BiologyKhaga · Class 6-8
Kadi kitni lambi, jaal kitna majboot: ecosystem mein khaane ka safar
School trip pe Ravi jungle ke van-kendra pahuncha. Guide didi ne bataya ki is jungle mein hazaaron hiran hain par baagh sirf kuch dus-bees. Ravi ne poocha, 'Itne kam baagh kyun? Aur khaane ki kadi aksar chaar-paanch kadam se aage kyun nahi jaati?'
Socho pehle… phir dekho jawab
Ravi ko laga shayad baagh ko khaana kam milta hai. Didi ne samjhaya: har kadam par khaane ki urja ka bada hissa jeev ke chalne, saans lene aur garmi mein kharch ho jaata hai; agle jeev tak bahut kam pahunchta hai. Isliye upar wale jeev kam hote hain, aur kadi chhoti rehti hai.
Didi Ravi ko jungle ke kinaare le gayi. 'Har ecosystem (khet, talaab, jungle) mein teen tarah ke jeev hain. Utpaadak: hare paudhe aur paani ke sookshm paudhe (algae), jo photosynthesis se suraj ki urja ko khane mein badalte hain. Upbhokta: shakahari (hiran, tidda), maansahari (mendak, baagh) aur dono khaane wale. Apghatak: bacteria aur fungus, jo mare jeev aur kooda tod kar poshak tatva mitti mein lautate hain.' Ravi ne sookhe patton ke neeche safed fungus dekha.
Ravi ne copy pe seedhi line kheenchi: ghaas → hiran → baagh. 'Yeh kadi hai,' didi boli, 'par jungle mein jaal hai.' Hiran ghaas bhi khaata hai aur patte bhi; ghaas ko tidda bhi khaata hai; tidde ko mendak aur chidiya. Ravi ki line ab teeron ka jaal ban gayi. 'Kai kadiyan jud kar food web banati hain. Jaal mein jitne zyada raaste, utna sthir ecosystem — ek jeev kam ho toh baaki raaste sambhal lete hain.'
Ab Ravi ke sawaal ki baari thi. Didi ne door daudte hiranon ki taraf ishaara kiya, 'Ghaas ki urja ka bada hissa hiran ke daudne aur sharir garam rakhne mein kharch hota hai; hiran ke sharir ka thoda hissa hi baagh tak pahunchta hai. Phir baagh ka bhi utna hi kharch. Isliye chaar-paanch kadam ke baad itni kam urja bachti hai ki ek aur jeev pal nahi sakta.' Ek baagh ko saal bhar mein itne hiran chahiye jitne ek poore gaon ki ghaas se palte hain — isliye ek baagh ka jungle bahut bada hota hai.
Gaon lautkar Ravi ne kadi soch lagayi: khet ka talaab sookha, phir mendak gaye, phir keede badhe, phir fasal kam hui, isliye kisaan ka nuksaan. Ravi ne apne school ke paas ka talaab saaf karwane ki baat panchayat mein rakhi — 'yeh mendakon ka ghar hai, hamare khet ka bhi.'
Tum Ravi hote toh panchayat ko talaab bachaane ke liye aur kya tark dete?
Humne kya kiya :- Jungle ke hiran aur baagh ki ginti se kadi ki lambai aur jaal ki majbooti ka kaaran samjha.
Isse kya hua :- Pata chala ki urja har kadam par ghat-ti hai, isliye upar wale jeev kam aur kadi chhoti; aur jaal jitna bada, ecosystem utna sthir.
Ghar pe try karo
Ek talaab ya gaon ke khet ka food web banao: kam se kam 8 jeev (algae, ghaas, tidda, machhar ka larva, mendak, chidiya, saanp, gaay) aur teer. Phir ek jeev ko kaat do (jaise mendak) aur likho: kis-kis par asar hoga? Phir ek apghatak jodo aur dekho kadi poori hui ya nahi.
Wow!
Ek baagh ko zinda rehne ke liye saal bhar mein itne hiran chahiye jitne ek poore gaon ki ghaas se palte hain — isliye ek baagh ka jungle bahut bada hota hai!
3 sawaal
- Ecosystem mein apghatak (decomposer) kaun hain?
Jawab dekho
Bacteria aur fungus. Bacteria aur fungus mare jeev aur kooda tod kar poshak tatva mitti mein lautate hain.
- Khaane ki kadi aksar chaar-paanch kadam se lambi kyun nahi hoti?
Jawab dekho
Har kadam par urja ka bada hissa kharch ho jaata hai. Har jeev khane ki urja ka bada hissa chalne, saans aur garmi mein kharch karta hai; agle tak bahut kam pahunchta hai.
- Food web food chain se zyada sthir kyun hai?
Jawab dekho
Ek jeev kam ho toh doosre raaste bache rehte hain. Jaal mein har jeev ke kai khane aur khane wale hote hain, isliye ek kadi tootne par poora jaal nahi tootta.
NCERT se jodo: NCERT Class 7 Science — paudhon aur jaanwaron mein poshan; Class 8 Science — conservation of plants and animals (idea in words)