life of a tree revealed in the rings

[Electric Comet]

interesting shot showing the fires during the life of the tree

[OFWW]

Did you know that tree rings do not show years, but show rainy seasons?

[Leon]

I always understood rings represent years, size of rings represent the climate for that year. Do you have a reference by any chance?

[OFWW]

I'll have to look for it, The reason it stuck in my mind was that those people looking for the ark could tell by lumber with the lack of rings in it. Which some people would discount, but also a friend of mine who was studying ice "rings" or layers that geologists used for the age of ice discovered that it actually bore record of rain or snowfall, which is why some rings were close and some wider in patterns. I'll look it up tonight.

[Spalted Walt]

You might want to rethink that:

[Leon]

;~) Well the Arc, is a super natural object and all that goes with that... ;~) But I would be interested in what you find.

[OFWW]

As the story goes, before the flood there was no rain. No rainy season, no rings, or very few?

Anyhow, here are a few page links, and basically the growth, or rainy season and the end of it determines the rings. So in area's that have a regular rainy season you will get a growth ring. In a severe drought it can be difficult to tell if there is a growth ring or not. I have included the areas of tropical forests to show that there can be multiple growth rings per year, and that basically a tree is a tree is a tree.

Here in the west I can remember seeing large trees with growth ring anomalies shown in the local museums of national parks where uncertainty prevailed in the reading of rings due to weather patterns.

Bottom line? Tree's don't have birthday's. :)

Annual rings generally exist in trees where the climate halts growth at some point during the year. In our country, winter causes this shutdown. In other countries, it is the dry season. Growth begins again in the spring or rainy season.

But what happens to trees growing in countries where there is no alternation between growth and rest periods?

For example, a country where it rains all year long! Remember that all trees grow by adding successive rings. So in such an area, the beginning and end of the growth period may occur any time during the year, depending on the local conditions.

Some trees in tropical forests, like the okoumé (Gaboon), manage to create several dozen very thin rings in a year, and never the same number from one year to the next. It is often difficult, even impossible, to distinguish them with the naked eye. In such cases, it is extremely hard to determine the age of the tree.

Dendrochronology is the study of climate change as recorded by tree growth rings. Each year, trees add a layer of growth between the older wood and the bark. This layer, or ring as seen in cross section, can be wide, recording a wet season, or narrow, recording a dry growing season. Because the rings are basically recording a good growing season or a bad growing season, they are indirectly recording more than just moisture. They also document temperature and cloud cover as they impact tree growth as well. This record of annual summer information is very important when you consider that certain types of trees grow slowly over hundreds and hundreds of years, and therefore contain a record of as many years of climate and climate change.

There are limitations to this research though. Trees in the temperate zone only record the growing season, so the winter season, no matter how dramatic, will not be seen in the ring record. Interestingly, trees in tropical regions grow year round and therefore show no real obvious annual growth rings. Therefore climate data from equatorial areas is difficult to piece out and use. The record is limited geographically in another way too. Trees do not grow in all places on Earth, therefore we don?t have a tree ring record of climate change for each region and ecologic niche globally. (No trees in polar regions, high in the mountains, in the ocean!!!)

[OFWW]

These pages are full of errors, and a good deal of it is written by those with narrow visions who think that what they see here in the US applies globally. They have pulled in some historic notes in order to add weight to their arguments, but they failed and the pages reflect it by asking for confirmations, etc.

See my reply to Leon, where it is easy to see that it is the growth season or lack of it that gives the rings. Sometimes multiple rings from one year to the next.

I have seen mentions of this in some of our national parks.

Disclaimer on this page, "In general tree's have one growth ring per year"

[Existential Angst]

OFWW wrote in news: [e-mail]:

Are ~those people~ the same ones who believe our square planet is only 6000 years old and the baby Jesus put all those dinosaur fossils here ~just to test our faith~ ?

[OFWW]

No, and this is not the place for that type of discussion.

[dpb]

The US FPL Wood Handbook --

See chap 3 for botany lessons. Short version is, in temperate climates such as most of the US, there is an annual growth and dormant season and so the growth rings can be associated with that yearly cycle. How prevalent they are is basically determined by the variety of the tree itself, spacing is related to environmental and local conditions. But it makes note that this is a temperate-zone characteristic and so to refer them as "annual rings" isn't necessarily accurate; use the term "growth rings" or "growth increment" instead.

OTOH, in many tropical woods it's essentially impossible to visually detect growth rings altho I note in the 2010 edition it includes the following: "... continuing research in this area has uncovered several characteristics whereby growth rings can be correlated with seasonality changes in some tropical species (Worbes 1995, 1999; Callado and others

2001)."

Shorter version is R. B. Hoadley's Understanding Wood, Taunton Press...although I don't believe it's been revised; there's certainly little to fault for a US audience and domestic woods on the subject albeit it's not a botany textbook, either (nor, of course, is the Handbook, but it is in more depth than Hoadley).

[Electric Comet]

it is not that simple some can be decades and longer as always it depends on many factors

dendrochronology is the study of the rings

there are photos of giant sequoia cross sections marked with historic events that are fun to see

[dpb]

On 01/06/2016 9:34 AM, dpb wrote: ...

First sentence 2nd paragraph is garbled -- I changed horses in midsentence on what was planning on writing and didn't get all the first outta' there that shoulda' been --

What was intended to say was impossible had to to with associating growth rings with a necessarily annual cycle in tropical regions, not that the growth increments are not visible.

[dpb]

An individual growth increment? I'm certainly not aware of anything that shows such a pattern. Reference????

...

Spacing, yes. Actual ring structure itself is simply a characteristic of the individual species. Now, yes, while there are lots of species, there are a (relatively few) characteristics into which individual trees fall.

[Leon]

And yet they are called "Annual" Growth rings. That still sounds like a new ring each year.

And from your link,

Each year, the tree forms new cells, arranged in concentric circles called annual rings or annual growth rings. These annual rings show the amount of wood produced during one growing season.

[dpb]

...

Or perhaps are you simply referring to a period of time such as a prolonged drought or the like that can bring a period of growth to near standstill for as long as the particular event lasts and sometimes for sometime thereafter before the specimen really fully recovers (presuming it survives and does do so eventually, of course)?

That sort of thing certainly happens for any number of reasons, weather patterns being the most notable for a given specimen. Over a longer period of time over a number of generations one may see other more longer-term trends although one may have to have some additional help in that the forest was uprooted in a devastating event such a a flood, buried in an anerobic environment and became fossilized or otherwise preserved in order for us to find rings to count and ponder over their meaning...a few thousand years for individual trees is their lifetime, a mere blink of the eye in geologic time.

The bristlecone pine is, afaik, the longest-lived single tree, reaching into the 5-6,000 yr neighborhood. The giant sequoias are mere youngsters in comparison in the 3-4,000 range.

What's really unusual is that the Pando quaking aspen grove is the oldest overall by a wide margin (80,000 to to perhaps as much as

1,000,000 by some estimates) but it's not the part you see; it (they? :) ) is a clonal colony of a single male quaking aspen. Individual stems are more like only 100-130 years in age but they come up from the underground root system, not by flowering/seed production. The whole grove of some 100 acres and 40-50,000 "stems" are identical clones genetically.

[dpb]

...

As noted earlier, that's fine for temperate-zone regions but "not so much" in tropical areas. US FPL points out that that is poor terminology...

And, from just a little farther down in the same link--

"Trees in Tropical Countries

Annual rings generally exist in trees where the climate halts growth at some point during the year. In our country, winter causes this shutdown. In other countries, it is the dry season. Growth begins again in the spring or rainy season.

But what happens to trees growing in countries where there is no alternation between growth and rest periods?

For example, a country where it rains all year long! Remember that all trees grow by adding successive rings. So in such an area, the beginning and end of the growth period may occur any time during the year, depending on the local conditions.

Some trees in tropical forests, like the okoumé (Gaboon), manage to create several dozen very thin rings in a year, and never the same number from one year to the next. It is often difficult, even impossible, to distinguish them with the naked eye. In such cases, it is extremely hard to determine the age of the tree."

[Electric Comet]

look at the sequoias

there are some great pics around with markings of historic events over the life of the tree the sequoias are special for sure and the annual ring does not apply as yo noted it is the growth ring and it can span decades trees are incredible the blue gum and sequoias are more so due to their size

[OFWW]

ROTFL, Annual growth rings the term fits to everyone's satisfaction. But that only works in areas with one growth cycle per year.

The last couple years here we have had two growth seasons each year, literally, played havoc with the veggies, but the tree's seemed to handle it fine. It would be nice to core the tree and then core it again just to see or verify what the tree did for those years. It isn't common, but it is not unusual.

Bottom line I guess we all see what we want.

And then a North American heads to Australia and gets confused because the toilet flushes opposite than it does here. ;)

[dpb]

On 01/06/2016 4:22 PM, Electric Comet wrote: ...

...

A _given_ growth ring for a sequoia (or any other tree in the temperate climatic zone) will absolutely _NOT_ span "decades". It'll be in accord with the growing seasons which are, and have been for the life of these trees, annual cycles.

It takes a place without these cycles for there to not be any correlation; that ain't where the redwoods are.