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annual or annular

Do you mean "annual rings"? "annular rings" is redundant. -phma

corrected

I agree that many people use the term "annual rings".

However, many other people use the term "annular rings", so I added back that term, resulting in:

"Growth rings, also referred to as tree rings or annual rings or annular rings, can be seen..."

Do I need to pick one of the many Google results (tree "annular ring" width) as a reference?

--68.0.124.33 (talk) 18:30, 8 November 2008 (UTC)[reply]

The growth ring is the annular region consisting of the earlywood and the subsequent latewood, moving away from the wood center (pith). Jclerman (talk) 12:53, 9 November 2008 (UTC)[reply]

radiocarbon calibration

How does dendrochronolgy correlate with C14 dating? Ping 20:56, 12 Aug 2003 (UTC)

Dendrochronology is one method used to calibrate C-14 dating--Vsmith 17:18, 16 Sep 2004 (UTC)

How is the fact that one of the more probable measurements of bristlecone pine ring thickness is ZERO factored into dendochronology using such measurements? (See tree ring thicknesses from Methuselah Walk) Wdanwatts 13:57, 17 Mar 2005 (UTC)

Zero width is not a measurement. It means missing ring. From patterns in several cores they have so been inferred. Thus, the graph is not relevant to the discussion. Jclerman 20:29, 3 October 2005 (UTC)[reply]

For relevant information, with descriptions of the cross-correlation methods, chronology building, math and software used, and answers about dendrochronological methodology, including principles and results, see the following websites and links therein given:

http://web.utk.edu/~grissino/

http://www.ltrr.arizona.edu/resources.html

Jclerman 22:07, 3 October 2005 (UTC)[reply]

For relevant info about the Methuselah chronology (eg, statistics describing the raw measurements file referenced in the graph, cross-correlations, etc) see:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/measurements/correlation-stats/ca535.txt

For the chronology derived from the data referenced in the graph, see:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/chronologies/northamerica/usa/ca535.crn

Jclerman 23:16, 3 October 2005 (UTC)[reply]

It looks like there are occassionally measurments where the rings are rather thin. This doesn't mean most of the measurments have zero thickness. Samboy 02:29, 12 Apr 2005 (UTC)

The actual count on that file is 4258 of 213232 measurements were reported as 0 (2% of the total, while the most probable width, 19 units, is only 3.5% of the total, and less that twice as probable as 0). How many "spacer" values are needed to shim ring width sequences in order to "help" a correlation between two sets? Wdanwatts 22:07, 12 Apr 2005 (UTC)

Surely this is all depends on what's being counted and how. How was the above dataset collected? Without knowing that, it's not possible to say that years with '0' values are included to aid comparison and correlation. I think the important thing to bear in mind is that dendro, like many other incremental dating techniques, can often lack precision (relatively) but still yield accurate results. In some ways the precision : accuracy relationship here is opposite to that of C14 dating (i.e. where measuring is precise, but results come with error margins that reduce accuracy). NickW 09:03, 13 Apr 2005 (UTC)

That is an excellent point! Is there any Wikipedian here who knows the requisite information? If so, would you care to enlighten us as to how these measurements were interpreted and used? Wdanwatts 13:22, 13 Apr 2005 (UTC)

Does anyone have any knowledge on how C. W. Ferguson came up with the number (and placement) of zero-width tree-rings? Dan Watts 20:06, 1 Jun 2005 (UTC)

Two methods. First, a very slow-growing tree commonly only lays down a partial ring, covering say 60% of the circumference of the live wood of the tree. Thus a ring may be missing from one core sample, but present in a second core sample from the same tree at a different point on the trunk's circumference. Second, very rarely an exceptionally slow-growing tree will not lay down a ring at all on its trunk in a poor (cold, dry) year; this can be detected by comparison with the rings of neighbouring, faster-growing trees which do show a narrow ring for the bad year in question, or by comparison with branches higher in the crown of the same tree, where the ring will be produced. - MPF 11:18, 11 Jun 2005 (UTC)

So the second method would be of no utility for a dead tree, and the first method could not be used particularly well if only a piece of a tree was available. Dan Watts 12:43, 11 Jun 2005 (UTC)

No problem on the second; although wood is of course only produced by a tree while still alive, once dead, the old wood remains available for study until such time as it decays away. In the case of Great Basin Bristlecone Pines studied by Ferguson, this is a very long time; he found trees that had been dead for several thousand years and was still able to study the growing conditions they had been alive in. As for the first, normal proceedure is to take several cores at different points so as to get several readings. The existence of incomplete rings was known about long before Ferguson's studies started, so he was well aware of the potential for its occurrence. Some trees have much poorer circuit uniformity than others; pines are generally very good (most rings are complete), while e.g. junipers are notorious for producing partial rings, making them much harder to study accurately. - MPF 14:29, 11 Jun 2005 (UTC)

Thank you for the information. It brings to mind a number of other questions. Are you stating that Ferguson found whole trees dead for thousands of years? Not pieces? I thought Bristlecones, especially the very old ones, usually have a strip of bark, not nearly totally circumferential. That is what the typical pictures show. So are the 2% zero widths those measurements in which no core taken from a tree found a ring but nearby trees matched with a thin ring in the same place? How self-similar are these ring histories? (e.g. auto-correlation coefficient) Dan Watts 01:07, 12 Jun 2005 (UTC)

Whole fallen trunks with major branches still on, which comes inbetween the two I guess. Yes, correct about the narrowness of some of the strips of bark (as e.g. Image:Inyo10.jpg), though the non-living part of the circumference was once alive and can still provide useful data for the earlier part of the tree's life. "So are the 2% zero widths ..." - yes; and quite good, as far as I know. - MPF 19:42, 12 Jun 2005 (UTC)

Addition of Fossil Examples/ Analysis of Fossils w/Dendrochronology techniques

I know in some Geological periods the days were shorter. (Days are progressively getting longer in duration.) But the cyclicity of the days and the years still is the constant. I know nothing about Dendrochronology/Growth ring, Tree ring's applied to fossils.

I do realize all fossil trees are not gymnosperm/ angiosperm types. MMcAnnis,YumaAZ

, (a higher correlation value stands out amongst lower values).

Unless I didn't understand it, it seems a self evident tautology with little relevance to the paragraph. From Tucson AZ, Jclerman 05:16, 7 December 2005 (UTC)[reply]

significance of the correlations : discussion request

Wouldn't the "missing ring" mean that it was ASSUMED to be there in order to help correlation look better with other cores? Dan Watts 20:39, 3 October 2005 (UTC)[reply]

If you have Core A with pattern 4 8 9 5 3 2, Core B with pattern 4 8 5 3 2, .... Core Z with pattern 4 8 9 5 3 2, you infer that in Core B the 3rd ring is missing. Note that the example with 5 rings is an oversimplification. One works with hundreds or thousands of rings. Jclerman 20:54, 3 October 2005 (UTC)[reply]

O.K. how does the autocorrelation function of core ring patterns look? (I.e. how many offsets allow reasonable matches?) Dan Watts 21:08, 3 October 2005 (UTC)[reply]

Descriptions of the cross-correlation methods, chronology building, math and software used, and any other answers about dendrochronological methodology and results are given in the following references:

http://web.utk.edu/~grissino/

In this reference it says: "COFECHA Tip #13: So, what value of mean interseries correlation (first page in the box, and found in Part 7 at bottom) should you have? I consider a value of 0.40 the minimum a tree-ring data set should have. I've seen values much higher in the American Southwest (0.55 to 0.70) while data sets for eastern species may range from 0.45 to 0.60. Data sets with very long complacent series, however, may have values less than 0.40." [1] This would seem to indicate that there exist MANY possible correlation offsets other than the one published. Dan Watts 20:09, 18 August 2006 (UTC)[reply]

http://www.ltrr.arizona.edu/resources.html

This reference doesn't have the word correlation. Dan Watts 20:09, 18 August 2006 (UTC)[reply]

Jclerman 21:46, 3 October 2005 (UTC)[reply]

In the Discussion page of Dendrochronology I've put a complete list of references to the stats and chronology of the graphed data. Jclerman 23:30, 3 October 2005 (UTC)[reply]

Does the discussion cover the autocorrelation of the tree rings as shown in

and the associated Cross-correlation these trees have as shown in

and what values are to be considered significant?

someone wanna put this in english?

really now :D how disputed are tree ring dates? and i got directed here from some link that was talking about 18 yrs without treerings anywhere on earth... or somethin to that affect - what's that about?

curious :D

The article is in English, read it.
The article has plenty of references, read some of them.
If you still have questions, contact the sites referenced and submit your questions.

69.9.31.103 16:51, 11 May 2006 (UTC)[reply]

The plots above show the correlation of the Bristlecone pine tree ring widths measured in the Methuselah walk area. The correlations are between different trees and each tree's autocorrelation (a measure of how repeatable the ring width history is). These noticably large correlations mean that the tree ring histories could (just as easily) be put together with different temporal offsets than the ones chosen. This would produce a different calibration curve for radiocarbon dating (or increase the uncertainty associated with the published curve.) Dan Watts 01:45, 12 May 2006 (UTC)[reply]

This is a one-sided point of view not validated by peer reviewed publications based on the original measurements and analyses. The specialists literature and databases reliably validate the correlations used for dating either by dendrochronology or by the radiocarbon calibrated scale. 150.135.48.155 03:10, 12 May 2006 (UTC)[reply]

The descriptions of the cross-correlation methods, chronology building, math and software used by the expert researchers, and any other answers about dendrochronological methodology and results are given in the following references:

http://web.utk.edu/~grissino/

http://www.ltrr.arizona.edu/resources.html

For relevant info about the Methuselah chronology (eg, statistics describing the raw measurements file referenced in the graph, cross-correlations, etc) see:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/measurements/correlation-stats/ca535.txt

For the chronology derived from the data referenced in the graph, see:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/chronologies/northamerica/usa/ca535.crn

This discussion has been undertaken in the previous sections, above this one.

150.135.48.155 03:20, 12 May 2006 (UTC)[reply]

While the above references give correlations for the chronology chosen, I have not seen where they address the question of what measure/method was used to choose this particular chronology and how robust the given solution is when compared to some other chronology. Dan Watts 14:55, 18 May 2006 (UTC)[reply]

18 years of no tree rings: someone snapped their fingers, the earth stood still for 18 years. No rotation of axis: annnddd.... NO-one noticed! !..(From the SonoranDesert[a participant in making changes(minor) to this article)])- ...-Mmcannis 02:34, 3 February 2007 (UTC)[reply]

Linkspam discussion for User:Jclerman

I'm a spam fighter and I've been cleaning up the mess left by a mass spammer. User:Jclerman reverted my edit and requested with this diff [2] that the merits of the ast.cac.washington.edu linkspam be discussed here. This spammer has used multiple accounts to add about 200 linkspams in the past month. Here is the evidence:

The ast.cac.washington.edu domain is going to be blacklisted and this will lock editting for any article that has that link. I hereby request that the ast.cac.washington.edu spam link be deleted from this article so that further disruption is avoided. Thank you. (Requestion 06:44, 8 April 2007 (UTC))[reply]

I have replaced it with a researchchannel.org link per User talk:Requestion/Archive_1#The original source for those links. This is a legitimate cable channel hosted by the University of Washington. Graham87 08:39, 8 April 2007 (UTC)[reply]

Replacing the ast.cac.washington.edu links with researchchannel.org links isn't a good idea because when ast.cac.washington.edu is blacklisted so will all of its mirrors. A blacklisted link will lock out all editing of an article until it is removed. This wiki-behavior frustrates lots of new editors who have never experienced it before. (Requestion 18:35, 8 April 2007 (UTC))[reply]

Linda is a well known bona fide scientist. You shouldn't block references to her work. Or you don't believe in global warming? Jclerman 22:27, 8 April 2007 (UTC)[reply]

OK, you seem to know more than I do. Help me here please. Is Linda the one who added 200 external linkspams to Wikipedia? Or was it someone else? (Requestion 08:52, 9 April 2007 (UTC))[reply]

No, and I don't see why she would do that. Many of the videos on that site are unrelated to her work. I've said more on your talk page. Graham87 12:57, 9 April 2007 (UTC)[reply]

"Growth rings"--?

Doesn't anybody else get it, that "growth rings" are in:

bones
teeth
shelled creatures,
and many: etc's....
oh, yeah, and TRee-types, (but not All tree types)(I think)

a note from the SonoranDesert/Ariz. --Mmcannis 21:39, 16 May 2007 (UTC)[reply]

Repeated Sentence

Hello, I'm a passing reader and notice that the sentence starting "Adequate moisture and .." is repeated.

effects of location on dating

The current article (2008-06-30) states that:

it [dendrochronology] can also match location because the climate across Europe is not consistent

I can see how you could match for age based on location or location if you knew the age by linking in with studied artefacts (cores, etc.) that were dated by other means. But, I can't see how you could take a sample and match it to a date and a location. Surely local variations mean that the rings in a tree are markedly different to those in another. Trees on one side of a hill get more sunlight and produce larger rings; trees get different moisture levels. One tree is shaded by a larger one, another isn't, the larger tree dies, the unshaded tree gets shaded by a faster growing neighbour. One tree competes for moisture in dense woodland whilst another stands alone in pasture land. Hence missing rings could occur in one tree but not in another in the same geographic locality. The article states that even different branches have different ring patterns, how does one cross-correlate then? How are such things accounted for? —Preceding unsigned comment added by 91.108.188.144 (talk) 00:12, 30 June 2008 (UTC)[reply]

@@ Line 13: / Line 13: @@
 :: Do I need to pick one of the many Google results (tree "annular ring" width) as a reference?
 :: --[[Special:Contributions/68.0.124.33|68.0.124.33]] ([[User talk:68.0.124.33|talk]]) 18:30, 8 November 2008 (UTC)
+:::The growth ring is the annular region consisting of the earlywood and the subsequent latewood, moving away from the wood center (pith). [[User:Jclerman|Jclerman]] ([[User talk:Jclerman|talk]]) 12:53, 9 November 2008 (UTC)
 == radiocarbon calibration ==