Red maple controversy   Robert Leverett
  Feb 16, 2007 10:25 PST 


   The Robinson State Park debate has brought up an interesting question
about the role, or potential role, of red maple in the Park under
several scenarios:

1. No management action,
2. Management actions aimed at regenerating species like oak and pine,
which drive the present plans to thin,
3. Selective management actions aimed specifically at reducing the
abundance of red maple.

I have mixed feelings about the future role in Robinson State Park.
Presently, its distribution presents no problems and the areas of mature
forest cover are in no danger of being over-run by red maple in the
foreseeable future. However, I would assume that its abundance is on an
upward trajectory. Regrettably, that trajectory has been exaggerated
somewhat in discussions about the species, but red maple is likely to
increase in abundance in the future. At least, that is the way Dr. Lee
Frelich sees it, as does DCR foresters.

My questions to those of you on the list, willing to share your
expertise follow.

1. What circumstances/events do you observe that lead to the most rapid
increases of red maple?
2. Under what conditions/actions is its presence most easily controlled?

3. Do you consider its rise in abundance good, bad, or neutral?
4. What pluses do you see for red maple? Value to wildlife, beauty,
5. What negatives do you see for the species?

One point I will make about the present abundance of red maple and where
you find it is this. I never see it in great abundance in Northeastern
old growth. I only see it abundantly represented where the forest has
been disturbed within the past 100+ years, usually as a consequence of
human activities. Timber-related activities, especially high grading,
often results in an increased abundance of red maple –although timber
harvesters are in a state of denial about this. While I have no doubt
that proper silvicultural treatments can control the surge of red maple,
the present growth in abundance, at least across Massachusetts, is more
the result of human activity than that of nature taking its course.
However, there are probably plenty of shades of gray needed in answers
to the above questions to avoid over-simplified descriptions of the role
of red ample. I would like to flush out as many of the details as
possible. Any observations any of you would care to make will be most
appreciated. I am especially interested in the experiences of the
foresters and forest ecologists among us, but comments by all are most

As I final comment, my questions are meant to spark a professional
debate about the silvics of the species and not to pass judgment on what
has been happening in Robinson State Park. The red maple debate has
existed outside of Robinson for years and is far from being resolved. So
perhaps it is time to bring the issue front and center.


Robert T. Leverett
Cofounder, Eastern Native Tree Society
Re: Red maple controversy
  Feb 16, 2007 11:40 PST 

I have lots of thoughts on red maple and high grading and I will try to put
some of those thoughts down over the weekend.

Deer like red maple sprouts and the proliferation of red maple trees in lots
of situations is because it sprouts so well from the stump.

Also, between 1965 and 2005 there was a very weak timber market for sugar
maple and even a weaker market for sugar maple's less favored cousin red maple.
I can recall administering timber sales in Massachusetts in the 1970's when
loggers would cut down perfect quality 18-20" DBH red maples because they
were marked as part of the sale but leave them in the woods because no one
would buy the logs or lumber. Now that the global furniture industry has moved
to China and maple from Russia is cheap and in demand for furniture we are
seeing an unprecedented demand for all maple. this time red maple is bringing as much money as red oak

Given that we went though a 4 decade period when Acer spp. was not in any
kind of demand it was often left as a dominant portion of residual stands after
harvesting. Maple trees tend to hold on to their ability to respond to
release better than many other species and so many valueless trees were left
after logging that they have quickly taken over and begun to dominate many woods.
Unfortunately red maple is such a brittle tree that anything can cause them
to degrade.

High grading is real and I believe red maple is one of the primary
beneficiaries of forest mismanagement in hardwoods.

Red maple generally make horrible wildlife den trees. They will rot and
develop hollows but the branches in the crown and bole tend to leave main trunk
of the tree at an acute upward angle...when the branches break or die, they
tend to leave openings that gather or accumulate moisture.   Critters don't do
as well living in a wet log. Sugar maple tends to have branches that can
come off the bole at a little more of a right angle and they often form the kind
of hole in the side of a upper tree stem you could imagine a raccoon being
photographed looking out from.

RE: Red maple controversy   Robert Leverett
  Feb 16, 2007 12:01 PST 


   Thanks for the quick response. Your expertise is extremely valuable.
I hope other foresters will weigh in.

   I was looking at the U.S. Forest Service Silvics Manual and came
across the following:

"Presently, red maple is important in many stands where it was formerly
a limited associate; it is enabled to increase by disturbances such as
disease, windthrow, fire, and harvesting. In southeastern Ohio, 6 years
after clear-cutting, a 3.4 ha (8.5 acres) mature oak-hickory stand, the
new stand contained more tan 2,200 red maple seedlings per hectare
taller than 1.4 m together with many yellow-poplar seedlings. The
original stand on the plot contained no red maple. There were occasional
red maples in nearby stands."

    One of the prescriptions from some of the public forestry agencies
(no need to name names) if my memory serves me correctly, for dealing
with the growth of red maple was clear-cutting. It never made much sense
to me. What is the prescription for its control in West Virginia?

RE: Red maple controversy   Ray Weber
  Feb 16, 2007 12:28 PST 

Thanks Russ. This current forest is mature with predominantly
oak, with some white birch, and some red maple mainly in
wetlands. The plan is to harvest, do ground scarification,
in theory to favor the oaks. The main question is, will this
harvest improve the possibility of red maple invading the closed
canopy forest in the future, or will leaving it as-is,
closed canopy and intact, lessen that possibility. Invasives
were mentioned as a threat here also. Also what is the problem
if red maple did become prominent? Its a native species up here.

Re: Red maple controversy
  Feb 16, 2007 12:39 PST 

Generally, no one is trying to control the spread of the tree but an awful
lot of foresters here are hoping red maple is a tree with a long commercial
future. It is not the high quality trees there are too many of, it is the
crappy ones that tend to dominate. Unfortunately crappy ones are what are being
favored as a primary stand component.

In most places red maple is less than 5% of the forest we have here but I
have worked in older second and third growth areas where as much as 20% of the
basal area is red is still a lot different than yellow poplar than
can develop in natural stands with 96-100% of the overstory poplar.

If the red maple is not stump sprout type of growth 10-15% of the stand is
about as much red maple as you will find. What I really like to see is
recently cut over land with a residual forest that is 50% hickory, 20% black
gum,15% beech and 15% red maple (NOT)...especially when you conduct a stump count
and realize that before logging the overstory of the area was 75-80% red,
white and black oak. In situations like this red maple can occupy 70% of the
overstory within fifteen years.

Re: Red maple controversy
  Feb 16, 2007 14:15 PST 

There is no problem with red maple dominating a forest but it is a tree of
limited utility to other non vegetative forest inhabitants. One thing that I
have noticed is red maple's ability to beat the crowns of neighboring trees to
pieces. Some trees are hard on their neighbors and red maple is worse than
many....ever notice what white pine tops look like when red maple is a
major stand component...especially if the red maples are co dominant?

RE: Red maple controversy   Ray Weber
  Feb 16, 2007 15:32 PST 

Ahh, thanks Russ. If its not dominating already, what is the risk that
it will "take over" long term? What are your feelings on an effect a
timber harvest taking oak out of that area would have on it, with
scarifiction of the understory taking place? Will that increase the odds
it will "invade"? The fear coming forth is that long term, red maple is
going to dominate the forest IF a timber harvest doesnt take place.

Re: Red maple controversy   John A. Keslick, Jr.
  Feb 16, 2007 15:32 PST 

I would suggest the tree farm treatments should keep these items in mind
when making decisions. Surely not the last word on the topic.

The address is case sensitive.

Ignorance of tree biology has been, and still is, the major cause of tree
problems worldwide.


John A. Keslick, Jr.
RE: Red maple controversy   Steve Galehouse
  Feb 16, 2007 15:34 PST 


   When I see red maple in old woods in my area it is often a canopy
constituent with a good clean bole and good sized--often 2' or more in
diameter, but never very frequent, either in the canopy or as part of
the understory.
   In disturbed areas like old fields and along highways red maple is
typically very common and multi-trunked, and generally found with tupelo
in the poorly drained areas or with green and white ash in the better
drained areas, with pin oak found in both. I've wondered if the reason
the red maples are so often multi-trunked in these areas might be due to
deer browse/rub or even rabbit damage as a sapling. These disturbed
areas will never produce a big woods, and the combination of maple and
tupelo or ash is aesthetically pleasing, especially in fall, so I see a
value there.
   It will be interesting to see if red maple replaces ash in these
disturbed areas to become even more common. The EAB is already here in
Cuyahoga County (Cleveland) and spreading rapidly along highway corridors.

Steve Galehouse
Re: Red maple controversy   Lee Frelich
  Feb 16, 2007 15:55 PST 


Red maple takes over in:

1. Temperate oak, white and red pine forests that have not had fire for the
last century (i.e. north central WI)
2. Cold temperate savannas that have not had fire for a long time (central WI)
3. Harvests in temperate oak and pine where red maple is left behind
(everywhere in the temperate zone)
4. Boreal red pine and black spruce forests that are experiencing warming
climate and lack of fire (Boundary Waters, MN)

Red maple can be controlled by frequent fire (Itasca State Park prescribed
burns are an example), by mechanical removal, and by late successional
species such as sugar maple and hemlock (it remains a component of the
forest, but seedlings are limited by shade, the Porcupine Mountains are an

The pluses for red maple are tourist attraction during October, it is used
to make paper and cardboard. It reaches huge sizes in old growtrh forests.
Negatives--it is taking over the temperate and southern boreal zones and
excluding other species.


RE: Red maple controversy   Ray Weber
  Feb 16, 2007 16:14 PST 

Lee would it be possible to simply control the red maple if it is seen,
rather than harvest to control it? Pull the seedlings that show by hand

There isnt a lot of red maple in most areas excepting one stand that I
know of thats an older stand of it. That stand is great looking in the
fall, and adds another good looking piece to the forest. Its in a
relatively wet area.

RE: Red maple controversy   Lee Frelich
  Feb 17, 2007 11:11 PST 


Yes, it is always possible for people to selectively weed the forest, but
that takes a fair amount of labor.

RE: Red maple controversy
  Feb 17, 2007 11:52 PST 
Would harvesting an area and grubbing out the understory and
scarifying ncrease the chances red maple would "invade", or would
leaving the canopy closed and understory intact be less of a

Re: Red maple controversy
  Feb 17, 2007 13:49 PST 

I cannot imagine a situation in the eastern forest where efforts to
specifically attack red maple are under consideration. I think that the germination
of red maple seeds can be incredible but I think that red maple seedlings are
so much favored as deer food that in even-aged situations, like a hard
timber harvest can cause, as many as 99% of the 40,000 seedlings per acre you can
start with will die within twenty years ...However, that still leaves 400 per
acre if there is no other competition.

Digging and pulling should be reserved for invasive and non native species
like Ailanthus (tree of heaven)

RE: Red Maple Discussion   Greenaway, Elinor
  Feb 20, 2007 11:05 PST 

" without fire the tulip poplar will not propagate " simply an incorrect statement. I am not sure what this discussion
is predicated on, but I'd suggest you contact the School of Forest
Resources at the University of Massachusetts and ask some of the
foresters there to chime in. There is quite a bit of fire ecology
expertise there and perhaps the folks in the state's own public
university can have some sway with the state forester.

I assume from this is the state forester's attitude that Mass. is not
green certified?

Lin Greenaway
(from state forest that IS green certified)

Red Maple Discussion - back to Roger   Robert Leverett
  Feb 21, 2007 08:21 PST 


    Gary Beluzo and I hope to put red maple ecology on the fall agenda
of the Forest Summit Lecture Series. In terms of speakers on the
subject, I know David Foster and am acquainted with Bill Patterson. Both
would make excellent speakers. David Foster has spoken at the Forest
Summit Lecture Series in the past.

    What makes the ascendency of red maple such a controversial issue is
the role that careless timber harvesting has played in the past, to
include the high grading that we see so much of in the Northeast. The
application of good silvicultural techniques is certainly one way of
dealing with what foresters usually regard as a growing problem, i.e too
much red maple. I have no doubt that the right kind of silviculture can
deal with an over-abundance of red maple, where it is deemed to be a
problem. But I am dubious about many of the timber operations that I
see. They don't look like good silviculture to me. So I am caught in the
un-enviable position of supporting a concept, and disparaging its actual

    What is unclear to me is how fast red maple spreads in various areas
of its range through natural processes. I'm 100% sure that logging
operations, which don't implement targeted silvicultural treatments
appropriate to the kind of regeneration desired, are one cause of the
spread of red maple, and in southern New England, a big cause. In the
circles that debate the red maple issue, its rapid spread is often
attributed to lack of timber harvesting as opposed to too much

    Places such as Robinson State Park may afford us with good test
sites to apply targeted silvicultural treatments, when determinations are
validly made that treatments are truly warranted. Any thoughts on the
subject? BTW, as of the present, that case has not been convincingly
made for Robinson SP. At least realistic timelines have not been

Re: Red Maple Discussion - back to Roger
   Feb 21, 2007 10:20 PST 

Bob -

My thoughts are that redmaple has such a wide range of tolerances and
perhaps ecotypes that it responds aggressively to many of the
disturbances inherent in eastern forests in the last few hundred
years, including logging, fire suppression, and also the demise of the
chestnut. What is not so apparent is that it readily seems to in
become more dominant in some sites and not others, and the why is more
difficult. Red maple is of course a vigorous stump sprouter as well as

RE: Piddling around in dendromorphometry as a cure for insomnia   DON BERTOLETTE
  Feb 21, 2007 11:54 PST 

You've articulated something that has been bouncing around in the back of my
head (these days, like a beebee in a boxcar!). One of the reasons that
traditional forestry measurements don't work for champion tree chasers is
exactly as you say...all the 'rules' were designed to make quick indifferent
estimates of a large number of trees, which as you say, average out in a
large enough population.
Any forestry concern taking the time to measure the trees we find glee in,
would soon go out of business. For that matter, if ENTS was a business
instead of a tightknit group of old-growth/champion tree enthusiasts, we'd
already be defunct.
The only true measure of volume is displacement, we'd just need a huge
graduated beaker!
Back to Don   Robert Leverett
  Feb 21, 2007 12:26 PST 


   You are quite right. As a former college statistics teacher, I have
long understood the role of the forestry formulas and methods and their
application of the law of averages versus the formulas and methods that
we apply to tighten down the numbers on the objects of our affection.
However, the very different purposes of our separate missions can be
easily misunderstood by others when it comes to answering questions
about which tree is biggest, tallest, etc. The natural assumption of
newspaper reporters, for example, is to turn to members of
timber-associated professions to get resolution for a tree dimension
question. But increasingly, that must change if we are to correct
historical records. We are, I think, gradually getting there.

    Long ago, a role that Will Blozan and I envisioned for ENTS was as
a behind-the-scenes support to American Forests on the National Register
of Big Trees and to the champion tree coordinators of the individual
states. I do think that goal is in sight, especially with Will Fell,
Scott Wade, and Bob Van Pelt serving in both capacities. We just need to
get more state tree coordinators to come on board with us. I'm hoping
that Will and Scott can turn the trick in the East. We must leave it to
you, Bob, Roman, etc. to do it in the West.

   As I last stood measuring the Jake Swamp Tree for goodness knows how
many times (I lost count long ago), I reflected on how financially
disastrous the ENTS methods would be for practicing foresters. The whole
profession would collapse if it sought to repeatedly measure to the inch
the non-commercial parts of trees, or a single tree. Several years ago,
I began to make a distinction between the purposes of acceptably
measuring aggregate timber volume versus figuring out how much trunk
and limb volume resides in a single tree such as the Sunderland Sycamore
...... and just for the heck of it.

   It still takes a fair amount of explanation to convince an outsider
that when it comes to individual tree statistics, we in ENTS are the
experts. But proving ourselves to others comes with the territory. I
used to be impatient, but have learned to be laid back - most of the
time. I often explain to others who wonder what we are all about that we
ARE clearly obsessed people to put so much effort out without so much as
a brass farthing's worth of monetary return.

   BTW, you haven't answered my question. At what point did you nod off
while reading "Piddling around in dendromorphometry as a cure for
insomnia" ? I need to know in the interests of sleep therapy.

Re: Red Maple Discussion - back to Roger   Andrew Joslin
  Feb 21, 2007 12:37 PST 

My observations in eastern Mass. and Rhode Island woods that have
been relatively undisturbed in the last 60-100 years is that red
maple is where it's expected to be - in low wet woods and does not
seem to be invasive or rampant in other ecotypes. It seems highly
improbable that leaving mature forest undisturbed would contribute to
the spread of red maple.

Over grazing by deer (for example) is causing so much more trouble in
the woods than "not managing" forest through cutting mature trees. If
red maple is better able to withstand deer browsing than other
hardwoods so be it. It does not make red maple the problem.

A mature Red Maple is a beautiful thing to behold:

Andrew Joslin
Jamaica Plain, MA
RE: Red Maple Discussion - back to Roger   Ray Weber
  Feb 21, 2007 12:44 PST 

Thanks for your observations.

We arent trying to "squelch" opposing opinions, but looking
for active discussion. This is a mature forest, undisturbed,
and actively "managing" it brings forth all kinds of possible
issues, invasives included.

This red maple issue was brought up as some kind of justification
to harvest oak, eliminate ALL the early successionals present such
as birch, and favor oak/white pine. That to us certainly far more
likely to invite in red maple than leaving alone, but that's where
we need input. Does harvesting increase that possibility or not?

RE: Back to Lin   Greenaway, Elinor
  Feb 21, 2007 14:28 PST 

Thank you, Bob -

I am always open for alternative viewpoints and new information, and I try
to keep a civil tone - a difficult task in a medium which removes all

In my district, we've tried to encourage other species with management
practices, but if we get red maple, we grow it. I just had a 100 acre
sale that is mostly red maple and the buyer is cutting 20", 2.5 log
trees that are clear nearly to the heartwood (so he says). OK, so it's
not oak, but it's better than hayscented fern (another competitive
native that is taking over our forest).

We've mainly focused on environmental conditions that inhibit other
species and consequently left an opening for the opportunistic red
maple, but I am curious about the paper Mr. Abrams wrote. He's here at
Penn State and I have seen several of his talks, but I don't remember
him addressing this subject.

I look forward to seeing your future post.

Lin Greenaway
RE: Back to Lin Re: Red Maple Discussion   Greenaway, Elinor
  Feb 21, 2007 19:34 PST 

In my district, red maple can make up 50 - 90% of a stand, especially in areas that had maple previously and were either clearcut or heavily thinned and were not fenced. We have high deer pressures and even though they will browse RM, they strongly prefer oak and Rubus. Doing regeneration plots, I've found 3 to 4 times as many RM seedlings (1 yr) as any other species even under predominately oak overstories. Few things eat its seed too. It's everywhere here and seems to sprout under a full canopy, without scarification and on any kind of site. And it sprouts from stumps. The low shade RM poles can create in an understory also seems to suppress oak regeneration even inside fences.   Truly an indomitable species.

I'm more expert with pine and fire adapted communities, but with RM selling so well, we're all taking another look at the species. Thank you again for this topic.

Lin Greenaway
Back to Lin again   Robert Leverett
  Feb 22, 2007 05:38 PST 


Are the markets for red ample in western PA all local ones or are they
associated with what Russ was describing, i.e. the Chinese furniture
business boom?

   I think the red maple publication by Marc Abrams is: Abrams, M. D.
1998. The red maple paradox. BioScience 48:355-364. Another
publication that includes red maple is: Forty-two years of succession
following strip clearcutting in a northern hardwoods forest in
northwestern Massachusetts by Taber D. Allison, Henry W. Art, Frank E.
Cunningham, and Rebecca Teed. If Taber gives me the go ahead, I'll send
you a copy.

   BTW, a colleague of Marc Abrams is Dr. David Orwig who is a member of
this list. Dave is a research scientist at Harvard Forest.

   More to come on the topic. We're on a roll.

Re: Red Maple Discussion - back to Roger   Lee E. Frelich
  Feb 22, 2007 07:05 PST 


Red maple now has a higher abundance of seeds trees across much of the
landscape due to lack of fire. Give then current number of seed trees, it
may be spread by logging, or lack of logging, or fire, or lack of fire,
because it is context dependent in each stand.

In late successional stands with light levels or 2-3% on the forest floor,
logging would raise light levels and might give red maple a chance to
increase in abundance, depending on other circumstances in the stand.

In stands dominated by earlier successional species (i.e. the scarlet oak
stands in Robinson) the light levels are already high enough (my guess is
around 10% of full sunlight) for red maple growth in the understory, and it
may eventually replace the oaks in the absence of any disturbance other
than individual tree death when the oaks reach old age. The same thing can
happen in red and white pine forests.

Light levels at the forest floor determine the success of mid-tolerant
species like red maple. Light levels at the forest floor are a function of
successional status of the overstory species (early successional species
cast less dense shade, often having 10% or more sunlight at the forest
floor), midtolerant overstories cast denser shade, leaving 5-10% sunlight
at the forest floor, and late-successional species generally cast very
dense shade, leaving 1-5% sunlight at the forest floor. For all stands the
level of shade is also partly determined by site quality (higher quality
sites casting denser shade). Other factor such as seedbed type and N
levels also influence the success of red maple seedlings and modify the
general results caused by the light gradient.

In Robinson there are stands that could go either way with and without


Red Maple Discussion - back to Lee   Robert Leverett
  Feb 22, 2007 07:52 PST 


   Thanks. This helps put a number of points into perspective. How long
do red maple seeds remain viable in the duff? This question may have
been answered, but I don't remember what the period is. In terms of
spread by fire, I presume you mean that the fire opens up an area
allowing extra light and then seeds from existing sources outside the
fire zone blow in and repopulate the burn area. Is that the process?

Re: Red Maple Discussion - back to Lee   Lee E. Frelich
  Feb 22, 2007 11:58 PST 


I don't know how long red maple seeds are viable once on the ground, but
the female trees produce seeds every year and germination percentage is
high, so seed longevity is not an important issue.

Fire can kill red maple seed trees (as long as duration of the flame in
minutes at the base of the tree is greater than 3 x bark thickness (cm)
squared), and can also increase light levels at the forest floor by killing
the forest sapling layer, thus allowing red maple seeds that come in from
outside the burned area to be successful.

Fire is most effective a removing red maple if it occurs when an understory
of red maple has invaded under oaks or pines, so that the differences in
bark thickness allow fires to kill the cambium of the maples but not the
oaks and pines. There would be no point to such a prescribed fire without
removing nearby red maple seed trees.


Re: Red maple controversy   Matt Largess
  Feb 22, 2007 11:58 PST 

Hello Everyone,

The Red Maple controversy is really great. I feel very close to (acer rubrum) its the state tree of Rhode Island and a big part of our states native forest. I feel sad when people call it invasive. Yesterday I went on a seven mile walk in Fisherville Brook an Audubon of nine hundred acres in Exeter Rhode Island. Red Maples in Rhode Island grow in swamp lands with black tupelo, American holly, Atlantic white cedar, mountain laurel, yellow birch, and white ash. Next to the swamp there is a lot of nice second growth white pine and above them on the hills is oak. I believe we have the best examples of Red Maple in New England. I recently lead a walk on Prudence Island and measured trees over fourteen feet around circumference. Some look very ancient, with years of broken tops, and trunks full of wildlife cavities. The great wildlife condos. I look at forests so different then most people but I also spend more time in them then most. We have so much to learn about their secret systems. I think the conference on Red Maple is a great idea, and Bob Leverett is a living forest legend, and his desire for discussion and study is what legends are made of. I leave tomorrow on a forest journey to Florida's bottom land hardwood forest it also has Red Maple. This trees range is incredible and of course her fall red color is beautiful. 

P.S. Tsuga Talk eastern Hemlock and Will's desire to save them in the Smokies is inspiring. I have been working saving Hemlock's in Rhode Island with Merit for years with great success. The wooly adelige has put this species at risk of extinction. Robinson State Park has some beautiful old Hemlock's some over ten feet in circumference. On walks there this summer I had people tell me that Hemlocks should be cut down because they were dying anyway. Our forest deserve better and feel that the Tsuga Project should include more then just the smoky mountains. I just finished a study of the Northwest camp AMC lands in northwest Connecticut and studied Hemlock tree rings of small trees that grew in suppression. One tree was seven inches in circumference and over 100 years old. There ability to grow in suppression like American Beech, makes them well worth preserving. And their symbiotic relationship with black bears, fisher, porcupine, and countless bird species all makes their preservation urgent. 

Matt "Twig" Largess
Certified Arborist
NE 0802
Voice of the Forest