A Biological Inventory of Seven Lakes Nature Preserve Alger County, Michigan
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A Biological Inventory of Seven Lakes Nature Preserve Alger County, Michigan By Ryne Rutherford, M.S. Biologist, Biophilia, LLC March 31, 2018 Photo 1. A picturesque fall day at Casey lake in October 2016. TABLE OF CONTENTS INTRODUCTION…………………………………………………………………………………..2 METHODS………………………………………………………………………………………......3 GEOLOGY AND LANDSCAPE SETTING………………………………………………………5 NATURAL COMMUNITIES………………………………………………………………………6 KINGDOM ANIMALIA…………………………………………………………………………..15 Birds………………………………………………………………………………………….15 Amphibians…………………………………………………………………………………..22 Reptiles……………………………………………………………………………………….24 Mammals…………………………………………………………………………………….26 Fish……………………………………………………………………………………...……27 Insects………………………………………………………………………………………...29 Miscellaneous Invertebrates………………………………………………………………..36 KINGDOM PLANTAE…………………………………………………………………………....37 Plants…………………………………………………………………………………………37 Bryophytes…...………………………………………………………………………………47 KINGDOM FUNGI……………………………………………………………………………......49 Free-living Fungi…………………………………………………………………...………..49 Lichenized Fungi………………………………………………………...…………………..52 LISTED SPECIES……………………………………………………………………………...….55 INVASIVE SPECIES………………………………………………………...……………………57 MANAGEMENT AND CONSERVATION…………………………………………………...…59 FUTURE INVENTORY AND MONITORING NEEDS………………………………….…….60 ACKNOWLEDGEMENTS……………………………………………………………………….62 LITERATURE CITED AND REFERENCES…………………………………………….……..63 1 Introduction The Seven Lakes Nature Preserve is tucked away in Michigan’s eastern Upper Peninsula, approximately 15 kilometers south of Lake Superior and the Grand Sable Dunes at Pictured Rocks National Lakeshore. This relatively pristine nature preserve occupies over 3,600 acres of classic Northwoods habitats, such as lakes, streams, bogs, pine forests, northern hardwood forests and boasts abundant wildlife. Strong elements of the deciduous forest biome to the south and the boreal forest biome to the north are represented. The goals of this project were (1) to provide a baseline biological inventory to be compared to future inventory and monitoring projects and (2) evaluate ecosystem health by assessing potential threats to the ecosystems at Seven Lakes Nature Preserve, such as invasive species, diseases and direct human impacts. Given the many habitats and great potential to support biodiversity we were not surprised to amass a list of 811 species. The list includes 328 animal species (116 birds, 12 amphibians, 5 reptiles, 15 mammals, 10 fishes, 159 insects and 11 other invertebrates), 327 plant species (299 vascular plants, 27 bryophytes, 1 algae) and 156 fungi species (82 free-living fungi, 74 lichenized fungi). Fourteen species found were state listed (Table 9) and one species, gray wolf (Canis lupus), is federally endangered. With looming threats from climate change and other anthropogenic causes there is no better time to document and study our flora and fauna. We believe this study will be an important piece of that not just at Seven lakes, but regionally. Photo 2. The beautiful female luna moth (Actias luna). 2 Methods Our research at Seven Lakes was scheduled to maximize the number of species we could detect during any given trip and to target state and federally listed species. A team of seven expert biologists assisted with data collection. Our initial sampling was conducted October 7-10, 2016 and focused on the collection and identification of fungi and lichens. Birds were also surveyed. The entire property was explored, and plans were made to focus on places with potential for rare species to be sampled on future visits. On May 7-11, 2017, we focused our efforts on amphibians, migrant birds and collecting bryophytes. Visual egg surveys were conducted for salamanders and wood frogs. Birds were sampled in the early morning and late evening. The edges of the airstrip seemed to be the most reliable spot for migratory songbirds and our efforts focused there. Owls were also surveyed after dark. Thirty 3’ by 4’ cover boards were deployed for snake and small mammal surveys. On June 10-13, 2017, we conducted breeding bird surveys throughout the property, and minnow trapped for small fish, amphibians and aquatic insects. We also used aerial nets to survey for odonata and butterflies and conducted terrestrial meander surveys for plants. On August 10-13, 2017, we checked the cover boards for snakes and small mammals and continued aerial net surveys for odonata, butterflies, bumblebees and other insects. Terrestrial meander surveys for plants also continued. Surveys were also conducted for fall migrant shorebirds at Moose Lake. On August 31-September 1, 2017, we visited areas that were not previously surveyed, completed the inventory of natural communities, surveyed for migrant songbirds and mammal tracks. On our final visit October 15-16, 2017, we picked up cover boards and surveyed for migrant waterfowl. Photos 3-4. Checking out a captivating moss (photo 3, left) and minnow trapping at Deerfoot Lake (photo 4, right). Photos by Darrin O’Brien. 3 Figure 1. Map of Seven Lakes. The original purchase area is shown in red and a later addition is shown in yellow. Map courtesy The Nature Conservancy. 4 Geology and Landscape Setting The entire area comprising Seven Lakes Natural Preserve is underlain by Cambrian age sandstone which is not directly exposed at the surface but comes close along the Fox River in the southern portion of the property. This is overlain by a variety of glacial deposits, which may be up to 200 feet thick, from the Wisconsin glaciation at the end of the Pleistocene epoch 9-12,000 years ago (LaBerge 1994). Coarse textured glacial till dominates much of the upland portion of Seven Lakes, while the lowland areas are composed of pitted outwash plains with occasional sandy ridges. Soils are composed of peat, poorly drained sands and extensively drained sands. Podzols are the dominant soil type (Albert 1995) (Photo 5). Ice blocks broken off glaciers melted in depressions to form lakes and ponds that have gradually become filled over the centuries and millennia by undecomposed peat to form bogs. The peat at Seven Lakes is likely several meters deep in places. This area is in a unique geographic position, sitting at the headwaters of the Fox River in the Lake Michigan watershed, yet much closer to Lake Superior which is only 13.5-18 kilometers away. Seven Lakes Nature Preserve sits about 100 meters higher than Lake Superior or 270-285 meters elevation. Its proximity to the lake and elevated location puts this area within the Lake Superior snow belt. Although snowfall amounts are not measured for this exact location (John Hermann personal communication). Photo 5. A soil profile along a roadcut on the main track into Seven Lakes. Notice the very thin organic layer on top (O horizon) and the robust gray layer in the middle (E horizon). Chunks of sandstone are visible underneath revealing the local bedrock type. This is an acidic, nutrient poor soil type characteristic of the boreal forest region. It was the predominant soil in the uplands at Seven Lakes. 5 Natural Communities Forests Forest comprises most of land at Seven Lakes Nature Preserve and can be divided into the following community types. Mesic Northern Forest was the dominant forest type and has been since the original land surveys in the 1800s (Albert et al. 1995). The hilly uplands underlaid by coarse textured glacial till are covered mostly by this forest type which occurs on over 50% of the land area at Seven lakes. Although mostly underlain by nutrient poor podzols, one area of Mesic Northern Forest is underlain by a loamy sand that is more nutrient rich and occurs east and west of Casey Lake. Likewise, the southeastern corner of the property between the Fox River and Moose Lake is similarly well developed. In the Casey Lake Hardwoods (Figure 2, Table 1). Sugar maple (Acer saccharum) is the dominant tree, with lesser amounts of yellow birch (Betula alleghaniensis) and black cherry (Prunus serotina) with the latter species occurring in unusually high abundance. White pine (Pinus strobis) once formed a super-canopy over this area and many very large stumps persist from the great cutover around 1900. Surviving relict white pine is rare on the property but occurs east of Casey Lake (Photo 6). The ground flora in the Casey Lake Hardwoods was particularly rich with Streptopus roseus, Prunus serotina, Trientalis borealis, Claytonia caroliniana, Erythronium canadensis, Hepatica americana, Carex gracillima, Carex deweyana, Carex artata, Carex intumescens, Smilicina racemosa, Dryopteris intermedia, Oxalis acetocella, Polygonum cilinode, Aralia nuticaulis, Spinulum annotonium, Huperzia lucidula, Dendrolycopodium dendroideum and Polygonatum pubescens. The uplands near Gopher, Spruce, Deerfoot and Centerline Lakes and extending north to Adam’s Trail, where the soil type is podzol, contain Mesic Northern Forest with greater amounts of red maple (Acer rubrum), American beech (Fagas grandifolia) and ironwood (Ostrya virginiana). Eastern hemlock (Tsuga canadansis) increases in abundance near lakeshores and streams. Virgin stands of eastern hemlock, likely several hundred years old occur on steep slopes along the Fox River downstream from Casey Lake (Figure 2, Table 1, Photo 7). It is worth noting that other tree species common in this forest type elsewhere in the Upper Peninsula, like ashes (Fraxinus sp.) basswood (Tilia americana) and red oak (Quercus rubra), were not found at Seven Lakes. It is also worth noting that nearly all the forests at Seven Lakes have all been logged in the past