Did you know the oldest tree on record is upwards of nine thousand years old? How often do we take a moment to think about how amazing trees are? From seed to snag, the life cycle of a tree is such an incredible organism at each stage in its life. We experience the beauty trees bring and their health benefits each day, but not everyone understands the importance of each stage of the life cycle of a tree.
While we know that plants start as seeds and grow into mature plants, there are many stages in-between as well as after maturity that benefit our planet. The seed grows to a sprout, seedling, sapling then to a mature tree, where then it starts its decline and eventually becomes a snag. Let’s take a closer look at each stage.
Seeds come in many different shapes and sizes. Inside, a seed has everything it needs to survive until it finds a safe place to grow. With the proper conditions for germination, seeds can take root and grow in many different terrains: yards, open fields, forest floors, rocky slopes, roadsides, and even in sand close to the beach. Some seeds come in a protective nut casing, such as an acorn, pecan, or walnut, while other seeds come from fleshy fruit, such as plums, currants, or black cherries.
Once the seed has found ideal conditions, it begins to sprout and needs to secure itself. There’s an embryo in each seed, however, not every seed will germinate or develop. As the roots push through the seeds that do grow, the sprouts can then start taking on water. The roots start spreading down into the ground and looking like an underground tree, while the sprout itself is still very small.
As the sprout grows out of the ground and becomes a seedling, it starts to compete with other trees and plants for the nutrients it needs. It will need enough water, sunlight, and space, all while being in danger of the elements. Fires, floods, ice, drought, being eaten by an animal, or being killed by disease are some of the dangers seedlings face before they move on to the next stage of the life cycle of a tree.
The seedling develops a harder stem that changes color from the previously soft, green stem and begins to have a thin protective bark. The majority of the roots by this point are near the surface of the soil, and if the seedling can survive this stage in the life cycle, it will continue to grow stronger and will eventually start creating its own food through photosynthesis.
Once the seedling grows to be over three feet tall, it becomes a sapling. Saplings have smoother bark than more mature trees and flexible trunks, which are usually between one and four inches in diameter. The young tree can still be considered a sapling even up to heights as tall as 15 feet. While the trees at this stage grow very quickly, they don’t produce seeds and are still in competition for survival from elemental threats and surrounding vegetation.
For commercial nurseries, the sapling is the stage where it will be transplanted to your yard. Saplings that are grown in nurseries are transported and planted when they’re closer to the 4.5-foot-tall range. Trees with longer lives stay saplings for a longer period of time than trees with shorter lives.
For the trees that survive through all of the obstacles faced as saplings, the next life cycle is a mature tree. In this stage, the mature tree will grow to its full size, it will start to produce flowers, reproduction occurs, the fruit of the tree will grow, and the new seeds it produces can start their own journey through the life cycle of a tree.
Depending on the species, a tree can start producing seeds as early as 15 years into its life and can produce seeds until it reaches 300 years. Some species stay in the maturity stage for a few hundred years, not producing seeds, before they move onto the next life cycle.
The best time to harvest a tree is during maturity, when it can be used for many products beneficial to humans. When mature trees stop producing seeds, they have a period of rest before continuing into the next stage of decline.
When a mature tree reaches the life cycle stage of decline, it’s due more to the external stressors from the elements and competition of nearby plants than the strength of the tree itself. This means that trees in decline aren’t defined only by their age but by specific characteristics that trees in decline show.
As harsh elements weaken the tree, the tree is also susceptible to disease and damage from tree-boring insects. The accumulation of all these external stressors weakens the tree to a point where it cannot get healthy again and starts to decay.
The final stage of the life cycle of a tree that is still standing is called a snag. Though the tree has been overcome and the death of the tree is near, there are many benefits the tree is still providing. The dead or decaying tree is essential for the biodiversity of a forest. The dead wood provides a home for insects and fungi, which feed the small mammals, which in turn become prey for the larger predators of the forest. The insects using the snag as shelter help break the tree down, and it gradually decomposes, and nutrients are returned to the soil.
With more nutrients back in the soil, the surrounding plants can absorb them and continue their growth and life cycle. Depending on the species of tree, it can decay rapidly within 2 to 10 years, or more slowly and take 100 years or more to decay.
The life cycle of a tree is a beautiful and amazing thing to experience! At Mr. Tree, we understand the importance of tree care and can help you keep your trees at their healthiest at each stage of their life cycle. Feel free to reach out with any questions you may have, we look forward to talking to you.