Temperatures are rising around the world, including in Canada, and that is concerning not only for human beings but for all forms of life, including trees. Heat stress can be as dangerous for trees as it is for people. The damage can be so extensive that tree removal in Kitchener becomes necessary. Nevertheless, there are things you can do to help trees cope with the stress more effectively.
Do Trees Have Ways of Cooling Themselves?
As the human body regulates its temperature in hot weather through perspiration, trees cool themselves through a process called transpiration. Trees have small openings in their stems, flowers, and leaves from which water evaporates to cool them down. The hotter the temperature, the more trees have to transpire to keep cool.
Both human beings and trees can experience heat stress due to dehydration. Trees absorb water from the soil through their roots rather than drinking water, but if the soil is too dry, they have insufficient resources with which to cool themselves through transpiration.
What Temperature Is Too Hot for Trees?
It depends on the type of trees and the climate they are adapted to. Obviously, trees in tropical regions have evolved to tolerate warmer temperatures. For trees in temperate regions, such as Ontario, between 70 and 85 degrees Fahrenheit is the ideal growing temperature. Photosynthesis slows down when the temperatures rise above 94 degrees Fahrenheit, and trees start to die if the temperature extends above 115 degrees Fahrenheit.
How Do Trees Get Too Hot?
Generally speaking, the temperature of a tree is roughly equivalent to the temperature of the air around it, meaning that the tree can suffer if the air temperature gets too high. However, there are situations in which the tree’s temperature can rise above that of the ambient air temperature.
For example, hot air rises through the process of convection. The movement of hot air can increase the tree’s temperature. A tree can also absorb heat that is radiated from nearby structures or surfaces or sunlight reflected from the soil surrounding it. Even sunlight reflecting from the surfaces of the tree itself can raise its temperature.
What Are Some Signs That Trees Are Experiencing Heat Stress?
At first, the signs of heat stress in trees can be very subtle. Branches may start to droop, while leaves may start to wilt and turn yellow, especially near the trunk at first. The leaves may show signs of scorching around the edges or rust-coloured spots. Eventually, the leaves die and start to fall off. A tree experiencing heat stress may have a sparse-looking canopy because of a lack of new growth. The bark of the tree can be burned from reflected heat and form lesions that leak sap. This is most prominent on the southern side of the tree.
What Can You Do To Help Protect Your Trees?
As the temperatures increase, there are some things you can do to prevent heat stress in your trees:
1. Water the trees regularly to prevent the soil from drying out. To prevent runoff, water the trees slowly, and to make sure it reaches all the roots, water deeply.
2. When the weather is hot, avoid pruning healthy branches to prevent unnecessary stress on the tree. If it is safe to do so, you can also postpone pruning dead branches until the temperature cools.
3. Organic mulch helps to lower the temperature of the soil and keep it moist. You can spread the mulch out to the edge of the canopy in a layer two to four inches thick. However, spreading mulch too close to the trunk can promote mould growth.
Some trees are more susceptible to heat than others, especially those that are very young, very old, or already unhealthy. If you have done everything you could and the tree has still died, the next step is to ask yourself, “Where can I find tree cutting services near me?” Find out about tree removal from Martin’s Tree Service.
Steve Martin
