Key Points Summary (~100 words, 5 bullets)

Three biodiversity levels: Genetic (within species — Rauwolfia vomitoria example), species (~1.5M described; India 45K plants, 100K animals), ecological (India: deserts to alpine meadows).
Species-area relationship: log S = log C + Z log A; Z = 0.1–0.2 for continents, Z = 0.6–1.2 for islands; described by Alexander von Humboldt.
HIPPO causes: Habitat loss (primary), Invasive species (Nile perch in Lake Victoria), Population/overexploitation, Pollution, cO-extinction; tropical forests reduced 14% → 6%.
India's conservation: 4 hotspots (WISH), 18 biosphere reserves, 106 national parks (Corbett oldest), ~566 sanctuaries; sacred groves = IN-SITU; cryopreservation = −196 °C; CBD signed Rio 1992; hotspot criteria: ≥1,500 endemic plants AND ≥70% habitat loss.
IUCN order (high to low risk): EX → EW → CR → EN → VU → NT → LC; Bengal tiger/Asiatic lion = EN; one-horned rhino/snow leopard = VU; DD ≠ safe.