How Trees Withstand the Extremes
Written by John Sepulveda, Certified Arborist WI-1454A
Trees are able to withstand some of the harshest environments and events. Since they are immobile, they’ve developed adaptations that allow them to survive in places that normally cause animals to leave or avoid. Trees have evolved and developed traits that help them to withstand droughts, fires, and even extreme cold. However, spring season temperature swings can cause problems for trees.
To survive in drought conditions trees have developed features to allow them to conserve water or find it elsewhere. In the leaves of a tree there are tiny pores that allow gas exchange. Water leaves these pores and evaporates. In environment in which the sun is too intense or there is not much water present, the tree can close these stomata to allow less exchange to occur. The roots also have a symbiotic relationship with a fungus that allows the tree to uptake more moisture from the soil.
Trees and Fire
Fire can be devastating to an ecosystem but there are trees that can withstand fire to an extent, and some that even reproduce because of fires. Trees that live in areas that commonly get wildfires develop thicker bark that is able to protect the inside of the tree from heat damage. The bark is also more fire-resistant so it keeps the tree from catching on fire. Some trees even will self-prune lower branches so their leaves do not start on fire in the upper parts of the canopy. A few species of trees will also reproduce or sprout up after a fire activates their seeds or burns up above-ground tree tissue.
Adaptations for the Cold
On the opposite end of the spectrum, trees are able to survive extreme colds as well. Coniferous trees have slender needles to minimize the amount of area that is exposed to the wind. They can also survive up to a year without leaves. Broadleaf trees will drop their leaves and begin winter dormancy to conserve energy as it costs more energy to keep cells alive in the winter than it does to make them dormant. To prevent freezing in the trunk wood, cells will also store water in the spaces between cells instead of in cells to prevent damage when the water freezes. The shape and size of a tree also adds to its ability to survive. The cone shape of conifers help prevent snow from accumulating on the branches and thus damage from the weight of the snow.
Why Trees are Vulnerable in the Spring
Despite these adaptations, trees are susceptible to sudden changes in temperature. When the weather is consistent and slow changing, trees are extremely strong. However, in the spring season, rapid and repeated changes between warmer and colder temperatures can lead to frost damage.
Hoppe is a full-circle tree care company celebrating its 50th year of excellent service to southeastern Wisconsin customers. We have a team of certified arborists and plant health care technicians on staff to provide expert diagnosis of tree and shrub issues, and recommendations for promoting healthy trees and shrubs. Our services include planting, pruning, removals, and prevention and treatment of insect and disease issues. If you would like an inspection of your trees or are considering planting new trees and shrubs in your yard, give us a call at 414.257.2111 to schedule a visit by a Hoppe certified arborist.