Q.Explain Raunkiaer classification in the world's vegetation based on the temperature.

Climatic factors are the class of abiotic ecological factors arising from the atmosphere and weather, and they are among the most powerful natural controls on plant life. Five specific factors fall under this heading. Light drives photosynthesis (fastest in the blue 400–500 nm and red 600–700 nm bands, weaker in green 500–600 nm) plus stomatal movement, germination, flowering and tuber/runner production; plants are grouped as heliophytes (light-loving) or sciophytes (shade-loving). Temperature sets the pace of every metabolic reaction, defines minimum/optimum/maximum thresholds for physiological activity, and organisms are grouped as eurythermal (wide tolerance) or stenothermal (narrow tolerance); water bodies also show vertical thermal stratification (epilimnion/metalimnion/hypolimnion), and Raunkiaer's four-way vegetation classification (megatherms/mesotherms/microtherms/hekistotherms) is temperature-based. Water, essential to every physiological process, reaches plants as atmospheric moisture, precipitation and soil water, and its salinity sorts organisms into euryhaline (wide tolerance) vs stenohaline (narrow tolerance) groups — this same broad/narrow ('eury-'/'steno-') pattern extends to habitat (euryoecious/stenoecious), wa …