We have all learned about photosynthesis in elementary school science class. It is the process where plants take light, water, and carbon dioxide from our air and turn it into released oxygen and much-needed glucose for the tree’s survival. Trees are creating for us a necessity of life and are also producing their own chemical energy.
We’ve all heard about the process, but have you thought about what a tree does with the glucose (energy) it creates for itself? Each tree distributes the resources that are created through photosynthesis in four ways. Depending on the species, some may disburse energy heavier in one area than another. In this blog, we will discuss these four areas and their role in a tree’s survival.
Growth is the most obvious function that comes to mind for the use of a tree’s resources. Tree growth doesn’t just indicate growth above-ground, but also the root growth below ground. Each is important for the vitality of a tree. While each species grows at a different rate, if stunted growth is observed, we need to start looking at nutrient deficiencies or problems in the tree.
Some trees grow quickly, leaving fewer resources for other areas. Other trees will grow at a slower rate, leaving more resources available to defense, storage, and maintenance. It is true that slower growing trees tend to be stronger trees. Silver Maples are a notoriously fast-growing species, which is great for those who want shade in their yard quickly, but also comes with repercussions of weaker wood.
We may not consider everything it takes for a tree to maintain itself and thrive, but there is so much happening on a cellular level that we cannot see. How a tree disburses its resources is for the most part predetermined by its species, but this can adapt to its environment and needs. It is a balancing act for each tree to distribute resources within its means to survive in the conditions they are in. While one tree will survive in conditions favorable to it, another species may be pushed beyond its ability to thrive in the same environment.
Reproduction is a primary goal for many plants. Some trees seem to spread so easily while others need the assistance of man to propagate. Fruit and seed production can be hindered because of an insect or disease problem. If a tree has to send too many of its resources to defense, reproduction will be hindered.
Have you ever wondered how a tree can survive the winter without its leaves? Or how do trees survive after being defoliated by the fall webworm?
The reason they can survive is because resources have been stored.
Trees store resources for not only the dormant season when they cannot produce photosynthesis but also for times of stress. Without these stored photosynthates, trees would be on a quick path to decline in a time of stress.
In the spring when trees start to come out of their dormant phase, they have to pull resources from storage to push the growth of their buds. Storage of energy resources is a critical function for the survival of trees.
Trees go through a lot of stressors in our landscapes. Between harsh weather, pollution, damage from people and equipment, insects and diseases, drought and flooding, they will face many things that reduce their vigor. Fortunately, our trees allocate resources to defend themselves from these things. Some defense mechanisms of trees are thorn growth, thickened leaves, cellulose and lignin that cannot be digested by many animals, and the process of compartmentalization. We have discussed in previous blogs that trees cannot heal wounds, but seal over wounds. This process of compartmentalizing seals wounds by the growth of walls or barriers that stop the spread of decay.
It is so important to keep our trees as healthy as possible, so resources are not allocated too heavily in any one of these functions. Mild stress can actually increase insect and drought resistance, but too much stress can cause a spiral of decline that a tree cannot overcome. While our trees generally do a great job of taking care of themselves, the landscape can offer many stressors not found in nature and sometimes our trees need our help.
Give your arborist a call for recommendations on how your trees could benefit from our services.