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Opis:
Plants and animals have fascinating adaptations for winter survival and extreme cold temperatures. Annuals and perennial trees have unique adaptations including producing over wintering seeds and dying back, dropping high surface area leaves to avoid desiccation and snow loads and pyramidal shapes. Rhododendron have a strategy in between deciduous trees and pines, firs and spruces. As temperatures drop to midi 30's F the leaves begin to droop. Just below freezing at 32, leaves begin to curl and are drooped to almost vertical to shed snow and ice. Below 20 or 25 degrees the leaves become curled up tight to reduce water loss/desiccation. When temperatures warm again they will unfurl and spread horizontally to maximize exposure to light and increase surface area for photosynthesis. It is a fascinating rapid dynamic temperature specific response. When Rhododendron leaves droop and curl in response to cold temperatures, they are not dying, they are responding in a unique way to insure their winter survival.
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