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Eco system class 12th

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Ecosystem
An Ecosystem Is A System Which Is Formed When A Community Of
Organisms Interacts With The Environment.
An Ecosys...
Equal To The Biosphere And Biomes. Essentially, They Are Regional
Ecosystems, While The Biosphere Is Larger Than All The P...
Terrestrial Ecosystems Can Be Found Anywhere Apart From Heavily
Saturated Places. They Are Broadly Classed Into:
The Fores...
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Eco system class 12th

  1. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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."

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