Bedrock shoreline survey of the Niagaran escarpment in Michigan's Upper Peninsula: Mackinac County to Delta County

[From the U.S. Government Printing Office, www.gpo.gov]

Bedrock Shoreline Survey of the Niagaran Escarpment in
Michigan's Upper Peninsula: Mackinac County to Delta County

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prepared by
Dennis A. Albert, Ecologist
Patrick J. Comer, Associate Ecologist
Richard A. Corner, Assistant Ecologist
David Cuthrell, Assistant Zoologist
Michael Penskar, Botanist
Mary Rabe, Zoologist

Michigan Natural Features Inventory
5th Floor Mason Building, Box 30444
Lansing, MI 48909-7944
for
Land and Water Management Division
(grant # 95 CD-0.02)
Completed December 31, 1995

ABSTRACT

Bedrock is exposed along large portions of the shoreline of the Great Lakes, especially in the
01 Upper Peninsula, providing scenic views of the Great Lakes. Increasingly the large portions of the
- Great Lakes shoreline are becoming inaccessible to the public as a result of residential
development. In this study we inventoried portions of the coastal bedrock, both in response to
extreme development pressure and because of the significant biological diversity that characterizes
much of the coastal bedrock. This report summarizes the results of 1995 plant community, rare
plant, and insect inventories along the Lake Michigan shoreline in Delta and Schoolcraft counties
and continued insect inventories along the Lake Superior shoreline of the Keweenaw Peninsula and
the Lake Huron shoreline of Drummond Island.
Differences in bedrock result in strikingly different shorelines with equally distinctive floras
and faunas. In this survey, we have concentrated on the Silurian-aged dolomite and limestone
along the northern shorc of Lake Michigan and on several islands in northern Lake Michigan.
Basic characteristics of the dolomite and limestone bedrock are described within the report.
While most of our sampling was conducted in one natural community, bedrock beach,
sampling was also conducted on bedrock glade, cobble beach, and bedrock cliffs. The greatest
diversity of rare plants occurs on bedrock beach, but bedrock glade also contains many rare plant
species. Diversity was much lower on cobble beach and bedrock cliffs. It is expected that faunal
diversity will be highest on bedrock beach and glade.
The entire shoreline of northern Lake Michigan, from St. Ignace, in Mackinac County, to
Menominee in Menominee County, was photo interpreted in preparation for the field surveys.
Aerial reconnaissance was conducted to further evaluate sites and to photograph portions of the
shoreline. Sampling of the vegetation of bedrock beach sites followed to collect data for the
improvement of MNFIs community classification. Surveys of rare plant and animal species were
conducted, as were general surveys for insects.
The 1995 surveys have resulted in the discovery of many new sites for both rare plants and
high quality bedrock beach. Several new bedrock glades were discovered, which added to our
understanding of this under-studied plant community. While no state-listed insect species have
been found to date, several new county records and disjuncts have been identified. Identification of
insect specimens from the surveys is ongoing.
Management recommendations will be made for the three high-quality bedrock beach sites,
Poverty Island, Summer Island, and Pt. Detour, that are largely state-owned. We recommend that
acquisition or conservation easements be sought for Goudreau's Harbor, which is recognized as
having both the largest stretch of dolomite bedrock shoreline in the state, and populations of both
state-listed plants and animals. Stony Point and nearby open dunes should also be considered for
acquisition. Although the bedrock beach supports no rare species, several rare plant species
Z_ occupy the surrounding dunes and there are high quality interdunal swales and bedrock on the
(:@O point.

ACKNOWLEDGMENTS

We would like to dmik the Coastal Zone Management Program of the Land and Water
Management Division, Michigan Department of Natural Resources, and The Nature Conservancy
for providing funding for this study. Special thanks go to Dr. Ted Cline of Photair who flew and
photographed the shoreline of Schoolcraft and Delta Counties; these oblique aerial photographs
provided many insights into the plant communities and geological structure of the shoreline that are
not available on vertical aerial photographs. We would also like to thank Patrick Ranguette for
sharing his knowledge of Little Summer, Poverty, and St. Martin Islands and for transporting us to
these islands with his boat; his knowledge of the area greatly increased the efficiency of our
inventory.
Several entomologists provided identifications, including G.M. Fauske (North Dakota State
University, for the Lepidoptera and Orthoptera); K.G.A. Hamilton (Agriculture Canada, for the
Cicadellidae in part); D.A. Rider (North Dakota State University, for the Pentatomidae); E.G.
Riley (Texas A&M University, for the Chrysomelidae); M.D. Schwartz (Agriculture Canada, for
the Miridae); and D.F. Schweitzer (Eastern Regional office of The Nature Conservancy, for the
Papaipema.

TABLE OF CONTENTS

INTRODUCTION I
BEDROCK OF THE NIAGARAN ESCARPMENT ............................................................................I
NATURAL CONUVIUNITIES OF THE COASTAL NIAGARAN ESCARPMENT .............................. 10
Bedrock Beach ............................................................................................................................. 10
Bedrock Glade .............................................................................................................................. 10
Alvar ............................................................................................................................................ 15
Dry Alkaline Cliff ........................................................................................................................ 15
Boreal Forest ................................................................................................................................ 15
SPECIAL PLANTS .................................................................................................................................... 15
INSECT SURVEYS ................................................................................................................................... 16

METHODS ................................................................................................................................................ 16
BEDROCK CLASSIFICATION AND MAPPING ............................................................................... 16
SURVEY SITE IDENTIFICATION .................................................................................................... 17
Air Photo Interpretation ................................................................................................................ 17
Aerial Reconnaissance .................................................................................................................. 17
Bedrock Shoreline Survey Sites .................................................................................................... 17
VEGETATION SAM[PLING ............................................................................................................... 17
SPECIAL PLANTS SURVEY METHODS .......................................................................................... 18
INSECT SURVEY METHODS ........................................................................................................... 18

RESULTS OF 1995 FIELD SEASON ........................................................................................................ 21
SUMMARY OF NIAGARAN ESCARPMENT BEDROCK SURVEY SITES ..................................... 21
Poverty Island ............................................................................................................................... 21
Summer Island ............................................................................................................................. 24
Point Detour ................................................................................................................................. 25
Krcgg Bay NE .............................................................................................................................. 26
Stony Point ................................................................................................................................... 28
Goudreau's Harbor ....................................................................................................................... 29
SUh1M[ARY OF SPECIAL PLANTS ................................................................................................... 29

PRELINIINARY RESULTS FROM 1994 AND 1995 INSECT SURVEYS ................................................. 30
SUMMARIES OF KEWEENAW PENINSULA SITES ....................................................................... 30
Agate Harbor ................................................................................................................................ 30
Dan's Point .................................................................................................................................. 30
Devil's Washtub ..................................................................
......................................................... 30
Horseshoe Harbor ......................................................................................................................... 31
Fish Cove ..................................................................................................................................... 31

SUNOAARIES OF DRUMMOND ISLAND SITES .............................................................................. 31
Maxton Plains West ...................................................................................................................... 31
Grand Marais Lake (Maxton Plains North) ................................................................................... 31
Maxton Plains Mddlc .................................................................................................................. 32
Maxton Plains East ....................................................................................................................... 32
Seamans Point .............................................................................................................................. 32
Warners Cove ............................................................................................................................... 32
Huron Bay .................................................................................................................................... 32
Big Shoal Cove ............................................................................................................................. 32
Bass Cove Road ............................................................................................................................ 33

SUMMARIES OF GARDEN PENINSULA SITES ............................................................................. 33

RECOMNENDATIONS ............................................................................................................................ 33
Poverty Island ..................................................................................................................................... 33
Summer Island .................................................................................................................................... 33
Point Detour ........................................................................................................................................ 34
Kregg Bay NE ..................................................................................................................................... 34
Stony Point .......................................................................................................................................... 34
Goudreau's Harbor .............................................................................................................................. 34

LITERATURE CITED ............................................................................................................................... 35

LIST OF APPENDICES ............................................................................................................................ 36
1. Maps Of Bedrock Shoreline Survey Sites ........................................................................................ 37
Il. Insect Species Occurrences ............................................................................................................. 44
III. Global And State Element Ranking Criteria .................................................................................. 51

LIST OF FIGURES
Figure 1. Map Of Bedrock Types And General Survey Area ............................................................... I I
Figure 2. Schematic Diagrams Of Vegetative Zones ........................................................................... 12
Figure 3. 1994 Survey Sites On The Keweenaw Peninsula .................. ............................................... 19
Figure 4 1994 Survey Sites On Drummond Island ..................... ......................................................... 20

LIST OF TABLES
Table 1. Summary Data For Bedrock Beach Survey Sites ................................................................... 22
Table 2. Summary Of Plant Communities And Rare Plant Occurrences For Survey Sites .................... 23

LIST OF PLATES
Plate 1. Dolomite and limestone shoreline of Schoolcraft and Delta Counties .....................................2
Plate 2. Dolomite and limestone shoreline of Schoolcraft and Delta Counties .....................................4
Plate 3. Dolomite and limestone shoreline of Schoolcraft and Delta Counties .....................................6
Plate 4. Rare Plants Of The Niagaran Escarpment ..............................................................................8

INTRODUCTION

Varying from vast sandy beaches at the base of towering sand dunes to stem cliffs and rugged coast
lands, the shorelines of the Great Lakes off-er a striking diversity of specialized habitat, that also provides
scenic beauty and recreational opportunity. Sections of this shoreline, especially along the southern
coast of Michigan's Upper Peninsula, are characterized by outcrops of resistant limestone and dolomite
bedrock. As well as contributing to incomparable vistas of the Great Lakes, this bedrock shoreline
creates a unique environment significant to protecting biological diversity.
Almost ten years ago, Asworth (1987) reported that 50 percent of the Great lakes shoreline had been
developed for residential, industrial, or commercial purposes. Furthermore, 83 percent of the shoreline
was in private ownership and thus could be developed at any tune. Rapid development has occurred
over significant portions of the Great Lakes shoreline during the last decade. Some of the finest
examples of bedrock beach surveyed in 1994 are now slated for development, both on the Keweenaw
Peninsula and Drummond Island. Unfortunately, development often locks the shoreline from public
access and represents a sigrnficant loss of habitat for plants and animals adapted to this unique
environment.
In response to extreme development pressure, this study was initiated to provide a more thorough
understanding of the significant biological diversity associated with bedrock shoreline communities and
to identify locations for conservation. This report summarizes the results of 1995 coastal bedrock
inventories along the southern coasts of Delta and Schoolcraft Counties in Michigan's Upper Peninsula.
Plates 1, 2, and 3 illusWate the bedrock of the study area and also the vegetation zones characteristic
of the bedrock shoreline. Plate 4 shows several of the special plants associated with limestone and
dolomite bedrock within the study area. Photos of the survey sites are also included in the site summary
section of the report.

BEDROCK OF THE NIAGARAN ESCARPMENT

The surface bedrock of Michigan is exposed in a series of concentric bands, increasing in age
outward from their approximate center near the Lower Peninsula town of Barryton (Ashworth
1987). One such band, the Niagaran Escarpment, extends from approximately Milwaukee,
Wisconsin, across the Upper Peninsula of Michigan and Ontario to Rochester, New York, arching
roughly along the outer margins of Lakes Michigan and Huron (Dorr and Eschman 1977). The
Niagaran Escarpment can be seen on modem maps as it extends in a northeasterly direction,
forming both the Door Peninsula of Wisconsin and the Garden Peninsula of Michigan. The
escarpment continues along the southern coast of the Upper Peninsula, where it is locally exposed,
to approximately the Straits of Mackinac, where it gradually curves southeast along the northern
Lake Huron shoreline, forming Drummond Island in Michigan, and Cockburn and Manitoulan
Islands in Ontario. It continues in Ontario as the Cape Hurd and Bruce Peninsulas, and then to the
Niagara region between Lakes Erie and Ontario. The Niagara River plunges over the Niagaran
Escarpment at Niagara Falls.
At the landscape scale, the major structural feature of this expansive escarpment is a
monocline (Ehlers 1973). The structure is loosely analogous to a very shallow bowl, with its
interior containing Lakes Michigan and Huron and its rim forming a cliff of varying height. Thus,
the rocks of the escarpment dip very gently towards the Great Lakes. The inclination averages
about 50 ft. per mile with a minimum and maximum dip of around 40 and 60 ft. per mile (Ehlers
1973).

Plate 1. Dolomite and limestone shoreline of Schoolcraft and Delta Counties.

Plate Ia. The bedrock shoreline at Kregg Bay NE is an argillaceous dolomite, containing
impurities such as sand, silt, or clay minerals. Argillaceous dolomite is characterized by a lack of
broad solution cracks. Pure limestone and dolomite, in contrast, are more soluble than argillaceous
dolomite.

Plate 1b. The dolomite at Goudreau's Harbor illustrates the broad solution cracks that typify
relatively pure limestone and dolomite bedrock. Note the perpendicular pattern of the solution
cracks. Vegetation can establish in these cracks, where there is greater protection from both wave
action and ice scour.

Plate 1c. On the Garden Peninsula and nearby islands in Lake Michigan, the bedrock tilts
downward 40 to 60 feet per mile toward the east. As a result of this tilt, bedrock cliffs are exposed
along the western edge of the peninsula and islands, as seen in this photograph of Poverty Island,
and bedrock beach occurs to the east, as seen in Plates Ia and I b, above.

Plate 1
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Plate 2. Dolomite and limestone shoreline of Schoolcraft and Delta Counties.

Plate 2a. This photograph of Seul Choix Point (Goudreau's Harbor) demonstrates the type of
information that can be interpreted from oblique aerial photographs. The extent of the offshore
dolomite ledges is evident on the photo, as are the major zones of the bedrock beach, including the
wave slash zone, vegetated beach, and conifer-dominated (boreal) forest, as well as a cobble beach
between the vegetated beach and the forest. Opening in the forest are also easily seen.

Plate 2b. The wave-splash zone on this portion of Goudreau's Harbor is quite broad. In the
background, scattered shrubs can be seen occupying cracks further from the shoreline.

Plate 2c. Broad cracks in the dolomite pavement of Poverty Island support a dense mat of
herbaceous plants. Ice scour probably eliminates both soil and plant accumulation on the
pavement between the cracks.

Plate 2

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Plate 3. Dolomite and limestone shoreline of Schoolcraft and Delta Counties.

Plate 3a. The dolomite pavement at the emtern edge of Summer Island has almost
perpendicular fractures, which support a turf of federally-threatened dwarf lake iris (Iris lacustris).
Conifer-dominated forest, characteristic of much of the bedrock along the shoreline, can be seen 'in
the background.

Plate 3b. On many of the bedrock shorelines, such as at Point Detour shown here, herbs and
shrubs carpet the bedrock near the forest margin. In the background, closer to the Lake Michigan
shoreline, vegetation occupies only cracks in the bedrock.

Plate 3c. On Summer Island, openings, called glades, occur within the boreal forest. The soils
in these opening are absent or thin, only an inch or two thick, and range from sands to organic soils
in depressions. Some glades are probably the result of human land use, while others result from
blow-downs during wind storms. Dominant trees in the forest include northern white-cedar,
balsam fir, tamarack, and white spruce. Paper birch and trembling aspen are also present.

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Plate 4. Rare plant species characteristic of the Niagaran Escarpment in the Upper Peninsula.

Plate 4a. A portion of an extensive, high quality alvar glade on the Garden Peninsula in
Delta County. Dwarf lake iris (Iris lacustris, federal and state threatened) is frequently a dominant
groundcover species in this region, foriiiing large clones on thin soils over limestone bedrock. The
photo displays a glade opening with a nearly continuous groundcover of iris. This is somewhat
unusual for the species, as it most often occurs on the margins of shoreline conifer-hardwood
forests along Lakes Huron and Michigan, especially on sandy to cobbly beach ridges.

Plate 4b. Close-up of dwarf lake iris and a frequent associate, the pinkish-flowered
gaywings (Polygala paucifolia). Although dwarf lake iris blooms from approximately mid-May to
early June, it can be readily recognized throughout the season by the diminutive stature of the
leaves and the nearly surficial, yellowish, narrow rhizomes.

Plate 4c. A close-up photo of Calypso orchid (Calypso bulbosa, state threatened),
growing in needle duff and thin soil over bedrock under a largely coniferous canopy. This rare
orchid species occurs in cedar swamps as well as dry mesic forests along the northern shores of
Lakes Michigan and Huron.

Plate 4d. Close-up photo of Richardson's sedge (Carex tichardsonii, state special
concern) during its peak blooming period in late May. This early season sedge occurs along
bedrock shorelines, occupying relatively dry microhabitats in alvar glades and along forest edges.
This species may be commonly associated with dwarf lake iris and other rarities, such as beauty
sedge (Carex concinna, state special concern).

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The Niagaran Escarpment, consisting almost entirely of limestone and dolomite, was formed
from resistant carbonate rocks (Ehlers 1973). Dolomite is similar to limestone, except it has a
threshold concentration of magnesium in its chemical composition and is generally more resistant
to erosion (recent geological terminology uses the term dolostone to describe the rock, reserving
the term dolomite for the mineral). The rocks were formed in the Silurian Period, during which
time marine waters covered the Michigan Basin. The waters over much of the Basin were deep
and most rocks of marine sediment origin were formed from precipitates of CaC03. However,
extensive reefs formed at the shallower margins of the basin. VAiile similar in chemical
composition to rocks formed from precipitates, rocks from these reefs were constructed of
skeletons and excretions of organisms and are comparatively resistant to erosion. Accordingly,
rocks of the Niagaran Escarpment, which were formed from reefs, resist erosive forces effectively.
The Niagaran Series, the group of rocks famfing the Niagaran Escarpment, consists of four
formations: Mayville Dolomite; Bumt Bluff Limestone and Dolomite; Manistique Limestone and
Dolomite; and Engadine Dolomite (Ehlers 1973). Figure I shows the major bedrock fonnations of
the study area and also indicates the general location of the six bedrock beach survey sites of the
study. Note that the bedrock shoreline pertinent to this study was characterized primarily by
Manistique Dolomite and, to a lesser extent, Bumt Bluff Limestone and Dolomite and Engadine
Dolomite.

NATURAL COMMUNITIES OF THE COASTAL NIAGARAN ESCARPMENT

Bedrock Beach

Bedrock beaches of dolomite were charactenzed by a zonal gradation of herbaceous vegetation
communities, changing in response to distance from the lake and each having a distinct physiognomy
(Figures 2A-F). Wave action and ice scrape had their greatest impact in the zones closest to the lake.
This wave splash or ice scour zone, which ranged from 4 to 24 in in width, was charactefistically devoid
of vegetation (Plates la and 2b). Adjacent to the inland side of the splash/scrape zone, a vegetated zone
was charactenzed by patchy establishment of vegetation interspersed by areas of exposed bedrock
(Plates lb, 2c, and 3a-b), Often, vegetation establishment was restricted to cracks in the bedrock
pavement, resultmg in a distinct checkerboard appearance (Plates lb, 2c, and 3a). Further inland, lack
of ice scour allows for the establishment of woody plants and denser assemblages of herbaceous plants.
Localized accumulations of sand and gravel or organic matenals on the bedrock surface further assist in
the establishment of shrubs and trees.

Bedrock Glade

Bedrock glades were sometimes found to occur between the open bedrock beaches and the
forests further inland (Plates 3c and 4a), The glades consisted of open, thin-soiled plant
communities don-driated by scattered, open-grown trees, scattered shrubs or shrub thickets, and a
partial turf of grasses and sedges. Bedrock exposures were frequently encountered within the
glades. Because bedrock glades were first identified as a characteristic zone along bedrock
shorelines of the Great Lakes in 1994 (Albert et al. 1994), there are currently minimal data
available to compare or adequately describe the community. However, the bedrock glade
community is currently being evaluated.

41'

r Point Goudreau's Harbor

<- Kregg Bay NE Nlayville Dolomite
Burnt Bluff Limestone and Dolomite
Nlanistique Limestone and Dolomite
E22 Engadine Dolomite
C + Point Detour

<- Summer Island

1+ Poverty island

Figure 1. Map of the study area showing major bedrock formations and general location of the six
bedrock beach survey sites. (Map from Ehlers 1973, p. 10).

A. Poverty Island

Sandai 11

Lake Michigan
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B. Summer Island

I andandCobble T 111sol Lake Michigan
Bedrock AL

Bore.11 Forest Glade ExlN)scd P-w-cment
19111 21 ni

Figure 2A and B. Schematic diagrams of vegetative zones representative of those encountered on
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Poverty Island (A) and Summer Island (B).

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C. Point I)e(our

Lake Michigan
I'hin Soil- E;Xposed [';I% C111CIll
sl)l.tlcc/ Fill Glade I Spaisely Vegetated
Ccdar/ AsIvii 181)1 1 69 n) 13 in

1). Kregg Bay NE

vegdated ill Fille Clack.,
Cobble Beach Ridge FXposed P;I% ellICIII Splash/ Crape
29 ill 4 in
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Figure 2C and D. Schematic diagrams of vegetative zones representative of those encountered on
Point Detour (C) and Kregg Bay NE (D).

E. Stony Point

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ob Ic 0 0 Lake Michie.111
InIci-dunal Wetland . . . . . . .
Forest Cobble Beach Ridge Sand/ Bedrock Splash/ Serape
Spruce/ Cedar/ Ced.11- 24 in
Aspen Exposed Bediock
32 in

F. Goudreau's Harbor

Lake Michigan

Cobble and Gravd/ Bedrock Vegetated Zone lSplash/ ScrIal )c,
Dense Cedar/ Spruce 24.5 in 1 9111

Figure 2E and F. Schematic diagrams of vegetative zones representative of those encountered on
Stony Point (E) and Goudreau's Harbor (F).

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Alvar

Dolomite or limestone pavement dominated by a plant community of herbs and grasses has
been called alvar. Both the bedrock beach and the bedrock glade are treated as types of alvar.

Dry Alkaline Cliff

Where Dry Alkaline Cliffs were encountered, they were sampled and the results included in
this report. Although the cliffs are generally low in botanical diversity, they are among the most
visually appealing features of the bedrock shorelines (Plate 1c).

Boreal Forest

The boreal forest is an extensive habitat of the northern latitudes and, on the North American
Continent, extends from Alaska to Newfoundland (Anonymous 1995). Most of the land on which
this forest type occurs was under large sheets of continental ice as recently as 10,000 years ago.
Due to the cool northern temperatures and the fact that the region was recently scraped to bedrock
during the ice age, minimal soil development has occurred and the region is characterized by very
shallow soils. The forest is dominated by coniferous vegetation, primarily spruce (Picea) and fir
(Abjes) species. Precipitation greatly exceeds evapotranspiration over the habitat and swamps,
bogs, and marshes are abundant in the boreal forest.
There is some debate as to whether Michigan's upland forests dominated by balsam fir
(Abies balsamea), white spruce (Picea glauca), tamarack (Larix laricina), and northern white-
cedar (Thuja occidentalis), along with white birch (Betuld papyrifera) and trembling aspen
(Populus tremuloides), should be considered part of the true boreal forest, since Michigan's upland
conifer forest supports a greater number of tree species than boreal forests fiirther north, and it also
occurs in a mosaic of northern hardwood forests. For this report we will use the term boreal forest
to include our conifer-dominated forests along the Great Lakes shoreline, and more specifically, on
dolornitic bedrock.

SPECIAL PLANTS

Michigan's bedrock shorelines and their related natural communities, particularly in the
Niagaran Escarpment region, support a rich and diverse assemblage of rare vascular plant species.
Some of these species are known to be endernic to the Great Lakes, including such notable plants
as dwarf lake iris (Iris lacustris) and Houghton's goldenrod (Solidago houghtonii), both of which
are listed as federal and state threatened. The majority of the globally known populations of these
two species are documented in Michigan, with major occurrences found in some bedrock shoreline
areas. A host of other rare plants can be found in a variety of shoreline and near-shore bedrock
habitats, ranging from cliff ferns, such as slender cliff-brake (Cryptogramma stelleri) and green
spleenwort (Asplenium viride), to several rare sedges (Carex scirpoidea, C richardsonfi, C.
concinna), grasses (Danthonia intermedia, Poa alpina), and plants such as Lake Huron tansy

(Tanacetum huronense), a species that can be found on sand dunes and cobble shores in addition
to bedrock sites.

INSECT SURVEYS

Bedrock and cobble shorelines of the Great Lakes contain many characteristic and endemic
plant species, which have the potential to support unique assemblages of invertebrates, especially
habitat restricted specialists. It is assumed that there some of the species found on the dolomite
pavement (alvar) of Drummond Island and along the Escanaba River will also be shared with the
dolomite pavement along the Great Lakes shoreline.
Little is known about the insect fauna of alvar regions and even less is known about alvar
insects in Michigan. In addition to our study, there are two ongoing research projects in Michigan
dealing with insects of alvar regions (S. Stephenson, pers. comm.; K. Hamilton, pers. comm.). So
far, leafhoppers (Cicadellidae) have received the most study in these habitats including leaffiopper
species that feed on little bluestern (Schizachyrium scopapium), prairie dropseed (Sporobolus
heterolepis), slender wheatgrass (Agropyron trachycaulum), small spikerush (Eleocharis eliptica),
and creeping juniper (Juniperus horizontalis). Leafhoppers are excellent environmental indicators
because only the smallest and lightest are regularly carried by wind, and these (subfamily
Typhlocybinae) are generally tree-feeding species. Most members of other leafhopper subfamilies
do not disperse rapidly or for a great distance (Hamilton and Langor 1987). In addition, many are
monophagous (feed on one species of plant) and females of many prairie species are entirely
flightless (Hamilton 1994). It has been determined that alvars and sandy areas of northern
Michigan have leafhoppers mostly characteristic of Canadian prairies. Sixteen western leafhopper
species are associated with such grasslands (Hamilton 1994). A primary goal of this study is to
qualitatively describe the insect community for distinct vegetative associations on a variety of
bedrock types, including the dolomite and limestone bedrock of the Niagaran Escarpment.

METHODS

BEDROCK CLASSIFICATION AND MAPPING

The bedrock classification used in this study was based on existing geological maps by Reed
and Daniels (1987) and Ehlers (1973). Ehlers did detailed mapping and classification of the
Paleozoic limestones and dolomites of the Niagaran Escarpment, including those of the shoreline in
Schoolcraft and Delta Counties.

SURVEY SITE IDENTIFICATION

Air Photo Interpretation

Photo interpretation of black-and-white and color aerial photography, maintained by the Land
and Water Division of the Michigan Department of Natural Resources, was used to identify
potential bedrock beach sites within the study area. The Lake Michigan shoreline of Michigan's
Upper Peninsula was evaluated from central Mackinac County to Menominee County. Photos of
the area were available at the scale of I inch equals 500 feet, I inch equals 780 feet, and I inch
equals 2000 feet, and proved excellent for mapping coastal bedrock. Although bedrock shoreline
could be easily identified using air photographs, cliffs were less evident and were verified with a
reconnaissance flight.

Aerial Reconnaissance

In addition to existing vertical imagery, reconnaissance flights were performed to provide
oblique air photographs of the area (see the cover and Plate 2a). The oblique photographs were
found to produce a more ecologically interpretable view of shoreline landscapes and were used to
further document the extent and quality of the sites identified from vertical imagery.

Bedrock Shoreline Survey Sites

Following air photo interpretation, sites were selected for field survey. Sites found to have
high quality areas of exposed bedrock shoreline and associated biota were field sampled. The six
sites where vegetation sampling was conducted were Poverty Island, Summer Island, Point
Detour, Kregg Bay NE, Stony Point, and Goudreau's Harbor. The general locations of these
survey sites are presented in Figure I and detailed maps for each survey site are presented in
Appendix I A - IF.

VEGETATION SAMPLING

Following site selection, intensive vegetation sampling was performed between June 21 and
July 21, 1995. Sampling was conducted along transects that were oriented perpendicular to the
shoreline and established along a meter tape extended from the shoreline to the forest zone. The
exact bearing and percent slope was measured and recorded for each transect. Schematic diagrams
showing slope, bedrock surface, moisture conditions, and approximate width of each vegetative
zone were produced for each transect. Vegetation was sampled by placing each species into one of
four relative abundance categories. Percent coverage values were estimated for each species as
well, by sampling each vegetation zone with a 5 x 5 m plot. Point sampling was conducted for
overstory species (>4 inches in diameter) using a BAF 10 prism in the glade and or forest zones,
and the presence of each shrub and herbaceous species was also recorded.

17
lot

SPECIAL PLANTS SURVEY METHODS

Prior to field inventories, the Michigan Biological and Conservation Database (BCD) was
consulted to determine the number and extent of previously documented special plant occurrences
likely to be encountered during surveys. These species formed the basis of a priority list to carry
into the field, with particular attention given to the rarest taxa, i.e. those with global and/or state
ranks of Gl-G3 and SI-S3 (see Appendix 3 for criteria used to assign ranks). Special priority was
also given to occurrences with historical to relatively old last observation dates, such that these
populations could be sought during surveys to determine their present status, extent, and condition.
Compiling a list of priority species also provided the opportunity to review phenologies and thus
anticipate the best period(s) in which to conduct bedrock surveys.
Special plants were inventoried primarily during natural community surveys as sites were
traversed and more or less systematically meander-searched to determine the general community
quality. Edges of communities and other ecotonal habitats were concentrated upon, as these
microsites were known to frequently support colonies of the target species. Richardson's sedge
(Carex fichardsonii), for example, was sought at the periphery of wet bedrock sites where habitat
transitioned into drier glades, whereas more exposed bedrock areas were searched for bulrush
sedge (Carex scirpoidea). When identified, special plant locations were noted on topographic
maps, and special plant forms were initiated for eventual occurrence updating or transcription of
new records. Where appropriate, voucher specimens were pressed and prepared for hebarium.
accessioning. Lastly, reference photographs of selected rare species were taken in representative
areas (see Plate 4a4d).

INSECT SURVEY METHODS

Field work was conducted at 16 sites throughout the summer of 1995 in C@ippewa, Delta, and
Keweenaw Counties, Michigan (Figures 1, 3, and 4). Three types of itisect surveys were
conducted in 1995. The first type of inventory, consisting of preliminary sunreys, was conducted
on some of the high quality sites that were identified by MNFI ecologists and botanists along the
mainland shoreline of Schoolcraft and Delta Counties, including Point Detcur and Kregg Bay;
other sites on the mainland did not receive a preliminary survey due to a severe mid-season illness
of the staff zoologist. A second type of survey was an intermediate level survey of Poverty, Little
Summer, and Summer Islands, where aerial and sweep netting, as well as light trapping was
conducted during three days of field visits in early June of 1995. A third type of insect survey was
the revisit of several high quality bedrock sites identified by ecologists and 'botanists during the
1994 surveys. These 1994-survey sites were visited two or three times during the spring, summer,
and early fall. Most of the results reported here are for Drummond Island sites identified in 1994,
with some insect sampling in 1995. See Albert et al. (1994) for detailed descriptions of these study
areas. Results from this study and fiwffier survey work by staff ecologists mill be used to focus
additional work in 1996.
Several methods were used for surveying insects. Insects were collected Akith aerial and sweep
nets. Light trapping, a method used to document the occurrence of nocturnal insects, was utilized
at four sites. Approximately half of the time at each site was spent making ageneral collection of
species present, while the remainder of the time was spent focusing on state or federally listed

t, F I P 111

7 8 9 10 11 12 14 15
16
5
mat- VAR
04
0
c 17
0
it$
20
19
I A T11w.
Ic
Freda Formation
3
1. Rockhouse Point - Graveraet River
2. Freda - Redridge
3. Portage Lake - Ship Canal West

Copper Harbor Conglomerate
4. Sevenmile Point
5. Fivemile Point - Eagle River.
Eagle Harbor
6. Cat Harbor
7. Eagle Harbor - Grand Marais Harbor
8. Silver Island: Grand Marais Harbor - Bailey Creek
9. Agate Harbor: Esrey Park - Lake Glazon
X 10. Dans Point
11. Devil's Washtub
12. Porters Island
13. Fort Wilkins State Park
14. Copper Harbor Lighthouse - Norland Trust
15. Horseshoe Harbor
16. High Rock North

Portage Lake Voicanics
Clio 17. Keweenaw Point: High Rock Bay - Keystone Bay
18. Keystone Point
6k 19. Fish Cove
20. Bete Gris - Bear Bluff

51C

10
10
I Wes igure 3. 1994 bedrock shoreline survey sites on the Keweenaw Peninsula. Insect survey results
10
0 10 Kildmelers from several of these sites are reported in this paper.

Queenston Shale
1. Maxton Plains West
2. Chippewa Point
3. Grand Marais Lake
4. Poe Point
5. Maxton Plains Middle
6. Raynolds Point
7. Maxton Plains East 4

Manistique Group (Dolomite)
j_1:1
a. Marble Head
qd,
QU, St I
Engadine Group (Dolomite)
9. Bass Cove - Little Shelter Bay
i o, Big Shoal Cove
11. Seamans Point
Manitoulin Dolonihe
12. Warners Cove Cabot 1-1cad Shale
Huron Bay
13. :.;i: Burnt Bluff Group

Manistique Group

4.,
ji Vvi u.,
A'NK

R
I A
;k@'j KYA
--f
xw ;'P.Vj@i
P.-4-

--EV"T Or A-".

in
RM
12v-
9

Figure 4. 1994 bedrock shoreline survey sites on Drummond Island. Insect survey results from
several of these sites are reported in this paper.

species including the state special concern red-legged spittlebug, (Prosapia ignipectus); the state
special concern and federal candidate (C2) Awerne borer moth (Papaipema aweme); the state
threatened northern blue butterfly (Lycaeides idas nabokow); the federally endangered Ohio
emerald dragonfly (Somatochlora hineana); the state special concern warpaint emerald dragonfly
(Somatochlora incurvata); and the state special concern and federal candidate (C2) tawny crescent
butterfly (Phydodes batesii).
Within the general collection category only certain target groups were given priority in
collecting, sorting, and identification, because these groups contain many habitat restricted species.
The groups included certain families within the Odonata (dragonflies and damselflies), Orthoptera
(grasshoppers and katydids), Herniptera (true bugs), and Homoptera (leafhoppers, spittlebugs,
planthoppers, and treehoppers). Species that could be identified in the field were recorded and
released. For species that required fiifther study for accurate identification, individuals were
collected and prepared following standard insect collection techniques. Insects were keyed to the
genus or species level using published references, or were sent to experts.

RESULTS OF 1995 FIELD SEASON

SUMMARY OF NIAGARAN ESCARPMENT BEDROCK SURVEY SITES

The bedrock portions of Schoolcraft and Delta Counties have been divided into six major sites
shown on Figure I (page 11). More detailed maps of each site are shown in Appendix 1.
Information is provided for each of these sites in a summary table (Table 1), which includes site
name, location (Township and Range), bedrock type, bedrock classification according to Ehlers
(1973), length of bedrock beach, average bedrock beach width, cliff length, ownership (state or
private), and level of development. Table 2 is a summary table of plant communities and rare
plant occurrences for each survey site. Rare plants are discussed within the bedrock survey sites
below.

Poverty Island

Poverty Island, approximately 150 acres in size, is located just southwest of Summer
Island. The island is nearly all bedrock sloping gently to the east. As a result, the island contains
low cliff all along the west shore (Plate I c), bedrock beach along the east shore, and dense boreal
forest throughout the island's interior. The bedrock beach, averaging 50 m wide, extends for
approximately 0.6 mile along the eastern shoreline. It contains a distinctive splash/scrape zone up
to 15 m wide that is sparsely vegetated with silverweed (Potentilla ansefina), low calamint
(Satureja arkansana), and harebell (Campanula rotundifolia). The vegetated zone (Plate 2c) has
about 20 percent cover, with shrubby cinquefoil (Potentillafruticosa), rush (Juncus balticus),
willow (Safix eriocephala), grass-leaved goldenrod (Euthamia graminifolia), and Ohio goldenrod
(Solidago ohioensis) among the dominant plant species. Rare plant species associated with this
bedrock beach are dwarf lake iris (Iiis lacustiis), beauty sedge (Carex concinna), and

Table 1. Sununa data for 1995 bedrock beach survey sites.
Site Township/ Bedrock Bedrock Bedrock Beach: Average Cliff Length Ownership' Level of
Range Type Classification Length (nii) Bedrock Beach (Mi) Developmene
Width (ft)
Poverty Island T36N R19W Dolostone 0.6 164 1.4 Nu U
Summer Island T36-37N R19W Dolostone Engadine Dolomite 1.8 98 0.7 N" M
Point Detour T37N R19W Dolostone 1.2 190 1.7 MI/P U
Kregg Bay NE T38N R18W Limestone Manistique 1.5 too -- MI/P H
Stony Point T41N R16W Dolostone Limestone and 0.5 138 P M
s Harbor IN R13W Dolostone Dolomite 2.0 110 P
1. MI = State of Nfichigan, P = private, MI/P = mixed State and private.
2. U undeveloped, M moderate development, H = heavily impacted by development.

Table 2. Summary of plant communities and rare plant occurrences for the 1995 bedrock beach
survey sites. A indicates that this is the first reported occurrence of a particular plant or
community at the survey site, whereas a indicates that it was previously known from the site.
An 0 indicates that the plant was known to exist at the location, although it was not found or
searched for in 1995.
Plant Community or Rare Plant Bedrock Beach Survey Site
Poverty Summer Point Kregg Bay Stony Goudreau's
Island island Detour NE Point Harbor
Communities
Bedrock Beach (G2G3,S2)
Dry Alkaline Cliff (G4,S3)
Boreal Forest (GU,S3?)
Bedrock Glade (GU,S3)
Plants
Asplenium viride (G5,S2S3) 0
Carex concinna (G4G5,S3) 0
Carex richardsonii (G4,S3S4) 0
Cryptogramma stelleri (G5,S3S4) 0
Danthonia intermedia (G5,S1S2) 0
Iris lacustris (G3,S3)
Solidago houghtonii (G3,S2S3)
Tanacetum huronense (G3Q,S3)
Thalictrum venulosum (G5,S2) 0
(GX,SX) = (Global Rank, State Rank). Refer to Appendix 3 for further information.
2Found on interior limestone cliff, not on alvar.

S_ -

Poverty Island: Dolomite pavement along southeast shoreline

Richardson's sedge (C richardsonii). The boreal forest that dominates the entire interior portion
of the island is a very high quality example of it's type for Michigan. Although the forests of this
island are continually blown down by gusts off Lake Michigan, there are a number of groves of
mature northern white-cedar (Thuja occidentahs), balsam fir (Abies balsamea), and paper birch
(Betuld papy?lfera). The lack of deer on the island has allowed for extensive thickets of Canada
yew (Taxus canadensis) to develop throughout the island interior. The alkaline cliff, varying from
2-8 in high, is among the more picturesque of the low cliffs in this part of Lake Michigan (Plate
Ic). It is sparsely vegetated throughout its face, but has a dense thicket of northern white-cedar
and balsam fir along the top. Poverty Island is wholly state owned. There is an abandoned
lighthouse located at the southern extreme of the island.

Summer Island

Totaling nearly 2,200 acres in size, Summer Island contains a diversity of forests and Great
Lakes shoreline. As with Poverty Island to the southwest, Summer Island is underlain by
fimestone-dolomite bedrock that dips gently to the east. However, there is much deeper soil
throughout Summer Island, and as a result, it supports both boreal forests and northern hardwoods
throughout the island interior. A west-facing dry alkaline cliff is located in the islands interior.
Survey of the cliff re-confirmed a previously known population of slender rock-brake
(Cryptogramma stelleri).
The bedrock beach extends for 1.6 miles along the easte _-.. shoreline. The width of the beach
ranges from 20-30 in. The splash/scrape zone varies from 8-16 in wide and is sparsely vegetated.

The vegetated zone (Plate 3a) contains less than 15% cover, with shrubby cinquefoil (Potentilla
fruticosa), Ohio goldenrod (Solidago ohioensis), Indian paintbrush (Castilleja coccinea), rush
(Juncus balticus), spike-rush (Eleocharis pauciflora), and false asphodel (Tofieldia glutinosa)
among the common plant species. Rare plant species found along the inland edge of the bedrock
beach were dwarf lake iris (Iris lacustris) (Plate 3a), beauty sedge (Carex concinna), and
Richardson's sedge (Carex richardsonii). Near the south end of the island, a small area of
bedrock glade (Plate 3c) extends another five meters inland from the shoreline. The glade is
dominated mostly by herbaceous plants, with patches of exposed bedrock at the surface. Hair grass
(Deschampsia cespitosa), low calamint (Satureja arkansana), bastard-toadflax (Comandra
umbellata), Kalm's St. John's wort (Hypericum kalmianum), and sedge (Carex eburnea) are
among the dominant vascular plant species. Several unidentified moss species were also common
throughout the glade. There is an active hunt camp and several access roads located adjacent to
the glade, so it is possible that the glade may be, at least in part, the result of past land use.
Portions of Summer Island fall on state forest land. Although there are several homes located on
the north end of the island, there are currently no permanent island residents.

1.. 7-

Summer Island: Bedrock beach and boreal forest along eastern shoreline.

Point Detour

Point Detour extends southeast ftom the southern tip of the Garden Peninsula (see cover
photo). Bedrock beach is found in four distinct segments totaling 1.2 miles in length along the
eastern side of the point. Between the segments of bedrock beach there are low cliffs and cobble
beaches. The width of the bedrock beach varies from 16 to 100 m, with the widest portion found
at the south end. The splash/scrape zone varies from 3 to 10 m wide and is sparsely vegetated.

The vegetated zone (Plate 3b) is best developed along the wide southern-most segment, where
vegetative cover reaches 70 percent and common plant species include beak-rush (Rhynchospora
capillacea), golden-seeded spike-rush (Eleocharis elliptica), rush (Juncus balticus), Ohio
goldenrod (Solidago ohioensis), dwarf Canadian primrose (Primuld mistassinica), spike-rush

%4*

i401
0

Point Detour: Low cliffs of broken dolomite.

(Eleocharis pauciflora), and low calamint (Satureja arkansana). A small portion of bedrock
glade (Plate 4a) is found along the inland mar& of the southern-most segment of bedrock beach.
This area is dominated by northern white-cedar (Thuja occidentalis), white spruce (Picea glauca),
shrubby cinquefoil (Potentilla fruticosa), hair grass (Deschampsia cespitosa), Ohio goldenrod
(Solidago ohioensis), and blue-joint (Calamagrostis canadensis). Along most of this shoreline
there is a low cobble ridge on the inland margin of the beach that supports a dense boreal forest of
white spruce, northern white-cedar, balsam fir (Abies balsamea), and quaking aspen (Populus
tremuloides). No rare plant species were encountered along this stretch of shoreline.
All but the southern tip of Point Detour falls on State Forest land. However, there is easy
access to this stretch of shoreline, so there is potential for habitat destruction from illegal use of off
road vehicles.

Kregg Bay NE

This is a one mile-long stretch of bedrock beach along two small points and a bay that extends
southeast into Lake Michigan. It is located just south of Charbaneou Lake and the Portage Bay
State Campground. The width of the bedrock beach varies from 17 to 28 m and is quite irregular
in rock structure and composition. The southern-most portions are similar in structure to the

bedrock beach at Point Detour, -with bleached dolostone containing cracks several inches wide.
There are also several large broken rocks and extensive inter-rock pools in this area. The splash
zone is generally about four meters wide and very sparsely vegetated. The vegetated zone
measures about five meters wide, and has a vegetative coverage of about 5 percent. Common plant
species in this area are hair grass (Deschampsia cespitosa), harebell (Campanula rotundifolia),
smooth aster (Aster laevis), and low calamint (Satureja arkansana).

_%_

aL -lot

.5Z

Kregg Bay NE: Fine cracks in argillaceous dolomite at Charbaneau Point.

Along the south side of Charbaneau Point, the dolostone is not bleached and contains very fine
cracks (Plate I a). Much of this exposed bedrock beach is probably inundated during high Great
Lakes water levels. Sand has washed down from the inland margins over the surface of portions of
this bedrock, providing habitat for many plant species. The splash/scrape zone in this area is
about I I in wide, and is completely unvegetated. The vegetated zone is covered with sand on five
percent of it's surface, with total vegetative cover reaching about 3 percent. Common plant species
along this stretch of shoreline are grass-leaved goldenrod (Euthamia graminifolia), sedge (Carex
viridula, C hystericina), rush (Juncus dudleyi), silverweed (Potentilla anserina), and hair grass
(Deschampsia cespitosa). The inland margin of the entire shoreline is a 1.5 to 5 m high cobble
ridge. Nearly all of the ridge supports dense boreal forest of white spruce (Picea glauca), northern
white-cedar (Thuja ocidentahs), quaking aspen (Populus tremuloides), and white pine (Pinus
strobus). No rare plant species were encountered along this shoreline.
The central portion of this shoreline is included within state forest land. Private tracts
containing vacation homes are found on both Charbaneau Point and Kregg Bay. Recent tree
removal and trail development have taken place inland along the west end of the this bedrock
beach. There is much potential for habitat destruction along this stretch of shoreline.

Stony Point

This 0.75 mile-long stretch of shoreline contains exposed bedrock similar in structure and
composition to that mentioned along Charbaneau Point. It contains fine cracks in mostly
unbleached dolomite. This portion of bedrock beach is clearly inundated during high Lake
Michigan water levels. There is a considerable amount of sand washed down onto this bedrock,
most of which is saturated with surface seepages. There is also a low cobble ridge located just
inland of the bedrock beach; this low ridge is backed by a narrow interdunal wetland (see photo
below). Farther inland is boreal forest of white spruce (Picea glauca), tamarack (Larix laricina),
balsain fir (Abies balsamea), and northern white-cedar (Thuja occidentahs).

tAA _&.I@

. .........

4 4

Stony Point: Fine argillaceous dolomite beach with interdunal swale in background.

The splash/scrape zone of this shoreline is about 24 in wide, and is almost entirely
unvegetated. The eight meter-wide vegetated zone contains roughly 30 percent vegetative cover,
20 percent open pools, and 50 percent exposed bedrock. Common plant species in the vegetated
zone are spike-rush (Eleocha?Is aciculafis), grass-leaved goldenrod (Euthamia graminifolia),
three-square bulrush (Scirpus americanus), sedge (Carex crinita), and Canadian rush (Juncus
canadensis). Most vegetation occurs where 1-2 inches of sand have accumulated on the bedrock
surface. No rare plants were located along this stretch of shoreline.
Stony Point is privately owned. It was offered to the State and rejected as a Natural Resources
Trust Fund nomination in 1995. There is easy access to the site from US-2, which passes nearby
along the Lake Michigan shoreline.

Goudreau's Harbor

This is among the most extensive and scenic stretches of bedrock beach in the state (Plates lb
and 2a-b). The bedrock beach of Goudreau's Harbor extends for over two miles along the west
side of Seul Choix Point. It is broken into a number of distinct segments that are probably
connected when Lake Michigan water levels are low. Past rare plant surveys have been conducted
along the entire length of this shoreline. Site visits for plant community characterization were
conducted at the east end near Seul Choix Point.
Although the width of bedrock beach at this site is quite variable, it averages 33 rn wide at the
east end. The splash/scrape zone (Plate 2b) is nine meters wide and is sparsely vegetated. The
vegetated zone (Plate 1c) is also quite sparsely vegetated, with common plant species including
rush (Juncus balticus), low calamint (Satureja arkansana), sedge (Carex W?Idula), northern bog
violet (Viola nephrophylla), silverweed (Potentilla anserina), Canadian rush (Juncus canadensis),
and shrubby cinquefoil (Potentillafruticosa). Wand of the bedrock beach, there is dense boreal
forest mostly dominated by northern white-cedar (Thuja occidentalis). A number of rare plant
species occur along this portion of shoreline, including dwarf lake iris (Iris lacustris), Lake Huron
tansy (Tanacetum huronense), oat grass (Danthonia intermedia), veiny meadowrue (Thalictrum
venulosum), Houghton's goldenrod (Solidago houghtonii), and green spleenwort (Asplenjum
Wride). Piping plovers (Charadrius melodus) are known to nest along this stretch of shoreline.
The Goudreau family owns nearly all of this shoreline. There are several homes built along the
edge of the bedrock beach. The lighthouse at Scul Choix Point is located just inland of the bedrock
beach, and lawns extend to the bedrock beach in several places.

SUMMARY OF SPECIAL PLANTS

Table 2 summarizes special plant occurrences for the six sites surveyed in 1995. Three new
occurrences were documented for beauty sedge (Carex concinna, state special concern), two new
occurrences for Richardson's sedge (C. iichardsonii, state special concern), and one new
occurrence for dwarf lake iris (Iris lacustris, federal and state threatened). One known occurrence
of Richardson's sedge, one known occurrence of slender cliff-brake (Cryptogramma stelleri, state
special concern), and two known occurrences of dwarf lake iris were observed, and updated
occurrence information for these populations was compiled. Completed forms for these
occurrences will be processed and entered into the statewide biological and conservation database.
The most significant occurrences are those of Point Detour, an extensive alvar glade community
that supports populations of Richardson's sedge, beauty sedge, and especially dwarf lake iris,
which dominates several large, high quality glade openings.

PRELIMINARY RESULTS FROM 1994 AND 1995 INSECT SURVEYS

SUMMARIES OF KEWEENAW PENINSULA SITES

Five sites in the Keweenaw Peninsula (Figure 2) were surveyed for insects during 1995. Most
of the survey work focused on the open bedrock glades. "le no state-listed insects were
collected here, we are gaining a better understanding of the insect communities that occur in
bedrock glades. In addition, several new state and county records and disjuncts were recorded as
part of this study. A total of 39 species of insects from the target groups have been recorded from
the Keweenaw Peninsula sites. A complete list of insects recorded by site is summarized in
Appendix 2.

Agate Harbor 0

The large open bedrock glade dominated by white pine (Pinus strobus), red pine (Pinus
resinosa), balsam fir (Abies balsamea), red oak Quercus rubra), and several species of shrubs
was sweep-netted on two occasions during the 1995 season. The site contains typical insect
species one would associate with these plant communities.

Dan's Point

Insect sampling was conducted within the bedrock glades north of M-26 and along the bedrock
shoreline north of the highway. Three species of dragonflies were recorded at the site including
Enallagma boreale, Leucorrhinia hudsonica, and Sympetrum obtrusum. Most of the insects from
this site, including many leaflioppers, are still being identified by experts. This site contains a high
quality alvar glade and further invertebrate survey work is recommended including black lighting
for nocturnal insects and land snail surveys.

Devil's Washtub

The broad glade that parallels the shoreline was sweep netted on two occasions in 1995. The
site is dominated by red pine (Pinus resinosa), white pine (Pinus strobus), and several shrub
species. There are also small openings that are dominated by grasses. Black lighting is
recommended for the glade so that we can continue to identify the insect communities that are
associated with these unique habitats.

Horseshoe Harbor

Sweep net samples and black lighting occurred at the eastern edge of the preserve in the
narrow bedrock glades which are dominated by conifers and various shrubs. Three species of
dragonflies were recorded from the preserve including Enallagma cyathigerum, Epitheca canis,
and Cordulia shurtle . Four species of noctuid moths in the Genus Catacol, a known commonly
as underwings, were recorded during the August black lighting. This included Catocala
concumbens, C relicta, C semirelicta, and C unijuga. Many other insects collected here in 1995
are still being identified and the final species list for this site will greatly increase.

Fish Cove

The bedrock glade west of the Montreal River was sampled. In addition, specific survey for
the Northern blue (Lycaeides idas nabokovi) was conducted here because the host plant
(Vaccinium cespitosum) is known from the area. Neither the plant nor the butterfly were located at
this site but fiirther survey is recommended due to the diminutive nature of the plant and the short
flight period of the butterfly.

SUMMARIES OF DRUMMOND ISLAND SITES

Insect survey work was conducted at five sites on Drununond Island during September 1994
and during the summer of 1995. The sampling on Dnunmond Island focused on open grassland
areas, pavements, and a few small bedrock glades. In addition to black lighting and sweep netting,
we also included Malaise trapping and pitfall trapping as insect survey techniques during 1995.
These samples, however, are still being processed and will be included in the final report. No
state-listed insects were recorded from Drummond Island during this survey yet several new county
records and disjuncts were recorded. A total of 118 species from the target groups was recorded
from Drummond Island. A complete list of insects listed by survey site is included in Appendix 2.

Maxton Plains West

Several sweep net samples were taken throughout the alvar grassland areas and one night of
blacklighting was conducted in 1994. Sixty-seven species of insects from the target groups have
been recorded from Maxton Plains West (Appendix 2) including 23 species of leafhoppers
(Cicadellidae). Some of the typical prairie species found here include Aceratagallia n. sp. (being
described by K.G.A. Hamilton), Flexamia delongi, and Chloroteffix unicolor.

Grand. Marais Lake (Maxton Plains North)

This site was surveyed one time during the summer of 1995. Sweep net samples were taken
within three separate glades near Grand Marais Lake. All of the leafhoppers have not yet been
identified from this site, but a species of Flexamia (probably F. delongi) has been recorded from
one of the glades.

Maxton Plains Middle

Sweep net samples were taken both in 1994 and 1995 at this site. A total of 30 species were
recorded from the target groups. Thirteen species of leafhoppers were recorded from this site
including Chloroteffix unicolor.

Maxton Plains East

Maxton Plains East contains one of the most disturbed alvar areas that were sampled for
insects. Sweep net samples were taken here in 1995 to be used in comparison with more pristine
alvar sites such as Maxton Plains Middle or Maxton Plains West. Only 9 species of leafhoppers
were taken at Maxton Plains East but this did include a Rexamia species.

Seamans Point

A single sweep net sample was taken here in 1994. The site contains both open pavement and
bedrock glade and further survey work is recommended.

Warners Cove

Two sweep samples and one night of black lighting was conducted at Warners Cove in August
of 1995. The pavement shoreline here is confined to less than a quarter mile and contained no
special insects. In addition to the shoreline, some very small glades fiirther inland were swnpled
for insects.

Huron Bay

Insect sampling at Huron Bay occurred along the shoreline in section 13 north of Helen's Lake
and in the small glade farther inland in section 12. Black lighting at this site occurred on one
occasion in 1994 and once in 1995, A total of 48 species from the target orders have been
recorded from the inland glade. This site also contains the leafhopper (Rexamia delongi), a
species associated with prairie.

Big Shoal Cove

The largest dolomite pavements in section 18 were sweep netted for insects. Although this site
is one of the richest sites on Drummond Island, containing nine special plants, no special insects
were recorded here during these surveys.

Bass Cove Road

This site is not a true alvar area but several dragonflies were observed feeding along the road
openings and basking on the gravel road margins. Eight species of dragonflies were recorded from
the site, none of which are state-listed or of conservation concern.

SUMMARIES OF GARDEN PENINSULA SITES

Insect survey work within the Garden Peninsula in 1995 was very preliminary in scope. The
two sites surveyed included Garden Southeast and Kregg Bay. Few insect sweep samples were
taken at these two sites and most of the insects collected are still being sorted or identified by
qualified personnel. Because new alvar areas were discovered in the Garden Peninsula in 1995 by
staff ecologists and botanists, fiirther animal survey work here is warranted. Included should be
more sweep samples, black lighting, pitfall trapping, and possibly Malaise trapping.

RECOMMENDATIONS

Poverty Island

This 150-acre island, with the exception of an abandoned lighthouse on the southern end, is
undeveloped and within state ownership. The island supports high quality examples of boreal
forest and bedrock beach, with three listed plant species. Human use of the island is minimal and
is restricted to occasional camping on the more accessible west side of the island. A lack of deer
has allowed for good northern white-cedar regeneration. Furthermore, Canada yew (Taxus
canadensis) is a dominant understory plant. In contrast, this preferred food species has been
severely overbrowsed in areas where deer are abundant. Owing to the high quality nature of the
mature forest comrnumty, and to the extent of bedrock beach and low cliffs, it is recommended that
Poverty Island be maintained as a low-use site, with no ffirther development for recreation. If
camping or docking areas are needed, it is recommended that they be placed in the formerly
occupied lighthouse area, where such structures would have no impacts. Owing to the high quality
status of its natural areas, Poverty Island should be considered for Natural Area dedication, a
status which would protect the island's sensitive resources but still provide recreational
opportunities.

Summer Island

This large island contains extensive second growth mesic northern forest as well as a margin of
boreal forest, and an interior limestone escarpment. Along the shoreline are extensive low cliffs
and a well-developed, approximately mile and a half long stretch of bedrock beach with associated
rare plant species. Although there is some development on this island, which contains significant
private lands, there is only seasonal use. The recommendations for this site are that the state owned
lands with high quality bedrock beach and rare plant species be maintained with no development,

and that private lands with significant natural features be considered for acquisition. Lastly,
landowner contact is suggested to educate private landowners about sensitive natural features and
the uniqueness of the bedrock beach resource.

Point Detour

Most of the significant areas within this site fall on state land. The site includes a collective
1.2 mile stretch of good quality bedrock beach; the coastal zone includes a portion of an extensive
bedrock glade at the tip of the Garden Peninsula. An extensive, exemplary bedrock glade
community covers much of the interior of the tip of the Garden Peninsula; most of this area
remaining intact. The bedrock beach and associated glade should both be protected. Our
recommendation is to pursue Natural Area dedication for this ecologically significant area, and to
apprise Forest Management Division of the sites' importance. The area supports a large
population of dwarf lake iris (Iris lacustiis) and several other rare plants, which may be impacted
by current timber management activities.

Kregg Bay NE

State land in this shoreline area is confined to the central portion of the shoreline, whereas
private tracts with vacation homes can be found on both Charbaneau Point and Kregg Bay.
Because of the potential for habitat destruction, it is recommended that Forest Management
Division be apprised of the sensitive nature of the shoreline and its periphery of dense boreal forest.
Land owner contact and registry should be conducted for the privately owned tracts.

Stony Point

While there were no rare species found on the Stony Point bedrock beach, there were high
quality interdunal swales, and also nearby occurrences of several listed Great Lakes endemic plant
species on surrounding coastal dunes, including Pitcher's thistle, dwarf lake iris, and Lake Huron
tansy. The combination of dunes and bedrock beach justify reconsideration of Land Trust
acquisition of this large tract in 1996.

Goudreau's Harbor

This site constitutes one of the most scenic and extensive stretches of bedrock beach in the
state, and is currently encompassed within private ownership. Several homes are built on the
periphery of bedrock exposures. Several rare plant species, including federally-listed Great Lakes
endemics, and at least one rare animal species, the federal- and state-endangered piping plover, are
known along these shores. Currently, the best approach for conservation would be to initiate and
maintain landowner contact regarding rare species and their sensitive, unique habitats. Landowner
contact may be the best approach to help determine if acquisition of this high quality area may
ultimately be feasible.

LITERATURE CITED

Albert, D.A., P. Comer, D. Cuthrell, M. Penskar, M. Rabe, and C. Reschke. 1994. Bedrock
Shoreline Surveys of the Keweenaw Peninsula and Drummond Island In Michigan's Upper
Peninsula. Michigan Natural Features Inventory. Lansing, MI 48909-7944. 94p.

Anonymous. 1995. The Boreal Forest and Its Wildlife. MCMXCII IMP. BV/IMP Inc. Wildlife
Fact File. Packet 85. Group 9: North American Habitats. Card 18. Printed in U.S.A.

Ashworth, W. 1987. The Late Great Lakes. An Environmental History. Wayne State University
Press. Detroit, Michigan 48201. 274p.

Ehlers, G.M. 1973. Stratigraphy of the Niagaran Series of the Northern Peninsula of Michigan.
Museum of Paleontology, Papers on Paleontology, No.3. University of Michigan. 200p.

Dorr, J.A. Jr., and D.F. Eschman. 1984. Geology of Michigan. Univ. of Michigan Press, Ann
Arbor. 470p.

Hamilton, K.G.A. Pers. comm. Biological Resources Division, GLBW Agriculture Canada,
CEF Ottawa KIA OC6 Canada.

Hamilton, K.G.A. 1994. Leafhopper evidence for origins of northeastern relict prairies (Insecta:
Homptera: Cicadellidae). Proceedings of the l3th North American Prairie Conference.
(1992) pp. 61-70.

Hamilton, K.G.A. and D.W. Langor. 1987. Leaffiopper fauna of Newfoundland and Cape
Brenton Islands (Rhynchota: Homptera: Cicadellidae). The Canadian Entomologist
119:663-695.

Reed, R.C. and J. D. Daniels. 1987. Bedrock Geology of Northern Michigan. Lansing , MI: State
of Michigan, Department of Natural Resources, Geological Survey Division. I map.
(1:500,000).

Stephenson, S. Pers. comm. Department of Botany, Michigan State University, East Lansing,
Michigan.

APPENDICES:

-1

APPENDIX 1:

Detailed Maps of 1995 bedrock Shoreline Survey Sites

37 0

FAIR PORT, MICH.
QUADRANGLE

S
@F IR A-N ff 7.

/79.

Bedrock Beach Poverty Island

Cliff

SCALE 1:24 000

KILOAETERS I
LET06 1000 2000
0
MLES
1000 7000 3000 4000 scuo soon 7000 Saco Saco 1.0000
FEEr

Appendix 1A. Extent o f Bedrock Beach/ Alvar and Dry Non-Acid Cliff Plant
communities surveyed on poverty Island. For convenience, this general survey area is
referred to as Poverty Island in the text.

FAIRPORT/ POINT DETOUR, MICH.
QUADRANGLES
177, IWO

SCALE 1:14 000

a K X 0&-1 _=s
loan 0 WT E.15 1000 Non
.5 0
wl CS
1000 a- lano 2000 3000 4000 Soon Soon 7000 9000 gooll 10000
FW

7, 7
lq.5-3

78.

Bedrock Beach

:
@-rk,p A N K S\
@-F XA-

Cliff

A,
tw-i r
T@A
P-E R 10 R ST E F 0 a F-S
T

10,

7 7

Summer Island
X

Appendix 1B. Extent of Bedrock Beach/ Alvar and Dry Non-Acid Cliff plant
communities surveyed on Summer Island. For convenience, this general survey area is
referred to as Summer Island in the text.

POINT DETOUR, MICH.
QUADRANGLE

F,@I.R

q-7
0
all

7:3
4@ Point Detour

Bedrock Beach

Cliff

SCALE la4 000

S X&M-rus 1 2
WETEn I Quo
1000
A 0
MUS
1000- 3000 4050 Saco coca 700D 9008 Saco 10000

Appendix 1C. Extent of Bedrock Beach/ Alvar and Dry Non-Acid Cliff plant
communities surveyed on Point Detour. For convenience, this general survey area is
referred to as Point Detour in the text.

DEVILS CORNER, MICH.
QUADRANGLE

E
-N;
-1
Ir

Uk
1.2

Bedrockseach

T Jc N
3-$ N

Owboneau Poft

/air If

Kregg Bay NE

SCALE 1:24 000
XXDWETM z
logo loca. zool)

WLCES
1000 a loco logo 3000 4000 Saco GOOD 7000 9000 9000 locou

Appendix 1D. Extent of the Bedrock Beach/ Alvar plant community surveyed in the
vicinity of Kregg Bay. For convenience, this general survey area is referred to as Kregg
Bay NE in the text.
?

5
-@j 84 -

7. 1
Marfistique
M
ICH.
NISTIQUE WEST
QUADRANGLE

7.2

86. J -j

"V7'. 6,

.54
N;:

.3w
Bedrock Beach

6a starw f. .1
1032

__izj.a
=44D
;/at
'0@
Stony Point
1P
N

SCALE 1:25 ON
a KILOMETERS 1 2
1000 METERS 1000 zwo
1 0 1
MILES
low a Iwo 2000 30M 4000 sm 70M 8= 90M 10000
FEET

Appendix 1E. Extent of the Bedrock Beach/ Alvar plant community surveyed on Stony
Point. For convenience, this general survey area is referred to as Stony Point in the text.

SEUL CHOIX POINT9 MICH.
QUADRANGLE @ /V
';629

x 617

j!
-7
711
q

Bedrock Beach

-22

xa2

G,wd)-Palis
Haro'Or

Goudreau's Harbor
27
5.95 Seul Choix
Point

Ll
Oa5z Guard Sta thouse

SCALE 1:24 000

0 MO&-mts
0 JETOS Z000

WLCS -
1000 1000 2000 3000 4000 SGOO 7000 8000 9000 10000
F E
Appendix 1F. Extent of the Bedrock Beach/ Alvar plant community surveyed in the
vicinity of Goadreaus Harbor. For convenience, this general survey area is referred to as
Goudreau's Harbor in the text.

Appendix 2. Insect Species Occurrences in 1994-95 for Michigan Bedrock Sites.

AH=Agate Harbor, DP=Dan's Point, DW=Devil's Washtub, HH=Horseshoe Harbor, FC=Fish Cove, MPW=Maxton Plains West, GML--Grand Marais Lake,
MPM=Maxton Plains Middle, MPE=Maxton Plains East, SP=Seamans Point, WC=Wamers Cove, HB=Huron Bay, BSC=Big Shoal Cove, BCR=Bass Cove Road,
GS--Garden Southeast, KB=Kregg Bay NE

HEMIPTERA AH DP DW HH FC MPW GML MPM MPE SP WC HB BSC BCR GS KB
Family Alydidae
Protenor belfragei 0 0 0
Family Miridae
Adelphocoris finolatus
Lygus lineolaris
Family Nabidae
Lasiomerus annulatus
Nabicula subcoleoptrata
Family Pentatomidae
Banasa dimidiata
Chlorochroa persimilis
Cosmopepla fintneriana
Euschistus tristigmus
Dygaster alternata
Homaemus aenifrons 0 0 0
Mormidea lugens 0
Neottiglossa undata
Family Reduviidae
Sinea diadema 0
HOMOPTERA
Family Cercopidae
@Ehrqphora cribrata
Clastoptera obtusy
Clastoptera saintcyri

Appendix 2. Continued.

Family Cicadellidae (cont.) AH DP DW HH FC MPW GML -MPM MPE SP WC HB BSC BCR -GS KB
Lepyronia coleoptrata
Neophilaenus lineatus 0 0
Philaenarchys bilineata
Philaenus spumah .us
Family Cicadellidae AH DP DW HH FC MPW GML MPM MPE SP WC HB BSC BCR GS KB
*Acertagallia n.sp. 0 0 0 0 0
Amplichephalus inimicus 0
Athysanus argentatus
Balanocems provancheri
Balclutha sp.
*Chlorotettix sp.
*Chlorotettix unicolor 40 0 40 0 0
Cicadula subcupraea
Cicadula smithi 1
Colladonus eburatus 0
Cuerna striata
Diplocolenus configuratus
Doratura stylata
Empoa latifasciata
Erythroneura sp.
Fitchana vitellina
*Flexamia sp.
*Flexamia delongi

I @ 0 91 di 41 0

Appendix 2. Continued

Family Cicadellidae (cont.) AH DP DW HH FC MPW GML MPM MPE SP WC HB BSC BCR GS KB
-*Graminella_fitchii 0 0
Helochara communis 0 0
Idiodonus morsei 0 0
Kyboasca sp. 0
Latalus sp. 0 0 0 0
Laevicephalus acus 0 40 0 0 0 9
Limoteffir spp. 0
Limoteffix balli
Limoteffix 0
pseudosphagneticus
Limoteffix urnura
Macropsis quadpimatulata 0
Macrosteles sp. 0 10 0
Neokolla hieroglyphica 0
Paraphelpsius sp.
Polyamia apicata
Psammoteffix lividellus
Scaphytopius sp. 0 0 0
Verdanus evansi .
Family Dictyopharidae 0
Scolopes sulcipes
Family Issidae 0
Bruchomorpha occulata
Family Me bracidae
Campylenchia latipes

Appendix 2. Continued

ORTHOPTERA AH DP DW HH FC MPW GML MPM MPE SP WC HB BSC BCR GS KB
Family Acrididae
Chorthippus curtipennis 0 0 0 0
Melanoplus islandicus 0 0
Stethophyma gracila
Trlmerotrqpi@ verriculata
Family Gryllidae
Allonemobius griseus 0
Family Tetrigidae
Nomoteffix cristatus
Family Tettigoniidae
Conocephalus brevipennis 0
Conocephalusfasciatus 0
-Conocephalus saltans
Neoconocephalus ensiger
Orchilium gladiator
ODONATA AH DP DW HH FC MPW GML MPM MPE SP WC M BSC JBCR GS KB
Family Aeschnidae
Aeschna constricta
Aeschna interrypta
Basiaeschnajanata
Family Coenagrionidae
Enallagma boreale
Enallagma c runculatum
Enallagma cyathigerum

t I 11 4 1

Appendix 2. Continued

AH DP DW HH FC MPW GML MPM MPE SP WC HB BSC BCR GS KB
Family CoEduliidae
Epitheca canis 0
Family Gomphidae
Gomphus spicatus
Family Libellulidae
Cordulia shurtleffi
Leucorrhiniafrigida
Leucorrhinja hudsonica 0
Leucorrhinia intacta
Libellulajulia
Libellula quadrimaculata
Sympetrum obtrusum 0
00
LEPIDOPTERA AH DP DW HH FC MPW GML MPM MPE SP WC RB BSC BCR GS KB
Family Lassiocampidae
Tolype velleda
Tolype laricis
Family Notodontida'e
Clostera albosigma 0
Gluphisia tentplognis 0
Family Arctiidae
Grammia virguncula 0
Family Noctuidae
Amphipoea interoceana 0
Anagraphafalcifera
Catocala antinympha
Catocala bn'sei's

Appendix 2. Continued

Family Notodontidae (cont.) AH DP DW HH FC MPW GML MPM MPE SP WC HB BSC BCR GS KB
Catocala concumbens
Catocala meski
Catocala relicta
Catocala semirelicta
Catocala sordida
Catocala unijuga
Enargia decolor
Enargia infimata
Euxoa perpolita
Faronta diffusa
Feltiajaculifera 0
Helotropha reniformis 0
4Z.,
1-0 Leucania multillinea
Litholomia napaea 0
Magusa orbifera
Nedra ramosula
Nephelodes mim .ans 0
Ochropleura plecta
Oligia bridghami 0
Oligia illocata
Papaipema harrisii 9
Papaipema ptersh
Phlogophora periculosa
Plusia conte ta
Protolampra brunneicollis

41 4 1

Appendix 2. Continued

Family Notodontidae AH DP DW HH FC MPW GML MPM MPE SP WC HB BSC BCR GS KB
(cont.)
Pseudoplusia includens
Spodopterafirugiperda
Sunira bicolorago
Syngrapha epidaea
Syngrapha rectangula
Trichosilia geniculata
Xestia adela Franclemont
Xestia collaris
Xestia smithii
Family Geometridae
MOS magnana
Cingifia catenari.a
-Lambdinafiscellaria

special mention in text
shadding = light trap site

APPENDIX III

GLOBAL AND STATE ELEMENT RANKING CRITERIA
Michigan Natural Features Inventory, 1995

GLOBAL RANKS
G1= critically imperiled globally because of extreme rarity (5 or fewer occurrences
range-wide or very few remaining individuals or acres) or because of some factor(s)
making it especially vulnerable to extinction.
G2= imperiled globally because of rarity (6 to 20 occurrences or few remaining
individuals or acres) or because of some factor(s) making it very vulnerable to
extinction throughout its range.
G3= either very rare and local throughout its range or found locally (even abundantly at
some of its locations) in a restricted range (e.g. a single western state, a
physiographic region in the East) or because of other factor(s) making it vulnerable
to extinction throughout its range; in terms of occurrences, in the range of 2 1 to 100.
G4= apparently secure globally, though it may be quite rare in parts of its range,
especially at the periphery.
G5= demonstrably secure globally, though it may be quite rare in parts of its range,
especially at the periphery.
GH = of historical occurrence throughout its range, i.e. formerly part of the established
biota, with the expectation that it may be rediscovered (e.g. Bachman's Warbler).
GU = possibly in peril range-wide, but status uncertain; need more information.
GX = believed to be extinct throughout its range (e.g. Passenger Pigeon) with virtually no
likelihood that it will be rediscovered.
STATE RANKS
S1 = critically imperiled in the state because of extreme rarity (5 or fewer occurrences or
very few remaining individuals or acres) or because of some factor(s) making it
especially vulnerable to extirpation in the state.
S2 = imperiled in state because of rarity (6 to 20 occurrences or few remaining
individuals or acres) or because of some factor(s) making it very vulnerable to
extirpation from the state.
S3 = rare or uncommon in state (on the order of 21 to 100 occurrences).
S4 = apparently secure in state, with many occurrences.
S5 = demonstrably secure in state and essentially ineradicable under present conditions.
SA = accidental in state, including species (usually birds or butterflies) recorded once or
twice or only at very great intervals, hundreds or even thousands of miles outside
their usual range.
SE = an exotic established in the state; may be native elsewhere in North America (e.g.
house finch or catalpa in eastern states).
SH = of historical occurrence in state and suspected to be still extant.
SN = regularly occurring, usually migratory and typically nonbreeding species.
SR = reported from state, but without persuasive documentation which would provide a
basis for either accepting or rejecting the report.
SRF= reported falsely (in error) from state but this error persisting in the literature.
SU = possibly in peril in state, but status uncertain; need more information.
SX = apparently extirpated from state.

51 41

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