So. For context. Watching a nature documentary the voice over guy gave the year that a species of tree died. The tree wasn’t a fossil. More like a dead stump you could walk up to and see.
I understand how they age trees to see their approximate age but how can they predict an exact year that tree died?
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These things are edited to save time on tv, he had to use a bit to take a sample to count the rings.
Also did he say what tree species? American chestnut died all around the same time because of a disease
First, it’s possible that he had that data from another source. If a permit was pulled to cut down that particular tree, like in a construction site, then that would tell you how long it’s been since it was cut down.
Alternatively, tree rings make a record of how much growth a tree goes through each year. With a lot of knowledge about the area, you might be able to line up things like droughts or floods from the historical record with the pattern of the rings.
Tree rings will be different widths depending on the climate (or stuff like pest outbreaks) each growing season. A drought or some other stressor will lead to narrow rings, while good growing conditions lead to wider rings. The pattern of thicker and thinner rings over time is like a bar code, and it is correlated among trees of the same species in the same region because they’re all experiencing the same climate. So if you have a dead tree, you can match up the pattern of thicker and thinner rings with the same pattern from an old living tree and figure out where in its history you are. In some places where tree rings are studied a lot, people have overlapped older and older tree ring records to make a climate record going back hundreds or thousands of years. They overlap living trees with dead trees and even use stuff like timbers in old buildings.
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