Tomahawk Lake Hemlocks State Natural Area

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Tomahawk Lake Hemlocks State Natural Area

Post by DonCBragg » Tue Jun 28, 2016 3:50 pm

Tomahawk Lake Hemlocks State Natural Area (TLHSNA) is one of 673 (as of 2016) areas formally protected by the State of Wisconsin to preserve the disappearing remnants of natural communities. TLHSNA ( ... sp?SNA=510) covers 244 acres in the Northern Highland-American Legion State Forest just south of Lake Tomahawk in Oneida County, Wisconsin.
Typical stand views of Tomahawk Lake Hemlocks State Natural Area in Oneida County, Wisconsin.
This parcel primarily protects a series of moraines and small kettles along the shores of a number of lakes, and is primarily a stand of old-growth eastern hemlock, with lesser amounts of sugar maple, yellow birch, and scattered supercanopy eastern white pine; some sections are dominated by second-growth northern red oak, bigtooth aspen, and sugar maple. Much of the stand has a dense hemlock understory; white-tailed deer browsing of the hemlock seems limited enough to permit natural hemlock regeneration across much of the stand.
Little Carr Lake, taken from TLHSNA

Parts of the old-growth hemlock were selectively cut in decades past, before the stand received protection, but many large hemlock, eastern white pine, and hardwoods remain. Large quantities of downed dead wood can also be found across the stand, further accentuating the old-growth nature of the property; I would estimate that the old hemlock, pine, and hardwoods in this stand are probably 150-200 years old. Most of northern Wisconsin was heavily lumbered in the late 1800s; this probably meant that this stand was mature timber at the time of the “big cut”, but probably not sufficiently high in volume for lumberjacks to be very interested in the stand (although it is quite possible that selected virgin pines and other trees may have been removed).
Large hemlock stump from earlier selective cutting in TLHSNA.
Summer coralroot (thanks Ed and Erik for helping me get this species right!).

Today, the stand is bisected by several paved roads, making access very easy (although diminishing the “wilderness” experience of the stand). The nearby lakes are well-developed with homes and cottages; the McNaughton Correctional Facility also borders part of the property (and probably makes it challenging to visit some of the stand without raising the concern of the guards).
Large, broken hemlock near large eastern white pine.
Eastern white pine supercanopy.

I visited this stand on June 28, 2016, with my trusty D-tape and TruPulse in hand. The dense hemlock under- and midstory made getting accurate heights tricky; the measurements below represent only a brief survey of a handful of locations in this stand. I believe most of the sine heights I present are underestimates of both the individual trees measured, as well as the species potentials in the TLHSNA.

Species DBH (inches) Height (feet)
Eastern hemlock 26.9 87.5
Eastern white pine 37.8 125.0
Yellow birch 25.7 ~60 (broken top)
Yellow birch 23.3 ~67 (broken top)
Eastern hemlock 27.4 92.5
Eastern hemlock 31.4 88.0
Sugar maple 20.8 81.0
Eastern hemlock 29.9 81.0
Northern red oak 25.7 85.0
Eastern hemlock 35.7 91.5
Northern red oak 24.7 79 (dead top)
Northern red oak 29.9 75.0
Eastern white pine 31.7 113.0
Bigtooth aspen 19.8 89.5
Northern red oak 18.4 100.0
Northern red oak 27.3 88.5
Eastern hemlock 32.5 80 (low estimate)
Eastern white pine 37.7 110 (low estimate)
Eastern hemlock 30.6 88.0
Eastern white pine 42.2 110 (low estimate)

The eastern white pines are the tallest and girthiest trees on this site, although many of the eastern hemlocks are also pretty wide, too. Most of the conifers on this site still show apical dominance and characteristics of good height growth, suggesting that they are not yet done with height increment. Across much of northern Wisconsin, stands with similar sites and levels of maturity are comparable in height for all species considered; eastern white pine heights of 110 to 130 feet are fairly common, with hemlock and other prominent hardwoods usually between 80 and 100 feet. Frequent wind events and ice/snow breakage during the winter help to constrain heights.
42.2 inch DBH eastern white pine.

TLHSNA is a good site for northern Wisconsin, and this preliminary survey justifies future visits to improve upon the size measurements (perhaps next during the winter, to help with visibility).
Last edited by DonCBragg on Wed Jun 29, 2016 8:39 am, edited 1 time in total.

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Re: Tomahawk Lake Hemlocks State Natural Area

Post by ElijahW » Tue Jun 28, 2016 7:48 pm


Cool report. From your pictures, I agree with the age assessment of 150-200 years. I don't know if any other species can compete with the beauty of the clear bole of an Eastern White Pine. Northern Red Oak, perhaps, or maybe Black Walnut come close, but in my opinion still can't quite compare. Thanks for sharing,

"There is nothing in the world to equal the forest as nature made it. The finest formal forest, the most magnificent artificially grown woods, cannot compare with the grandeur of primeval woodland." Bob Marshall, Recreational Limitations to Silviculture in the Adirondacks

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Re: Tomahawk Lake Hemlocks State Natural Area

Post by edfrank » Tue Jun 28, 2016 10:47 pm

The photo marked Indian Pipe is really Monotropa hypopithys or Pinesap or sometimes Dutchman's Pipe. Indian Pipe is in the same genus but is Monotropa uniflora.
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Re: Tomahawk Lake Hemlocks State Natural Area

Post by Erik Danielsen » Wed Jun 29, 2016 5:56 am

I'd suggest the wildflower is in fact not a Monotropa at all but one of the Coralroot Orchids in genus Corallorhiza, probably C. maculata. Corallorhiza, Monotropa, and Epifagus (beechdrops) cover most of the odd non-green parasitic forest flowers you'll find in temperate eastern NA.

Glad to hear that deer browse has been low enough for good regeneration. Are the winters up there cold enough to keep the adelgid relatively suppressed?

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Re: Tomahawk Lake Hemlocks State Natural Area

Post by DonCBragg » Wed Jun 29, 2016 8:43 am

Thanks Ed and Erik for pointing out my misidentification of the Indian pipes...In looking at the pictures closer, I believe it is probably summer coralroot (Corallorhiza maculata)...

Regarding your inquiry about the adelgid, so far this invasive has not arrived in the area yet, although I suspect when it does it will hammer hemlocks here as bad as elsewhere...Such a tragic shame, as this is such a spectacular species that will be sorely missed when the adelgid arrives...

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Re: Tomahawk Lake Hemlocks State Natural Area

Post by wisconsitom » Wed Jun 29, 2016 11:38 am

Wish I could disagree about future adelgid impacts, but I can't. True, winters in N. Wisconsin feature some of the coldest air outbreaks to be found anywhere in the US, but with today's anomalous weather patterns, who knows how long we've got that to count on. As it stands, I am quite sure that sections of N. Wisconsin and adjacent Upper Michigan hold the finest and largest remaining eastern hemlock stands anywhere.

And of course, it wouldn't be a post by me if I did not drag some political commentary into the brew: Quite simply, the political "leadership" in this state today-and for the foreseeable future, thanks to unprecedented gerrymandering-will see places like this leveled if some logger can make a few dollars off of it. To top it off, this same group of conservation experts has all but shut down the previously excellent in-house forestry management for private landowners, leaving them at the mercy of private guys, some of whom are excellent but many of whom advocate that landowners with hemlock eliminate it from the stand. Yes, this is happening. I know of one rolly-polly parcel not too awful far from this site, a 160-acre tract, that was full of old-growth hemlock, beech and sugar maple. That landowner was convinced that he needed to get rid of "all those goofy hemlocks". So yes, they are all gone. Such is being repeated region-wide.

In some ways, this makes me happy that some landowners are going too far the other way, and having no woodlot management done. At least, they won't fall prey to these tactics. Cheery guy, aren't I? I better quit. But thanks for posting.

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