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Botanist from Michigan

Hello, I am Greg. Measuring trees and estimating vegetation structure by species for the soil survey in western Michigan is my day job. I lead hikes every spring in the GSMNP and always carry a DBH tape. My metric DBH tape always throws foresters off, because the increments of cm DBH looks a great deal like straight inches, and vice versa.
by gjschmidt
Tue Mar 25, 2014 9:05 pm
 
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Re: Is it time for a National Big Tree Database/website?

Am I missing something here (I may be, I have not been following long)? Doesn't this forum already recommend a database? http://treesdb.azurewebsites.net/Map
The database is pretty nice, since it displays your choice of measurement units. I have been browsing the forum for new listed size measurements with great interest. However, it doesn't appear that many of the records in the forum make it into the database. Is this just a matter of taking the time to enter the data into the database site?

Also a parting thought about taxonomy and nomenclature. Whichever name someone uses for a tree should refer back to a standard taxonomy and spelling (see http://www.bonap.org). Also, the interest that this group has in quality size measurements reminds me of the scrutiny that phytogeographers use before accepting new county records for plant distribution maps. Perhaps NTS could talk to John Kartesz about linking tree size with tree distribution (e.g. query the BONAP database to report a list of tree species of a certain size class that occur in your county).
by gjschmidt
Tue Mar 25, 2014 9:43 pm
 
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Re: Botanist from Michigan

Sadly to say, I have only an analog clinometer and a tape. Last year was the first year that I began using it regularly for the NRCS, and I am well aware of the potential error of finding the top correctly. I am not sure if my employer would buy a rangefinder in the near term. I was temped to use a clinometer on a backcountry hike in the Smokies for what was perported to be the largest chestnut oak (south of Cades Cove), but I didn't want to hold up the group while I unrolled the tape. Ken Wise was on that hike; I think that he said that he knew Will Blozan. I'll be there again for the Annual Wildflower Pilgrimmage next month.
by gjschmidt
Wed Mar 26, 2014 9:46 am
 
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Re: Botanist from Michigan

I have just acquired a Nikon Forestry PRO Laser Rangefinder/Hypsometer.
http://www.forestry-suppliers.com/product_pages/Products.asp?mi=78521&title=Nikon%AE+Forestry+PRO+Laser+Rangefinder%2FHypsometer&itemnum=91140


A new world of forest stratum height is opened up to me. It has a choice of 1st hit and last hit, and can do either a "sin" based measure or traditional "tan" based measure.
by gjschmidt
Sat May 10, 2014 11:23 am
 
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Re: Florida Tree Species Diversity vrs Appalachia

In terms of tree species per unit area, south Florida fairs quite well relative to Appalachia. It is rivaled by the Florida panhandle, and exceeded by them in terms of vascular plant diversity. See http://www.bonap.org/diversity/diversity/diversity.html for some maps I made a few years ago. See the BONAP Facebook page for a few newer tree maps.

The problem with tropical Florida is that many of the native trees may not be as large as those counted as trees further north (the official definition of "tree" in vegetation classifications is any woody plant exceeding 5 m or 16.4 ft in height). Sometime early this year I will try to categorize each species by size and plot another map. Initially I am considering trees that normally reach only in the 5 to 15 meter range as "small trees".
by gjschmidt
Fri Jan 16, 2015 11:53 pm
 
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Tree species size distribution of temperate vs. tropical

I was trying to determine what the typical canopy heights are in the Eastern United States (not just maximums) as compared to the tropical rain forests. I also wanted some sort of base line to compare forests in my area. I found the perfect reference for this:
King, D. A., S. J. Wright, and J. H. Connell. 2006. The contribution of interspecific variation in maximum tree height to tropical and temperate diversity. Journal of Tropical Ecology. 22:11–24. http://ctfs.arnarb.harvard.edu/Public/pdfs/King_Wright_Connell_JTropEcol_2006.pdf
They measured woody stems greater than 4 m tall at 7 sites in the Eastern United States (MA, IN, KY, TN, NC) using a laser range finder. They had an average of 19.7 species per site and a total of 69 (mostly broadleaf deciduous, mesophytic) species. They averaged the three tallest trees for each species by site, or just the tallest of the less common species. In comparison, they got data from Barrow Colorado Island in Panama for 84 species. In both cases, the canopy top out at around 30 m (100 feet) tall in old growth forest with exceptional trees reaching 40 m (130 feet). What they found was that even though the tropical forest trees are more diverse than in the temperate zone trees as expected, the diversity of the subcanopy was disproportionately much more diverse. Most of the trees in the temperate zone forests have potential to reach the canopy (we have few true subcanopy species), whereas most tree species in the tropics reach maturity short of reaching the canopy. In other words, due to the more intense vertical light and year round growing season (the authors conclude), many more tropical species can specialize in the subcanopy niche.

Here are some graphs derived from data in the appendix of the paper.
image001.png

image004.png
image007.png

image005.png

Basically tuliptree and white pine still rank as the tallest trees in "typical" old growth forests, not just in exceptional forests.

image006.png
by gjschmidt
Sat Jan 31, 2015 2:47 pm
 
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Re: Tree species size distribution of temperate vs. tropical

I've finally finished my tree diversity maps using BONAP data. I have two size classes: small trees and medium to large trees. In these maps it is apparent that the most tree diversity on a per unit land area is in Alabama and the Florida panhandle. But in terms of small trees, tropical Florida takes first place.

t_3hab13_MediumLargeTrees.jpg
t_3hab12_SmallTrees.jpg

For more plant geography maps and to see enlarged versions of the above map, use link below.

http://bonap.org/2015_SpecialtyMaps/Density%20Gradient%202015/Density%20Gradient%202015.html
by gjschmidt
Fri Mar 27, 2015 7:07 pm
 
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Blandford Nature Center - Grand Rapids, MI

Today, my son and I rode our bikes to the Blandford Nature Center on the west side of Grand Rapids, armed with a DBH tape and a Nikon laser rangefinder. I have been curious about the baseline height of forest canopy around the city of Grand Rapids, and the height of the apparent tallest trees. Along Leonard Avenue, nearby, it seems that larger white pine, Norway spruce, and cottonwoods in front yards can reliably reach just above 30 m (100 ft). Oaks generally go to 25 m (80 ft). The nature center itself isn't particularly exceptional or large, yet intact stands of mature mesophytic forests as seen along its ravines is a rarity in the city. About half the trees have lost their leaves, so I hoped to get a better shot at heights. I used the "sine" setting as opposed to the defunct tangent based method, so I knew that I was more likely to err on the low side. This was not an exhaustive search for the largest trees, but I focused on an area east of the visitor center where Google Earth LIDAR suggested had the tallest trees.

The winner, so far, is tuliptree (Liriodendron tulipifera) at 37.6 m (123 ft). It seems that this is slightly taller than the tulip I measured at Warren Woods a couple years ago, but much thinner at only 82.7 cm (32.6 in) wide (Warren Woods had one at 36.8 m (120 ft) tall and 159.5 cm (5.2 ft) in diameter). We are near the northern extent of the natural range of tuliptree in Michigan. The northern-most stand with tuliptree, that I've seen so far, is only a couple miles further in a woods on the north side of I-96 just west of Alpine Ave (I've become rather good at spotting tuliptree crowns from a distance).

Here's a listing of other trees I felt compelled to measure:

Species ht (m) dbh (cm) ht (ft) dbh (in)
Prunus serotina 31.4 71.5 103.0 28.1
Quercus rubra 32.0 103.1 105.0 40.6
Acer saccharum 27.4 90.1 89.9 35.5
Carya cordiformis 31.8 60.2 104.3 23.7
Acer saccharum 29.4 78.9 96.5 31.1
Populus deltoides 33.2 71.7 108.9 28.2
Liriodendron tulipifera 33.2 71.0 108.9 28.0
Liriodendron tulipifera 35.6 80.1 116.8 31.5
Liriodendron tulipifera 37.6 82.7 123.4 32.6
by gjschmidt
Sun Nov 01, 2015 6:13 pm
 
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Michigan datbases entries

I recently visited Fabius State Game Area in St. Joseph County. Though many of the game areas are fairly cut up and invaded by multiflora rose and garlic mustard, there are a few nice stands. One such stand includes a tuliptree that I initially measured at 39.0 m tall with my laser hypsometer. But eventually, after wandering around the game area, I came across the same tree from the other direction without realizing it at first; I got a reading of 40.2 m (131.9 ft or 43.97 yd). Under most circumstances, at least hypothetically, the instrument with it's "sine" method is more likely to underestimate (as opposed to traditional clinometer and ground tape "tangent" methods), so I recorded the higher number.

I entered this tree along with a decent sized red oak in the Trees Database:
https://treesdb.azurewebsites.net/Browse/Sites/37964/Details

This is the tallest tree reported for Michigan thus far in the tree database. Though someone did have a spreadsheet which reports a slightly taller tuliptree in southeast Michigan, it has yet to be recorded here:
https://treesdb.azurewebsites.net/Browse/States/20/Details

My only issues with the database are that while I have "m" selected to display metric units, it treats everything as feet when I entered it. Also, I wish it would accept diameters, since this is what I had recorded using a dbh tape, and is what I visualize when looking at a tree. I suppose that others lack dbh tapes and visualize trees in terms of how many people it takes to hug a tree. I get that. I also understand that we actually measure circumference regardless of what the tape says, and that a elliptical tree would have a smaller basal area than implied by its circumference. But making the option of centimeters and diameter would make it easier for me to enter data.

For some reason, the Fabius State Game Area site doesn't show up on the map yet, even though it does have coordinates. Perhaps a delay?
by gjschmidt
Fri Jun 17, 2016 9:29 am
 
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