The exclusion of evidence
> I don't feel complete with basing my decisions on a solution of evidence unless all of said evidence supports the solution. That is rarely the case however. It seems there is always some sort of fly in the buttermilk somewhere...
I think that what we are doing, if without putting numbers on probabilities, is weighing alternate scenarios and identifying the single scenario that is so much more likely than any plausible other that it has to be the best explanation, the correct answer.
I'm sure we've all worked on problems where there were competing alternate scenarios/explanations no one of which was so obviously more likely as to be the best basis for a conclusion. That situation is nearly invariably resolved by just bearing down and finding more evidence to weigh. The true moment is when one scenario "clicks" and there are no serious discrepancies that remain to suggest some other unexamined, but better, scenario may yet be more probable.
The "ah-hah" moment
When I was a whipper-snapper running around digging up pins I had a difficult time resolving issues between conflicting monuments. I was probably under the impression that all the surveyors prior to me were in some sort of collusion with knowledge that I wasn't privy to.
My ah-hah epiphany came when I realized that there existed on the ground several surveys. To successfully even determine which survey came first I realized I would have to peel the layers off one by one and look at several different surveys, the whole time aligning the forensic field evidence with recorded documents.
Some are wrought with lazy error or incompetence, some are proper perpetuations of the survey that best needs to be retrace. I remember thinking that this "field work" stuff was a lot more complex than digging up two pins and setting a new one on line between the two..
that was my "ah-hah" moment...B-)
The "ah-hah" moment
> My ah-hah epiphany came when I realized that there existed on the ground several surveys. To successfully even determine which survey came first I realized I would have to peel the layers off one by one and look at several different surveys, the whole time aligning the forensic field evidence with recorded documents.
Yes, reconstructing many surveys really does require putting oneself in the shoes of some prior surveyor and taking into account what realistically he (it usually was a "he" back then) had knowledge of. Where things typically go haywire is when some grossly mistaken survey leaves obvious markers that are easy for later surveyors find and use upon the expedient, but lazy, assumption that the earlier surveyor had made a diligent attempt to locate those corners.
unexplained discrepancies
> > I wonder if there are experts in tree hacks/markings both modern and historic. I wonder what they would be called.
>
> It does vary greatly by region and species.I've seen blazes and refs scribed in pines in Northern New Mexico that were near 100 years old.... which it was meant? No one else that I can think of makes their daily bread by interpreting such evidence. Probably only the surveyor that has walked those specific woods for enough time to learn the language is capable.
>
>
> *apologies to Bob Heinlein and Valentine Michael Smith
I was making a rhetorical statement. I don't know what thingy to affix at the end of the sentence.
I read mention of approximate growth rates and I apologize if this was discussed prior, but have you cored the live trees to count the growth rings since the original scar was created?
> I read mention of approximate growth rates and I apologize if this was discussed prior, but have you cored the live trees to count the growth rings since the original scar was created?
No, the growth rate of the Live Oaks was based upon measurements of many bearing trees that have been recovered over the years in the area. a figure in the range of 14 to 16 years per inch is most typical, with outliers only in very shallow or well watered soils (neither of which is the case here) or where the marking had a significant girdling effect (there was no mark at all called for by the 1902 surveyor on the Live Oak). In the case of the 5-inch oak that is standing dead, it would be possible to cut it down to block the scar, but would take some dendrochronological analysis of other living oaks in the vicinity to determine when the tree probably died to get an estimated age on the scar.
As for the Cypress, a figure of 10 years per inch is a typical value for a tree growing along a creek that is seasonally dry. One that grows along a creek or river that is constantly flowing may grow at twice that rate, i.e. about 5 years per inch.
A cypress would certainly be easier to core than a Live Oak, but I'd think about all that could be determined by coring is an estimated growth rate. It would take much more invasive and destructive methods to expose the scar.
I have cored oak trees before with very dense growth rings. It was not easy. I would try a cordless drill next time.
It is possible to intersect the scar and come up with an approximate date range for when it was scarred. That could support or completely disprove a theory.
It will not confirm that it was a man made blaze.
> I have cored oak trees before with very dense growth rings. It was not easy. I would try a cordless drill next time.
>
> It is possible to intersect the scar and come up with an approximate date range for when it was scarred. That could support or completely disprove a theory.
>
> It will not confirm that it was a man made blaze.
Cutting and blocking the 5 in. Live Oak that is standing dead would be the method of choice since it's already dead and blocking will clearly show the profile of the scar (which coring would not, of course). It should give the number of years after the scar that the tree died, but won't determine when the tree died.
It may well be, though, that in the case of a Live Oak that is as stunted as that one appears to be, annual growth rings may be very difficult to distinguish.
One element to Live Oaks that I'd think would be important is that at a normal rate of growth for the Texas Hill Country, i.e. about 16 years per inch of diameter, the ring spacing would be about 32 per inch. On a stunted tree, the ring spacing could be more than 64 per inch.
> One element to Live Oaks that I'd think would be important is that at a normal rate of growth for the Texas Hill Country, i.e. about 16 years per inch of diameter, the ring spacing would be about 32 per inch. On a stunted tree, the ring spacing could be more than 64 per inch.
How do you know that?
So your 40" Live Oak under normal growth as you state is 640 years old but this one could possibly be as much as 914 years.
..and it has grown only 7-10" since 1902.
I find this interesting. Any other tree like this specimen in the area?
I like discussions like these because it gives me reason to spend a few minutes researching and learning about fascinating topics. Dendrochronology is kind of interesting to me.
You don’t have to see the entire tree core or know when a tree died to possibly determine the year a blaze occurred. You only have to match a specific scale pattern to a master chronology specific to your area. Modern digital scanners and image processing software has made ring detection much easier. One software program states that medium sized tree rings (.5mm) can be detected with 80%-100% accuracy with a push of a button.
We usually used the core tool to determine if there was a scar that was made at roughly the correct time period, then we would cut into the tree to look for scribing. Areas around section corners sometimes show the results of exhaustive corner searches. Over the years, people have cut into many trees looking for scribing. The trees have healed over and now all look like potential bearing trees with healed over axe marks. The scribing is something you can hang your hat on.
> > One element to Live Oaks that I'd think would be important is that at a normal rate of growth for the Texas Hill Country, i.e. about 16 years per inch of diameter, the ring spacing would be about 32 per inch. On a stunted tree, the ring spacing could be more than 64 per inch.
>
> How do you know that?
As I noted above: by measurements on actual, identifiable trees.
> So your 40" Live Oak under normal growth as you state is 640 years old but this one could possibly be as much as 914 years.
No, 64 growth rings per inch would be 32 years per inch of diameter. So, if a 5-inch Live Oak were growing at that rate, it would be about 160 years old. This wouldn't be the case in the above example, though, since, judging by the scar, the tree was marked too heavily and appears to have been stunted after marking. It grew at one rate before marking and at another afterwards. In my files, I have examples of this in other heavily marked trees of definite identity.
> ..and it has grown only 7-10" since 1902.
We're discussing two different Live Oaks: the 40 in. Live Oak that is almost certainly the Live Oak that the 1902 surveyor reported as having a diameter of 30 inches and the 5 in. Live Oak standing dead with the hack scar.
> I find this interesting. Any other tree like this specimen in the area?
Yes, I have examples of plenty of Live Oak bearing trees marked at different times between the 1850's and the early 20th century. This is what I base my estimates of growth rates of Live Oak bearing trees upon since it should be understood that a tree with a mark cut into it will not be expected to grow as quickly as one that wasn't marked.
> I like discussions like these because it gives me reason to spend a few minutes researching and learning about fascinating topics. Dendrochronology is kind of interesting to me.
>
> You don’t have to see the entire tree core or know when a tree died to possibly determine the year a blaze occurred. You only have to match a specific scale pattern to a master chronology specific to your area. Modern digital scanners and image processing software has made ring detection much easier. One software program states that medium sized tree rings (.5mm) can be detected with 80%-100% accuracy with a push of a button.
Do they mean the interval at which the spring-summer pattern repeats is 0.5mm or the summerwood ring is 0.5mm wide?
It would be interesting to see how much variation there is in tree ring pattern just from place to place on one tract. When I have a chance, I'll probably cut and block the 5 in. Live Oak that is standing dead and, for comparison, some other dead Live Oak that appears to have been killed by the recent drought, but otherwise to have been growing normally.
> We usually used the core tool to determine if there was a scar that was made at roughly the correct time period, then we would cut into the tree to look for scribing. Areas around section corners sometimes show the results of exhaustive corner searches. Over the years, people have cut into many trees looking for scribing. The trees have healed over and now all look like potential bearing trees with healed over axe marks. The scribing is something you can hang your hat on.
The special problem presented by Live Oaks in Central Texas is that there is a real risk of killing or seriously injuring the tree by making the sort of large cut that would be needed to dissect an old, overgrown mark. In the case of Live Oaks, those old marks are often visible as traces on the bark even after the scar in the wood has overgrown. The other wrinkle with Live Oaks is that you're run the risk of cutting into the trunk only to find that it has a rotted center where the mark had been.
I'm liking ultrasound tomography better and better.
> > > One element to Live Oaks that I'd think would be important is that at a normal rate of growth for the Texas Hill Country, i.e. about 16 years per inch of diameter, the ring spacing would be about 32 per inch. On a stunted tree, the ring spacing could be more than 64 per inch.
> >
> > How do you know that?
>
> As I noted above: by measurements on actual, identifiable trees.
>
> > So your 40" Live Oak under normal growth as you state is 640 years old but this one could possibly be as much as 914 years.
>
> No, 64 growth rings per inch would be 32 years per inch of diameter. So, if a 5-inch Live Oak were growing at that rate, it would be about 160 years old. This wouldn't be the case in the above example, though, since, judging by the scar, the tree was marked too heavily and appears to have been stunted after marking. It grew at one rate before marking and at another afterwards. In my files, I have examples of this in other heavily marked trees of definite identity.
>
> > [b]..and it has grown only 7-10" since 1902.
>
> We're discussing two different Live Oaks: the 40 in. Live Oak that is almost certainly the Live Oak that the 1902 surveyor reported as having a diameter of 30 inches and the 5 in. Live Oak standing dead with the hack scar.
>
> > I find this interesting. Any other tree like this specimen in the area?
>
> Yes, I have examples of plenty of Live Oak bearing trees marked at different times between the 1850's and the early 20th century. This is what I base my estimates of growth rates of Live Oak bearing trees upon since it should be understood that a tree with a mark cut into it will not be expected to grow as quickly as one that wasn't marked.
Kent, I was only discussing the 40" Live Oak.
The great grandfather senior Live Oaks here are estimated to be 1500 years old.
Do they mean the interval at which the spring-summer pattern repeats is 0.5mm or the summerwood ring is 0.5mm wide?
I'm not sure. WinDENDRO is the software I was looking at.
It would be interesting to see how much variation there is in tree ring pattern just from place to place on one tract. When I have a chance, I'll probably cut and block the 5 in. Live Oak that is standing dead and, for comparison, some other dead Live Oak that appears to have been killed by the recent drought, but otherwise to have been growing normally.
You would want to compare the growth rings that occurred prior to the scar (if they were not rotted out). I would bet if you knew where to look, you could identify the 1816 Mount Tambora eruption, where there literally was no summer. Followed by the 1883 Krakatoa eruption. Both of these are said to have significantly affected the growth of trees for several years.
EDIT: Looks like Texas had some major droughts in 1720, 1756, 1822, 1884-1886 (began immediately after the Krakatoa eruption. The 1883-1886 time period looks like it would be the easiest to spot.
> Kent, I was only discussing the 40" Live Oak.
> The great grandfather senior Live Oaks here are estimated to be 1500 years old.
Given a growth rate of between 14 and 16 years per inch for large Live Oaks in the Texas Hill Country, that 40-inch Live Oak is probably between 560 and 640 years old. The apparent growth of about 10 inches in the 112 years between 1902 and 2014 would give a rate of 11 years per inch, which probably is best interpreted as a difference in how the diameter was measured in 1902 and how I measured it.
I measured the circumference and would bet that in 102 it was just eyeballed face on with the vara tape (0.9 varas = 30 inches). To test that idea, I suppose I could go through all of the bearing tree calls I can find that the County Surveyor gave in his field notes in the area between 1889 and 1902 to see if they all would be nearly equivalent to 0.1 vara muliples.
I was thinking that it may have been eyeballed too or wrongly measured.
You know someone may have also wrote an 0 for a 6...:-)
carry on
> I was thinking that it may have been eyeballed too or wrongly measured.
Well, I've looked at other surveys that the same surveyor made in the area and have found bearing trees with the following diameters reported by him:
[pre]
Dia. as Reported Vara Equivalent
12" Cypress (1902) 0.35 varas
30" Live Oak (1902) 0.9
4" Live Oak (1891) 0.12
10" Live Oak (1891) 0.3
10" Live Oak (1891) 0.3
8" Live Oak (1891) 0.25
4" Live Oak (1888) 0.12
20" Live Oak (1888) 0.6
24" Live Oak (1888) 0.7
15" Live Oak (1888) 0.45
[/pre]
It may be that he eyeballed the smaller trees (as one could easily do) and only measured the larger diameter trunks.
