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snow monsters, juhyou, frost-covered trees

Snow Monsters, Juhyou, Frost-covered Trees

Many plants can be damaged or killed by freezing temperatures or frost. This will vary with the type of plant and tissue exposed to low temperatures.
Tender plants, like tomatoes, die when they are exposed to frost. Hardy plants, like radish, tolerate lower temperatures. Perennials, such as the hosta plant, become dormant after first frosts and regrow when spring arrives. The entire visible plant may turn completely brown until the spring warmth, or will drop all of its leaves and flowers, leaving the stem and stalk only. Evergreen plants, such as pine trees, will withstand frost although all or most growth stops. Frost crack is a bark defect caused by a combination of low temperatures and heat from the winter sun.
Vegetation will not necessarily be damaged when leaf temperatures drop below the freezing point of their cell contents. In the absence of a site nucleating the formation of ice crystals, the leaves remain in a supercooled liquid state, safely reaching temperatures of −4°C to −12°C. However, once frost forms, the leaf cells may be damaged by sharp ice crystals. Hardening is the process by which a plant becomes tolerant to low temperatures (cryobiology).
Certain bacteria, notably Pseudomonas syringae, are particularly effective at triggering frost formation, raising the nucleation temperature to about −2°C. Bacteria lacking ice nucleation-active proteins (ice-minus bacteria) result in greatly reduced frost damage.

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Filename:356950.jpg
Album name:Fauna & Flora
Rating (1 votes):55555
Keywords:#snow #monsters #juhyou #frost #covered #trees
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Date added:Feb 07, 2011
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