NEET ECO-01 — Everything on One Sheet

ABIOTIC FACTORS: Temperature (most important) > Water > Light > Soil Strategies: Regulate (mammals) | Conform (fish) | Migrate (birds) | Suspend (hibernate/aestivate/diapause) Hibernate = winter cold | Aestivate = summer heat | Diapause = zooplankton developmental arrest

POPULATION ATTRIBUTES: r = b - d | N by quadrat or mark-recapture [N = (n_{1}×n_{2})/m] Age pyramids: broad base = expanding | uniform = stable | narrow base = declining

GROWTH MODELS: Exponential: dN/dt = rN → J-curve (unlimited resources) Logistic: dN/dt = rN(K-N)/K → S-curve (limited resources) MAX growth rate at N = K/2 | Growth = 0 at N = K | N_t = $N_{0}$e^(rt)

SIX INTERACTIONS: +/+ Mutualism: Rhizobium-legume, lichen (algae+fungi), mycorrhiza -/- Competition: Gause's Paramecium experiment → competitive exclusion +/- Predation: prey defenses = cryptic coloration, Batesian mimicry, Mullerian mimicry, cardiac glycosides (Calotropis) +/- Parasitism: Lice/ticks (ecto), Plasmodium/tapeworm (endo), cuckoo-crow (brood) +/0 Commensalism: Orchid-mango, barnacle-whale, cattle egret-cattle -/0 Amensalism: Penicillium → Staphylococcus

ENERGY FLOW: Unidirectional (cannot recycle) | Lindeman's 10% law: 10% transfers, 90% → heat NPP = GPP - Respiration | Most productive: tropical rainforest > coral reef > estuary

DECOMPOSITION (FLCHM): Fragmentation (earthworms) → Leaching (water) → Catabolism (bacteria/fungi) → Humification (humus) → Mineralization (inorganic nutrients) Accelerated by: warm + moist + N-rich | Retarded by: lignin + cold + dry

ECOLOGICAL PYRAMIDS: Energy: ALWAYS UPRIGHT (10% law — thermodynamic law) Biomass: Inverted in AQUATIC (phytoplankton high turnover) Numbers: Inverted in TREE ecosystems (1 tree, many insects)

NUTRIENT CYCLES: Carbon: photosynthesis (in) ↔ respiration + decomposition + combustion (out) | Ocean = 71% of Earth's $CO_{2}$ Phosphorus: SEDIMENTARY ONLY — NO gaseous phase (unlike C and N)

SUCCESSION: Primary: bare substrate (rock/lava) → Lichens (pioneer!) → Mosses → Herbs → Shrubs → Trees (climax) Secondary: disturbed soil → faster (seed bank + soil present) Xerosere = on rock | Hydrosere = in water Climax = stable, self-perpetuating, in equilibrium with climate

NEET TOP FACTS (auto-answer):

1. Always upright pyramid = ENERGY (no exceptions)
2. Pioneer species = CRUSTOSE LICHENS (not mosses, not grasses)
3. Phosphorus = NO GAS PHASE (sedimentary only)
4. Max logistic growth at N = K/2
5. Ocean = 71% $CO_{2}$ storage
6. NPP = GPP - Respiration (Net < Gross always)
7. Most productive ecosystem = Tropical rainforest
8. r = b - d (intrinsic rate = births minus deaths)