivity
Primary Productivity Secondary Productivity
GROSS Net
PRIMARY PRIMARY
PRODUCTIVITY PRODUCTIVITY
(gpp) (Npp)
ECOSYSTEM
ECOSYSTEM
Class-12th... 100% NCERT based
For CBSE,ICSE and State Boards
•Ecosystem:
- The interaction between biotic and abiotic components is known as Ecosystem
-Term was coined by Tansley
-Structural and Functional unit of nature
•Types of Ecosystem
i) On the basis of area
Terrestrial Aquatic
Ecosystem Ecosystem
ii) On the basis of Nature
Natural
NOTE:
Man made
Eg: Aquarium
Eg:Forest,Pond
etc
Earth is
Global
Ecosystem
,• Ecosystem- Structure and Function
✓ Ecosystem Structure
i) Species composition: Identification or counting of plant and
animals species found in an ecosystem
ii)Stratification: Vertical distribution of different species in
different levels in an ecosystem
Ex-Herbs---->Shurbs---->Trees
iii)Trophic Level: Each successive level in a food chain is known as
trophic level
iv)Standing crop: Amount of biomass of living organism present at
particular time. Measured by dry and wet weight
v)Standing state: Amount of inorganic nutrients present in a
particular time in ecosystem
✓ Ecosystem Functions
1.Productivity
2.Decomposition
3.Energy flow
4.Nutrient Cycle
•Productivity
-Rate of biomass production is called productivity
-Expressed in gm^-²yr^-¹ or Kcalm^-²yr^-1
✓ Types of Productivity
Primary Productivity Secondary Productivity
GROSS Net
PRIMARY PRIMARY
PRODUCTIVITY PRODUCTIVITY
(gpp) (Npp)
