Question: When you cut down a tree there are rings in the wood that tell you how old the tree is. Do these rings have any other use or tell us anything more?
What happens is that most places on earth have seasons. The tropics usually have a “wet” season and a “dry” season. Most of Australia has warmer and cooler seasons. So the wood that grows in one season grows better than the wood that grows in another season, making a “ring”. Since the seasons come in a yearly cycle, each ring corresponds with one year. The size of a particular ring can tell us about how good or bad a year was for growing, so the rings have climate information. If there has been fire, or a volcanic eruption, then different minerals might get incorporated into the ring for that particular season, so a detailed investigation of the chemical composition of different rings can also give information about significant events.
I’d love to know how accurate the things are that can be extracted from trees. Near where I used to work in San Francisco there’s a forest of the biggest trees on earth, the redwoods. Near the entrance they have a cross-section of a tree that shows how wide they are and there are little labels of which ring corresponds to which year. It’s amazing to think that a tree can stand for a thousand years. What I’d like to know is whether an analysis of the chemical composition of the tree can show you how the air changed during the industrial revolution, for example. I bet the changes are too small, and that all it would tell you would be local stuff, like how much sun and rain they had in a given year, and therefore something about temperature.
The same thing can be achieved with ice cores. Some sheets of ice have remained undisturbed for so long that you can extract stuff from them and effectively analyse the earth’s atmosphere back in time.
Hi henf! I don’t think I can give you a better answer than Kieran and Matt but I’ll give you my version!
My understanding is the width of each ring can tell you how “good” the growing conditions were in that year. A fat ring in the trunk means that the tree did a lot of growing in that year because there was a lot of water and sunlight available. A thin ring might mean there was a drought, a lack of sunlight, or too few nutrients in the soil.
It’s what Kieran and Mat have said. I don’t have much else to add.
The information from tree rings and ice core is that they can also be matched to core samples taken of the Earth. This is how scientists can confirm when volcanic eruptions and ice ages happened. They all match with similar chemistries.
What happens is that most places on earth have seasons. The tropics usually have a “wet” season and a “dry” season. Most of Australia has warmer and cooler seasons. So the wood that grows in one season grows better than the wood that grows in another season, making a “ring”. Since the seasons come in a yearly cycle, each ring corresponds with one year. The size of a particular ring can tell us about how good or bad a year was for growing, so the rings have climate information. If there has been fire, or a volcanic eruption, then different minerals might get incorporated into the ring for that particular season, so a detailed investigation of the chemical composition of different rings can also give information about significant events.
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Kieran’s right. There’s a history there of stuff that’s happened.
http://www.sciencealert.com.au/news/20101910-21457.html
I’d love to know how accurate the things are that can be extracted from trees. Near where I used to work in San Francisco there’s a forest of the biggest trees on earth, the redwoods. Near the entrance they have a cross-section of a tree that shows how wide they are and there are little labels of which ring corresponds to which year. It’s amazing to think that a tree can stand for a thousand years. What I’d like to know is whether an analysis of the chemical composition of the tree can show you how the air changed during the industrial revolution, for example. I bet the changes are too small, and that all it would tell you would be local stuff, like how much sun and rain they had in a given year, and therefore something about temperature.
The same thing can be achieved with ice cores. Some sheets of ice have remained undisturbed for so long that you can extract stuff from them and effectively analyse the earth’s atmosphere back in time.
0
Hi henf! I don’t think I can give you a better answer than Kieran and Matt but I’ll give you my version!
My understanding is the width of each ring can tell you how “good” the growing conditions were in that year. A fat ring in the trunk means that the tree did a lot of growing in that year because there was a lot of water and sunlight available. A thin ring might mean there was a drought, a lack of sunlight, or too few nutrients in the soil.
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Hi henf.
It’s what Kieran and Mat have said. I don’t have much else to add.
The information from tree rings and ice core is that they can also be matched to core samples taken of the Earth. This is how scientists can confirm when volcanic eruptions and ice ages happened. They all match with similar chemistries.
0