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Word of the Week: Dendrochronology

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Welcome to Word of the Week! Stay tuned for a new word each Friday to amp up your nature vocabulary!

Dendrochronology [den-droh-kruh-NOL-uh-jee] (noun): the study of data from annual tree ring growth.

This word of the week is truly a mouthful! Dendrochronology comes from the Greek words for tree, dendron, and time, khronos. The usefulness of this data isn’t only limited to people who study trees, it has applications in many different scientific fields from archaeology to climate studies.

Dendrochronology is based on the principle that in temperate climates (like High Park) trees will only grow one ring per year. Working from the outside to the inside, you are examining the entire lifespan of that tree! The width of each individual ring is based on how much water the tree absorbed that year. Wetter, warmer years will create thicker rings, while years of drought or cold weather will create thinner rings.

Dendrochronologists must also determine the pattern of the rings. Looking at how thin or thick each ring is, they must match the pattern to the master guide of that area to more accurately determine the tree’s age. Currently, these master chronologies can date back 13,000 years!

Although it is interesting to know about the life of individual trees, compiled data from hundreds of trees in an area begins to build a picture of past climates. Climatologists have studied tree rings for decades in order to discern what effects past periods of climate change have had on tree growth. Although dendrochronology largely focuses on how natural changes in climate impacted plant life, the data can be used to map how anthropogenic climate change will affect plant life in the future.

The next time you’re out for a walk in High Park, challenge yourself to find the widest tree, the smallest tree, or the tallest tree. Think of the life this tree has lived, imagine how the land has changed around it. If you happen to find a fallen tree, try studying the growth rings to determine how old it is or how many droughts it has lived through.