Beaver Island Research Articles

The Hydrologic Response to a Meteotsunami in an Isolated Wetland: Beaver Island in Lake Michigan, USA

AbstractMeteotsunamis are both a well‐known and poorly understood phenomenon. In particular, the influence of and disturbance by meteotsunamis on isolated coastal wetlands is largely unknown. This paper documents a case illustrating how water levels in an incipient foredune/swale complex in northern Lake Michigan responded to a meteotsunami event. We identified potential meteotsunami influence on wetland water levels through slope‐break and wavelet analysis, verified the presence of meteotsunami waves at surrounding lake water level gauge stations with wavelet analysis, analyzed both regional and small‐scale meteorological data to establish what source of atmospheric forcing resulted in meteotsunami formation, and used a hydrodynamic model to simulate lake surface response and meteotsunami generation. On 20 July 2019, an atmospheric bore wave propagating away from a convective storm formed a meteotsunami event in Lake Michigan that struck Sand Bay, Beaver Island and generated a 36 cm increase in subsurface wetland water levels over the course of a 1‐hr period. The potential for multiple sources of meteorological forcing and secondary wave refraction highlights several challenges with predicting generation of and effects from meteotsunami events. Additionally, while irregular, the effects of these events on isolated wetland systems have the potential to alter hydrologic and sediment budgets, vegetation growth, and dune stability; yet meteotsunami influence on isolated wetlands is an understudied phenomenon. The event presented in this study make a strong case for focused research on coastal wetland response to meteotsunamis (and meteotsunami‐like events) to address this understudied impact given its implications for coastal processes and resiliency.

Detection of hybrid Pyganodon grandis and P. lacustris (Bivalvia: Unionidae) using F- and M-type mitochondrial DNA sequences and geometric morphometrics

ABSTRACTPyganodon grandis and P. lacustris, widespread and common species in North America, are known to co-occur across parts of their distributions. These mussels are genetically distinguishable with a sequence divergence between 9% and 13% for the mitochondrial (mt) DNA barcoding region, cytochrome c oxidase subunit I (COI), which is well beyond thresholds for distinct species. The objectives of this study were to (1) confirm the presence of two genetically distinct species (P. grandis and P. lacustris) in Font Lake and Lake Geneserath on Beaver Island in northern Lake Michigan, (2) identify hybrids using mitogenotype mismatch and (3) compare species and populations morphometrically. Of the 212 specimens sequenced, 146 (68.9%) were found to be heteroplasmic, with successful amplifications of both maternally (F-type, from mantle tissue) and paternally (M-type, from gonad tissue) inherited mt DNA sequences. Mismatches in species identity of the F- and M-type COI sequences were found in 22 specimens (15.1% of heteroplasmic specimens), with these being considered putative hybrids. Geometric morphometric analyses of shell shape reliably differentiated specimens by species (identified using COI sequences) and between lakes, correctly assigning 97.4% of homoplasmic and heteroplasmic specimens with matching mitogenomes to both species and lake of origin. The shape of putative hybrids generally resembled those of the F-type mt DNA sequence that was recovered. This study confirms that hybridization does occur between sympatric Pyganodon species. Additionally, our results reemphasize the value of modern morphometric techniques for distinguishing among species and populations with overlapping morphological variability.

Use of Spotted Knapweed/Star Thistle (Asterales: Asteraceae) as the Primary Source of Nectar by Early Migrating Monarch Butterflies (Lepidoptera: Nymphalidae) from Beaver Island, Michigan

Use of Spotted Knapweed/Star Thistle (Asterales: Asteraceae) as the Primary Source of Nectar by Early Migrating Monarch Butterflies (Lepidoptera: Nymphalidae) from Beaver Island, Michigan

Swimming responses of larval and juvenile freshwater fishes to nearshore and offshore water sources

AbstractDispersal of young fish through wind‐driven currents has a growing research focus in large freshwater lakes; however, the influence of behaviour on such dispersal has not been tested. Fish may orient to different environmental cues and use swimming behaviours to navigate towards or retain their position within important habitats. To examine the ability of larval and juvenile fishes of the Laurentian Great Lakes to perceive and orient to nearshore or offshore habitats, we carried out a series of behavioural trials in a flume in which fish choose between different combinations of nearshore and offshore water, and well water. Water and a natural assemblage of larval and juvenile nearshore fish (Dominant species: white sucker, Catostomus commersonii, and spottail shiners, Notropis hudonius) used in the experiment were collected from northern Lake Michigan near Beaver Island. Results of our study suggest that young fish are capable of distinguishing and responding to different water sources, indicating a potential to orient within their environment, such as through the use of olfactory cues. We did not see a difference in fish response to changing concentrations of water cues, possibly suggesting that the threshold for fish response occurs at lower concentrations than were tested in our experiments. This preliminary study into orientation of Great Lakes fishes demonstrates the capacity of these fish to orient to cues in water sources and indicates the need to consider active movement in future studies of larval dispersal and habitat choice in the large freshwater lakes.

A mesocosm investigation of the effects of quagga mussels (Dreissena rostriformis bugensis) on Lake Michigan zooplankton assemblages

Abstract Dreissenid mussels are known to disrupt the base of the food web by filter feeding on phytoplankton; however, they may also directly ingest zooplankton thereby complicating their effects on plankton communities. The objective of this study was to quantify the effects of quagga mussel feeding on the composition and size structure of Lake Michigan zooplankton assemblages. Two mesocosm (six 946 L tanks) experiments were conducted in summer 2013, using quagga mussels and zooplankton collected near Beaver Island, MI, to examine the response of zooplankton communities to the presence and absence of mussels (experiment 1) and varying mussel density (experiment 2). Mesocosms were sampled daily and zooplankton taxa were enumerated and sized using microscopy and FlowCAM® imaging. In experiment 1, the presence of quagga mussels had a rapid negative effect on veliger and copepod nauplii abundance, and a delayed negative effect on rotifer abundance. In experiment 2, mussel density had a negative effect on veliger, nauplii, and copepodite abundance within 24 h. Multivariate analyses revealed a change in zooplankton community composition with increasing mussel density. Ten zooplankton taxa decreased in abundance and frequency as quagga mussel density increased: except for the rotifer Trichocerca sp., treatments with higher mussel densities (i.e., 1327, 3585, and 5389 mussels/m 2 ) had the greatest negative effect on small-bodied zooplankton (≤ 128 μm). This study confirms results from small-scale (≤ 1 L) experiments and demonstrates that quagga mussels can alter zooplankton communities at mesoscales (~ 1000 L), possibly through a combination of direct consumption and resource depletion.

An Annotated List of the Orthoptera of Beaver Island, Lake Michigan

An Annotated List of the Orthoptera of Beaver Island, Lake Michigan

Microbial community diversity patterns are related to physical and chemical differences among temperate lakes near Beaver Island, MI.

Lakes are dynamic and complex ecosystems that can be influenced by physical, chemical, and biological processes. Additionally, individual lakes are often chemically and physically distinct, even within the same geographic region. Here we show that differences in physicochemical conditions among freshwater lakes located on (and around) the same island, as well as within the water column of each lake, are significantly related to aquatic microbial community diversity. Water samples were collected over time from the surface and bottom-water within four freshwater lakes located around Beaver Island, MI within the Laurentian Great Lakes region. Three of the sampled lakes experienced seasonal lake mixing events, impacting either O2, pH, temperature, or a combination of the three. Microbial community alpha and beta diversity were assessed and individual microbial taxa were identified via high-throughput sequencing of the 16S rRNA gene. Results demonstrated that physical and chemical variability (temperature, dissolved oxygen, and pH) were significantly related to divergence in the beta diversity of surface and bottom-water microbial communities. Despite its correlation to microbial community structure in unconstrained analyses, constrained analyses demonstrated that dissolved organic carbon (DOC) concentration was not strongly related to microbial community structure among or within lakes. Additionally, several taxa were correlated (either positively or negatively) to environmental variables, which could be related to aerobic and anaerobic metabolisms. This study highlights the measurable relationships between environmental conditions and microbial communities within freshwater temperate lakes around the same island.

Phytoplankton Seasonality along a Trophic Gradient of Temperate Lakes: Convergence in Taxonomic Compostion during Winter Ice-Cover

A gap in our understanding of phytoplankton seasonality in temperate lakes exists mainly due to the lack of information collected during the winter months. We summarized seasonal changes of phytoplankton biomass and taxonomic composition relative to water-column biogeochemical conditions in 6 lakes located on Beaver Island and 1 site in Lake Michigan in close geographic proximity to each other (<20 km apart). A number of physical—chemical parameters (e.g., temperature, DOC) were similar between lakes, but lakes towards the interior of the island had lower pH, alkalinity, and conductivity. Moreover, lakes at the interior of the island supported 2-fold greater phytoplankton-chlorophyll and carbon compared with perimeter lakes, and phytoplankton taxonomic composition differed considerably during the ice-free period (April–December). Interestingly, the winter phytoplankton assemblages were strikingly similar in all 7 lakes, when large populations of phyto-flagellates (Chrysophyceae and Cryptophyceae) occurred under the ice at low light and temperatures < 4 °C. Given the mixotrophic capabilities of these phytoflagellates, we suggest seasonal convergence reflects the community response to under-ice conditions, which promotes the occurrence of an important component of annual phytoplankton biomass.

Mormon and Irish Landscapes on Beaver Island, Lake Michigan – niche construction and socio-ecological inheritance in the nineteenth century

ABSTRACTBeaver Island, Michigan was a unique settlement location for Irish America in the late nineteenth century. Families of Irish descent migrated to northern Lake Michigan and reproduced many aspects of the rural, fishing and farming lifeways of Ireland. They had to negotiate the cultural landscape and material conditions that had previously been established on the island, notably by a Mormon sect that occupied the island between 1848 and 1856. The inheritance of landscapes by one community from another can be understood through the concept of niche construction theory. This can be used as a lens to understand how the Mormons shaped their cultural landscape and what this meant for the socio-ecological legacy taken over by their Irish replacements. We also notice the Irish influence on the Beaver Island Lumber Company who came after them. Utilising archaeological and historical data, we undertake a macro-analysis to investigate the shaping of structures and landscapes as interactive influences of one cultural group on another across time. Each new group selectively utilised aspects of the extant ecology and built environment according to their own needs and worldviews, and thus transformed the island's landscapes again for subsequent inhabitants.

Recent and historic eutrophication of an island lake in northern Lake Michigan, USA

Lake Geneserath is located on Beaver Island in northern Lake Michigan, USA. It exhibits evidence of recent eutrophication, despite limited anthropogenic activity in the watershed. The primary goal of this study was to determine the time scale of trophic state change in Lake Geneserath and the influence of multiple stressors. Sediment cores from the shallow northern and deep southern basins of Lake Geneserath were collected and sectioned at 0.5-cm intervals over the topmost 10 cm and at 1.0-cm intervals for the remainder of the core. Total phosphorus, percent organic matter, and chlorophyll derivative concentrations were measured in each section, and core chronology was established using 210Pb. Diatom assemblages were quantified from evenly distributed sections in each core. Geochemical variables in the southern basin core indicate historic (AD ~ 1450–1650) and modern (1848-present) periods of eutrophication, coincident with human disturbance and climate warming events. Geochemical variables in the northern basin core confirm accelerating eutrophication after 1950. The fossil diatom assemblages in both basins shifted from species favoring low nutrients to more nutrient-tolerant taxa. A change from periphytic to planktonic diatom species, concurrent with reduced percent organic matter in the northern basin core, indicates rising water level during the second half of the twentieth century. Lake Geneserath was subject to multiple stressors and its trophic status increased with recent residential development and climate warming.

Fish community size structure of small lakes: the role of lake size, biodiversity and disturbance

Aquatic community body size distributions are highly predictable with decreasing abundance and increasing body size. This basic relationship has led to significant increases in our understanding of the internal regulation processes of aquatic communities. However, most of our understanding of the patterns of community size structure is derived from large aquatic systems with little known about the dynamics of small lakes. Processes that promote predictable, or deterministic, community size structure likely differ with levels of biodiversity and disturbance patterns, both of which frequently co-vary with ecosystem size. Here we examine the influence of lake size, fish species richness, and natural disturbance regime on fish community size structure in six small lakes (<200 ha) on Beaver Island, Michigan, USA. Fish communities in three of the six lakes exhibited a deterministic size structure and it appears that disturbance regime is the most obvious barrier to developing and/or maintaining stable and predictable community size structure. In this study, lakes with less than 10 species and lakes experiencing periodic winterkills exhibited stochastic size structure. Lake size did not show any clear relation to fish community size structure. Collectively our results shed some light on the conditions that promote (or do not promote) deterministic size structure.

Colonization of the Beaver Island Archipelago by deer mice (Peromyscus maniculatus gracilis): mtDNA evidence for multiple origins

The Beaver Island group in Lake Michigan comprises nine islands ranging from 0.3 to 144 km2, lying approximately 30 km west of Michigan’s Lower Peninsula (LP) and 15 km south of the Upper Peninsula (UP). The islands have been isolated from mainland Michigan for most of their postglacial history, but were connected to the mainland LP during the low-water Chippewa stage (ending about 7400 years before present (YBP)). Although plants and animals could have colonized the islands during the Chippewa period, flooding during the subsequent Nipissing high-water stand means that the smaller islands have been colonized more recently. We analyzed 481 bp of mitochondrial D-loop sequences from woodland deer mice (Peromyscus maniculatus (Wagner, 1845)) on six of these islands in northern Lake Michigan to elucidate the mainland origin and minimum number of colonization events for this species. Surprisingly, the distribution of haplotypes on the islands suggests that the populations on most islands likely had separate recent origins on the mainland UP. Approximate Bayesian computation supports a scenario in which individual islands were colonized separately by distinct groups of mice. Together, the data suggest multiple colonization events from the UP, rather than expansion from a bottlenecked population or a single colonization event.

Island Explorations: Discovering Effects of Environmental Research-Based Lab Activities on Analytical Chemistry Students

Motivating students in analytical chemistry can be challenging, in part because of the complexity and breadth of topics involved. Some methods that help encourage students and convey real-world relevancy of the material include incorporating environmental issues, research-based lab experiments, and service learning projects. In this paper, we describe an approach that combines all three of these methods by integrating environmental research-based activities into the second-year undergraduate analytical chemistry course. We discuss the development, implementation, and preliminary evaluation of the research-based labs employed during the new summer analytical chemistry course. Students perform environmental investigations of sites on Beaver Island, Michigan, and prepare reports to contribute to an ongoing research project analyzing these locations that began in the 1970s. Preliminary impacts on analytical students were examined using pre- and postsurveys, including the Chemistry Attitudes and Experiences Qu...

Application and transferability of Great Lakes coastal wetland indices of biotic integrity to high quality inland lakes of Beaver Island in northern Lake Michigan

Biological indicators or indices of biotic integrity (IBI) have been developed for land management and regulatory agencies to categorize the condition of a given ecosystem. IBIs are more widely used in lotic systems and those that can be used over wide geographic regions or multiple systems are deemed most valuable. Lacustrine wetlands have intrinsic complexity and multidimensionality making them very difficult to classify. This, in turn, greatly affects the transferability of indices created for explicit regions and wetland types. Similarly, due to scarcity, relatively pristine reference conditions are seldom included in IBI calibration and represent a critical end of the disturbance continuum. The robustness and transferability of macroinvertebrate and fish IBIs created for fringing lacustrine and drowned river mouth wetlands of the Great Lakes for use in wetlands occurring in inland-lakes on islands within the Great Lakes were tested. Islands within the Laurentian Great Lakes contain unique and critical habitats that have received little attention, but also require specialized tools for monitoring and management. Inland-lake wetlands of Beaver Island, Lake Michigan, were ranked a priori along a disturbance gradient based on adjacent land use/cover. Transferability of the pre-existing Great Lakes IBIs was determined by correlating the site-specific IBI rank with the site-specific disturbance ranks. Results indicated that the IBIs were not directly transferable and may require substantial modification.

Assessment of remnant unionid assemblages in a selection of Great Lakes coastal wetlands

Populations of native unionids have been in steady decline over the past century. The invasion of dreissenid mussels (Dreissena polymorpha and Dreissena rostriformis bugensis) in the mid-1980's impacted already imperiled unionid populations by greatly increasing their regional extinction rates. A selection of Great Lakes coastal wetlands around Michigan was surveyed to locate remnant populations of native unionids. Physical and chemical parameters were measured in coastal wetlands to evaluate the importance of these habitat parameters to remnant unionid assemblages. We assessed fouling rates by dreissenids on unionids and used artificial substrates to estimate dreissenid colonization densities. Live unionids were found in coastal wetlands of the Les Cheneaux Islands, the Lake St. Clair delta, and North Maumee Bay with significantly higher unionid fouling in the Les Cheneaux Islands compared to the other two sampling areas (F2,76=4.97, p=0.0095). No live unionids were documented in Beaver Island, Garden Island, Grand Traverse Bay, or Saginaw Bay wetlands. Dreissena colonization densities on artificial substrates averaged 19,213m−2 at one site in North Maumee Bay, and 10,425m−2 in Saginaw Bay, but no colonization occurred in the wetlands of Beaver Island, Garden Island, the Les Cheneaux Islands, or Grand Traverse Bay while Dreissena presence in the open water of these regions was evident. Dreissena colonization densities on artificial substrates increased with measures of anthropogenic disturbance and decreased with higher water level fluctuations and aerial exposure. Specific conductance, turbidity, and magnitude of water level fluctuations were important predictors of Dreissena colonization on artificial substrates.

Microsatellite Genetic Structure and Cytonuclear Discordance in Naturally Fragmented Populations of Deer Mice (Peromyscus maniculatus)

The Great Lakes impose high levels of natural fragmentation on local populations of terrestrial animals in a way rarely found within continental ecosystems. Although separated by major water barriers, woodland deer mouse (Peromyscus maniculatus gracilis) populations on the islands and on the Upper Peninsula (UP) and Lower Peninsula (LP) of Michigan have previously been shown to have a mitochondrial DNA contact zone that is incongruent with the regional landscape. We analyzed 11 microsatellite loci for 16 populations of P. m. gracilis distributed across 2 peninsulas and 6 islands in northern Michigan to address the relative importance of geographical structure and inferred postglacial colonization patterns in determining the nuclear genetic structure of this species. Results showed relatively high levels of genetic structure for this species and a significant correlation between interpopulation differentiation and separation by water but little genetic structure and no isolation-by-distance within each of the 2 peninsulas. Genetic diversity was generally high on both peninsulas but lower and correlated to island size in the Beaver Island Archipelago. These results are consistent with the genetic and demographic isolation of Lower Peninsula populations, which is a matter of concern given the dramatic decline in P. m. gracilis abundance on the Lower Peninsula in recent years.

Movement of smallmouth bass within the Beaver Island Archipelago, northern Lake Michigan

Fish movement may vary across a wide array of aquatic ecosystems and may be related to the overall size of the system inhabited. We investigated movement of smallmouth bass in Lake Michigan because this information is lacking for larger systems. A total of 16 smallmouth bass were surgically implanted with ultrasonic transmitters within the Beaver Archipelago, northern Lake Michigan. During 2007–2008, a maximum of one location per individual was recorded daily during three specific tracking periods – pre-spawn, spawning, and post-spawn – to determine diurnal movement patterns. Movement was evaluated as site fidelity, minimum displacement rate, maximum excursion rate, and distance from shore. Smallmouth bass exhibited greater maximum excursion rates during the spawn period compared to pre-spawn. Movement rates did not differ between tracking periods; however, movement rates were greater during the spawn period in 2007 than 2008. Both sexes moved further offshore to deeper water during post-spawn, but females were located further offshore than males during this period. Annual site fidelity was more evident during post-spawn than during spawning for both sexes. Two smallmouth bass emigrated outside of the Archipelago, suggesting this population may be more “open” in terms of individuals moving throughout northern Lake Michigan than previously thought. These results indicate smallmouth bass may move greater distances in larger aquatic systems and therefore larger management units (in terms of total area) should be established in Lake Michigan to account for these greater excursion distances.

Seasonal dynamics of three inquiline species in isolated island populations of Sarracenia purpurea L. in Lake Michigan

AbstractA seasonal survey of the abundances of three inquilines species in Sarracenia purpurea L. leaves was conducted by sampling 240 leaves from three pitcher plant populations on Beaver Island in Lake Michigan, United States. Leaf characteristics such as fluid pH, fluid volume, and keel length were quantified. The study focused primarily on the larvae of three dipteran inquiline species – the midge, Metriocnemus knabi Coquillet, the mosquito, Wyeomyia smithii (Coquillet), and the flesh fly, Fletcherimyia fletcheri Aldrich. Dipteran inquiline abundances varied with sampling season. Most pitchers contained one of the three studied inquilines species. Mosquito abundances were low relative to the other inquilines. In samples collected soon after new leaves open, a mixture of mosquito and midge larvae was characteristic. We related inquilines abundances to leaf parameters using generalized linear mixed models. The midge and mosquito responded differently to leaf parameters during different sampling seasons, where as the flesh fly showed no response. The most important leaf parameters were pH and percent of total leaf volume filled with fluid (relative volume). The midge and mosquito were more likely to be present in pitchers with low pH and higher fluid volume. Our results indicate that pitchers of isolated northern populations of S. purpurea are inhabited by a less diverse insect community than reported elsewhere. Our study also suggests that site isolation may play an important role in the seasonal variation of inquiline community structure.

Irish in Michigan. "Discovering the Peoples of Michigan" series by Seamus P. Metress, Eileen K. Metress

126 MichiganHistoricalReview Seamus P. Metress and Eileen K. Metress. Irish in Michigan. "Discovering the Peoples ofMichigan" series. East Lansing: Michigan State University Press, 2006. Pp. 92. Appendices. For further reference. Illustrations. Index. Paper, $11.95. "Discovering the Peoples ofMichigan" is a series of short books intended to introduce nonacademic readers to the state's ethnic contributors. Irish in Michigan, which was written by an anthropologist and a professor of public health, delineates patterns of Irish setdement and argues the case for cultural persistence, particularly in terms of Irish republicanism. Chapter one outlines five periods of Irish immigration toAmerica since 1640 and makes brief references to places where persons from Ireland settled in Michigan. The second chapter, on Detroit, is especially useful in its discussion of how the Irish faced far less anti-Catholicism than their East Coast counterparts due to the earlier French Catholic setdement of that area. Chapter three covers Gaelic-speaking immigrants on Beaver Island, and the Irish of theUpper Peninsula and eastern and western Michigan. This chapter is most useful when the authors rely on secondary sources, such as studies of Irish copper miners by William Mulligan and Timothy O'Neil. Genealogists, however, might also appreciate the biographical details drawn from booster publications. Those interested in Protestant Irish ancestors will find little here about them, because, the authors maintain, they either assimilated or belonged to the "English landlord class" (p. 31). Thus, they were not really Irish. The book's final chapter focuses on the maintenance of Irish identity in a time when many Irish people are moving out of Irish neighborhoods. This section often conflates Irish republican activism with ethnicity and insists upon cultural persistence without much evidence. A discussion of Irish organizations and how many people belong to them, particularly in relation to how many people in Michigan claim Irish ancestry,would have been useful. Readers should be aware of thevolume's unusually heavy-handed Irish republican slant. The Metresses are entitled to their political views, but extreme republican politics are reflected throughout the book, as in references not toNorthern Ireland (a name deliberately omitted) but to "the sixnortheastern counties stillunder British occupation" (p. 10). Readers are also informed that the Irish Civil War (1922-1923) was "fought over partition" (p. 10). That is not true. Although die-hard republicans remember itotherwise, Irish republicans divided over whether to swear an oath of allegiance to theBritish king. The Metresses also claim that 1.5 to BookReviews127 2million people died in the Irish potato famine. The best estimate, by Joel Mokyr, is that 1,082,000 to 1,498,000 perished between 1846 and 1851. For thatmatter the authors assert that "a strong case can be made" that the famine was "opportunistic genocide" perpetrated by "English overlords" who exported Irish food to England (p. 7). Cormac 6 Grada, James S. Donnelly, Jr., and Mary E. Daly have long since challenged this nationalist interpretation. The Metresses should have acknowledged the debate over this question of genocide. Educators or those unfamiliar with Irish nationalism might keep these concerns inmind. Catherine M. Burns University ofWisconsin, Madison Joseph L. Peyser and Jose Antonio Brandao, eds. Edge of Empire: Documents ofMichi/imackinac, 1671-1716. Translated by Joseph L. Peyser. East Lansing: Michigan State University Press for theMackinac Island State Park Commission, 2008. Pp. 192.Appendices. Bibliography. Index. Maps. Notes. Cloth, $39.95. Although Jose Antonio Brandao and the late Joseph L. Peyser tided their compilation of Michilimackinac-related documents Edge of Empire, their volume makes clear that the post was central to the survival of New France. The usefully annotated documents in the editors' collection highlight the innerworkings of the fur trade in the pays d'en haut, or "Upper Country," and provide a rare glimpse into everyday life in a far-flung outpost of France's transatiantic empire. The French established Michilimackinac in the heart of Ottawa territory to protect the valuable beaver-pelt trade and to support the missionary efforts of the Society of Jesus (Jesuits). The documents in this book illustrate the first decades of this vital post's existence. One document, a "Statement of Expenditures" compiled by Michilimackinac's commander, underscores the post's value to New France...

Genetic diversity and spatial genetic structure of Pinus strobus (Pinaceae) across an island landscape inferred from allozyme and cpDNA markers

The Beaver Island Archipelago (BIA) provides a model system to address the impact of long-term isolation on genetic diversity and gene flow. Low lake levels are assumed to have caused the BIA to be attached to mainland Michigan for at least 4000 years (10000 yr B.P.- 6000 yr B.P.), eventually, rising lake levels would have kept the islands isolated since 6000 yr B.P. If the island populations of a plant species in the BIA were indeed once continuous with the mainland of Michigan, then we would expect similar levels of genetic diversity in populations of such a species on the islands vs. the mainland. We compared levels of allozyme genetic diversity of 20 plots of Pinus strobus in the BIA with two mainland populations in northern Michigan. In addition, if pollen is a primary agent of gene flow across islands, a low degree of allozyme differentiation among the island populations of P. strobus in the BIA would be evident. Furthermore, since seed dispersal is more limited than pollen dispersal in P. strobus, a more pronounced spatial genetic structure (SGS) is expected in allozymes than in cpDNA markers. To gain insights on the pattern of seed and pollen dispersal among the 20 plots, we further analyzed spatial autocorrelation using Moran's I-statistics for both data sets [biparentally inherited, allozymes and paternally inherited, cpDNA microsatellites (cpDNA SSR)]. We found a similar level of allozyme variability in both the BIA (mean He = 0.080) and the two mainland populations (mean He = 0.078). As predicted, we observed a low but significant degree of genetic divergence among populations for allozymes (mean FST = 0.033 across 20 plots). Our allozyme-based SGS analysis revealed significant evidence of SGS (i.e. isolation-by-distance; slope β = −0.194 from regression analysis of observed averaged Moran's I values against the logarithm of the upper bound of six distance classes). In contrast, little evidence of SGS was found in cpDNA SSR data across the BIA (β = 0.013). These results suggest that although gene flow via seed dispersal is somewhat limited, pollen flow has been sufficient to maintain genetic diversity and prevent differentiation across the island landscape over several thousand years of isolation.