most trees grow a layer of wood each year.when the tree is cut down, the layers can be seen as rings in the trunk.and counting the number of rings tells you how old the tree is!
Answers
Answer:
Most trees grow a layer of wood each year. When the tree is cut down, the layers can
be seen as rings in the trunk. And counting the number of rings tells you how old the
tree is!
Tree rings also speak of the weather changes that have occurred during the life of a
particular tree. In a season of good rainfall, the rings will be thick and during drought,
the growth is slowed down and the rings will be thinner. Trees like the bristlecone
pines, sequoias and redwoods of California are living records of variations in climate
for the last 9000 years! Studying the changes in tree ring patterns is a science called
‘dendrochronology’. Dendrochronology is the dating of climate changes in the past
through study of tree rings to understand life in ancient.
Explanation:
Dendrochronology is useful for determining the precise age of samples, especially those that are too recent for radiocarbon dating, which always produces a range rather than an exact date. However, for a precise date of the death of the tree a full sample to the edge is needed, which most trimmed timber will not provide. It also gives data on the timing of events and rates of change in the environment (most prominently climate) and also in wood found in archaeology or works of art and architecture, such as old panel paintings. It is also used as a check in radiocarbon dating to calibrate radiocarbon ages.[2]
New growth in trees occurs in a layer of cells near the bark. A tree's growth rate changes in a predictable pattern throughout the year in response to seasonal climate changes, resulting in visible growth rings. Each ring marks a complete cycle of seasons, or one year, in the tree's life.[2] As of 2020, securely dated tree-ring data for the northern hemisphere are available going back 12,310 years.[3] A new method is based on measuring variations in oxygen isotopes in each ring, and this 'isotope dendrochronology' can yield results on samples which are not suitable for traditional dendrochronology due to too few or too similar rings.[4]