十万个为什么·科学阅读30篇（4）

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树木如何在寒冬中避免被冻成冰棍？

Trees avoid freezing damage by converting starches into sugars, lowering the freezing point of sap like antifreeze.
Cell walls thicken and become more flexible, preventing ice crystals from puncturing membranes.
Water moves out of living cells into intercellular spaces, where freezing causes less harm.
Deciduous trees shed leaves to reduce water loss and stop photosynthesis until spring returns.
Evergreens retain needles coated in waxy cuticles that slow evaporation and resist cold drying winds.
Some species produce special proteins that inhibit ice nucleation—stopping crystals from forming inside cells.
Bark insulates inner tissues, while dormant buds seal themselves with protective scales and resins.
Roots stay active just below the frost line, absorbing limited water when soil isn’t fully frozen.
Maple trees concentrate sugar in early spring, enabling sap collection for syrup before full thaw.
Climate change disrupts these adaptations, causing premature budding and increased winter injury risk.