Structure and Function of Ecosystems (Short Summary)
Introduction
Ecological Balance: Yeh nature ka balance hai, jisme living (biotic) aur non-living (abiotic) components interact karte hain to maintain stability. Isko "balance of nature" bhi kehte hain.
Ecosystem: Nature ka ek functional unit, jisme living organisms (plants, animals, microbes) aur unka physical environment (air, water, soil, sunlight) energy flow aur nutrient cycling ke through interact karte hain.
1. Definition aur Types
Definition: Ecosystem mein living organisms (biotic) aur unka physical environment (abiotic) ek specific area mein interact karte hain.
Types:
Terrestrial: Jaise forests, grasslands, deserts.
Aquatic:
Lentic: Still water, jaise ponds, lakes.
Lotic: Flowing water, jaise rivers, streams.
Artificial: Human-made, jaise aquarium, cropland.
2. Components of Ecosystem
Abiotic Components: Non-living cheezein jaise sunlight, temperature, water, soil, air, nutrients.
Biotic Components:
Producers (Autotrophs): Plants aur algae jo photosynthesis se energy banate hain. Example: Grass.
Consumers (Heterotrophs):
Primary Consumers: Herbivores jo producers ko khate hain. E.g., deer, rabbit, grasshopper.
Secondary Consumers: Carnivores ya omnivores jo primary consumers ko khate hain. E.g., frog, spider.
Tertiary Consumers: Carnivores ya omnivores jo secondary consumers ko khate hain. E.g., snake, hawk.
Top Consumers: Apex predators jo kisi ke prey nahi hote. E.g., lion, tiger, eagle.
Decomposers (Saprotrophs): Dead organic matter (detritus) ko break karke nutrients recycle karte hain. E.g., bacteria, fungi.
3. Energy Flow
Primary Source: Sun.
Flow: Energy ek direction mein move karti hai – producers se consumers aur decomposers tak.
10% Rule: Har trophic level se agle level tak sirf ~10% energy transfer hoti hai, baki heat ya metabolism mein lose ho jati hai.
Food Chain: Energy transfer ka linear sequence (e.g., grass → grasshopper → frog → snake).
Food Web: Kai food chains ka interconnected network, jo zyada stable hota hai kyunki multiple food sources hote hain.
4. Biomass aur Productivity
Biomass: Kisi area mein living organisms ka total dry weight, measured in g/m² ya kg/ha. Isko "standing crop" bhi kehte hain.
Productivity: Biomass production ki rate.
Primary Productivity:
Gross Primary Productivity (GPP): Producers dwara photosynthesis se capture kiya gaya total energy.
Net Primary Productivity (NPP): GPP minus respiration losses (NPP = GPP - Respiration). Yeh consumers ke liye available hoti hai.
Secondary Productivity: Consumers dwara biomass production ki rate.
Ecological Pyramids:
Pyramid of Numbers: Har trophic level par organisms ki number. Yeh inverted ho sakta hai (e.g., ek tree par bahut saare insects).
Pyramid of Biomass: Har level ka biomass. Aquatic ecosystems mein inverted ho sakta hai (e.g., phytoplankton < zooplankton).
Pyramid of Energy: Hamesha upright hota hai kyunki har level par energy loss hoti hai.
5. Key Concepts
Nutrient Cycling: Nutrients jaise carbon, nitrogen, phosphorus ka biotic aur abiotic components ke through recycling.
Ecological Succession: Ecosystem ka long-term development ya recovery after disturbance.
Keystone Species: Aisi species jinka ecosystem par unke biomass ke proportion mein zyada impact hota hai.
Biomes: Climate aur vegetation ke basis par bade geographic areas (e.g., tropical rainforests, deserts).
6. Practice Questions (MCQs)
Document mein 50 multiple-choice questions hain jo ecosystem ke concepts test karte hain, jaise:
Ecosystem ki definition aur types.
Biotic aur abiotic components.
Producers, consumers, aur decomposers ka role.
Energy flow, food chains, aur food webs.
Biomass, productivity, aur ecological pyramids.
Productivity ko affect karne wale factors (e.g., sunlight, water, nutrients).
Specific examples jaise phytoplankton ka producer role aur producers ko remove karne ka impact.