You are free to discuss this material with anyone and consul

You are free to discuss this material with anyone and consult any source (credit must be given with a proper citation to the source). You may work collectively but written work MUST BE absolutely independent of other student\'s work and other sources. Red Spruce has lived for many generations at high elevations in the White Mountains of New Hampshire, yet mortality in response to cold winter temperatures occurs frequently. Offer THREE hypotheses as to why red spruce has not evolved complete tolerance of the winter temperatures it regularly experiences.

Solution

Red spruce achieves a minimal level of mid-winter cold hardiness for a northern temperate confier, making the species susceptible to freezing injury. Several environmental stress factors are indiviually linked to the freezing injury in red spruce, which increases its susceptibility further. No sole-agent has been identified to cause this effect in red spruce. Of all the possible environmental factors that influence red spruce cold hardiness, interactions between acid mist and mid-winter thaws have the greatest potential to increase the risk of freezing injury. Due to no adaptation in red spruce for freezing cold temperature, there number is reducing day by day.