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2011
THE MICHIGAN BOTANIST
109
MATERIALS AND METHODS
Study areas
The Huron Mountain Club has maintained a 2500-ha reserve for over a century in Michigan's
Huron Mountains that border Lake Superior (Figure 1). The reserve contains extensive forests of oldgrowth mesic hemlock and hardwoods, which have been the subject of several studies over the years
(Braun 1950; Willis and Coffman 1975; Woods 2000; Woods 2008; Marx and Walters 2008). Oldgrowth white pine stands are uncommon in the mesic forests of the Huron Mountains, but scattered
emergent pines are a component of many hemlock-northern hardwoods stands in the Upper Midwest.
During 2007-2008, I established two adjacent permanent plots totaling 2.5 ha by Fisher Creek in the
Huron Mountain Club Reserve, located within 46Â~51.4'-51.6' N and 87Â~52.9'-53.1'W. Plot maps are
on file in reports to the Huron Mountain Wildlife Foundation (www.hmwf.org). The north plot
(FCN) covered 1.58 ha of white pine-hemlock-northern hardwood forest, which included a few
canopy gaps of 0.02-0.03 ha. The adjacent 0.92-ha south plot (FCS) contained an atypical white
pine-white spruce stand that was described by Thompson (1985) and Simpson et al. (1990). Fahey
(2011) reported that the oldest white pine among core samples at the Fisher Creek stands was -210
y. FCN and FCS were similar in elevation and topography (little relief). Most of FCS soils were classified as Evart-Pelskie-Sturgeon complex with deep, poorly drained, permeable soils that form in
silty and sandy alluvium and most of FCN as Kalkalska-Waiska complex of deep, well-drained, permeable soils on sandy outwash (Schwenner 2007).
Estivant Pines is the largest preserved tract of old-growth white pine in Michigan, located in a
206-ha sanctuary of the Michigan Nature Association, south of Copper Harbor near the tip of the Keweenaw Peninsula (Figure 1). This important stand lacks previous demographic study. During 2010,
I established a 0.78-ha permanent plot (EPU) in a white pine stand known as Cathedral Grove. This
upland plot followed the top of a broad ridge. A second 0.75-ha plot (EPG) was established to the
west on a lower plateau, separated from EPU by a 20-30 m wide ravine. The Estivant plots were located within 47Â~26.2'-26.4' N and 87Â~52.8'-53.1'W. Estivant plot maps are on file in reports to the
Michigan Nature Association (www.michigannature.org). EPG was chosen because it contained
large gaps (0.03-0.06 ha) in the forest canopy and a number of white pine saplings and seedlings,
which were rare elsewhere in Estivant Pines. Below the emergent pines at Estivant, sugar maple and
balsam fir were dominant. The oldest pine sampled in the plots by Fahey (2011) was -260 y. EPU
sloped gradually downhill from northeast to southwest, but with a low aspect that is unlikely to differ in vegetation effects from the flatter EPG. Soils at both EPU and EPG were classified as Arcadian-Dishno-rock outcrop complex of cobbly and gravelly fine sandy loams (Tardy 2006).
Methods
Within the plots all living stems 5 cm were mapped by recording the x and y coordinates of each
stem with a grid of measuring tapes. Stem diameters were measured at breast height (1.4 m). For mortality data, snags (dead stems) 20 cm dbh (diameter breast height) were also mapped and measured.
Along transect lines running across the plots, small saplings (= 1.0-4.9 cm dbh) were tallied by
species in a continuous strip of 2- x 4-m quadrats (all stems 2 m from the lines). Transect lines were
mostly located along N-S and E-W lines (with a few exceptions that followed major plot axes), spread
out to cover all sections of the plots. Some transect locations in FCN and EPG were chosen to pass
through canopy gaps to monitor long-term changes in tree regeneration within the gaps. This likely biases the sapling densities reported for these plots. Transect lengths totaled 652 m in FCN, 290 m in
FCS, 312 m in EPU, and 392 m in EPG. Size class distributions of all individual living stems were
tabulated for this paper for demographic analysis and to provide a record for ecologists who revisit the
permanent plots in the future. Nomenclature follows Barnes and Wagner (2004).
RESULTS
At the Fisher Creek site of the Huron Mountain Reserve, FCN was covered
by a hardwood-white pine-hemlock (in order of basal area) forest (Table 1).
White pine dominated the larger size classes; most pines were emergent over a
