Re: [IUFRO RG 7.02 FORPATH] [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs PLUS other oak dendrochronology question: enclosed phloem
4:43 p.m.
Hi Mike, and others who have responded,
Kevin Smith's review "An organismal view of dendrochronology" in
Dendrochronologia mentions examples of white rings that develop in poplar
and birch in response to insect defoliation or crown loss in winter
storms.
I am not sure what would cause dark rings in oak, but agree that it is
something that is activating a compartmentalization response and/or
creating a barrier zone. Because these occurrences are a complete, single
growth ring that encompasses the whole tree, I suspect an environmental
factor.
Mike, you might check for a correlation between the year of the ring and
winter injury, late or early frost, an extreme winter or summer
temperature event, or maybe even flooding or insect defoliation.
In response to Ed Barnard, I don't think these rings indicate oak wilt, as
infections in white oaks that survive the first year generally show up as
incomplete and spotty dark rings, with additional partial dark rings in
the same affected areas the following year in surviving white oaks. Among
oaks, red oaks die very quickly of oak wilt, so you wouldn't see this long
term survival.
On a different dendrochronology note:
If anyone is familiar with "islands" of enclosed phloem in red or live
oaks that apparently generate a new layer of xylem-generating cambium
after cambium injury please let me know. I have found this response in
several oak species after attack by the cambium-feeding gold-spotted oak
borer (GSOB), Agrilus coxalis, which is now a problem pest in Southern
California.
I am developing methods of back-dating such enclosed phloem to reconstruct
the history of the pest's residence and spread within and among stands,
and determine onset of tree mortality after attacks. So I need to know
other factors -- biotic or environmental -- that may generate similar new
layers of xylem external to patches of enclosed phloem. I have enclosed
pictures of the enclosed phloem and response wood that develops after GSOB
attack if inner phloem has not been killed by very heavy attacks and/or
pathogens associated with this decline.
Thanks!
Paul Zambino
<><><><><><><><><><><><><><><><><><><><><
Paul Zambino, Ph.D.
Plant Pathologist, Forest Health Protection
Southern California Shared Service Area
San Bernardino NF - SO
602 S. Tippecanoe
San Bernardino, CA 92408-3430
Ph: (909)382-2727 FAX: (909)383-5586
Cell: (909)215-0394
Email: pzambino(a)fs.fed.us
<><><><><><><><><><><><><><><><><><><><><
"Barnard, Ed" <barnare(a)doacs.state.fl.us>
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Please respond to
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Re: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Folks (and particularly Mike Albers),
Very interesting! I really have no idea, being for the most
part a Pathologist in Florida dealing primarily with pines. As a
pathologist, a thought comes to mind, but you should try to verify even
the possibility of this with someone who deals with oak wilt (caused by
Ceratocystis fagacearum). You are (as I understand it) in an area where
this disease occurs, and red oaks are susceptible hosts, often displaying
vascular staining or streaking. Most of the time infected red oaks die,
but I do know that if infections of some vascular wilts are not lethal,
recovery can occur, sometimes ?compartmentalizing? the pathogen in
interior vascular tissues ? together with its associated vascular
staining. Any chance that these trees might be oak wilt survivors? This
could possibly be evaluated in a laboratory.
Ed
From: rg70300-forent-bounces(a)lists.iufro.org
[mailto:rg70300-forent-bounces@lists.iufro.org] On Behalf Of Mike Albers
Sent: Thursday, November 19, 2009 11:44 AM
To: rg70300-forent(a)lists.iufro.org
Subject: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Any idea what would cause dark rings in red oak logs as in the attached
pictures?
The dark rings run the length of the logs. So far this has been seen on a
number of sites in 3 or 4 counties in Minnesota. Not all red oak trees on
a site have the dark rings.
My first guess is that it is a barrier zone resulting from a wound or
injury of some type. However it seems strange that it forms a complete
cylinder that reaches the ends of the logs. I didn't see any logs where
the dark ring only went part way around a log. Also there were some logs
that had obvious injuries with decay and discoloration but these logs did
not form rings or even have distinct barrier zones going even part way
around the log.
I've only looked at logs like this while in the mill, not on the site
where they were harvested. At first, the thought was that these rings were
the result of something happening 16 to 17 years ago. This will take more
investigation, but it looks to me like the time period varies anywhere
from 6 to 35 years. Also at this time I can't say if the time period
varies ibetween sites, or if the time period varies from log to log on the
same site.
Any suggestions would be appreciated.
Mike Albers
Forest Health Specialist
MN DNR-Forestry
1201 E. Hwy. # 2
Grand Rapids, MN 55744
(218)-327-4115_______________________________________________
IUFRO Mailing List
To post a message to all list members, send email to:
rg70300-forent(a)lists.iufro.org
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10:34 a.m.
New subject: Enclosed phloem
Thanks Paul for the note to the forum. I'm replying to all with some
trepidation, if we need to confer further on this, just email me.
The apparent islands of enclosed phloem seen in transverse section can
occur with injury from low-intensity fire as well as from other forms of
mechanical injury. The trick is to kill enough of the vascular cambium
locally while allowing enough living tissue to de-differentiate and to
then reorganize to form a new vascular cambium to close the killed area
and isolate the phloem that is now embedded. I can't say that it happens
often, but sure, the bugs aren't the only source of wounds that produce
that effect.
Kevin.
Kevin T. Smith, Ph.D.
Plant Physiologist and Project Leader, Research Work Unit NRS-10
USDA Forest Service
271 Mast Road, Durham, NH 03824, USA
Voice: 603.868.7624 Fax: 603.868.7604
Cell: 207.351.5671
Email: ktsmith(a)fs.fed.us
Paul Zambino <pzambino(a)fs.fed.us>
Sent by: rg70200-forpath-bounces(a)lists.iufro.org
11/24/2009 09:09 AM
To
<rg70300-forent(a)lists.iufro.org>rg>, <rg70200-forpath(a)lists.iufro.org>rg>,
Mike.Albers(a)dnr.state.mn.us
cc
Subject
Re: [IUFRO RG 7.02 FORPATH] [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red
oak logs PLUS other oak dendrochronology question: enclosed phloem
Hi Mike, and others who have responded,
Kevin Smith's review "An organismal view of dendrochronology" in
Dendrochronologia mentions examples of white rings that develop in poplar
and birch in response to insect defoliation or crown loss in winter
storms.
I am not sure what would cause dark rings in oak, but agree that it is
something that is activating a compartmentalization response and/or
creating a barrier zone. Because these occurrences are a complete, single
growth ring that encompasses the whole tree, I suspect an environmental
factor.
Mike, you might check for a correlation between the year of the ring and
winter injury, late or early frost, an extreme winter or summer
temperature event, or maybe even flooding or insect defoliation.
In response to Ed Barnard, I don't think these rings indicate oak wilt, as
infections in white oaks that survive the first year generally show up as
incomplete and spotty dark rings, with additional partial dark rings in
the same affected areas the following year in surviving white oaks. Among
oaks, red oaks die very quickly of oak wilt, so you wouldn't see this long
term survival.
On a different dendrochronology note:
If anyone is familiar with "islands" of enclosed phloem in red or live
oaks that apparently generate a new layer of xylem-generating cambium
after cambium injury please let me know. I have found this response in
several oak species after attack by the cambium-feeding gold-spotted oak
borer (GSOB), Agrilus coxalis, which is now a problem pest in Southern
California.
I am developing methods of back-dating such enclosed phloem to reconstruct
the history of the pest's residence and spread within and among stands,
and determine onset of tree mortality after attacks. So I need to know
other factors -- biotic or environmental -- that may generate similar new
layers of xylem external to patches of enclosed phloem. I have enclosed
pictures of the enclosed phloem and response wood that develops after GSOB
attack if inner phloem has not been killed by very heavy attacks and/or
pathogens associated with this decline.
Thanks!
Paul Zambino
<><><><><><><><><><><><><><><><><><><><><
Paul Zambino, Ph.D.
Plant Pathologist, Forest Health Protection
Southern California Shared Service Area
San Bernardino NF - SO
602 S. Tippecanoe
San Bernardino, CA 92408-3430
Ph: (909)382-2727 FAX: (909)383-5586
Cell: (909)215-0394
Email: pzambino(a)fs.fed.us
<><><><><><><><><><><><><><><><><><><><><
"Barnard, Ed" <barnare(a)doacs.state.fl.us>
Sent by: rg70300-forent-bounces(a)lists.iufro.org
11/21/2009 11:09 AM
Please respond to
"IUFRO RG 7.03.00" <rg70300-forent(a)lists.iufro.org>
To
"IUFRO RG 7.03.00" <rg70300-forent(a)lists.iufro.org>
cc
Subject
Re: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Folks (and particularly Mike Albers),
Very interesting! I really have no idea, being for the most
part a Pathologist in Florida dealing primarily with pines. As a
pathologist, a thought comes to mind, but you should try to verify even
the possibility of this with someone who deals with oak wilt (caused by
Ceratocystis fagacearum). You are (as I understand it) in an area where
this disease occurs, and red oaks are susceptible hosts, often displaying
vascular staining or streaking. Most of the time infected red oaks die,
but I do know that if infections of some vascular wilts are not lethal,
recovery can occur, sometimes ?compartmentalizing? the pathogen in
interior vascular tissues ? together with its associated vascular
staining. Any chance that these trees might be oak wilt survivors? This
could possibly be evaluated in a laboratory.
Ed
From: rg70300-forent-bounces(a)lists.iufro.org
[mailto:rg70300-forent-bounces@lists.iufro.org] On Behalf Of Mike Albers
Sent: Thursday, November 19, 2009 11:44 AM
To: rg70300-forent(a)lists.iufro.org
Subject: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Any idea what would cause dark rings in red oak logs as in the attached
pictures?
The dark rings run the length of the logs. So far this has been seen on a
number of sites in 3 or 4 counties in Minnesota. Not all red oak trees on
a site have the dark rings.
My first guess is that it is a barrier zone resulting from a wound or
injury of some type. However it seems strange that it forms a complete
cylinder that reaches the ends of the logs. I didn't see any logs where
the dark ring only went part way around a log. Also there were some logs
that had obvious injuries with decay and discoloration but these logs did
not form rings or even have distinct barrier zones going even part way
around the log.
I've only looked at logs like this while in the mill, not on the site
where they were harvested. At first, the thought was that these rings were
the result of something happening 16 to 17 years ago. This will take more
investigation, but it looks to me like the time period varies anywhere
from 6 to 35 years. Also at this time I can't say if the time period
varies ibetween sites, or if the time period varies from log to log on the
same site.
Any suggestions would be appreciated.
Mike Albers
Forest Health Specialist
MN DNR-Forestry
1201 E. Hwy. # 2
Grand Rapids, MN 55744
(218)-327-4115_______________________________________________
IUFRO Mailing List
To post a message to all list members, send email to:
rg70300-forent(a)lists.iufro.org
List info and Archive:
http://www.iufro.org/science/iufro-mailing-lists/overview/ [attachment
"IMG_1261 Q Agrif GSOB attacks sm.JPG" deleted by Kevin Smith/NRS/USDAFS]
[attachment "IMG_1291 Q Agrif Possible GSOB layers sm.JPG" deleted by
Kevin Smith/NRS/USDAFS] [attachment "IMG_0386 Q agrif GSOB response
crpsm.JPG" deleted by Kevin Smith/NRS/USDAFS] [attachment
"IMG_0244crp1sm.JPG" deleted by Kevin Smith/NRS/USDAFS]
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2:45 p.m.
New subject: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs PLUS other oak dendrochronology question: enclosed phloem
Hi Paul,
I've seen a similar phenomenon in smooth-barked (young) Japanese
chestnut trees inoculated with Cryphonectria parasitica using a cork
borer wound extending to the vascular cambium. The infection runs
along the vascular cambium, destroying it, but does not extend up to
the outer periderm. True callus forms in the secondary phloem (a
component of bark), grows outward from the infected area and
lignifies. A new vascular cambium differentiates and hooks up with
the original vascular cambium where that has not been infected.
Meanwhile, the phellogen in the outer periderm continues to be
active, and it expands in response to the growing callus, so the
phelloderm is not disfigured. The net result is an inclusion of
infected xylem and phloem (bark) tissues.
This also occurs in scarlet oak (Q. coccinea) in response to C.
parasitica, resulting in the swollen butt syndrome described by Nash
and Stambaugh. That syndrome would be the example you are requesting
in oak.
I've attached some pictures, with some annotation below each
picture. The annotation below the last picture turns into a more
general discussion. If needed, I can annotate the tissues in the
photos, but hope not to in the interest of time. What you can see
here are fairly clear examples of the developmental anatomy of the
phenomenon.
Fred
Frederick V. Hebard, PhD
Staff Pathologist, Meadowview Research Farms
American Chestnut Foundation
14005 Glenbrook Ave.
Meadowview, VA 24361
Email: Fred(a)acf.org
Web: http://www.acffarms.org
Phone: (276) 944-4631
Fax: (276) 944-0934
On Nov 23, 2009, at 3:43 PM, Paul Zambino wrote:
Hi Mike, and others who have responded,
Kevin Smith's review "An organismal view of dendrochronology" in
Dendrochronologia mentions examples of white rings that develop in
poplar and birch in response to insect defoliation or crown loss in
winter storms.
I am not sure what would cause dark rings in oak, but agree that it
is something that is activating a compartmentalization response and/
or creating a barrier zone. Because these occurrences are a
complete, single growth ring that encompasses the whole tree, I
suspect an environmental factor.
Mike, you might check for a correlation between the year of the
ring and winter injury, late or early frost, an extreme winter or
summer temperature event, or maybe even flooding or insect
defoliation.
In response to Ed Barnard, I don't think these rings indicate oak
wilt, as infections in white oaks that survive the first year
generally show up as incomplete and spotty dark rings, with
additional partial dark rings in the same affected areas the
following year in surviving white oaks. Among oaks, red oaks die
very quickly of oak wilt, so you wouldn't see this long term survival.
On a different dendrochronology note:
If anyone is familiar with "islands" of enclosed phloem in red or
live oaks that apparently generate a new layer of xylem-generating
cambium after cambium injury please let me know. I have found this
response in several oak species after attack by the cambium-feeding
gold-spotted oak borer (GSOB), Agrilus coxalis, which is now a
problem pest in Southern California.
I am developing methods of back-dating such enclosed phloem to
reconstruct the history of the pest's residence and spread within
and among stands, and determine onset of tree mortality after
attacks. So I need to know other factors -- biotic or environmental
-- that may generate similar new layers of xylem external to
patches of enclosed phloem. I have enclosed pictures of the
enclosed phloem and response wood that develops after GSOB attack
if inner phloem has not been killed by very heavy attacks and/or
pathogens associated with this decline.
Thanks!
Paul Zambino
Clemson F2s 1990 Jap 2-3:93
The inoculation point is at 3 o'clock. Multiple islands of true
callus formed around here and merged. Sometimes only one island
forms. The new vascular cambium is visible at 5 and 6 o'clock and
merged with the old at 7:30 o'clock. At 7 o'clock the infection has
extended outward from the original vascular cambuim to infect the new.
Clemson F2s 1990 Jap outside 2-3:93
Intact outer periderm at point of inoculation. Round inoculation
hole now only a slit, almost completely occluded by expansion of true
callus and outlying bark tissues.
Clemson F2s 1990 Jap cut 2-3:93
Tangential section through phloem and lignified true callus.
Clemson F2s 1990 Jap x-sect 2-3:9
The inoculation point is at 3 o'clock. The new cambium did not hook
up with the old one here because the fungus invaded out from the
cambium to the outer periderm at 7 and 11 o'clock. This is similar
to how the dutch elm disease fungus colonizes out into the phloem
from xylem, as described by B_____ (Clyde Brashier?) in Canada in the
70s. That invasion by the dutch elm disease fungus is also similar
to how Verticillium albo-atrum colonizes out from the xylem of
alfalfa. Both wilt fungi entering into a perthophytic phase
subsequent to a more-or-less biotrophic phase in the xylem.
<><><><><><><><><><><><><><><><><><><><><
Paul Zambino, Ph.D.
Plant Pathologist, Forest Health Protection
Southern California Shared Service Area
San Bernardino NF - SO
602 S. Tippecanoe
San Bernardino, CA 92408-3430
Ph: (909)382-2727 FAX: (909)383-5586
Cell: (909)215-0394
Email: pzambino(a)fs.fed.us
<><><><><><><><><><><><><><><><><><><><><
"Barnard, Ed" <barnare(a)doacs.state.fl.us>
Sent by: rg70300-forent-bounces(a)lists.iufro.org
11/21/2009 11:09 AM
Please respond to
"IUFRO RG 7.03.00" <rg70300-forent(a)lists.iufro.org>
To
"IUFRO RG 7.03.00" <rg70300-forent(a)lists.iufro.org>
cc
Subject
Re: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Folks (and particularly Mike Albers),
Very interesting! I really have no idea, being for the
most part a Pathologist in Florida dealing primarily with pines.
As a pathologist, a thought comes to mind, but you should try to
verify even the possibility of this with someone who deals with oak
wilt (caused by Ceratocystis fagacearum). You are (as I understand
it) in an area where this disease occurs, and red oaks are
susceptible hosts, often displaying vascular staining or
streaking. Most of the time infected red oaks die, but I do know
that if infections of some vascular wilts are not lethal, recovery
can occur, sometimes “compartmentalizing” the pathogen in interior
vascular tissues – together with its associated vascular staining.
Any chance that these trees might be oak wilt survivors? This
could possibly be evaluated in a laboratory.
Ed
<mime-attachment.jpeg>
From: rg70300-forent-bounces(a)lists.iufro.org [mailto:rg70300-forent-
bounces(a)lists.iufro.org] On Behalf Of Mike Albers
Sent: Thursday, November 19, 2009 11:44 AM
To: rg70300-forent(a)lists.iufro.org
Subject: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Any idea what would cause dark rings in red oak logs as in the
attached pictures?
The dark rings run the length of the logs. So far this has been
seen on a number of sites in 3 or 4 counties in Minnesota. Not all
red oak trees on a site have the dark rings.
My first guess is that it is a barrier zone resulting from a wound
or injury of some type. However it seems strange that it forms a
complete cylinder that reaches the ends of the logs. I didn't see
any logs where the dark ring only went part way around a log. Also
there were some logs that had obvious injuries with decay and
discoloration but these logs did not form rings or even have
distinct barrier zones going even part way around the log.
I've only looked at logs like this while in the mill, not on the
site where they were harvested. At first, the thought was that
these rings were the result of something happening 16 to 17 years
ago. This will take more investigation, but it looks to me like
the time period varies anywhere from 6 to 35 years. Also at this
time I can't say if the time period varies ibetween sites, or if
the time period varies from log to log on the same site.
Any suggestions would be appreciated.
Mike Albers
Forest Health Specialist
MN DNR-Forestry
1201 E. Hwy. # 2
Grand Rapids, MN 55744
(218)-327-4115_______________________________________________
IUFRO Mailing List
To post a message to all list members, send email to: rg70300-
forent(a)lists.iufro.org
List info and Archive: http://www.iufro.org/science/iufro-mailing-
lists/overview/
<mime-attachment.jpeg><IMG_1261 Q Agrif GSOB attacks
sm.JPG><IMG_1291 Q Agrif Possible GSOB layers sm.JPG><IMG_0386 Q
agrif GSOB response
crpsm.JPG><IMG_0244crp1sm.JPG>________________________________________
_______
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noon
New subject: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs PLUS other oak dendrochronology question: enclosed phloem
Hi Colleagues,
This is from my view, caused due to frost damage. You can find this on oaks
and other plants like Euonymus, Ilex, Douglas-fir ... The injured xylem
temporarily conducts enough water to allow functions, which also allows
formation of new sapwood outside the damaged tissue. All this particularly
when the frost is not severe enough to kill, phloem, cambium or sapwood.
Check the book of Sinclair and Lyon: Diseases of Trees and Shrubs. There are
some images under frost and freeze damage that resemble what you have on
oaks.
I do not think there is any biotic organism on oaks that can do this.
Cheers,
Yilmaz
Yilmaz Balci, Ph.D.
Assistant Professor
University of Maryland
Department of Plant Sciences and Landscape Architecture
2114 Plant Science Building
College Park, MD, 20742-4452
Phone (office-2114): 301_405 9744
Phone (lab-2180): 301_405 0314
Fax: 301_314 9308
http://www.psla.umd.edu
On 11/24/09 1:45 PM, "Fred Hebard" <Fred(a)acf.org> wrote:
Hi Paul,
I've seen a similar phenomenon in smooth-barked (young) Japanese
chestnut trees inoculated with Cryphonectria parasitica using a cork
borer wound extending to the vascular cambium. The infection runs
along the vascular cambium, destroying it, but does not extend up to
the outer periderm. True callus forms in the secondary phloem (a
component of bark), grows outward from the infected area and
lignifies. A new vascular cambium differentiates and hooks up with
the original vascular cambium where that has not been infected.
Meanwhile, the phellogen in the outer periderm continues to be
active, and it expands in response to the growing callus, so the
phelloderm is not disfigured. The net result is an inclusion of
infected xylem and phloem (bark) tissues.
This also occurs in scarlet oak (Q. coccinea) in response to C.
parasitica, resulting in the swollen butt syndrome described by Nash
and Stambaugh. That syndrome would be the example you are requesting
in oak.
I've attached some pictures, with some annotation below each
picture. The annotation below the last picture turns into a more
general discussion. If needed, I can annotate the tissues in the
photos, but hope not to in the interest of time. What you can see
here are fairly clear examples of the developmental anatomy of the
phenomenon.
Fred
Frederick V. Hebard, PhD
Staff Pathologist, Meadowview Research Farms
American Chestnut Foundation
14005 Glenbrook Ave.
Meadowview, VA 24361
Email: Fred(a)acf.org
Web: http://www.acffarms.org
Phone: (276) 944-4631
Fax: (276) 944-0934
On Nov 23, 2009, at 3:43 PM, Paul Zambino wrote:
Hi Mike, and others who have responded,
Kevin Smith's review "An organismal view of dendrochronology" in
Dendrochronologia mentions examples of white rings that develop in
poplar and birch in response to insect defoliation or crown loss in
winter storms.
I am not sure what would cause dark rings in oak, but agree that it
is something that is activating a compartmentalization response and/
or creating a barrier zone. Because these occurrences are a
complete, single growth ring that encompasses the whole tree, I
suspect an environmental factor.
Mike, you might check for a correlation between the year of the
ring and winter injury, late or early frost, an extreme winter or
summer temperature event, or maybe even flooding or insect
defoliation.
In response to Ed Barnard, I don't think these rings indicate oak
wilt, as infections in white oaks that survive the first year
generally show up as incomplete and spotty dark rings, with
additional partial dark rings in the same affected areas the
following year in surviving white oaks. Among oaks, red oaks die
very quickly of oak wilt, so you wouldn't see this long term survival.
On a different dendrochronology note:
If anyone is familiar with "islands" of enclosed phloem in red or
live oaks that apparently generate a new layer of xylem-generating
cambium after cambium injury please let me know. I have found this
response in several oak species after attack by the cambium-feeding
gold-spotted oak borer (GSOB), Agrilus coxalis, which is now a
problem pest in Southern California.
I am developing methods of back-dating such enclosed phloem to
reconstruct the history of the pest's residence and spread within
and among stands, and determine onset of tree mortality after
attacks. So I need to know other factors -- biotic or environmental
-- that may generate similar new layers of xylem external to
patches of enclosed phloem. I have enclosed pictures of the
enclosed phloem and response wood that develops after GSOB attack
if inner phloem has not been killed by very heavy attacks and/or
pathogens associated with this decline.
Thanks!
Paul Zambino
Clemson F2s 1990 Jap 2-3:93
The inoculation point is at 3 o'clock. Multiple islands of true
callus formed around here and merged. Sometimes only one island
forms. The new vascular cambium is visible at 5 and 6 o'clock and
merged with the old at 7:30 o'clock. At 7 o'clock the infection has
extended outward from the original vascular cambuim to infect the new.
Clemson F2s 1990 Jap outside 2-3:93
Intact outer periderm at point of inoculation. Round inoculation
hole now only a slit, almost completely occluded by expansion of true
callus and outlying bark tissues.
Clemson F2s 1990 Jap cut 2-3:93
Tangential section through phloem and lignified true callus.
Clemson F2s 1990 Jap x-sect 2-3:9
The inoculation point is at 3 o'clock. The new cambium did not hook
up with the old one here because the fungus invaded out from the
cambium to the outer periderm at 7 and 11 o'clock. This is similar
to how the dutch elm disease fungus colonizes out into the phloem
from xylem, as described by B_____ (Clyde Brashier?) in Canada in the
70s. That invasion by the dutch elm disease fungus is also similar
to how Verticillium albo-atrum colonizes out from the xylem of
alfalfa. Both wilt fungi entering into a perthophytic phase
subsequent to a more-or-less biotrophic phase in the xylem.
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<><><><><><><><><><><><><><><><><><><><><
Paul Zambino, Ph.D.
Plant Pathologist, Forest Health Protection
Southern California Shared Service Area
San Bernardino NF - SO
602 S. Tippecanoe
San Bernardino, CA 92408-3430
Ph: (909)382-2727 FAX: (909)383-5586
Cell: (909)215-0394
Email: pzambino(a)fs.fed.us
<><><><><><><><><><><><><><><><><><><><><
"Barnard, Ed" <barnare(a)doacs.state.fl.us>
Sent by: rg70300-forent-bounces(a)lists.iufro.org
11/21/2009 11:09 AM
Please respond to
"IUFRO RG 7.03.00" <rg70300-forent(a)lists.iufro.org>
To
"IUFRO RG 7.03.00" <rg70300-forent(a)lists.iufro.org>
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Subject
Re: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Folks (and particularly Mike Albers),
Very interesting! I really have no idea, being for the
most part a Pathologist in Florida dealing primarily with pines.
As a pathologist, a thought comes to mind, but you should try to
verify even the possibility of this with someone who deals with oak
wilt (caused by Ceratocystis fagacearum). You are (as I understand
it) in an area where this disease occurs, and red oaks are
susceptible hosts, often displaying vascular staining or
streaking. Most of the time infected red oaks die, but I do know
that if infections of some vascular wilts are not lethal, recovery
can occur, sometimes ³compartmentalizing² the pathogen in interior
vascular tissues together with its associated vascular staining.
Any chance that these trees might be oak wilt survivors? This
could possibly be evaluated in a laboratory.
Ed
<mime-attachment.jpeg>
From: rg70300-forent-bounces(a)lists.iufro.org [mailto:rg70300-forent-
bounces(a)lists.iufro.org] On Behalf Of Mike Albers
Sent: Thursday, November 19, 2009 11:44 AM
To: rg70300-forent(a)lists.iufro.org
Subject: [IUFRO RG 7.03 FORENT] Fwd: Dark rings in red oak logs
Any idea what would cause dark rings in red oak logs as in the
attached pictures?
The dark rings run the length of the logs. So far this has been
seen on a number of sites in 3 or 4 counties in Minnesota. Not all
red oak trees on a site have the dark rings.
My first guess is that it is a barrier zone resulting from a wound
or injury of some type. However it seems strange that it forms a
complete cylinder that reaches the ends of the logs. I didn't see
any logs where the dark ring only went part way around a log. Also
there were some logs that had obvious injuries with decay and
discoloration but these logs did not form rings or even have
distinct barrier zones going even part way around the log.
I've only looked at logs like this while in the mill, not on the
site where they were harvested. At first, the thought was that
these rings were the result of something happening 16 to 17 years
ago. This will take more investigation, but it looks to me like
the time period varies anywhere from 6 to 35 years. Also at this
time I can't say if the time period varies ibetween sites, or if
the time period varies from log to log on the same site.
Any suggestions would be appreciated.
Mike Albers
Forest Health Specialist
MN DNR-Forestry
1201 E. Hwy. # 2
Grand Rapids, MN 55744
(218)-327-4115_______________________________________________
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<mime-attachment.jpeg><IMG_1261 Q Agrif GSOB attacks
sm.JPG><IMG_1291 Q Agrif Possible GSOB layers sm.JPG><IMG_0386 Q
agrif GSOB response
crpsm.JPG><IMG_0244crp1sm.JPG>________________________________________
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3 comments
4 participants
participants (4)
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Fred Hebard -
Kevin Smith -
Paul Zambino -
Yilmaz Balci