Rucker Area Curve

Rucker Area Curve

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TOPIC: Rucker - Area Curve
http://groups.google.com/group/entstrees/browse_thread/thread/45e7ab37127111be?hl=en
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== 1 of 1 ==
Date: Fri, Jan 25 2008 6:36 pm
From: "Edward Frank"

ENTS,

I came across this correspondence fro two years ago. I don't think anyone has pursued it and it might be worth a shot:
..
It might be interesting to look at the clustering of tall species by
plotting Rucker points against increasing acreage. The X-axis would
display increasing acreage and the Y axis would display the Rucker index
for the corresponding acreages. The minimum value on the X-axis would be
that number against which 10 canopy species (or an alternate number)
were tallied. This approach could provide us with a simple means of
making site to site comparisons. The labor-intensive nature of the
analysis would necessitate doing this for only a modest subset of our
ENTS sites. What do you think?

Bob
Rucker-area curve? tpdig-@ysu.edu
Dec 08, 2004 13:41 PST
Bob, Will et al.,

That's essentially the same concept as a species-area curve, but applied to tree
height index. Obviously surveying an entire area will give you all species
present, but there is typically some much smaller area that is meaningfully
representative in terms of species richness or diversity. Increasing the
sampling effort yields a steadily lower chance of finding new species (the
asymptote of the curve is the total number of species present). I think the same
would prove true for a Rucker Index. For example, the Rucker for Zoar Valley NY
is currently a little over 136', which includes about 70 acres of streamside
terraces. I believe the Rucker Index for the ~8-acre Skinny Dip Terrace (likely
the tallest) may be around 131'. I'd be curious to calculate the mean Rucker
Index for a set of small plots just big enough to encompass ten canopy species
each (on Skinny Dip Terrace these plots might be as small as 1/2 acre).
Labor-intensive, of course, but would probably yield some interesting results.

Tom

== 2 of 5 ==
Date: Sat, Jan 26 2008 4:07 pm
From: dbhguru@comcast.net

Ed,

Over the past several years, I've done many formal and informal exercises by starting out with a particular tall tree site and then expanding the geographical area to analyze the impact of the expansion on the Rucker Index. I haven't published much on the subject, but a mountain of work has been done.

Much of my early focus on MTSF was driven by my fascination with three tall tree hot spots. After I was satisfied that I had the measure of the individual area, I expanded their boundaries until I merged them. I then extended the merged region into adjacent areas, always keeping an eye on the Rucker Index. Since that early analysis, I've done the same thing for MSF, Ice Glen, the area around Monica's house, and parts of Northampton and Stockbridge. John Eichholz and I were well into a Deerfield watershed analysis before he dropped out of sight.

Beyond pure statistics, the challenge of interpreting the Rucker Index for an expanding geographical area requires that we identify the critical factors affecting the index. As a minimum, as one proceeds to study a region, one needs to track:

(1) variations in topography,

(2) age structure of the forest,

(3) past and recent land use,

(4) the region's overall climate and individual microclimates,

(5) species native to the area and their relative abundance,

(6) the growth potential of each native species for the latitude,

(7) negative impacts on tree species such as insect infestations and blights.

By tracking the above, one can make great progress in understanding changes in the Rucker Index as geography expands. One can get pretty good at predicting RHI changes as the area of study expands. For instance, expanding a core area that contains mature forest into a surrounding region of young stuff isn't likely to raise the Rucker Index unless additional species that grow tall are picked up in the 80 to 100 year age range. Predicting what may happen is often just that simple.

In my past, voluminous e-mail communications about MTSF, I often concentrated on the Todd-Clark Ridge, an area encompassing about 1,400 acres out of roughly 6,600 for the entire SF. Todd-Clark includes an elevation change of 1,300 feet and includes slopes facing all cardinal directions. The RHI for MTSF stands at 136.2. The Rucker for Todd-Clark is 135.0, and the region on just the north side of Todd-Clark is around 133.5. Expanding from outside the boundaries of MTSF into the immediate adjacent state forests and farther onto private lands changes the RHI not a whet. Expanding to the entire Berkshire Region raises the Rucker from 136.2 to 138.8. Extending to the entire state of Massachusetts raises the Rucker Index to 140.6. This means that MTSF represents 96.9% of the full state RHI. If I combed every nook and cranny of the state, I seriously doubt that I could raise the state index to 142. I'm not even confident of raising it another full point, but consider that to be a pr
obable theoretical limit. What I am confident of is that MTSF will continue to hover between 96% and 97% of the state index.

How significant is Mohawk's RHI relative to the state's? The contiguously drawn geographical area that accounts for Mohawks 136.2 RHI is at most 2,500 acres. The state has about 5,050,000 acres of land. So an area comprising a tiny 0.05% of the total land mass represents 96.9% of the state's Rucker index. That's pretty significant.

What this line of RHI analysis illustrates to me is the possibility that if one can locate a relatively small area of extremely high productivity and if the species occurring within the small area are naturally tall, then the small site's RHI can be disproportionally high for the land area represented. This expectation is true for Massachusetts. I think it is true for New Hampshire and is likely to be true for Pennsylvania and New York. I suspect we can add North Carolina and Tennessee courtesy of the Smokies. I had no specific expectations when starting down this path, but I doubt that I thought any single site would be more than 80% of its state's RHI. But then, what did I know?

Bob

== 3 of 5 ==
Date: Sat, Jan 26 2008 4:32 pm
From: "Edward Frank"

Bob,

A summary of some of your exercises on this theme would be interesting. I was thinking that another way to look at this question would be for a particular location, what would be the minimum are required to generate a RHI of 100? (or some other value) The area of the "site" would be defined by the boundaries of a particular topographic expression, such as the "slopes and valley floor" of such and such a stream, or as Tom suggested a particular terrace along a river. Otherwise the area could be defined as a circle equal in diameter to the two most distant trees included in the RHI. Some general discussion of the concept and the results might be fruitful.

Ed

== 4 of 5 ==
Date: Sat, Jan 26 2008 4:43 pm
From: DON BERTOLETTE

Bob-
Along with Ed's suggestion, I'd of course be interested in the spatial relationships between various classifications of Rucker Indices...is your data sufficiently organized that Gary could perform such a GIS analysis?
-Don

== 5 of 5 ==
Date: Sat, Jan 26 2008 6:16 pm
From: dbhguru@comcast.net

Don,

I could get a large amount of data into a form that Gary could use, but it would take time to build the lat-long coordinates.

Bob

==============================================================================
TOPIC: Rucker - Area Curve
http://groups.google.com/group/entstrees/browse_thread/thread/45e7ab37127111be?hl=en
==============================================================================

== 1 of 5 ==
Date: Sun, Jan 27 2008 7:13 am
From: dbhguru@comcast.net

Don,

Absent of computer wisardry that reveals heretofore unseen relationships, if we find a good white pine site in western Massachusetts, barring disturbance, we can be assured of tall white pines within 75 to 150 years that will commonly range in height from 115 to 130 feet. Stands with 120-footers would be common. If lots of sites are allowed to mature into the above age range, a respectible number of sites will have trees that push to between 130 and 140 feet. These sites will tend to be on the sides of ravines, shallow or deep. Reliable sources of water are critical. But above 140, the increasing height curve dips dramatically. An extremely small number of Massachusetts sites support great whites between 140 and 150 feet in height. Presently, we have documented trees above 140 at 10 separate sites. We have documented 150-footers at 4 locations, and 160-footers at 2 locations.

From my perspective, sites with 160-footers represent onc class of true arboreal gems of Massachusetts that we should admire and protect. Currently we have located 7 trees in all Massachusetts that exceed 160 feet in height. One tree is isolated and the others are in stands. Why haven't we found more? There are plenty of trees that are in the requisite age range and occupying good growing sites. I believe that we are looking at the maximum performance for the species in New England when we get into the 160 and above range and there aren't even a collection of statistical outliers. Currently a single white pine has the possibility of exceeding 170 feet within the next few years in not only Massachusetts, but all New England. That tree is the Jake Swamp white pine.

How are the taller trees spatially arranged? They tend to be clumped, often in close proximity within stands. If you find one, you have a high probability of finding a second close by. I presume that a small cluster of trees is competing for the best habitat. As the stand reaches old growth status and the pine density thins, the spatial arrangement of the tall trees reflects the overall thinning of the stand, i.e they become farther apart. Still, there can be a clustering of 2 or 3 trees that achieve great stature.

What is most surprising to me is the height consistency within geographical areas and individual stands. The white pines behind Monica's house along the Broad Brook corridor vary in age from 60 to 200 years. The area can produce a 130-foot white pine, but 140 seems almost out of the question. Why is that? More on this topic in a future e-mail.

Bob

== 2 of 5 ==
Date: Sun, Jan 27 2008 8:21 am
From: ForestRuss@aol.com

Bob:

I have been making my annual growth measurements of selected trees at
Crummies Creek and I think that there is growing proof that very large does not
necessarily mean very old...even in the woods.

In my work I get the chance to count the rings on stumps anytime I want but
I have long wanted to be able to assess interior growth rates from external
bark and physical characteristics when trying to guess the age of trees,
especially when I am trying to select the very best individuals to retain for
years, possibly decades to come during timber sale preparation.

I have a course of several dozen trees that I have been monitoring
individually for up to twelve years and below are some of the diameter growth rates.
The interesting thing I want to mention is that I regularly encounter red oak
trees that sustain such growth rates well into their mid 40''s diameter wise
and in open grown trees easily up to 58-60" DBH or around 15' CBH.

Diameter growth in superior trees can be significantly higher than what is
listed below. Most of the red oak trees in this sample are codominant and
average between 50 and 65 feet of telephone pole type of stem in terms of
straightness and limb and defect free. The property was severely logged in a
diameter limit cut a little over 20 years ago.

Most of the below growth rates, especially the red oaks should sustain for
at least another 15 or 20 years but some of the largest and most dominant trees
will grow 1/4" rings for at least another 50 years.

I have looked at the stumps of thousands of trees harvested for timber in
some of the more productive parts of West Virginia and have encountered numerous
yellow poplar trees with more than a decade of sustained annual growth rates
of 2+" with rings over 1" wide. Red oak trees rarely sustain 1" rings for
more than 5 years.

I have several dozen more trees to measure before the winter is out but now
that more trees have 8 to ten years growth since measurements start the
numbers are easier to crunch.

Russ

Russ

Species Starting DBH Years growth 2008 DBH

Black walnut 15.4 10 19.3

Red oak 21.9 10 26.9

Red oak 20.0 8 24.0

Red oak 13.3 8 15.4

Red oak 18.0 8 20.5

Black walnut 15.4 8 17.4

Red oak 12.4 8 15.5

Basswood 14.1 8 16.3

Black walnut 17.1 8 19.7

White ash 17.2 8 20.2

Sugar maple 11.7 8 13.4

Sugar maple 15.3 8 17.0

All of the trees with the 8 year measurements suffered some crown damage
during a 2003 ice storm and all sugar maples were severely damaged. Other
species I have yet to measure include red maple, cherry, white oak, cucumber,
white ash and a lot of poplar.

Russ

== 3 of 5 ==
Date: Sun, Jan 27 2008 12:21 pm
From: DON BERTOLETTE

Bob-
Emergent crowns everywhere face the same exposure to weather...would you say that the locations that currently harbor the tallest trees are favored by protecting topography?
-Don

== 4 of 5 ==
Date: Sun, Jan 27 2008 2:07 pm
From: dbhguru@comcast.net

Russ,

Interesting data. Do you have a good feel for how much faster species grow on a good West Virginia site compared to a good Massachusetts site for red oak, white oak, sugar maple, red maple, and white pine? What I've observed on the good white pine sites is that long after radial growth has slowed considerably, height growth continues to eventually build a long, straight bole with a lot of total volume.

Bob

== 5 of 5 ==
Date: Sun, Jan 27 2008 6:47 pm
From: ForestRuss@aol.com

Bob:

I think yellow poplar is the closest thing to white pine there can be in
terms of growth characteristics. Yellow poplar trees with a clear stem and very
little taper can easily reach 100 feet. The total tree height can be
significantly higher and I have measured fallen poplar trees that were still over
8" in diameter at 120'....nothing compared to an old growth white pine or
hemlock but not bad for a 100 year old tree. I think that unless the crown is
damaged in some way and their is sufficient competition to encourage height
growth that yellow poplar really can take on a white pine form. Older stands of
yellow poplar can really give good pine stands a run for their money in the
race for volume but I think poplar might produce more usable fiber.

The red oak will grow long and tall but I think that black oak can beat red
oak in the lack of taper contest. Red oak will commonly reach size
proportions double what I often encountered in New England, especially in total stem
length. In western Mass you can find red oak trees up to 40" in diameter but
most trees are less than 100 total feet and rarely have more than 40' of stem
height before if breaks into the crown. Most large diameter red oak trees I
have seen in New England had fairly rapid taper or a major fork close to the
ground.

My guess is if you were to find the mother of all fantastic red oak trees in
Massachusetts growing on a good site and the same example for West Virginia I
would probably add 30 to 40' of perfect stem to the bottom of the
Massachusetts red oak and add 20" in diameter...but that would only be for a 150+ year
old tree in Massachusetts but it could be a 100 year old tree on the best WV
sites.

White pine was my bread and butter for all the years I worked in New England
but out of over 9,000 trees I tallied and sold in 2007 only 21 were
softwoods and all were Virginia pine.

Most of the white pine here is in plantations and there is no weevil. It
was often planted on worn out farm land before deer became too plentiful. The
growth rates here for white pine can be extremely good and I have seen many
trees harvested that had sustained periods of 1" growth rings. About ten
years ago I cruised a white pine plantation that was 30 years old and the largest
white pine were between 30 and 36 inches in diameter at over 100' tall.

Native white pines are so rare in central WV that I almost never mark them
and the older patches I have encountered would rival MTSF...and there is no way
I would sell such high quality trees for $20/MBF..so they stay.

I have heard that there is a 70 year old white pine plantation near Parsons,
WV that has in excess of 100,000 board feet per acre.

Sugar maple can grow taller in total height and usually can produce a tall
tree with little taper. The two that can be very impressive are basswood and
ash with both trees potentially having a clean, defect free stem up to 100'
before breaking into the crown. I used to be thrilled to find basswood trees
in Massachusetts with 30 feet of stem.

Russ

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