Rings: Questions for Neil
05, 2004 05:16 PDT
ENTS is as much about revering great tree age
as tree size. When the
two attributes go together, the result seems to fit our notion
supposed to happen with trees, but I for one, am also a fan of
For the benefit of our readers, would
you be willing to take the
time to answers a few questions that I suspect are in quite a
When you are next up my way, I owe you a beer or an ice cream
Take your pick. Now to the questions.
1. Which species are easiest to date in terms of ring
2. What's the story with missing rings, false rings, and
3. Which species give the best climate signals?
4. Which trees have provided the greatest surprises for you, Ed,
5. What is the oldest tree you have personally dated?
6. For the species you study, have you observed in north-south
Oops, I think I may have exhausted my
credit? Sorry to ask so many
questions, but inquiring Ents just have to know. It will be
to see how your experience compares with that of Lee's, Dave's,
Questions for Neil
& Neil Pederson
05, 2004 19:10 PDT
OK, Bob. Here are a few answers. I'll try to keep 'em brief.
Which species are easiest to date in terms of ring
It would probably conifers with well-developed latewood bands
red pine and most of the southern pines. Larch, when growing
isn't too bad. Ring porous species, especialy oaks, are not too
either. Diffuse porous species like black gum/tupelo, maple,
can be a nightmare. There are dependencies; depends if they are
suppressed, depends on growth rates, depends if you are looking
rings in the sapwood or heartwood. Rings of diffuse porous
are much easier to deal with in the heartwood. It doesn't make
easy, though [see #2].
What's the story with missing rings, false rings, and
Missing rings are also called locally absent rings. This is a
term since they may be missing only at coring height on one side
the tree. If it were easier to core closer to the crown, there
likely be fewer missing rings. Locally absent rings are
with stress: droughts, cold summers in treeline forests,
events, etc. I've come across some spruce trees in the lower
Valley with 10-15 missing rings over the last 30 years or so.
has made collections from the northernmost trees on Earth, north
Siberia on the Taymir Peninsula. During an extremely cold
good proportion of larch essentially stopped growing or had very
little radial growth. The tech that was working up those cores
went crazy. Crossdating such trees is like solving a complex
or puzzle. I've had the same experience recently with some
suppressed red maple. Hopefully we'll have something written up
that later this year.
For well-studied species [conifers, oaks], false or multiple
are linked to a hiccup in seasonal climate. In conifers, a
wet spring followed by a drought will cause the tree to begin
cells that look like latewood. A resumption of normal to wet
will cause formation or earlywood-like cells. The end of the
season will stimulate the growth of normal latewood cells. This
occurs a lot in southern pines. Larson's book on cambial growth
some amazing pictures of this.
Dave Stahle's PhD was a study of false springs in the midwest.
used oaks and found false bands of growth related to spring
have to admit I haven't studied this work enough yet to discuss
Myvonwynn Hopton has worked up several chronologies of
black birch and cucumbertree, trees not commonly studied via
tree-ring analysis. From her experiences with these trees it
that false rings are a significant problem. One cucumbertree had
false rings on one radii!! We figured this out because the other
radii from that tree "only" had 5 false rings. The
core with 25 false
rings is not datable for much of its inner "80 years."
Which species give the best climate signals?
For the eastern US, this question may cause an arm wrestling
between Dave Stahle and Ed Cook. Baldcypress [Dave] and eastern
hemlock [Ed] are probably the best. Eastern white pine is among
least sensitive. We will be learning much more about eastern
and northern white-cedar soon. Post, white and chestnut oak are
fairly sensitive, especially for drought studies. Tulip-poplar
Atlantic -white-cedar are looking pretty good as new species
study. There is so000o much to discover!
Which trees have provided the greatest surprises for
you, Ed, etc.?
Hmm, this is a hard question. Can't speak for Ed. I'm not sure
species have surprised me as much as situations, but that may be
related to what I'm interested in right now. I get surprised at
trees can handle and what they are capable of: suppressed red
growth [or the lack thereof] or persistence during suppression
chestnut oak. Things like that. The age of a black birch Ed
years ago [>350 years] was a surprise.
What is the oldest tree you have personally dated?
I was lucky to be a tech during the beginning of our lab's
project. As a part of the project I dated [though it was more of
flirtation] a Siberian larch in western Mongolia that dated to
1240s. It was likely a seedling around the time Ghengis Khaan
Asia and was pushing west into eastern Europe. Pretty neat to
In the eastern US the oldest living tree would be a black tupelo
from Saratoga County, NY with an inner ring date of 1436 [not
to the oldest known tupelo].
For the species you study, have you observed in
I've just finished revisions on a paper to be
published later this
year describing higher January temperature sensitivity of white
chestnut oak [and to a lesser degree red oak and pignut hickory]
the southern Hudson Valley versus the same species in the
Adirondack mountains. It was exactly the opposite from what I
expected. The best thing I can surmise is that the lack of
snow cover/pack in the southern HV versus the north plays an
important role in root mortality and drives this temperature
sensitivity. Needs testing though!
I think I may have exhausted my credit?
Nope, not at all. I enjoy ENTS and I'm sorry I don't have the
to reply as much or as promptly as I would like. I learn so much
I hope this wasn't too jargonny. Let me know if some things are
A frosty barely pop would be nice.