Ecosystem project class 12th

1. Ecosystem
An Ecosystem Is A System Which Is Formed When A Community Of
Organisms Interacts With The Environment.
An Ecosystem Is Basically An Organism Community Which Interacts
With One Another And Their Environment In Such A Way That Energy
Is Transferred Between Them And System-Level Processes Like The
Cycle Of Elements Emerge.
The Ecosystem Is The Core Concept In Ecology And Biology, And
Serves As The Building Block Of Biological Organization Where
Organisms Interact With Each Other Simultaneously And With The
Environment As Well. Therefore, Ecosystems Are A Step After The
Ecological Community Level ( In Which Organisms Of Different
Species Interact With One Another) And Are At A Stage Below Or

2. Equal To The Biosphere And Biomes. Essentially, They Are Regional
Ecosystems, While The Biosphere Is Larger Than All The Possible
Ecosystems.
Ecosystems Include The Living Organisms Alonside The Dead
Organic Matter Which They Produce, The Abiotic Environment Which
These Organisms Inhabit And Exchange Elements, For Example,
Soils, Water, The Atmosphere, Etc, And The Interactions With The
Components. Ecosystems Follow The Concept That The Living
Organisms Must Continually Interact With One Another And With
Their Environment To Create Complex Systems With Different
Emergent Properties, Like That "The Whole Is Greater Than The Sum
Of Its Parts" Or "Everything Is Connected".
Different Types Of Ecosystems
There Are Essentially
Two Kinds Of
Ecosystems; Aquatic
And Terrestrial. Any
Other Sub-Ecosystem
Falls Under One Of
These Two Headings.
Terrestrial Ecosystems

3. Terrestrial Ecosystems Can Be Found Anywhere Apart From Heavily
Saturated Places. They Are Broadly Classed Into:
The Forest Ecosystems
They Are The Ecosystems In Which An Abundance Of Flora, Or
Plants, Is Seen So They Have A Big Number Of Organisms Which Live
In Relatively Small Space. Therefore, In Forest Ecosystems The
Density Of Living Organisms Is Quite High. A Small Change In This
Ecosystem Could Affect The Whole Balance, Effectively Bringing
Down The Whole Ecosystem. You Could See A Fantastic Diversity In
The Fauna Of The Ecosystems, Too. They Are Further Divided Into:
 Tropical Evergreen Forest: These Are Tropical Forests That
Receive A Mean Rainfall Of 80 For Every 400 Inches Annually.
The Forests Are Characterised By Dense Vegetation Which
Comprises Tall Trees At Different Heights. Each Level Is Shelter
To Different Types Of Animals.
 Tropical Deciduous Forest: There, Shrubs And Dense Bushes
Rule Along With A Broad Selection Of Trees. The Type Of Forest
Is Found In Quite A Few Parts Of The World While A Large
Variety Of Fauna And Flora Are Found There.
 Temperate Evergreen Forest: Those Have Quite A Few Number
Of Trees As Mosses And Ferns Make Up For Them. Trees Have
Developed Spiked Leaves In Order To Minimize Transpiration.
 Temperate Deciduous Forest: The Forest Is Located In The
Moist Temperate Places That Have Sufficient Rainfall. Summers
And Winters Are Clearly Defined And The Trees Shed The
Leaves During The Winter Months.
 Taiga: Situated Just Before The Arctic Regions, The Taiga Is
Defined By Evergreen Conifers. As The Temperature Is Below

4. Zero For Almost Half A Year, The Remainder Of The Months, It
Buzzes With Migratory Birds And Insects.
The Desert Ecosystem
Desert Ecosystems Are Located In Regions That Receive An Annual
Rainfall Less Than 25. They Occupy About 17 Percent Of All The
Land On Our Planet. Due To The Extremely High Temperature, Low
Water Availability And Intense Sunlight, Fauna And Flora Are Scarce
And Poorly Developed. The Vegetation Is Mainly Shrubs, Bushes, Few
Grasses And Rare Trees. The Stems And Leaves Of The Plants Are
Modified In Order To Conserve Water As Much As Possible. The Best
Known Desert Ones Are The Succulents Such As The Spiny Leaved
Cacti. The Animal Organisms Include Insects, Birds, Camels, Reptiles
All Of Which Are Adapted To The Desert (Xeric) Conditions.
The Grassland Ecosystem
Grasslands Are Located In Both The Tropical And Temperate Regions
Of The World Though The Ecosystems Vary Slightly. The Area Mainly
Comprises Grasses With A Little Number Of Trees And Shrubs. The
Main Vegetation Includes Grasses, Plants And Legumes That Belong
To The Composite Family. A Lot Of Grazing Animals, Insectivores
And Herbivores Inhabit The Grasslands. The Two Main Kinds Of
Grasslands Ecosystems Are:
1. Savanna: The Tropical Grasslands Are Dry Seasonally And Have
Few Individual Trees. They Support A Large Number Of
Predators And Grazers.
2. Prairies: It Is Temperate Grassland, Completely Devoid Of Large
Shrubs And Trees. Prairies Could Be Categorized As Mixed
Grass, Tall Grass And Short Grass Prairies.

5. The Mountain Ecosystem
Mountain Land Provides A Scattered And Diverse Array Of Habitats
Where A Large Number Of Animals And Plants Can Be Found. At The
Higher Altitudes, The Harsh Environmental Conditions Normally
Prevail, And Only The Treeless Alpine Vegetation Can Survive. The
Animals That Live There Have Thick Fur Coats For Prevention From
Cold And Hibernation In The Winter Months. Lower Slopes Are
Commonly Covered With Coniferous Forests.
Aquatic Ecosystems
The Aquatic Ecosystem Is The Ecosystem Found In A Body Of Water.
It Encompasses Aquatic Flora, Fauna And Water Properties, As Well.
There Are Two Main Types Of Aquatic Ecosystem - Marine And
Freshwater.
The Marine Ecosystem
Marine Ecosystems Are The Biggest Ecosystems, Which Cover
Around 71% Of Earth's Surface And Contain 97% Of Out Planet's
Water. Water In Marine Ecosystems Features In High Amounts
Minerals And Salts Dissolved In Them. The Different Divisions Of
The Marine Ecosystem Are:
 Oceanic: A Relatively Shallow Part Of Oceans Which Lies On The
Continental Shelf.
 Profundal: Deep Or Bottom Water.
 Benthic Bottom Substrates.
 Inter-Tidal: The Place Between Low And High Tides.
 Estuaries
 Coral Reefs
 Salt Marshes

6.  Hydrothermal Vents Where Chemosynthetic Bacteria Make Up
The Food Base.
Many Kinds Of Organisms Live In Marine Ecosystems: The Brown
Algae, Corals, Cephalopods, Echinoderms, Dinoflagellates And
Sharks.
The Freshwater Ecosystem
Contrary To The Marine Ecosystems, The Freshwater Ecosystem
Covers Only 0.8% Of Earth's Surface And Contains 0.009% Of The
Total Water. Three Basic Kinds Of Freshwater Ecosystems Exist:
 Lentic: Slow-Moving Or Till Water Like Pools, Lakes Or Ponds.
 Lotic: Fast-Moving Water Such As Streams And Rivers.
 Wetlands: Places In Which The Soil Is Inundated Or Saturated
For Some Lenghty Period Of Time.
The Ecosystems Are Habitats To Reptiles, Amphibians And Around
41% Of The World’s Fish Species. The Faster Moving Turbulent
Waters Typically Contain A Greater Concentrations Of Dissolved
Oxygen, Supporting Greater Biodiversity Than Slow Moving Waters In
Pools.
An Ecosystem Has Two Basic Components
I) Abiotic Components
Ii) Biotic Components
The Relationship Between The Abiotic Components And The Biotic
Components Of The Ecosystem Is Termed 'Holocoenosis'.
Abiotic Components

7. Those Include The Non-Living Or Physico-Chemical Factors Like Air,
Soil, Water And The Basic Compounds And Elements Of The
Environment.Abiotic Factors Are Classified Broadly Under Three
Categories: Climatic Factors, Including The Climatic Regime With
Physical Factors In The Environment Such As Light, Atmospheric
Temperature, Wind, Humidity, Etc; Edaphic Factors, Which Relate To
The Composition And Structure Of The Soil Like Its Chemical And
Physical Properties – Like The Soil Type, Soil Profile, Organic Matter,
Minerals, Soil Water, And Soil Organisms. Inorganic Substances Like
Water, Carbon, Sulphur, Nitrogen, Phosphorus And So On. Organic
Substances Like Proteins, Lipids, Carbohydrates, Humic Substances
Etc.
Biotic Components
It Consists Of The Living
Parts Of The Environment,
Including The Association
Of A Lot Of Interrelated
Populations That Belong To
Different Species Inhabiting
A Common Environment.
The Populations Are Those
Of The Animal Community,
The Plant Community And The Microbial Community. The Biotic
Community Is Divided Into Autotrophs, Saprotrophs And
Heterotrophs. Autotrophs (From Greek : Auto - Self, Trophos -
Feeder) Are Called Producers, Transducers Or Convertors, As Well.

8. Those Are Photosynthetic Plants, Normallu Chlorophyll Bearing,
Which Synthesize A High-Energy Complex Organic Compound ( Or
Food) From The Inorganic Raw Materials Utilizing The Aid Of The
Sunt, And This Process Is Called Photosynthesis. Autortophs Form
The Core Of All Biotic Systems.
In Terrestrial Ecosystems, Autotrophs Are Usually Rooted Plants. In
The Aquatic Ecosystems, The Floating Plants Referred To As
Phytoplankton And The Shallow Water Rooted Plants – Macrophytes
- Are The Main Producers.
Heterotrophs (From Greek: Heteros - Other; Trophs - Feeder) Are
The Consumers, Normally Animals That Feed On The Other
Organisms. Consumers Are Also Referred To As Phagotrophs (Phago
- To Swallow Or Ingest) While Macroconsumers Are Normally
Herbivores And Carnivores. Herbivores Are Called First Order Or
Primary Consumers, For They Feed Directly On Green Plants. For
Example, Terrestrial Ecosystem Consumers Are Cattle, Deer, Grass
Hopper, Rabbit, Etc. Aquatic Ecosystem Consumers Are Protozoans,
Crustaceans, Etc.
Carnivores Are Animals That Prey Or Feed On Other Animals. Second
Order Consumers Or Primary Carnivores Include Those Animals That
Feed On Herbivorous Animals. For Example, Fox, Frog, Smaller
Fishes, Predatory Birds, Snakes, Etc.
Third Order Consumers Or Secondary Carnivores Are The Animals

9. That Feed On Primary Carnivores. For Example, Wolf, Owl, Peacock,
Etc. Some Larger Carnivores Prey On Secondary Carnivores.
Quaternary Consumers Or Tertiary Carnivores Include Those
Animals Which Feed Upon Secondary Carnivores. For Example, the
Lion, The Tiger, Etc. Those Are Not Eated By Any Other Animal. The
Larger Carnivores Which Cannot Be Preyed On Further Are Also
Called The Top Carnivores.
Saprotrophs (From Greek Again: Sapros - Rotten; Trophos - Feeder)
Are Called The Reducers Or Decomposers. They Break The Complex
Organic Compounds In Dead Matter Down (Dead Plants And
Animals). Decomposers Don’t Ingest The Food. Instead They Secrete
A Digestive Enzyme Into The Dead, Decaying Plant Or Animal
Remains And Digest This Organic Material. The Enzymes Act On The
Complex Organic Compounds In The Dead Matter. Decomposers
Absorb A Bit Of The Decomposition Products To Provide Themselves
With Nourishment. The Remaining Substance Is Added As Minerals
In The Process Of Mineralisation To The Substratum. Released
Minerals Are Utilised Or Reused As Nutrients By Plants - The
Producers.
Ecosystem Components
(Structure)
Ecosystems Might Be
Observed In A Lot Of Ways, So
There Isn’t A Set Of
Components WhichMake Up
An Ecosystem.However, All
Ecosystems Have To Include

10. Both Abiotic And Biotic Components,The Interactions, And A Known
Source Of Energy. The SimplestBut Least Representative Of Ecosystems
Therefore Contains Just One Living Plant – The Biotic Component,In A
Small Terrarium With Light Exposure To Which Water Source With
Essential Nutrients For The Plant’s Growth Has Been Added – The Abiotic
Environment. The Other Extreme Is The Biosphere,Which Has All Of
Earth's Organisms And The Interactions Between Them And Earth’s
Systems – The Abiotic Environment. And Of Course,The Majority Of
Ecosystems Fall In Between The Extremes Of Complexity.
At A Core Functional Level, EcosystemsNormally Contain Primary
Producers Able To Harvest Energy From Sunlight By Photosynthesis And
To Use The Energy To Turn Carbon Dioxide With Other Inorganic
Chemicals In The Organic Building Blocks Of Life.The Consumers Feed
Upon This Captured Energy, While Decomposers Not Only Feed On The
Energy, But Also Break Up The Organic Matter Into The Inorganic
Constituents, For Them To Be Used Again By The Producers.Those
Interactions Among The Producers And Organisms Which Consume And
Decompose Are Called Trophic Interactions, ComposedOf Trophic Levels
In The Energy Pyramid, And The Most Energy And Mass Are In The
Primary Producers,At The Base, While The Higher Levels Of The Pyramid,
Beginning With The Primary Consumers That Feed On Primary Producers,
The Secondary Consumers Which Feed On These, And So Forth. Trophic
Interactions Are DescribedIn A More Detailed Form As The Food Chain,
Which Organizes The SpecificOrganisms By The Trophic Distance From
The Primary Producers,And With Food Webs,WhichMap The Feeding
Interactions Between All The Organisms In The Ecosystem.Together,The
ProcessesOf Matter Cycling And Energy TransferAre Essential In Finding
Out Ecosystem Function And Structure And Defining The Kinds Of
Interactions Between The Environment And Its Organisms. It Should Also
Be Noted Most Ecosystems Have A Wide Array Of Species,And The
Diversity Ought To Be Considered PartAnd Parcel Of The Ecosystem
Structure.
Ecosystem Processes(Function)
By Definition, All Ecosystems Cycle Matter And Use Energy, And The
ProcessesDefine The Fundamental Ecosystem Functions As Well.

11. Energetic ProcessesIn An Ecosystem Are Normally DescribedBy
Speaking Of Trophic Levels That Define The PositionOf Organisms
According To Their Level Of Feeding In ComparisonTo The Original
Energy Taken In By Primary Producers.Always The Energy Doesn’t Cycle
And EcosystemsNeed A Continuous Inflow Of High-Quality Energy In
Order To Maintain Their Function And Structure. For This Reason,
Ecosystems Are "Open Systems" Needing A Net Inflow Of Energy To
Continue Over Time - Without The Sun, Our Biosphere Would Shortly Run
Out Of Energy!
Energy Inputs To EcosystemsDrive The Flow Of Matter Within Organisms
And Their Environment In A ProcessCalled BiogeochemicalCycling. Our
Biosphere Gives A Good Example Of The Process,As It Exchanges Matter
With And Interacts With The Lithosphere,Atmosphere And Hydrosphere,
Driving The Earth’s BiogeochemicalCycles Of Nitrogen, Phosphorus,
Sulfur, Carbon And The Other Elements. An Ecosystem Process Is
Dynamic, Undergoing Strong Seasonal Cycles Responding To Changes In
The Solar Irradiation; Causing Fluctuations In The Primary Productivity;
Varying The Inflow Of Energy From Photosynthesis And Carbon Dioxide
Fixation Ointo Organic Materials During The Year; Driving Remarkable
Annual Diversity In The Carbon Cycle, Which Is The BiggestOf All Global
BiogeochemicalCycles.The Fixed Organic Carbon In Plants Becomes
Then Food For Decomposers And Consumers,Who Degrade This Carbon
Into Forms With Less Energy, And Finally Releasing This Photosynthesis-
Fixed Carbon Back Into Carbon Dioxide In Our Atmosphere,Creating The
Global Carbon Cycle. The Nitrogen BiogeochemicalCycling Also Uses
Energy, Because Bacteria Fix The Nitrogen Gas From The Atmosphere In
Reactive Forms Useful To Living Organisms With Energy From Organic
Materials Or From The Sun And From Plants. Ecosystems Cycle Sulfur,
Phosphorus And Other Elements As Well. Because BiogeochemicalCycles
Are Determined By The Transfer Of Matter Between The Environment And
Its Organisms, They Are Good Examples Of Ecosystem-LevelProcesses.
History Of The Ecosystem Concept
The Word "Ecosystem" Was Coined First By Roy Clapham In 1930.
However, It Was The Ecologist Arthur Tansley That Fully Defined An

12. Ecosystem Concept. In The Classic Article From 1935, Tansley
Defined An Ecosystem As:
"The Whole System,… Including Not Only The Organism-Complex,
But Also The Whole Complex Of Physical Factors Forming What We
Call The Environment".
The Ecosystem Concept Signalled A Critical Step In The Study Of
Ecology, As Tansely Used The Term Specifically To Replace The
Previous "Superorganism" Concept, Which Stated That Communities
Of Organisms Comprised Something Like A Higher-Level And More
Complex Organism - A Mistaken Conception Which Formed A
Theoretical Barrier For Ecological Scientific Research. Though
Tansely With Other Ecologists Used The Ecosystem Idea Together
With The Now Abandoned Concept Of An Ecological "Climax" (The
"Final“ Or "Equilibrium" Type Of Ecosystem Or Community Arising
Under Some Environmental Conditions), The Idea Of Ecosystem
Dynamics Now Replaces This. Eugene Odum, The Major Figure For
Advancing The Study Of Ecology, Made The Ecosystem Concept Into
A Central Part In The Seminal Textbook On Ecology, By Defining
Ecosystems As:
"Any Unit That Includes All Of The Organisms (Ie: The "Community")
In A Given Area Interacting With The Physical Environment So That A
Flow Of Energy Leads To Clearly Defined Trophic Structure, Biotic
Diversity, And Material Cycles (Ie: Exchange Of Materials Between
Living And Nonliving Parts) Within The System Is An Ecosystem."