Characteristics of Significant Forest Patches

Characteristics of Significant Forest Patches

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TOPIC: Characteristics of Significant Forest Patches
http://groups.google.com/group/entstrees/browse_thread/thread/4a1ff12bfb263782?hl=en
==============================================================================

== 1 of 9 ==
Date: Tues, Aug 26 2008 11:48 am
From: "Edward Forrest Frank"

ENTS,

We are often faced with the question of what makes this patch of forest "significant' or mundane. Much of the focus of this group is on large trees. but that is not the only factor we consider. What might these other criteria be that makes a patch of forest noteworthy? I suggest the following initial short list. I want people to think about this question and add their own ideas and perspective to the question. I know many of you do not participate often because you do not feel you are an expert in the subject being discussed, however this is a question of perspective and opinion more than expertise. I encourage everyone who has an idea or opinion to share it with the group on this discussion list.

Characteristics of Significant Forest Patches

1) Large trees
2) Old trees
3) Trees with character
4) Intact ecosystems
5) Unusual assemblages of flora

1) Large trees: This is one of the most straight forward of the criteria. The size of a tree is fairly easily measured. A forest with a number of particularly large trees, and even better large trees of several different species is certainly significant. The size of the trees found on a site needs to be considered with respect to the local area, perhaps the state, as well as the broader regional scale. If we looked at only the national champions for the species as the basis for determining what was large, then every site would need to compete with the GSMNP. Few sites could compare with the great trees found there. But a more reasonable comparison recognizes that there are regional differences in the size to which trees can grow. In an area where the maximum size is much shorter, that shorter height should be the basis for determining relative size of the trees in the region. Also in areas that have been virtually cut bare in recent history, a forest with large trees could be considered significant even if it was not large on a broader regional scale.

2) Old Trees: Clearly a forest with a number of old trees is significant. Much of the Eastern United States was virtually clear-cut in the past 100 to 150 years. Trees older than that are uncommon and significant. It is hard to estimate the ages of trees by appearance alone, but as someone gains familiarity with a species with occasional real ages from core samples or cross sections better estimates of the ages of trees can be made. As always some people are more conservative with their age estimates while others tend to more liberal, but at a particular location or set of locations, even people with different perspectives likely will be able to agree on what are the older specimens. For many of the less-long lived species there is little actual core data available upon which to base age estimates. The focus of dendrochronology efforts is typically to find long lived specimens to determine longer and older tree ring chronologies and for the most part the trees not known to be long lived are ignored.

3) Trees with character: This is a somewhat subjective category, but a particular tree or forest segment with these characteristics would likely be recognized by a wide number of people. Josh Kelly a couple years ago used the phrase "aged with adversity" and this is really the focus of this characteristic. Don Bertolette in response said, "I really liked your phrasing "aged with adversity", as some of the oldest trees of several species that come to mind (foxtail pine in the Sierra Nevada's, bristlecone pine in the Sierras and White Mtns., western juniper) are growing on relatively depauperate sites, in environmentally extreme climatic conditions." So we have the concept of trees that have character because they have been aged by adversity. This would include many of the stunted forests growing under harsh environmental conditions. The age of these trees may not be easily apparent hidden by their unusual form, and certainly they are not large for the species, but they do have character.

4) Intact ecosystems: this would a a forest that had been minimally impacted by people. In the east there are virtually no forests that are pristine, so the degree of impact would need to be considered with respect to other forests in the region. Thus a forest in a heavily impacted area might be considered under this category even if might fail to make the grade in a different region. Other impacts to be considered is that species such as chestnut have been lost by indirect human impact. People have spread these invasive species which have had serious impacts even if a particular forest has not been cut. In this category I would include what are called old-growth forests and primary forests. Older recovering second growth forest can be considered if the character of the forest is approaching that of an intact forest system from the region.

5) Unusual assemblages: This category would include forests with an unusual assemblage of trees and other plants. Lee Frelich has talked about the Rock Elm forest in Minnesota near the boundary between prairie and forest. Other such forests might include those growing in various types of barrens in which the assemblage is restricted by the geologic conditions. We should also consider those forests such as are growing in a mixed condition like trees in swamp setting or trees in desert setting. These are not what we would normally consider a forest, but they are a vital part of the ecosystem. The old growth post oak systems in the cross- timbers areas of Oklahoma and Texas are a good example of this type of assemblage.

This is the first run through of the idea, and by no means set in stone. I am looking for the input of other people. As I see it we need to have some discrete criteria, aside from simple tree size that would enable us to define an area as a significant forest patch.

Ed Frank

== 2 of 9 ==
Date: Tues, Aug 26 2008 2:19 pm
From: Lee Frelich

Ed:

Sounds like a good start on the list. Its the same as one I would have
come up with.

Lee

== 3 of 9 ==
Date: Tues, Aug 26 2008 3:33 pm
From: "Steve Galehouse"

Ed-

I find "relict" woods, vestiges of previous climates and forests, to be very
interesting.
Here in N Ohio we still have a few tamarack bogs, with associated plants
like pitcher-plant, sundews, gray birch etc., as well as pockets of white
pine-hemlock, all surrounded by beech-maple or diluted mixed mesophytic
forests. It's always interesting to see which associations "hang on".

Steve

== 4 of 9 ==
Date: Tues, Aug 26 2008 4:54 pm
From: LISA BOZZUTO

Ed,

Significant woods that come to mind:

1. even-aged or uneven-aged pure stands of any species. I have vivid images of being in pure stands of hemlock, white birch and sugar maple. when walking through such places it feels like a unique world has been created

2. woods with water. streams: waterfalls and ponds all add a rich dimension of sounds,smells and sensations

3. ground cover: walking on a carpet of winterberry, partridgeberry or goldthread can effect every step that's taken.

these are just a few thoughts. I think the list of what contributes to making woods significant is endless and totally in the eye of the beholder.

Lisa

== 5 of 9 ==
Date: Tues, Aug 26 2008 6:30 pm
From: Gary Smith

Should there be a minimum size requirement to be considered a
significant patch?

== 6 of 9 ==
Date: Tues, Aug 26 2008 7:08 pm
From: Josh Kelly

Ed,

Great discussion on significant forest sites. I have two comments:

1) Thanks for crediting me with the "age with adversity" principle,
however, I was not the one who came up with that. That would be the
fellow who worked with bristlecone pine in the White Mtns of
California. I'm blanking on his name right now. Maybe someone else
will remember.

2) I think that forests with unusual structural complexity are
notable. This structural complexity often comes in two forms:
accumulated biomass and geologic. Older forests tend to have a
tremendous amount of structure in the form of nesting cavities, snags,
coarse woody debris, moss, tip-up mounds etc. Forests of any age
growing on boulderfields or other rocky situations also have copious
structure for wildlife to utilize. Structurally complex forests often
are synonymous with "primary" and "old-growth" forests but not always.

Thanks for starting this thread!

Josh

== 7 of 9 ==
Date: Tues, Aug 26 2008 7:19 pm
From: turner

ENTS: I have always been fascinated by "Patches" that contain species
or groups of species that are outside or at the limits of their normal
range of site. Good subject to make one think.

TS

== 8 of 9 ==
Date: Tues, Aug 26 2008 7:34 pm
From: Gary Smith

Dr Schulman?

== 2 of 4 ==
Date: Wed, Aug 27 2008 4:25 am
From: neil

correct - Dr. Edmund Schulman wrote an article with this general idea
54 yrs ago: http://www.sciencemag.org/cgi/content/citation/119/3091/396

nice post, Ed.

neil

== 3 of 4 ==
Date: Wed, Aug 27 2008 6:08 am
From: bob leverett

Ed,

Like Lee says, your list would be his list and mine as well. I'd forests with historic importance. Bryant Woods in Cummington, MA fits criteria (1)-(4) plus the historic addition.
There is a 6th criteria, aesthetics, which is in the eye of the beholder, but nonetheless important. It is worthwhile dicussion some of the elements of aesthetics in a forest context. Large well-formed trees, gnarly trees with large outstretched limbs, open space, streams, vivid colors, etc. are contributors.

Bob

== 2 of 5 ==
Date: Thurs, Aug 28 2008 1:53 pm
From: Larry

Ed,
What about Historical Trees or Forests. Many gatherings, speeches,
writings, treaties, battles, etc., were held under certain Trees or
places. Most Historical places have Trees. Larry

== 3 of 5 ==
Date: Thurs, Aug 28 2008 3:24 pm
From: "Edward Forrest Frank"

Larry,

I commented on historical values in my email yesterday. I am thinking of developing a second set of criteria dealing with historical, cultural, recreational, and aesthetic value of a tree or forest patch. This would be a parallel analysis structured much the same as the biological considerations in this initial set of criteria I proposed. If you have a particular phrasing you want to suggest or a way to give historical significance of a site some numerical value that could be applied fairly among many sites, I welcome your suggestions.

Ed

== 4 of 5 ==
Date: Thurs, Aug 28 2008 3:28 pm
From: "Edward Forrest Frank"

Ren,

I really like this idea and will try to figure out how exactly to incorporate it into the list of criteria. If you have a particular phrasing you want to suggest or a way to evaluate the significance of this "whatever we decide to call it" site to or methodology to assign it some numerical value that could be applied fairly among many sites, I welcome your suggestions.

Ed

== 5 of 5 ==
Date: Thurs, Aug 28 2008 8:44 pm
From: Ren

I call them Forest Islands. Their significance is in direct
relationship to their uniqueness in their neighborhood environment. In
a very rural area with numerous Forest islands they don't have the
same significance they have in a suburban or urban environment as
these more urban environment lack the ecological assets the island
Forests presearve. . Many urban parks have wild places that few people
visit that are the essence and core of the whole parks uniqueness. Are
these forests or just another of an urban attempt to manage nature.?
I'd say their ecological diversity of plant and animal life is an
important part of how we rate and judge them.In order to attach
numerical values we first have to quantify how we're judging their
value and and the importance of their individual characteristics in
terms of larger and more rural forests. If say we gave them a 7 for
unique diversity of trees, but maybe a -4 for urban trash, or an 8 for
the age of the trees. Once a valaution list is made then it needs to
be applied to the candidates to see if it holds up over a number of
comparable sites. Ren

==============================================================================
TOPIC: Characteristics of Significant Forest Patches
http://groups.google.com/group/entstrees/browse_thread/thread/4a1ff12bfb263782?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Aug 30 2008 10:21 pm
From: DON BERTOLETTE

Ed-
I have meant to reply to your Forest Patch post for awhile now...your first stab was very well thought out! My responses that follow, aren't likely to be much more than random musings...

I thought that Steve, Lisa, and Turner added good points.

I was pleased that nobody used the phrase "climax", not so much that it's out of vogue these days, but that they recognized that there are very few places so uniquely protected that even-aged single-species stands last for long. It has been my experience that even-aged single-species stands are the first response to a natural (or for that matter, unnatural) catastrophe. I stand of 400 year old shasta red firs outside of Red Bluff California, was the first substantial vegetative response to a volcanic outflow. By appearance (deep fissured bark characteristics, large limbs, gnarly tops, large diameter, coarse woody debris) the stand would meet many criteria for old-growth forest.

But it failed two criteria that I think stand as the primary criteria...heterogeneity of vertical structure and horizontal species composition...there was only one species of vegetation, shasta red fir, which had created a dense canopy and a incredibly deeply mulched (by cwd) ground cover. An oddity, but so species-depauparate that it wouldn't qualify under the criteria of heterogeneity of species compostion.

By the above comments, and others not made, forest ecosystem characteristics that have in the past been referred to as old-growth forest ecosystem characteristics (OGFEC), merit mention in the 'Patch list'. Each of the five characteristics of Significant Forest Patches could easily be subsets of an OGFEC description.

Like Gary, the "Patch" size should be discussed. Biologically, the Patch size requirement may be larger than that needed for other Patch categories (for example, a Historic Tree, or stand), so clearly size requirement should vary with category.

I liked the "Unusual Assemblages" category, as it works well for a number of places I'm familiar with (for one, a NW California "stand" of Shore Pines (Pinus contorta var. contorta if my dendrology of 1969 holds up) that are sufficiently stunted because of the soil type to be called The Pygmy Forest)

I sure agree with Steve regarding "relict" trees/forests. More than just remnants (which would be a term I'd apply to stands that have evaded man's greedy grasping), relicts are those assemblages that have found (usually a topographically protective area) locations with climatic and environmental conditions that have persisted unusually long times...an example would be an assemblage of five needle pines (western white, foxtail, whitebark), Brewer's spruce, and mountain hemlock that grow only in northern californian hanging glacial valleys (by definition the hanging valleys were secondary (read older) to the primary glacier that left them "hanging", or a few similar locations in the central Sierra Nevadas. They are relicts from "another time", and as an ecosystem have had the resilience to persist through thousands of years there, when almost all of the rest of their species types have not.

And yes, the category of trees with "character" is well chosen. We has humans develop character as we encounter the widening breadth of experiences over time. Trees large enough to emerge above the forest's crowns, will develop character too, as they face the variety of climatic conditions that time will throw at them, whether it be rime ice, winds, droughts, or such.

Do I have anything new to add? It's peripheral, literally and physically...management of most of these 'significant patches' should inculcate the tenets of conservation biology, where core OGFECs should be protected by buffering areas of forests, so that the qualities of the core may expand. Connectivity of cores across a landscape should be insured by protection of forested corridors, where natural vectors can continue the exchange of energy and matter. While the integrity of these areas need be protected, these areas should be utilized for educational purposes such that a groundswell of community support develops.

That's all for now...
-DonRB

== 2 of 5 ==
Date: Sun, Aug 31 2008 12:58 pm
From: "Edward Forrest Frank"

Don,

I am sure I will be working on this idea for awhile so I will ponder your comments and those of the others before the next "update" of the significant forest patch criteria is presented for critiquing.

You reference below a stand of 400 year old Shasta Red Fir. You state that the stand would fail to meet all of the criteria for old-growth because they lack the heterogeneity of species composition, and the heterogeneity of vertical structure and horizontal species composition, You do not state specifically, but is it your contention that this stand is "not significant" because it fails to meet all of these criteria? Or do you think it is "significant", in spite of the absences? It would likely fit in the category of a primary system whose character was determined solely by natural processes, in this case the landscape being reset by a volcanic flow.

Monoculture stands are interesting, but I a unsure how they should be dealt with. Are they significant? Are they an unusual enough of a assemblage to merit some special consideration or category? I do not want to include something for every forest, because what purpose would a listing serve if every forest fit into one or more of the categories so that each was significant? On the other hand, I am trying to include forest patches that deserve recognition even if they do not meet the generic old-growth / big tree criteria.

You mention the term "as old-growth forest ecosystem characteristics (OGFEC)." Do you have a specific listing of these criteria upon which you are basing your arguments? If you have such a detailed listing of criteria, publish it to the list, or a link to where it can be found online.

You say, "Each of the five characteristics of Significant Forest Patches could easily be subsets of an OGFEC description." One of the primary goals of the listing was to devise a way to include those segments of forest that are in some way significant, even if they did not meet all of the characteristics of an old-growth forest ecosystem. The idea that some old-growth forests could also have each of the characteristics is true, but is in a sense putting the cart before the horse. I want to be inclusive of those forests that do not fit the generic definitions.

Size of a patch is a matter of opinion. I think a small patch may be significant even if it is not adequate in terms of buffering forests, or connectivity to be the core of a future larger forest with old growth characteristics. How these areas are dealt with in terms of management is, I think, a separate consideration from whether a particular area is significant or not. Clearly those areas with the potential to serve as a core forest or a forest corridor deserve special consideration when applying long term management plans. They should be treated differently from area due to small size that may be ephemeral in a longer view. Perhaps a different or more radical management strategy needs to be developed for the tiny patches. I think that identifying and rating these small patches is important and should not be overwhelmed by management considerations that may favor less dramatic or valuable patches simply because these lower quality patches are larger and easier to manage.

I am also interested in Ren's Forest Island ideas and am still working on how to fit it into an overall analysis plan. I want to include the ideas you are suggesting in an overall plan, but am trying to figure out where they should fit.

Ed

== 4 of 7 ==
Date: Tues, Sep 2 2008 12:59 pm
From: DON BERTOLETTE

Ed-
Even though I'm retired, it has taken me longer than I thought to get a response back to you. I've had some cpu issues that have caused me to work offline in a word document, which I'm pasting below, with my comments interspersed IN ITALICIZED FONT:

Don,
I am sure I will be working on this idea for awhile so I will ponder your comments and those of the others before the next "update" of the significant forest patch criteria is presented for critiquing.
You reference below a stand of 400 year old Shasta Red Fir. You state that the stand would fail to meet all of the criteria for old-growth because they lack the heterogeneity of species composition, and the heterogeneity of species composition. You do not state specifically, but is it your contention that this stand is "not significant" because it fails to meet all of these criteria?

PERHAPS "SIGNIFICANCE" AS STATED IN YOUR CRITERIA STATEMENT IS RATHER BROAD/UNDEFINED...AS I LOOKED AT YOUR CRITERIA, THEY ALL RESONATED WITH ME AS SUBSETS OF OLD-GROWTH FOREST ECOSYSTEMS (OGFE), WITH ONLY SMALL CONSTRAINTS (eg, LARGE, WHICH CAN BE, BUT IS NOT ALWAYS THE CASE). THAT SAID, I WOULD SAY THAT A 400 YEAR OLD STAND OF SHASTA RED FIRS DOESN'T CONSTITUTE AN OGFE, JUST BECAUSE IT HAS 'OLD' AND 'LARGE' CRITERIA COVERED. IT IS NOT AN ECOSYSTEM THAT WILL PREVAIL ACROSS TIME. IT IS WHAT USED TO BE CALLED A STAGNATED STAND, ALBEIT A LARGE AND OLD ONE. IT HAD NOT A SINGLE SEEDLING, SAPLING GROWING OF ANY SPECIES. IS IT A STAND OF SIGNIFICANCE? DOES IT NEED TO BE SAVED? WILL MONEY'S EXPENDED TO ADVANCE IT'S STATUS BE WELL-SPENT? I'D SAY NO IN EACH CASE...

Or do you think it is "significant", in spite of the absences? It would likely fit in the category of a primary system whose character was determined solely by natural processes, in this case the landscape being reset by a volcanic flow.

I WOULD CONSIDER IT AN ODDITY, BUT ONE NOT LIKELY TO PERSIST, SAY THROUGH A HUMAN LIFETIME...ONE THING THAT DEFINES OUR AWE OF TREES IS THEIR OVERARCHING LONGEVITY...THE FACT THAT ASPEN, AS BEAUTIFUL AS THEY ARE, ARE PIONEERS AND SELDOM LIVE MORE THAN A HUMAN LIFETIME (LESS THAN ONE CENTURY) DIMINISHES THEIR CLAIM FOR OGFE STATUS IN MOST EYES...IS THEIR CLONING NATURE SIGNIFICANT? DOES THE CLONED STAND PREVAIL MORE THAN A LIFETIME? I'D SAY YES, AND COULD ARGUE FOR A 'SIGNIFICANT' STATUS (LARGEST LIFE FORM?).

Monoculture stands are interesting, but I a unsure how they should be dealt with. Are they significant? Are they an unusual enough of a assemblage to merit some special consideration or category?

TEMPORALLY, I'D SAY THAT SPECIES OR INDIVIDUALS THAT ARE NOT CAPABLE OF EXTENDING THEIR DOMINANCE OVER A SITE BEYOND THEIR FIRST GENERATION WOULDN'T BE PARTICULARLY SIGNIFICANT.

I do not want to include something for every forest, because what purpose would a listing serve if every forest fit into one or more of the categories so that each was significant? I AGREE, MOST OF THE TIME, I'M A "LUMPER"...;>)

On the other hand, I am trying to include forest patches that deserve recognition even if they do not meet the generic old-growth / big tree criteria. THAT SEEMS REASONABLE

You mention the term "as old-growth forest ecosystem characteristics (OGFEC)." Do you have a specific listing of these criteria upon which you are basing your arguments? If you have such a detailed listing of criteria, publish it to the list, or a link to where it can be found online.

WHILE NOT WANTING TO SEEM VAGUE, MY SENSE OF WHAT CONSTITUTES AN OGFE HAS EVOLVED OVER A COUPLE OF DECADES. I ONCE ACTIVELY PURSUED THE 'HOLY OLD-GROWTH VAIL' LIKE MANY OTHERS, AND THE CLOSER WE GOT, THE MORE ELUSIVE THE QUEST BECAME. BUT I'LL LIST SOME CRITERIA THAT I THINK WOULD STAND UP TO SOME LEVEL OF SCRUTINY:
1)THE OGFE SHOULD HAVE A STRUCTURAL HETEROGENEITY, THAT IS TO SAY THAT THERE SHOULD BE MULTIPLE LEVELS OF CANOPIES, SUCH THAT SINGLE TREE OR PATCH BLOWDOWNS ALREADY HAVE 'VOLUNTEERS' IN PLACE TO TAKE ADVANTAGE OF THE NEW OPENING IN THE STRUCTURE; 2)THE OGFE SHOULD HAVE A HETEROGENEITY OF SPECIES COMPOSITION, THAT IS TO SAY THERE SHOULD BE A MOSAIC OF SPECIES ACROSS THE OGFE'S LANDSCAPE, REFLECTING DISTURBANCE PATTERNS, WHETHER THEY BE BLOWDOWNS, FIRES, DIFFERING SOIL EXPOSURES, ETC., ENRICHING THE OGFE'S BIODIVERSITY, AND BOLSTERING THE OGFE'S RESILIENCE WHEN FACED WITH DISTURBANCES (NATURAL, MAN-CAUSED, EVEN IF MAYAN......). 3)THE OGFE SHOULD HAVE A TEMPORAL HETEROGENEITY, WHICH IS TO SAY THAT THE STAND DISPLAYS THE INTERPLAY OF SPECIES COMPETITION FOR DIFFERING ENVIRONMENTAL CONDITIONS, WHAT FORESTERS MIGHT CALL AN ALL-AGED STAND (SIMILAR TO STRUCTURAL HET., BUT SPECIFICALLY SHOWING INTRA-SPECIES AGE RANGES THAT APPROXIMATE MIN-MAX FOR THE TYPE AND REGION. IN OTHER WORDS, OPTIMAL USE OF SITE RESOURCE. 4)OGFEs SHOULD DISPLAY THE EFFECTS OF LONG EXPOSURE TO THE ENVIRONMENTAL BATTERING THAT TIME UNLEASHES, PARTICULARLY ON EMERGING CROWNS AND RIVERINE CORRIDORS.

You say, "Each of the five characteristics of Significant Forest Patches could easily be subsets of an OGFEC description." One of the primary goals of the listing was to devise a way to include those segments of forest that are in some way significant, even if they did not meet all of the characteristics of an old-growth forest ecosystem. The idea that some old-growth forests could also have each of the characteristics is true, but is in a sense putting the cart before the horse. I want to be inclusive of those forests that do not fit the generic definitions. THAT SEEMS REASONABLE...

Size of a patch is a matter of opinion. I think a small patch may be significant even if it is not adequate in terms of buffering forests, or connectivity to be the core of a future larger forest with old growth characteristics. SEEMS REASONABLE, ESPECIALLY WITH FURTHER DEVELOPMENT OF THE CONTEXT OF 'SIGNIFICANCE'

How these areas are dealt with in terms of management is, I think, a separate consideration from whether a particular area is significant or not. WHILE A SEPARATE CONSIDERATION, CERTAINLY ONE APPROPRIATE FOR SIGNIFCANT 'PATCHES', WHEN I USE THE WORD MANAGEMENT, IT IS NOT NECESSARILY IN THE PERJORATIVE...THE NPS 'MANAGES' LANDS IN ITS PURVUE QUITE WELL, ON THE WHOLE..

Clearly those areas with the potential to serve as a core forest or a forest corridor deserve special consideration when applying long term management plans. They should be treated differently from area due to small size that may be ephemeral in a longer view. I ESPECIALLY LIKE YOUR USE OF 'EPHEMERAL', AS IT SHOWS AN AWARENESS OF THE ROLE OF 'TIME' IN DEFINING 'SIGNIFICANCE'

Perhaps a different or more radical management strategy needs to be developed for the tiny patches. I think that identifying and rating these small patches is important and should not be overwhelmed by management considerations that may favor less dramatic or valuable patches simply because these lower quality patches are larger and easier to manage. SEEMS REASONABLE...

I am also interested in Ren's Forest Island ideas and am still working on how to fit it into an overall analysis plan. I want to include the ideas you are suggesting in an overall plan, but am trying to figure out where they should fit. I FELT THAT REN'S FOREST ISLAND IDEA WAS A SUBSET OF THE CONSERVATION BIOLOGIST'S CORE-BUFFER-CORRIDOR CONCEPTUALIZATION.

IT'S CLEAR THAT YOU'VE THOUGHT A LOT ABOUT THIS! AN ADDITIONAL CONSIDERATION MIGHT BE WHAT IMPACT THE LOOMING 'CLIMATE CHANGE' SCENARIO WILL HAVE ON THE EXISTENCE OF THESE SIGNIFICANT PATCHES/STANDS/FORESTS...
-DONRB

==============================================================================
TOPIC: Old Growth Forest Ecosytems/ Significant Forests
http://groups.google.com/group/entstrees/browse_thread/thread/4a1ff12bfb263782?hl=en
==============================================================================

== 1 of 2 ==
Date: Mon, Sep 8 2008 4:45 pm
From: "Edward Forrest Frank"

Don,

A few thoughts on your last post. You are right about the vagueness of my term "Significant." It is meant to be defined by the list of items it includes, much like many old growth definitions. A significant forest is one that contains number of these criteria, with the criteria and measurement of the criteria subject to change as the definition evolves. It is an iterative process, but I do need a more general description to frame the concept at this formative stage. As I see it a significant forest is one that meets a portion of the initial criteria I suggested. As people make comments I plan to revise the existing categories to incorporate the good ideas suggested, and weed out the weaknesses within my initial suggestions. When a new idea is suggested it may be something I had not thought about. In that case I need to decide if it fits within the existing framework and can simply be added. Perhaps it is a good idea, but does not fit within the structure I have envisioned. Then I need to decide if my proposed structure needs to be revised, or if the idea would fit in a different section of a broader plan rather than within the significant forest definition itself. In the first pass the suggestions I made are simply what seemed to fit with the concept in my mind.

You have presented a list of criteria for your OGFE (Old Growth Forest Ecosystem):

WHILE NOT WANTING TO SEEM VAGUE, MY SENSE OF WHAT CONSTITUTES AN OGFE HAS EVOLVED OVER A COUPLE OF DECADES. I ONCE ACTIVELY PURSUED THE 'HOLY OLD-GROWTH VAIL' LIKE MANY OTHERS, AND THE CLOSER WE GOT, THE MORE ELUSIVE THE QUEST BECAME. BUT I'LL LIST SOME CRITERIA THAT I THINK WOULD STAND UP TO SOME LEVEL OF SCRUTINY:

1)THE OGFE SHOULD HAVE A STRUCTURAL HETEROGENEITY, THAT IS TO SAY THAT THERE SHOULD BE MULTIPLE LEVELS OF CANOPIES, SUCH THAT SINGLE TREE OR PATCH BLOWDOWNS ALREADY HAVE 'VOLUNTEERS' IN PLACE TO TAKE ADVANTAGE OF THE NEW OPENING IN THE STRUCTURE;

2)THE OGFE SHOULD HAVE A HETEROGENEITY OF SPECIES COMPOSITION, THAT IS TO SAY THERE SHOULD BE A MOSAIC OF SPECIES ACROSS THE OGFE'S LANDSCAPE, REFLECTING DISTURBANCE PATTERNS, WHETHER THEY BE BLOWDOWNS, FIRES, DIFFERING SOIL EXPOSURES, ETC., ENRICHING THE OGFE'S BIODIVERSITY, AND BOLSTERING THE OGFE'S RESILIENCE WHEN FACED WITH DISTURBANCES (NATURAL, MAN-CAUSED, EVEN IF MAYAN......).

3)THE OGFE SHOULD HAVE A TEMPORAL HETEROGENEITY, WHICH IS TO SAY THAT THE STAND DISPLAYS THE INTERPLAY OF SPECIES COMPETITION FOR DIFFERING ENVIRONMENTAL CONDITIONS, WHAT FORESTERS MIGHT CALL AN ALL-AGED STAND (SIMILAR TO STRUCTURAL HET., BUT SPECIFICALLY SHOWING INTRA-SPECIES AGE RANGES THAT APPROXIMATE MIN-MAX FOR THE TYPE AND REGION. IN OTHER WORDS, OPTIMAL USE OF SITE RESOURCE.

4)OGFEs SHOULD DISPLAY THE EFFECTS OF LONG EXPOSURE TO THE ENVIRONMENTAL BATTERING THAT TIME UNLEASHES, PARTICULARLY ON EMERGING CROWNS AND RIVERINE CORRIDORS.

You have a workable definition based on the structural pattern of trees in a forest. I do however disagree with the overall concept as you have outlined it. The big area of disagreement basically concerns everything. You suggest - heterogeneity of species composition - There are many locations and situations in which the long term tree population consists of a single species. Consider the Mangrove swamps along the coast. These are essentially a monoculture because they are tolerant of salt water flooding, while virtually every other species is not. Similarly large areas of the northernmost forests in North America may be populated by essentially a monoculture of black spruce, or with sporadic patches of other species. Other environmental conditions or circumstances can create a forest in which only one species or a couple species are present. By your criteria number 2, these could not be old growth because they lack a heterogeneity of species. I think that forests of this type should be considered old growth when the trees involved are old (I recognize the vagueness of the term old)

In your third criteria you would require a heterogeneity of ages of trees - a multi-aged stand. The problem with this requirement in my opinion is it does not seem to consider the scale of disturbances. In a system in which most of the disturbances are small scale a variety of ages will be present because the entire stand will not be affected by a single disturbance. In areas that have large scale disturbances - such as big forest fires, blowdowns, volcanic eruptions - large areas will be affected, and essentially the forest will all be restarted in a single event, rather than the piecemeal disturbances that would generate a patchwork of multiage stands. On a broader scale these single aged stands are part of a broader multi-aged system, but on a smaller scale they are single aged. So, I think a stand dominated by trees of a single age could be considered old growth.

Your first criteria says that there should already be understory trees present, volunteers to take the place of the upper canopy trees as they are lost. All I can say about that is why?

You also talk of persistence of the forest over time. Essentially al of the forests are in some state of dynamic equilibrium. The balance they achieve between or with a species is dependant on the environmental conditions, the existing species present, and the frequency and size of disturbance. The forests do not achieve a stable state, but one that is changing at least slowly through time. So whether a forest is stable long-term in its present configuration is a moot point. It will be or will not be depending on the time frame you are considering. So a 400 year old Shasta Fir forest created by a 400 year old volcanic flow is stable or has been for the last 400 years - to my mind long enough to be considered old growth - eventually I expect it will be replaced by a more diverse species forest, or be reset again by another disturbance, or some similar event. So if long term stability is to be a criteria for old growth, then depending on the scale to be considered there are lots of old growth forests or none. Then the problem falls back on the old question of how old is old growth.

Don, you have been working on this question for a long time, while I am just starting to wrestle with the concepts. I am trying to better understand your viewpoint that has led you to propose this list. You have said what you think are good criteria, could you elaborate on the why of you list? I suppose there is the argument that these are unusual circumstances and there could be exceptions to the general rule in special cases. A listing of criteria that is too broad really defines nothing. One that is too specific leaves out items that should otherwise have been included.

Ed

== 2 of 2 ==
Date: Mon, Sep 8 2008 9:26 pm
From: DON BERTOLETTE

Ed-
I recognized your dilemma as soon as I tried to formulate a new context to relate everything into! I don't really have a better answer yet, although I have expended energies in that direction. More on that later...
Regarding my OGFE criteria, your last statement is truest! That is, "A listing of criteria that is too broad really defines nothing. One that is too specific leaves out items that should otherwise have been included." I can extend the definition considerably, and fall prey to the other end of the spectrum, and choosing the middle is a compromise that is "equally" unsatisfying.

Heterogeneity is a big word, and not commonly used. But it is so accurate a descriptor that I continue its use. When I refer to heterogeneity of structure, I'm referring to a landscape (I use this word because it has larger acreage connotations, although not exclusively so) where one would physically see a multi-storied forest with some kind of dynamic balance from tallest to lowest crowns. These layers may reflect ages of same species, they may reflect different species with different shade tolerance. Or both across the landscape, as the topography might dictate, going from riparian corridors to ridgelines.
When I refer to heterogeneity of species composition, I'm referring to the mosaic that develops over time in response to different disturbance regimes. In the Southwest, fire is a common disturbance and across a wide continuum of burn intensities, the landscape will reflect a mosaic of both structure and species compositions (fire within that range of burn intensities doesn't burn like the cinematic wall of fire that turns mother earth to a ground zero moonscape). In the Northeast, wind event periodicity is sufficiently short, that many species don't get a chance to develop old-growth forest ecosystem characteristics (if you get hurricane return intervals of 80 years and it takes balsam fir 100 years to develop ogfe characteristics, it just isn't going to happen landscape wide.
With regard to my proferred 400 year-old Shasta redfir stand, it is an actual stand, we did visit it (I was detailed from Kentucky to Northern California on an Old-Growth Timber Inventory detail (leave it to the USFS to reflect its true nature, huh Joe?!?!)). Ed, when I speak of a monocultural stand, I should be more specific. Anybody doing a releve (ecologist's version of a forest inventory) would have found a grand total of 1 species...no ground forbs, no shrubs, no bushes, no seedlings, no saplings, no immature boles, nothing but huge old 36" to 44" Shasta red firs. Had the stand been 350 years younger, foresters would have referred to it as a stagnating stand. At four hundred years old, it was dying before our eyes, in the final stage of stagnation.
If that stand is significant, it is because it is rare that you see such a classic stand stagnation, not because its an old-growth forest ecosystem. Which we decided it wasn't, after having a similar discussion to the one you and I are having.
What about an old-growth black gum forest ecosystem such as are occasionally found around Athol, Massachusetts and other nearby locations? There's much more out there than black gums, so it is nowhere as depauperate as my Shasta redfir stand. The black gum stands may be a perfect example of a significant stand that needs protection, for several reasons...one, they are in my frame of reference an old-growth forest ecosystem, albeit light on biodiversity, but they do have size, age, and character-laden criteria nailed...and two, they are situated in bogs much of the time, and those bogs are unique habitats that have value of their own, but more to my liking, they are a history of the pollens that have wafted across their water bodies across many centuries, perhaps multiple millenia, and form layers that a palynologist can analyze and tell you how long and with what proportional presence the black gums, and other species that are represented there by their pollen, had.
I agree with you on the mangrove forests, and they would be appropriately significant for exactly that reason. Yes, I can't think of any rule that doesn't have exceptions except this one, maybe...;>}
While it isn't a popular stance in this forum, I pretty much like Oliver and Larson's "Forest Stand Dynamics" definitions of old-growth and especially how they differentiate that from True Old-growth. Essentially, they say that for any given stand (I prefer forest ecosystem) True Old-growth status wouldn't be conferred until the stand consisted of the cohort that was subsequent to the first stand formed after disturbance. And of course there'd be constraints on even that simple definition...the Shasta red fir stand will die, not due to a disturbance, but due to atrophy and attrition...subsequent stands that eventually develop may not achieve True Old-growth status within the first generational response.
Your mention of scale is critically important in my mind, in these discussions. It's probably the most difficult Old-growth "precept" to grasp, and I feel inadequate to the task of fully explaining it. In terms of acreages and landscapes, it's completely variable across regions and species, which is to say that any attempt to explain the significance of scale is region and species specific. What size does a significant or old-growth stand/forest ecosystem need to be? What ever size it takes for the stand/forest ecosystem to develop another word I have grown dependent on in this type of discussion..."resilience"...what is resilience? For me, it's the multi-pathway support that an ecosystem gets from the degree of bio-diversity that it has developed, in response to the region-typic/species-typic disturbance regime.
I think I'll stop here, and let us both take a break...:>} I'm pretty much answering these off the top of my head, with little access to the many papers and books that formed these views nearly 20 years ago, however randomly presented by me...
-Don
PS:Good questions!

== 2 of 17 ==
Date: Tues, Sep 9 2008 4:37 am
From: "Edward Forrest Frank"

Don,

Ok, we can pause the discussion for now. I can see where you are coming from in your responses.

Ed

== 3 of 17 ==
Date: Tues, Sep 9 2008 9:28 am
From: dbhguru@comcast.net

Don,

You've put a lot on our plates and done it very well. Your thinking has matured mightily over the years. Most of what you say resonates well with me. Still there is a lot that can be productively discussed, agreed on, and debated further on the subject of old growth defnitions. In that spirit, I would call attention to one point you make. First a quote.

"While it isn't a popular stance in this forum, I pretty much like Oliver and Larson's "Forest Stand Dynamics" definitions of old-growth and especially how they differentiate that from True Old-growth. Essentially, they say that for any given stand (I prefer forest ecosystem) True Old-growth status wouldn't be conferred until the stand consisted of the cohort that was subsequent to the first stand formed after disturbance."

I don't recall anyone in our forum who has voiced significant disagreement with Oliver and Larson's definition of old growth except me. Maybe others do, e.g. Ed. Anyway, my disagreement with Oliver and Larson's definition centers around their threshold for passage to old growth. I view the threshold as arbitrary - not to mention difficult to apply. Take some of the hemlock-hardwood forests of the Porcupine Mountains, for instance. There are hemlocks that Lee has dated in the Porkies to over 500 years of age and trees in that age class are still around. If we assume the 500-year age class began life as a response to a stand-leveling disturbance, must we wait for the last hemlock to die before we declare the area a legitimate old growth forest? In the intervening period ( 500 years BP to now) forest gaps developed and new growth appeared in the gaps at different times resulting in today's multi-aged forest. Some of the hemlocks that have grown back in the gaps are themselves 250
years old or older. Some are under 100 years, i.e. many age classes.
In most eastern forests, trees identified at a site over 250 years in age signals the existence of or at least onset of the old growth stage. Other characteristics associated with old growth may or may not be present, but if the requisite characteristics are there, why would we withhold old growth status waiting for the last of the trees in the preceived original cohort to die? How would we know when the last of the "original" trees had passed on? Unless we're there at the time of the stand-leveling disturbance, marking and tracking the new growth or subsequently coring all the older-appearing trees, how would we know when a threshold had been reached? We're talking about at least two or three and maybe four or five maximum human lifs spans strung together end to end - a rather long period of observation.
As a conceptual model of how a forest may develop at ground level after a stand leveling disturbance, the Oliver and Larson definition of old growth has some value, but not as a set-in-concrete definition. I'm willing to acknowledge their contribution, but not to treat their definition as more than a model. In fact, I am inclined to believe that any definition we propose to encapsulate some hypothesized state of existence of a forest should be recognized and treated as a kind of limited ideal or abstraction - not to be taken too literally or applied too broadly. Not to belabor the point, but absolutes, cutoffs, and thresholds should always be viewed circumspectly when definitions are crafted to apply to the natural world in areas governed by multiple micro and macro processes acting over time and on diffirent time scales.
Looking at individual examples, is Cook Forest in PA "true old growth"? Is Fife Brook in Monroe SF? Are the forests in the Great Smokies that have heretofore been called virgin, true old growth? I lean toward the concept of certifying that old growth characteristics are present. There would be no absolute point of passage. A site could be rich in some characteristics, low in others, and perhaps missing one or two entirely and still qualify as an old growth site. I guess that reveals me as a "characteristics person" trusting that the processes are there and playing out in an endless spectrum of results.
On the idea of characteristics and without muddying the water too much, what about introducing canopy development criteria in the identifying of old growth forest ecosystems? Some criteria could be species specific. For example, how about the requiring the development of reiterations for key species such as redwoods and hemlocks. The reiterations represent the process of growth, breakage, regrowth, etc. often over several centuries for hemlocks and maybe millennia for redwoods? Unfortunately, for eastern hemlocks reiterations seem to be a phenomena that occurs in some geographical areas that have old hemlocks, but not in other areas.

Bob

== 4 of 17 ==
Date: Tues, Sep 9 2008 10:14 am
From: DON BERTOLETTE

Bob-
In Zorzinian fashion, I'll respond in the body of your text, IN SMALL CAPS...

From: dbhguru@comcast.netTo: entstrees@googlegroups.comSubject: [ENTS] Re: Old Growth Forest Ecosytems/ Significant ForestsDate: Tue, 9 Sep 2008 16:28:35 +0000

Don,

You've put a lot on our plates and done it very well. Your thinking has matured mightily over the years. Most of what you say resonates well with me. YOU MENTORED ME WELL...Still there is a lot that can be productively discussed, agreed on, and debated further on the subject of old growth defnitions. I THOUGHT THERE MIGHT BE RESPONSES, NOTHING I'VE SAID HAS YET BEEN CANONIZED! In that spirit, I would call attention to one point you make. First a quote.

"While it isn't a popular stance in this forum, I pretty much like Oliver and Larson's "Forest Stand Dynamics" definitions of old-growth and especially how they differentiate that from True Old-growth. Essentially, they say that for any given stand (I prefer forest ecosystem) True Old-growth status wouldn't be conferred until the stand consisted of the cohort that was subsequent to the first stand formed after disturbance."

I don't recall anyone in our forum who has voiced significant disagreement with Oliver and Larson's definition of old growth except me. Maybe others do, e.g. I USED TO KEEP TRACK OF PAST OG DISCUSSIONS, BUT I'VE GONE THROUGH SEVERAL COMPUTER FAILURES, AND LOST MUCH OF WHAT I TRIED TO RETAIN, PLUS THE SHEAR BULK OF WHAT HAS PASSED OVER THE LAST DECADE OR SO IS DAUNTING...ED DESERVES A LOT OF CREDIT FOR HIS EFFORTS TO RETAIN THE "WHEAT" AND WAFT AWAY THE 'CHAFF'.

..Ed. Anyway, my disagreement with Oliver and Larson's definition centers around their threshold for passage to old growth. I view the threshold as arbitrary - not to mention difficult to apply. Take some of the hemlock-hardwood forests of the Porcupine Mountains, for instance. There are hemlocks that Lee has dated in the Porkies to over 500 years of age and trees in that age class are still around. If we assume the 500-year age class began life as a response to a stand-leveling disturbance, must we wait for the last hemlock to die before we declare the area a legitimate old growth forest? In the intervening period ( 500 years BP to now) forest gaps developed and new growth appeared in the gaps at different times resulting in today's mu lti-aged forest. Some of the hemlocks that have grown back in the gaps are themselves 250 years old or older. Some are under 100 years, i.e. many age classes. In most eastern forests, trees identified at a site over 250 years in age signals the existence of or at least onset of the old growth stage. Other characteristics associated with old growth may or may not be present, but if the requisite characteristics are there, why would we withhold old growth status waiting for the last of the trees in the preceived original cohort to die? How would we know when the last of the "original" trees had passed on? Unless we're there at the time of the stand-leveling disturbance, marking and tracking the new growth or subsequently coring all the older-appearing trees, how would we know when a threshold had been reached? We're talking about at least two or three and maybe four or five maximum human lifs spans strung together end to end - a rather long period of observation. I WAS TEMPTED TO WAX CASUAL AND SAY SOMETHING LIKE, "MY, AREN'T WE GETTING IMPATIENT" OR "HEY, TRUE ENTS WOULD BE MORE PATIENT WITH THIS LITTLE PASSAGE OF TIME"...BUT YEAH, PART OF WHAT MAKES 'OLD-GROWTH' SO PRECIOUS TO US IS EXACTLY THIS, THAT IT IS SOMETHING THAT IS GREATER THAN US, THAT IS MORE COMPLEX THAN WE UNDERSTAND YET, AND HAS BEEN REMARKABLY PATIENT WITH US, WHILE WE WHITTLE AWAY THEIR NUMBERS.

As a conceptual model of how a forest may develop at ground level after a stand leveling disturbance, the Oliver and Larson definition of old growth has some value, but not as a set-in-concrete definition. I'm willing to acknowledge their contribution, but not to treat their definition as more than a model. In fact, I am inclined to believe that any definition we propose to encapsulate some hypothesized state of existence of a forest should be recognized and treated as a kind of limited ideal or abstraction - not to be taken too literally or applied too broadly. Not to belabor the point, but absolutes, cutoffs, and thresholds should always be viewed circumspectly when definitions are crafted to apply to the natural world in areas governed by multiple micro and macro processes acting over time and on diffirent time scales. I SO AGREE!!!

Looking at individual examples, is Cook Forest in PA "true old growth"? Is Fife Brook in Monroe SF? Are the forests in the Great Smokies that have heretofore been called virgin, true old growth? I lean toward the concept of certifying that old growth characteristics are present. There would be no absolute point of passage. A site could be rich in some characteristics, low in others, and perhaps missing one or two entirely and still qualify as an old growth site. I guess that reveals me as a "characteristics person" trusting that the processes are there and playing out in an endless spectrum of results.I M VERY MUCH AN "INCLUSIVE" DEFINITION KIND OF GUY, AND WOULD IN A REFINED EFFORT ON THIS TOPIC TRY TO IMPART THE VALUES OF INCLUSIVE DEFINITIONS, IN ORDER TO PROTECT THOSE CANDIDATES WHOSE POTENTIAL FOR OLD-GROWTH STATUS IS NOT YET FULLY UNDERSTOOD...I BROUGHT IN OLIVER AND LARSON TO INTRODUCE THE CONCEPT OF LEVELS OF "OLD-GROWTHEDNESS"...I'M STILL PRETTY SOLID ON THE 400 YEAR OLD SHASTA RED FIR STAND BEING LEVELLED AT SIGNIFICANT, AND NOT SUBSTANTIALLY OLD-GROWTH, BUT COULD BE SWAYED IN THE LIGHT OF FURTHER CONSIDERATION.

On the idea of characteristics and without muddying the water too much, what about introducing canopy development criteria in the identifying of old growth forest ecosystems? Some criteria could be species specific. For example, how about the requiring the development of reiterations for key species such as redwoods and hemlocks. The reiterations represent the process of growth, breakage, regrowth, etc. often over several centuries for hemlocks and maybe millennia for redwoods? Unfortunately, for eastern hemlocks reiterations seem to be a phenomena that occurs in some geographical areas that have old hemlocks, but not in other areas. CERTAINLY, NORTHWESTERN TEMPERATE RAIN FORESTS HAVE EXCELLENT EXAMPLES OF MULTI-LAYERED CROWNS (I THINK THAT JERRY FRANKLIN WAS INFLUENCED BY HIS BEING NURTURED BY THEM FIRST). AND FOR THAT MATTER, THE GREAT SMOKY MOUNTAIN NP FORESTS. THE WHOLE IDEA OF SCALE IN MY MIND CAME FROM STUDIES OF SINGLE TREE GAP STUDIES IN THE EASTERN FORESTS...
NOW, WHAT'S YOUR THINKING ON THE CONCEPT OF 'RESILIENCE' AND HOW IT MIGHT RELATE TO DISCUSSIONS OF FOREST ECOSYSTEMS?
-DONRB
Bob

== 5 of 17 ==
Date: Tues, Sep 9 2008 10:21 am
From: dbhguru@comcast.net

Don,

I'll ponder the topic of resilience a bit and then respond. BTW, I think this is an excellent discussion and my hat is off to both you and Ed for your leadership in thinking through the concepts and nuances. Let's keep this one on the front burner.

Bob

== 6 of 17 ==
Date: Tues, Sep 9 2008 10:45 am
From: "Edward Forrest Frank"

ENTS,

What do I mean by a significant forest? That is a hard question to answer, but it is something I need to try to articulate better than a definition by listing. If you look across the landscape particularly in the east, there are plenty of forests. The majority of Pennsylvania is wooded. A hundred years ago the state was all but denuded by farming and logging operations. The majority of these forests are typical of second growth or third growth that has sprung up after the land was cleared. These forests lack the old trees and complex structure found in an old growth ecosystem. The trees present are typically those characteristic of a young forest, rather than an old one. From an environmental and personal perspective I would say that even a poor quality forest is better than none at all, but really the best that can be said about many of these stands is that they have trees, The are mundane in nature, ordinary to poor in quality. Within this background are smaller patches and stands that have unusual or exceptional qualities or characteristics. The goal of trying to define a significant patch is to make a clear distinction between these ordinary mundane forests and these uncommon or exceptional stands.

ENTS is typically focused on the size of trees. Size is one characteristic that can be used to distinguish a exceptional stand or patch of trees from the average. However size is not the only criteria that can be used, and I do not believe it is the best criteria. Old growth is another standard used to distinguish exceptional stands. However there are many different definitions of old growth and therefore it is hard to apply the standard equitably. The practical problem with many of the old growth definitions is that they are dependant on a knowledge of the age structure of a stand, and that information is not often available or practical to collect.

What I also see out there are also stands of trees that consist of unusual assemblages of species. These may include relict pockets from previous climatic conditions. These exist as a long-term ecosystem but may have neither many old trees or trees of great size. In other areas where there are extreme climatic or environmental conditions, are unusual forests in which the number of species present is limited and the size of the trees is also often small. The trees trees may be old, but they may not have the typical characteristics of full sized trees or old trees grown in less harsh environments. If an assessment is to be made of stands and pockets of forest that are worth documenting or worth preserving, there should be a criteria that would allow the inclusion of these uncommon forests and exclude the average, poor, and mundane stands.

A significant forest patch is one that includes trees and forest stands with uncommon characteristics. These patches typically exhibit relatively minimal effects of direct human disturbance, may include trees of unusually large size, may have significant numbers of old trees, may include forests with an unusual species compositions or relict tree populations, may exhibit hat are generally defined as old growth characteristics, and may include those patches that exhibit the effects of growth in a harsh or marginal environment.

At this point I can not yet escape the listing of criteria as a basis for a definition, but I am working on it. It is sort of a cased of you know one when you see one...

Ed

== 7 of 17 ==
Date: Tues, Sep 9 2008 11:39 am
From: ForestRuss@aol.com

Ed:

My own guide lots of times when I am passing into or through a patch of
significant older woods is usually the understory as much as it is the overstory.
The forest floor in an older woods often appears to be as complex and
diverse as the overstory and sometimes much more so. Through the years I have had
the opportunity to pass through and spend time in many significant patches
of woods but as I search through my memory banks it was more often the
complexity and diversity of the understory that caused me to step back and look at
what was standing above me before my appreciation sank in.

This has been a very interesting discussion.

Russ Richardson

== 8 of 17 ==
Date: Tues, Sep 9 2008 12:02 pm
From: DON BERTOLETTE

Ed-
It's hard not to assign values, isn't it...;>}
-DonRB

== 10 of 17 ==
Date: Tues, Sep 9 2008 12:07 pm
From: "Edward Forrest Frank"

Don,

I eventually want to assign values - numerical values based upon a series of guidelines fro each value.

Ed

== 11 of 17 ==
Date: Tues, Sep 9 2008 12:07 pm
From: DON BERTOLETTE

Russ-
I wholeheartedly agree! From my perspective, the understory is one of the best measures of site richness, and a significant part of the basis for a forest's resilience. Think bio-diversity...
-DonRB

== 15 of 17 ==
Date: Tues, Sep 9 2008 2:34 pm
From: dbhguru@comcast.net

Ed, Don, et al,

I think that most of the value of exploring the significance of a forest site, or sites in general, lies in the on-going discussions rather than in any end results, although I am not opposed to working out a numerically based, soup to nuts, system. However, on-going discussions are indispensible to keeping the subject on the radar screen for both the committed and the public.
We can likely agree on the raw elements of a system of judging significance. Reaching concensus on the numerical weights assigned to the constituent criteria is another matter. Still, continued exploration of a numerically based weighting systems has value aside from an end result. The exploration phase keeps us sharp in our thinking.
I presume that most of us in ENTS assign high value to tree size, but do we seek absolute or relative weights? I prefer assignment of values that are relative instead of absolute. I see less value in comparing a southern swamp forest to a New England hemlock-hard wood forest than comparing swamp to swamp and hemlock-hardwood to hemlock-hardwood.
Like the two of you, I tend to put extra value on forests that excel in their diversity. Rarity is also a very important criteria. As a consequence, the dwarf jack pine forest in Acadia NP ranks high with me although its trees are not old, nor are there that many species present.
Just some stray thoughts.

Bob

== 17 of 17 ==
Date: Tues, Sep 9 2008 6:54 pm
From: DON BERTOLETTE

Ed/Bob-
I was actually thinking of non-numeric values...
-DonRB

== 2 of 11 ==
Date: Mon, Sep 15 2008 4:00 pm
From: DON BERTOLETTE

Ed/Bob/Lee/Ents-
Certainly Lee's definition takes out a lot of the equivocation, and nears the ultimate in simplification...and there's for sure a place for that.
However, if charged with finding fault with Lee's definition, I'd point out that most of those same managing agencies are the least acceptable standards for defining old-growth, short of the timber industry.
If I were to advocate for an o-g defintion, it would be towards the "inclusive" end of the spectrum (which in the instance of your significant tree listing is totally in line with your intent, I think). This allows sufficient leeway to include candidates that we don't know a lot about, allows for hubris on our part thinking we know more than we do, and would serve as a very functional definition for this application.
If researchers need a more exclusive definition, that's fine, they need the clarity of a yes/no, either/or dichotomous decision and that's fine for their purpose.
-DonRB

== 3 of 11 ==
Date: Mon, Sep 15 2008 4:20 pm
From: "Edward Forrest Frank"

Don,

That really isn't what I am saying. I am suggesting including the definition as used by the management agency as on of the characteristics, and incorporating characteristics representing a more inclusive interpretation of old growth as individual categories within my significant characteristics listings. My goal is not to make a new definition of old growth but to delineate what are biological significant forest segments whether or not they would fit within a generic old growth definition. For example some forests that are breeding or nesting territories of endangered species, or populations that are relict populations from a previous climatic regime, might not fit a general old growth definition but are still significant in my mind.

It is funny in a way, before being involved with trees my main focus was karst processes. A karst landscape is on in which landforms present were formed predominantly by the dissolution of bedrock. The devil is in the details here as well. Along with the dissolution processes, mechanical erosion and mass wasting process are also taking place. Whatever surface feature you examine has aspects of both mechanical and dissolutional processes. The boundaries between the two are not clear-cut. So one of the common topics of discussion was how to define karst to be inclusive enough to suit some people and yet distinctive enough to suit others. This is a parallel situation to that of defining old growth. The definitions you tend to favor reflect your intended usage of the definition. The definitions are always to a large degree arbitrary and the placement of the boundaries demarking the limits of the definition are also arbitrary.

Ed

== 4 of 11 ==
Date: Mon, Sep 15 2008 5:02 pm
From: "Edward Forrest Frank"

Don,

I don't disagree with what you say about my intent. My thinking is that I really don't want to be forced to deal with the arguments about how old growth is to be defined every time I want to apply this list of criteria to a site. I see the list as being used as an arguing point for whether or not a particular forest should be protected, managed in a certain way, or to serve a commercial logging purpose. If it meets the old-growth definition of the respective management agency, then that should be a tabulated as a characteristic that makes the forest significant. As a second line of argument I want to make a listing, each as its own category, of each of the characteristics that would be present in a more inclusive definition of old growth. In this way both the regulatory definitions and better and more inclusive old growth definitions are both incorporated. I still need to figure out how to describe a category of "other" to " include candidates that we don't know a lot about, allows for hubris on our part thinking we know more than we do." I am trying to avoid making just another definition for old growth to achieve this goal. I thin a listing of characteristics is a better way to go about what I am trying to do.

I stated before that I do not think it is ENTS role to come up with an exclusive regulatory definition for old growth and in fact I think exclusive definitions are a bad idea even for regulation. Each forest needs to be evaluated with respect to the species present, disturbance history, and the character of the other forests in the area. If a specific (age threshold) date is generated to satisfy a regulatory need for a specific site it should be by this evaluative process or a similar evaluative process. A simple age for an area, without this accompanying process for each site, will without any doubt be misapplied to other forests where this age definition is inappropriate. The definition needs to be determined on a site by site basis to make sure the numbers generated are appropriate. I would not be against a blanket statement that forests with trees beyond a certain age are old growth as aspect of a hard cutoff criteria, but I know that this would then become the defacto standard. A regional definition might be developed, but I am not entirely comfortable with this idea either.

In Sept 2006 I posted the following old growth definition as a starting point for debate: The primary characteristic of an Old-Growth forest is that it contains a substantial percentage of old trees in a setting that exhibits only limited human impact. These forests are generally characterized as late-successional or climax forests for a particular regional or environmental regime. Canopy openings formed by natural processes, such as wind throw and fire, and populated by younger trees are often found contained within the larger old-growth forest. Another forest classification system defines Primary or Natural Heritage forests as "forest with a continuous heritage of natural disturbance and regeneration." (Frelich and Reich, 2003). The sets of trees and forests encompassed by each definition overlap in part, but are not completely congruous. An Old-Growth forest that looses all or a majority of its old trees through natural processes ceases to be old-growth, but may still be a Primary or Natural Heritage forest. A forest that has been disturbed by logging or selective logging may over time regain the status as an Old-Growth forest, but would no longer be a Primary forest. The major problem with many definitions of Old-Growth is the attempt to quantify the definition. Whether a particular forest is old-growth or not depends on the context of the other forests in the area or region, upon the disturbance history of the site, and upon the mix of trees present on the site. This qualitative definition is proposed as a purely quantitative definition is only applicable for forests in a limited region or setting. For research purposes, academic purposes, and management purposes these localized definitions may be workable and useful, but they can not be applied over the broad spectrum of forests found around the country and world. For practical purposes there is a need to develop a list of criteria that can be used to distinguish Old Growth forest and old trees from younger secondary forest and trees. A good overview starting point for many of these characteristics is defined in a document from the Ontario Agricultural Extension Notes: Old Growth Definitions:
http://www.lrconline.com/Extension_Notes_English/pdf/oldgwth.pdf This should be a beginning for further discussions of when in a forest, what features and characteristics tells someone that this is an old tree and this is an old forest. I look forward to further elaborations on this subject. There are numerous words and phrases in the definition that may be parsed in a discussion of old growth. I will enumerate them: 1) forest; 2) substantial percentage; 3) old trees; 4) limited human impact; 5) late successional or climax forest; 6) regional of environmental regime.

I realize in this post I used the verboten phrase climax forest, but as a conceptual entity I don't have a problem with the term. I also in hindsight realize that it lacks some of the structural concepts others have been suggesting and does not deal with the understory composition component of a high quality old growth forest setting.

Ed Frank

== 5 of 11 ==
Date: Mon, Sep 15 2008 8:07 pm
From: Randy Brown

Well Don,

I sense a trick question here. Not sure how I gave the impression
that I knew the answer, but anyway.

Rather than try to define a term that, in a pique of idealistic
naivety, was metaphorically applied to a situation it which it didn't
belong, let me speculate in general why their isn't a good answer.

So let's say you define 'virgin' as being free from the influence of
man. More practically it's at what point is a given disturbance
caused by man become relatively insignificant when compared to
subsequent natural disturbances. Correct me if I'm wrong, but aren't
many different forests types governed very strongly by their
disturbance regimes? So for a hypothetical example, a pacific NW
forest on Mt Saint Helens that got fried a couple hundred years ago
might not look a whole lot different than a big clearcut of similar
age. Same idea for Logpole pine forests in Yellowstone that burn down
in episodic large fires.

On the other hand you have tropical rainforests with an order of
magnitude more species, that one can expect to take longer to
reassemble all the diversity in structure and species composition that
one would associate with the lack of human disturbance.

And then you have the magnitude of the disturbance in area, time it
persisted, and intensity in any given location. All these factors
will influence the speed of the regeneration process. As a thought
experiment lets pretend everyone move out of NW Ohio tomorrow. The
forest in this area has been heavily fragmented into little woodlots
of varying size, and all wetland areas of significant size were
drained. On the rolling glacial moraines you both larger and more
closely space woodlots ( ~100 acres is a big one). You would expect
these areas to recover first because they would retain more of their
native species composition. On the other end of the scale you have
the extensively drained and cleared areas of the Great Black Swamp.
The first problem is the woodlots are smaller and more widely
scattered so this will slow down the forest succession. The other big
problem is amount of time it would take all the drainage canals to
silt up and restore something resembling the original hydrology. And
that's over a space of 10-20 miles.

So my point is that each general type of forest ecosystem probably has
it's own answer. And since we've already worked over so much of our
original forest it's possible we'll never have a terrible satisfying
answer in some cases. But on the other hand, just because a forests
is significantly disturbed, doesn't mean it shouldn't be protected
from being turned into a shopping center.

-Randy

== 8 of 11 ==
Date: Mon, Sep 15 2008 8:29 pm
From: "Edward Forrest Frank"

Randy,

I have excerpts of a couple of your points below rather than your complete argument. You are certainly right that the magnitude of the disturbance would affect the recovery rate. The point you alluded to, but did not state, is that the type of disturbance is also a factor.

Changing the hydrologic flow of a region will have a longer term effect than some other types of disturbances. In fact a change to the hydrology of an area may not recover at all, but be replaced by another forest type. Many swamp and bog areas are metastable. They retain water because there has not been an outlet eroded to drain them. A dissected stream pattern is the eventual fate of swamps and the more stable form in a landscape. So drained swamps would more likely be converted to something else over time rather than reform as they were originally.

Another consideration is not just the size of the disturbance but the shape. Much like edge effects reaching into the interior of a small forest fragment, I would think that a recovering patch with more edge to area would recover faster than say a broad square or circular area with less edge to area.

There is the question of the context of the disturbed area. If the areas around the disturbed are also affected, then the ultimate seed source for repopulating and regenerating is farther away than if an area is surrounded by relatively undisturbed forest.

There has been some references to the effect that some of the forest types and associations found in pre-Pleistocene times are now extinct. The same species are present but they are not grouped in the same way in present day forests. So there is a potential to generate something different entirely from what you started with, depending on the sequencing of the species that repopulate the area.

Ed

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