5.1.7
Energy ek ecosystem mein aise flow karta hai jaise ek leaky bucket brigade ho. Har baar jab ek trophic level se doosre ko hand-off hota hai, roughly 90% energy lost ho jaati hai, aur sirf lagbhag 10% agले level tak pahunchti hai. Isliye food chains chhoti hoti hain aur isliye gazelles se kaafi kam lions hote hain.
Definition The 10% Rule (Lindeman's Law)Average par, ek trophic level par biomass ke roop mein stored energy ka sirf lagbhag 10% agले trophic level par biomass mein convert hota hai. Baaki ~90% lost ho jaata hai — zyaadatar heat ke roop mein (respiration ke through), plus jo khaaya nahi gaya, digest nahi hua, ya excrete ho gaya.
Key vocabulary (cloze yourself):
Ek trophic level ek food chain mein ek feeding position hai (producer, primary consumer, etc.).
Gross production = total energy captured/eaten. Net production = energy jo actually respiration ke baad new biomass ke roop mein stored hoti hai.Levels ke beech transfer ki efficiency ko ecological (trophic) efficiency kehte hain.
Energy Second Law of Thermodynamics ki paalan karta hai: har energy conversion imperfect hota hai aur kuch energy unusable heat ke roop mein dump kar deta hai. Ek organism jo energy leta hai usse poora store nahi kar sakta. Socho food energy kahan jaati hai?
Toh "10%" woh fraction hai jo next level ke liye new biomass ke roop mein available hoti hai jise woh actually kha sake.
Maano E n n
Isse levels ke across chain karo. Agar har step fraction f = 0.10
E n = E 1 ⋅ f ( n − 1 )
Kyun? Har arrow ek baar f n ( n − 1 ) f
Worked example Producers par 10,000 J se start karo (f = 0.1
Level (n
Naam
Energy E n = 10000 ⋅ 0. 1 n − 1
1
Producer (grass)
10,000 J
2
Primary consumer (gazelle)
1,000 J
3
Secondary consumer (lion)
100 J
4
Tertiary consumer (bada predator)
10 J
5
Quaternary
1 J
Yeh step kyun? Har row = pichli row × 0.1. Level 5 tak almost kuch nahi bachta — isliye food chains 4–5 links se zyaada rarely hoti hain.
Worked example Example 1 — Efficiency nikaloProducers 8,000 kJ store karte hain; herbivores 640 kJ biomass banate hain. Transfer efficiency kya hai?
Step 1: E n E n + 1 × 100 Kyun? Efficiency = biomass out ÷ biomass in.
Step 2: 8000 640 × 100 = 8% Interpretation: ~10% rule ke close hai; "10%" ek average hai, real values ~5–20% hoti hain.
Worked example Example 2 — Top level predict karoEk grassland 500,000 J fix karta hai. Clean 10% rule use karke, tertiary consumer (level 4) tak kitni energy pahunchti hai?
Step 1: E 4 = E 1 ⋅ 0. 1 4 − 1 = 500000 ⋅ 0. 1 3 Exponent 3 kyun? Teen arrows level 1 aur level 4 ko separate karte hain.
Step 2: = 500000 ⋅ 0.001 = 500
Worked example Example 3 — Pyramids of energy kabhi invert kyun nahi hoteKyunki E n + 1 < E n Yeh matter kyun karta hai? Ek pyramid of energy hamesha upright hota hai, number/biomass ke pyramids ke unlike jo invert ho sakte hain (jaise ek bada tree bahut saare insects ko feed karta hai).
Common mistake Steel-manned misconceptions"Khoya hua 90% bas gayab ho jaata hai."
Kyun sahi lagta hai: agला level clearly kam paata hai, toh lagta hai energy vanish ho gayi.
Fix: Energy conserved hoti hai — yeh destroy nahi hoti, mostly heat ke roop mein transform hoti hai (respiration) aur faeces/dead matter ke zariye decomposers ko pass hoti hai. Yeh food chain se nikallti hai, universe se nahi.
"Exactly 10% hamesha transfer hota hai."
Kyun sahi lagta hai: naam 10% kehta hai.
Fix: 10% ek rough average hai. Real ecological efficiencies ~5–20% range mein hoti hain organism ke hisaab se (cold-blooded animals heat par kam waste karte hain, toh higher efficiency).
"Energy nutrients ki tarah recycle hoti hai."
Kyun sahi lagta hai: hum "nutrient cycle" sunte hain, toh assume karte hain energy bhi cycle karti hai.
Fix: Nutrients cycle karte hain; energy ek taraf flow karti hai aur heat ke roop mein exit karti hai. Ecosystems ko constant sun input isliye chahiye kyunki energy recycle nahi hoti.
Recall Feynman: 12-saal ke bachche ko explain karoSocho tum ek line mein dosto ke saath paani ki bucket pass kar rahe ho, lekin har dost pite waqt har 10 cups mein se 9 gira deta hai. Paanchwe dost tak almost kuch nahi bachta! Food energy waise hi hai jaise woh paani: har animal zyaadatar energy body heat aur poop ke roop mein "gira deta hai" jab woh move karta hai aur zinda rehta hai. Toh sirf thoda sa top predator tak pahunchta hai — isliye tons of grass hoti hai, kam rabbits hote hain, aur sirf kuch hi foxes hote hain.
"Ten to the top, ninety in the heat-shop."
Ya: P roducers → 10% → P rimary → 10% → S econdary... "har level ek tenth rakhta hai, baaki breath (respiration) ko deta hai."
Energy transfer ka 10% rule kya hai? Average par sirf ~10% energy ek trophic level par agले level par biomass banti hai; ~90% lost ho jaati hai.
Khoya hua ~90% energy zyaadatar kahan jaata hai? Zyaadatar respiration se heat ke roop mein, plus uneaten material, faeces aur excretion.
E1 se start karke efficiency f ke saath level n par energy ka formula? E n = E 1 ⋅ f ( n − 1 )
Food chains zyaadatar 4–5 links tak kyun limited hoti hain? Repeated 10% transfers ke baad itni kam energy bachti hai ki ek aur level support nahi ho sakta.
Kya energy ek ecosystem mein cycle karti hai? Nahi — energy ek taraf flow karti hai aur heat ke roop mein exit karti hai; sirf nutrients cycle karte hain.
Pyramid of energy hamesha upright kyun hota hai? Kyunki efficiency < 100%, har higher level hamesha neeche wale level se kam energy hold karta hai.
Losses ko kaunsa thermodynamics ka law explain karta hai? Second Law — energy conversions hamesha kuch energy heat ke roop mein dissipate karte hain.
Producers 8000 kJ → herbivores 400 kJ; efficiency? (400/8000)×100 = 5%.
Second Law of Thermodynamics
Trophic efficiency = En+1 / En x100
Short food chains 4-5 links
