11, 2004 07:43 PST
I've been wearing my ecological restoration hat a lot lately.
restoration point of view, it's often helpful to look at
conditions (conceptually similar to "natural or historical
variability). The tree measuring ENTS is doing is definitely
the precision and accuracy part of the equation, but by
measuring only the
tallest trees you can find (I understand the calling!), isn't
halfway there? You're getting the top range of variability
(let's say of
the population of old trees), but in terms of restoration of
remnant populations, it would be valuable to have the lower
range of old
Questions for Jess and Will
11, 2004 09:36 PST
Good question. You point to a bias in
our treatment of tree growth.
I usually think in terms of how well a tree species can do for a
conditions. It is hard for me to think in the other direction,
there are exceptions. For instance, the dwarf pitch pines that
a couple of summits in the Mass Taconics and I think several
tops in the Catskills reflect a waist to head-high forest that
perpetuates itself forest generation after forest generation. It
natural to acknowledge what the species is doing in these
environments. So I readily accept that to fully appreciate and
understand Pinus rigida, we need to study its capacity to
the range of conditions in which we find it.
Extending this thinking to the other
species seems to be the logical
move. But do we seek the best a species does when growing in
dwarfed form - or do we look for the most extreme case of
Looks like we need to add a good
yardstick or even foot ruler to our
Questions for Jess and Will
11, 2004 18:57 PST
I too am interested in the performance of a species across a
conditions...ponderosa pines on the Kaibab Plateau (includes
District of USFS and the Grand Canyon) have had a continued
more than 8,000 years
) on soils that
are in lay terms, shallow and not very rich in nutrients. So few
exceptionally tall or large diameter trees are to be found
(tough area for
the champion tree hunter!). However, as a forest restorationist,
of variation that this gene set exhibits after a multi-millenial
run is very
interesting data. It may be instructive to know that 300 year
pines naturally ranged from 21"dbh to 57"dbh, and
heights ranged from 67' to
Particularly to other land management agencies that don't have
array of ponderosa pines as relatively undisturbed as ours.
Questions for Jess and Will
11, 2004 19:56 PST
Bob, Don, Colby, other ENTS
All of you have seen these stunted trees or pictures of them.
Many do not
reach "breast height" or if they do they are
relatively far up the trunk of
the tree. If you were to try and document these stunted trees in
shorthand format for larger trees at what height would you measure the
circumference? I would suggest a point just above the root flair
with the actual height from the ground specified. Any comments
I must confess I am fascinated by these stunted forms and would
like to see
and participate in documenting the trees in such a forest.
At the other extreme are the Giant Sequoias and the like that
are so large
root flare may extend upward of thirty feet, and if on a slope
on side of a
cbh may be on the ground at the upper end and high of the ground
downslope side. But all in all you can still measure something
like a cbh
for them. Bob Van Pelt has done a very nice job of mapping the
of many of these trees and has shown virtual slices of the
trunks of these
trees at varying heights.
Questions for Jess and Will
12, 2004 18:27 PST
I too am fascinated by the "bonsai" segment of
old-growth...when they are of
human dimension, it's possible and I'd think desirable to
"map" it like BVP
(good practice in humility, in the face of what BVP accomplishes
superlative end of the spectrum!!!).
Your comments about redwoods recall my forestry classes at
U., with labs up the street in the coastal redwoods...simple
epic...dbh measurements required art, and a red rubber
ball...we'd impale the
hook of a D-tape into a red rubber ball, and after carefully
like getting fly fishing line out there) up some tape, we'd swing
around the base (we'd be on a 80-100% slope, on topside of tree
would often be 350 inches in circumference (not uncommon to
foot dbh redwoods less than a mile from classrooms). Had to make
catch, as the back side was often 15 to 25 foot above the base
downhill side...all this with ferns growing over your head, and
5-7 months a
year, muddy. Caulked boots were standard wear (like a golf shoe
many more spikes and much sharper). Ah, those were the days!
Forest Study Plan
12, 2004 18:50 PST
Bob, Don, and other ENTS,
I am sure we have enough of a brain trust here on the ENTS
to work out a good strategy for looking at these dwarf stands of
Bob Leverett showed some slides of the dwarf pitch pines on some
Massachusetts mountains during the forest summit a few weeks
trees were spaced relatively close together, but did not look
formed a continuous canopy. I would suggest the following
characterize a site such as this:
I would do a transect line across an area inhabited by these
specific direction of the transect and initial starting point
selected prior to visiting the site based upon topo maps of the
would provide a degree of randomness to the location of the
initial starting point and ending point of the transect could be
via GPS and marked with a small cairn in case the site merited
visit at a future time. Every tree that had any part of its
within a set distance, say ten feet of the transect line would
Measured would be the distance along the transect line from the
point, the distance from the transect line to the left or right
tree, the circumference of the tree, the height of the tree, and
spread of the tree.
I would make a measuring pole the length of the set distance to
from the transect line. A short right angled bend could be
placed at one
end of the pole. This would make it easy to determine if a tree
within the study width and enable the measurer to accurately
place the tree
at a correct distance along the transect line. Each tree right
would be numbered sequentially. The circumference would be
measured at the
same height for each tree. That height would be determined by
observations made at the site and noted in the field notes. The
measurement could be done using any tape, even a short cloth
available for a dollar. The most efficient way to measure height
averaged less than 15 feet would be to use a rigid measuring
crown spread would be measured as per Will's measuring document.
Additional information could also be noted such as height to the
living branch, live crown ration, etc. Of course species would
be noted if
more than one were present.
The location information and crown spread could be used to
create a map of
the trees (crown spread represented as a circle) and the area of
versus open space could be calculated. For trees that have only
their canopy within the measuring distance there is an equation
that can be
used in a spreadsheet to calculate the area of the arc segments
outside of the boundaries. That is one example of a calculation
be made. Additional notes could be made based upon things you
found in the
field of interest. Whether a tree is mature or just a sapling
noted. Clumps of other vegetation within the transect area would
noting and identifying...
I would photograph each tree measured with a digital camera - a
cost -. Since each tree would be given a unique number. A number
could be used to show the tree's number in the photo. I am
something like the flippable numbers used to mark prices in
Illustrative characteristics could be photographed, with a
scale, for use
in any reports or presentations.
A second group of trees that should also be measured in the
process is any
tree within the grove or site that warrant special attention,
tree, the shortest tree, the one with the greatest diameter, or
special characteristics. They should also be located with
respect to the
transect, maybe by using the laser range finder. The results
tabulated on a separate list.
The ages of the trees should be determined. Perhaps a couple
cored. If there was a dead tree in the grove a slab could be cut
examination with a small handsaw. Evidence of disturbance events
noted. Boundaries for the dwarf tree area should be noted on the
GPS could be used to confirm placement of these boundaries.
Dwarf Forest Study Plan
12, 2004 19:46 PST
My preferences for canopy closure are:
1)aerial photography (digital orthophotoquads cover most of the
states at nearly one meter resolution...
2)if on ground, a GRS densitometer, as found at
with an excellent write-up on
12, 2004 20:00 PST
Thanks for the suggestion. I looked at the website you listed. I
skimmed the paper by Stumpf listed and downloaded it for a more
examionation. In my first impression, I am wondering about the
applicablility of the (vertical) densiometer in a canopy that
may only be 5
feet off the ground and very stragglely. Also, I don't have a
while I do have a tape measure and compass. But the idea
With regard to aerial photos, I am thinking the scale we are dealing with may be a problem. The canopy spread for a particular tree may only be a few feet across and would barely be distinguishable on most air photos. At this point I am just tossing out ideas and thinking about the problem. The purpose of the post was to fish for ideas and to pique someone elses interest in the problem. I would like to try it myself, but probably won't have time till next summer.
I know you mentioned the resolution of one meter for the orthophotoquads. But to make reasonable measurements you need to be measuring something significantly larger than the minimum resolution of the photograph.
12, 2004 20:20 PST
You have done well with things easily at hand, a "McGuyver"
of the transect
Re densitometer, I hadn't been envisioning 5 foot tree heights
to Bob's pigmy forest), it would work equally well for a tall
densitometer inverted (ie, "looking down" instead of
The thing I like about the densitometer, is that it's
technology...abs plastic tubing, levels, wires, plexiglass.
and it's accuracy dependent on operator field skills...plus, its
applications is limited only by the user's imagination.
I still like the aerial view...doesn't cost much to rent a
aerial photos with a digital camera. Easiest way to determine
crown level vegetation, even with DOQQs and small crowns...when
large enough to perceive, new boundary...
Dwarf Forest Study Plan
16, 2004 09:35 PST
a quick reply related to sampling dwarf forests. Depending on
you actually want to characterize, a series of fixed area plots
for us in past on dwarf communities in the southern Taconics and
Shawangunks in New York (see references below). Briefly, you
fixed area plots and measure soils, overstory vegetation (dbh,
etc.) within them, and understory veg, in a series of smaller
and D.A. Orwig. 1995. Community and radial growth dynamics
of a 320 year old pitch pine rock outcrop community in
York. Oecologia. 101:353-360.
D.A. Orwig, and D.R. Foster. 2002. History and dynamics of a
ridgetop pitch pine community: Mount Everett, Massachusetts.
Forest Paper Number 25.
D.A. Orwig, and D.R. Foster. 2002. Vegetation and
disturbance history of a rare dwarf pitch pine community on
Massachusetts. J. of Biogeography 29: 1455-1467.
18, 2004 21:23 PST
I have had a couple of stray thoughts I wanted to add to the
dwarf forest mix.
1) I am curious to what degree the stunted Jack Pines talked
about by Bob
L. are of that form because of the climate directly, and what
part of that
has been imprinted on their genetic code by thousands of years
selection from living in that harsh climate. Seeds from cones
from one of these dwarf forests could be collected and then
planted in an
area known to grow large pine trees. Records could be kept over
of several years of the growth of these particular seedlings.
long-term study could be done as a side piece to an existing or
long term study, could be grown on a university setting study
perhaps grown by a commercial grower. If the trees indeed have a
genetic contribution to their diminutive form, and stayed small
they could even have a place in the landscaping business.
2) When I was doing cave research in The Bahamas, one of the
I was looking at for an overview were areas containing dense
of pits. The individual pits were located on a fairly flat
3-10 feet across and dropped vertically 15-30 feet. Several
been working on them and had previously deduced their origin. The
was that there had never been any good pictures taken that gave
perspective of the pits and their surroundings. I had the idea
of taking a
tall step ladder to one of these areas with us. Then shooting
the ladder we could get a better angle to show the pits, pit
the surrounding flat areas. There was a line up of people in at
session waiting their turn to take pictures from atop the
the dwarf forest areas were not too far up the trail from a
road access, a
good step ladder could do wonders for taking pictures of the
and the surrounding terrain.
Dwarf Forest Study Plan
23, 2004 05:30 PST
In regards to sampling dwarf forests, it might be best to survey
of random plots within the forest. Based on aerial photography
initial site visit, the study area can be stratified. Then,
using a GIS a
grid system can be placed over the area and plots chosen at
belt transect method could also be used and would probably be
time-consuming and easier to implement. However, random plots
more accurate information. Having said this, the sampling method
depends on the information one would like to obtain.
Although I have not sampled the pitch pine/scrub oak forests on
of Mt. Everett, while conducting research on the remainder of
the forest I
have often found myself atop the mountain in this dwarf forest.
be a great deal of variability depending upon slope aspect,
micro-topography, substrate, and disturbance history (and therefore,
degree of succession). I have sampled some of these dwarf
forests on other
sites on the mountain using a systematic sampling scheme to
forest communities and to characterize species composition and
structure within each community, including basal cover, relative
frequencies, and height. This method was developed to
eastern portion of the mountain, including a smaller pitch pine
to the east of the summit. This sampling scheme was adequate to
desired information. However, to fully understand and
dwarf communities random plots would be better.
Harvard Forest conducted research on the pitch pine/scrub oak
the summit of Mt. Everett. They utilized a random plot sampling
that seemed to work well.
Motzin, G., D.A. Orwig, and D.R. Foster. 2002. History and
dynamics of a
ridgetop pitch pine community, Mt. Everett, MA. Harvard
Petersham, MA. Harvard Forest Paper No. 25.
They aslo published a paper in the Journal of Biogeography in
can't seem to find the paper at the moment for the whole
Dwarf Forest Study Plan
23, 2004 18:49 PST
I have gotten a post concerning the plan from Dave Orwig and
concerning the idea of a belt transect versus a plot format. I
designed a forest survey and have been looking for input.
these numbers are for comparison purposes what would be the
weaknesses of various plot plans. For example: a) a single plot
by 100 feet, and b) four random plots 50 feet by 50 feet, c) a
transect 20 feet wide by 500 feet. All of them cover the same
a) A single plot site that was larger would provide much more
that portion of the forest and allow better internal comparisons
to be made
between tree within the plot.
b) Four random plots (or selected plots even) would provide
four separate areas of the site. There is a much greater chance
document variations in the site.
c) A transect would show variation in the forest along a single
ideally it would provide information on the transition between
of the forest and another. More than one transect section could
I also believe it would be easier to implement than the other
What thoughts do you have on why one design variation would be
the others? What are the benefits and weaknesses of each of the
design options? I would be interested in hearing more details of
methods you used in your research and why you choose that