Put A (Tree) Ring On It!
January 11, 2023
Think about this question for a moment, “How does a tree grow?” You might think about your experiences in the forest surrounded by towering trees and consider their height. Trees are taller each year, right? However, contrary to this thought, trees actually grow out and not up. They get larger every year by growing a new layer of cells on the outside of their current mass. Think of tree growth not like a tower made of blocks that gets taller as you place a new block on top, and instead like a set of nesting dolls that grows bigger after the previous doll is encased in the next.
Now, most will know that aging a tree is as simple as counting its growth rings after being cut down (or by a core sample on a living tree). Each ring you see on a stump or wood cookie represents one year of tree growth. A ring is characterized by a thin darker outer circle and a lighter inner circle.
Competition and Growth
Tree rings can tell us how old a tree is but they can also tell us other stories. Stories of intense competition and periods of strong growth. They tell us about previous climate conditions and can show evidence of draught years, wet years, and unfavorable growing temperatures. They can also tell us about the health of the forest and the success of forest management.
This stump (pictured above) in particular tells us the story of a hemlock tree who started its early years of life in unfavorable conditions. It was most likely competing with other young trees for light and soil to photosynthesize and consume needed nutrients. We can see that by the hemlock’s 30th year of life, conditions worsened. The rings here are so small that a magnifying glass is needed to count them. Right after this period of darkness and slow growth, the forest was logged. This tree no longer had to compete for light and soil nutrients, so it was able to grow much larger and faster than it had in previous years.
We can infer from the size of the rings when the previous harvest happened. We can also tell that when this tree was cut down, it was again in a period of slow growth. Many trees had grown up around it, once again competing with this hemlock for necessary resources. This tree has a story, just like every other tree in the forest. Each ring shows us how it persevered through different weather events and forest conditions. This stump comes from DLLT’s recent harvest on Daugherty Ridge and its removal will be part of the story of the trees left behind that will now get the chance to grow larger, much faster.
