Nature is the law of balance in action. After fresh growth and longer days of light, plants and trees prepare for colder weather. Deciduous trees save the energy maintenance of keeping leaves alive which would otherwise have less photosynthesis in conditions of a light deficit. They withdraw nutrients and through the chemical reactions of sugars and tannins the leaves turn colour and fall. Metabolism slows and the roots become more dormant in the cold. This is actually a good time to plant a tree, as the tree has less demand for nutrients and water, and is less shocked by a new environment.
While humans scramble for layers of clothing and turn on heating in their homes, trees stand naked in the chill, with hardy specimens handling temperatures down to – 70 °C through the production of proteins that allows the space between cells to freeze, rather than the cells themselves. These temperature decreases are also good for killing pests and disease that would harm trees.
With the increasingly unpredictable temperature fluctuations and the increase in milder winters in some parts of the world, trees have less time to adapt. This will result in the death of more species due to periods of extreme cold, as well as to pests and disease from milder winters. More adaptable trees and exotic species will also migrate to new areas, as new habitable regions appear for them. In years to come we will see there has been a large shift in species migration.