Cover Photos courtesy of Cindy Glase, Michigan Technology University; cover design by
Lisa M. Dellwo; manuscript production by Deb Fargione
Preface
Realizing the importance of National Parks as pristine areas for scientific research, Phyllis
Green, Superintendent of Isle Royale National Park, gathered us as a group of
distinguished scientists to offer a strategic plan for scientific research in the Park during
the next few decades. We met at the Park in August 2008, and were in frequent contact
through the fall of 2008 as we prepared this report. We hope that this plan helps to
indicate the unique characteristics and values of Isle Royale National Park, to prioritize
research initiatives and management strategies to foster scientific research in the Park, and
to show how scientific research in the Park can contribute to a greater understanding of
ecology, natural ecosystems, and the global changes that are wrought by humans.
Respectfully submitted, January 2009
William H. Schlesinger, Cary Institute of Ecosystem Studies, Millbrook, NY (Chair)
Viney P. Aneja, Department of Marine, Earth, and Atmospheric Sciences, North
Carolina State University, Raleigh
F. Stuart Chapin III, Institute of Arctic Biology, University of Alaska, Fairbanks
Nicholas Comerford, North Florida Research and Education Center, Department of
Soil and Water Science, University of Florida, Quincy
James P. Gibbs, College of Environmental Science and Forestry, State University of
New York at Syracuse
Thomas Hrabik, Biology Department, University of Minnesota, Duluth
Patrick Megonigal, Smithsonian Environmental Research Center, Edgewater,
Maryland
Monica G. Turner, Department of Zoology, University of Wisconsin, Madison
John Whitaker, Department of Ecology and Organismal Biology, Indiana State
University, Terre Haute
Strategic Plan for Scientific Research in Isle Royale National Park
I.
Isle Royale as a National Park
A.
Location, Geology, and Vegetation
Isle Royale National Park is located amidst Lake Superior at 47o 60‘ N; 88o 55‘ W. Technically
part of Michigan‘s Upper Peninsula, the Park is closer and shares greater biogeographic affinity
to Minnesota and Ontario. The main island consists of ridges of metamorphic and igneous rock
of Precambrian age that extend to a peak elevation of 1394 feet above the nominal water level of
183 feet in Lake Superior. The underlying geology was scoured by several glaciations, the most
recent uncovering the island landscape about 12000 years ago. The main island is surrounded by
400 smaller islands that vary widely in size (Figure 1).
Figure 1. Isle Royale National Park.
The vegetation of the island contains a transition between boreal forest to the northeast and
northern hardwood forest to the southwest. This transition is not simply a result of climate:
toward the southwestern end of the island, soils show a marked increase in depth and localized
calcareous parent materials promoting hardwood forests. Between many of the ridges lie small
lakes and wetlands that receive internal drainage from local watersheds. During the past 500
years, changes in vegetation appear related to increasing precipitation (Flakne 2003), and today
the vegetation, except on outlying islands, is shaped by the browsing patterns of a large
population of moose.
B.
Brief History of the Park
It is likely that Native Americans inhabited the island throughout the Holocene, and there is
evidence that American Indians mined copper on Isle Royale 4500 years ago. The island was
first visited and claimed by the French in 1671, and became a possession of the United States in
1783. By the mid 1800s, the island supported various mining operations, largely for copper,
resulting in forest harvest for lumber and firewood. It also served as a base for fur trappers and
fishermen. There is a history of natural and anthropogenic forest fire on the island, with a
particularly extensive fire in 1936.
Recognizing its beauty, the philanthropist, Albert Stoll led the effort to acquire all 133,788 acres
of the island, which were deeded to the National Park Service in 1940. Today, there are no roads
on the island; the main and surrounding islands are accessible only by boat, seaplane, canoe or
kayak. The National Park Service maintains a ferry service from Houghton, Michigan to the
park, a seasonal headquarters on Mott Island, visitor centers at the Rock Harbor and Windigo,
and a dormitory for visiting researchers on Davidson Island. There are 165 miles of trails and
various camping areas on the main island, which provide the major access for operations at
potential research sites.
C.
Legacy of Ecological Research at Isle Royale
Isle Royale is home to one of the most well-known and influential studies of population
ecology—the long-term predator-prey interactions between moose and wolf. The arrival of the
moose on the island in the early 1900s was followed by an explosion in its population and a
devastation of its food resources by the 1930s. With the arrival of wolves in the late-1940s,
predation began, and the moose and wolf populations have fluctuated in delayed synchrony for
the past 60 years. This was a powerful, real-world test of the theory of predator-prey relations
postulated by Lotka and Volterra in the 1930s. Presentations of the moose-wolf dynamics at Isle
Royale are found in the pages of many introductory ecology textbooks, and a recent paper
documenting the history of the work to 1994 (McLaren and Peterson 1994) has been cited more
than 120 times. The studies of moose-wolf dynamics continue, with ongoing work to document
the genetic diversity of both populations, the effects of inbreeding, and the tripartite link of
moose and wolves to the condition of the underlying vegetation (Vucetich et al. 2002; Vucetich
and Peterson 2004; Wilmers et al. 2006).
Isle Royale National Park has also provided a research venue for ecological investigations in a
number of other subject areas, including studies of the atmospheric deposition of organic
pollutants and mercury (Czuczwa et al. 1984; Swackhamer et al. 1988), controls of grazing and
herbivory (Bryant et al. 1991; Pastor et al. 1993), biogeochemistry (Stottlemyer and
Toczydlowski 1999a, b; Stottlemyer, Toczydlowski and Herrmann 1998), and the genetic
variation and maintenance of lake trout (Guinand et al. 2003). Annual scientific citations to Isle
Royale research exceed 500 (Figure 2, Appendix A). Outside research funding has doubled in
the past 10 years—to approximately $650,000 annually (Appendix B).
Figure 2. Annual citations to scientific research publications on Isle Royale, accessed from the
Web of Science, July 2008.
D.
Purpose Statement
Purpose statements, outlined in the park‘s General Management Plan (1999), are based on
legislation and legislative history, other special designations and National Park Service policies.
These statements reaffirm the reasons why Isle Royale is a national park and provide the
foundation for park management and use. They are:
1.
2.
3.
4.
5.
E.
Preserve and protect the park‘s wilderness character for use and enjoyment
by present and future generations
Preserve and protect the park‘s cultural and natural resources and
ecological processes
Provide opportunities for recreational uses and experiences that are
compatible with the preservation of the park‘s wilderness character and
park resources
Provide park-related educational and interpretive opportunities for the
public
Provide opportunities for scientific study of the ecosystem components
and processes, including human influences and use and share the findings
with the public.
Park as Critical to Answering Current Environmental Questions
Isle Royale National Park provides a unique, natural laboratory for ecological and environmental
studies. Because of its isolation and pristine conditions, studies can be performed in the Park
that can be done nowhere else. The Park provides a baseline for recognizing and quantifying the
impacts of global environmental change, on climate, on environmental chemistry, and on
biodiversity. The Park has a number of established studies and long-term data sets that are
unparalleled among the nation‘s premier ecological research sites (Appendix C). With limited
species diversity and few exotic species, the Park is an ideal laboratory in which to apply
systems ecology to ascertain the mechanisms controlling the diversity and stability of natural
landscapes. Its isolation makes access difficult, so visitation at Isle Royale National Park is a
robust indicator of the current base-level of societal interest and demand on national parks (cf.
Pergams and Zaradic 2008).
F.
Networking
The Park is one of nine sites participating in the Great Lakes Inventory and Monitoring Network,
which aims to provide accurate inventories of species diversity and monitoring of the population
fluctuations of major groups. For some parks, such as Isle Royale, the monitoring program also
extends to basic chemical parameters of lake water, and all parks inventory changes in regional
land cover and land use that affect park attributes. Many of these data are available via the
Internet now or will be in the near future. (http://science.nature.nps.gov/im/units/glkn/)
G.
Establishment and Objectives of the ―Blue Ribbon‖ Committee
Recognizing the importance of refining a vision for the future of research at Isle Royale National
Park, Superintendent Phyllis Green, working with Ann Mayo-Kiely of the Isle Royale Institute
of Houghton, Michigan, formed a committee of scientists (Appendix D) to visit the Park, receive
briefings on past and current research, and draft a 10-year strategic plan for its research
priorities. The group visited the Park in late August 2008 and completed its task—this report—
in December 2008. The panel was guided by a list of questions submitted by the Park Service
and by access to various, prior planning and management documents, including the Isle Royale
General Management Plan (1999),Water Resources Management Plan (2006), and Natural
Resources Management Plan (1999)
I.
Unique Attributes of Isle Royale National Park
A.
An Isolated Location for Baseline Studies
Isle Royale National Park is a pristine location in which to monitor ongoing, continental
environmental change, and, as an isolated island, the Park allows scientists to see the distribution
of anthropogenic pollutants and the dispersal of both native and non-native species without the
confusion of local sources. As an isolated archipelago of islands and waters with wilderness
character, Isle Royale offers a unique opportunity to conduct research to understand the causes
and consequences of environmental change, minimally confounded by other influences.
Throughout the United States, parks, natural areas and wilderness locations are increasingly
surrounded by human activity that is expanding in area and becoming more intensified. Because
the surrounding landscape can strongly influence local ecosystems (often called the landscape
‗context‘), human activities outside park boundaries influence biotic communities and ecosystem
processes within protected areas. For example, adjacent land-use changes may increase the
invasion of exotic species, alter the connectivity of habitats, change habitat quality, and impact
animals that move beyond protected zones (e.g., by hunting). Thus, land use in the region
surrounding a park can confound long-term studies of population dynamics. The isolation of Isle
Royale ensures that such confounding effects are greatly reduced in ecological studies.
Furthermore, because it is often so difficult to disentangle the effects of climate change from the
effects of land-use change, the isolation of Isle Royale offers a unique opportunity to detect the
climate signal and changes in other environmental parameters, as outlined below.
1.
Isle Royale as a baseline for studies of atmospheric deposition
The interaction between the atmosphere and the underlying surface is increasingly recognized as
an important factor in many studies of regional and global change. Atmospheric deposition
determines many ecosystem properties, in particular acidification, eutrophication of water bodies
due to excess nitrogen, and the bioaccumulation of mercury and persistent organic pollutants
(POPs). Deposition of atmospheric nitrogen to land and water surfaces contributes significant
inputs to terrestrial ecosystems and water bodies, affecting ecosystem health. Critical load is the
amount of deposition above which ecosystem properties are negatively affected and is intended
as a protective threshold. The National Academy of Sciences (NAS) has recommended that the
EPA consider the critical load approach to a wide variety of problems in ecosystem management.
Isle Royale National Park is strategically located in an isolated and pristine setting, offering an
opportunity to study changes in nitrogen, sulfur, mercury and POPs deposition. To the south of
Isle Royale on the US mainland, the Mid-West region has witnessed increased agricultural
activity, especially in the production of corn to meet the national agenda for biofuels. This has
triggered a greater use of synthetic fertilizer, insecticides and pesticides. Vast quantities of
ammonia and POPs are associated with intensive crop production in agroecosystems (Aneja et al.
2008). Moreover, the Ohio River Valley has the largest number of the nation‘s fossil-fuel power
plants, emitting nitrogen oxides (NOx) and mercury. To the north of Isle Royale, the Canadian
province of Alberta is producing oil from oil sands. This anthropogenic activity is introducing
sulfur dioxide and various volatile organic compounds into the environment. These emissions are
significant in magnitude, and subsequently provide inputs of reactive nitrogen, sulfur, mercury,
and POPs to the terrestrial and aquatic ecosystems via atmospheric deposition.
The Community Multiscale Air Quality (CMAQ) model (Byun and Schere, 2006) can be used to
characterize air quality before and after the implementation of a target regulation and to evaluate
relationships between changes in emissions and pollutant concentrations or atmospheric
deposition. Clean Air Act regulations are expected to reduce atmospheric deposition of NOx;
however, ammonia and mercury remain unregulated. Isle Royale provides a unique location to
track changes in the emissions, transport and deposition of these pollutants as sources and
regulations change during the coming decades.
2.
Biogeochemical controls on mercury cycling
Mercury contamination is a widespread cause of surface water impairment in the north-central
United States, where inland lakes are a common landscape feature (Wiener et al. 2006). Isle
Royale is uniquely suited for investigations of why elevated mercury occurs in some inland lakes
but not others. Despite the relatively pristine and remote location of the park, there is a wide
range of mercury concentrations in fish (30-1720 ng g-1 wet weight; Kallemeyn, 2000) that may
be explained on the basis of landscape patterns and biogeochemistry.
Elevated mercury levels have been reported in some inland lakes of Isle Royale, affecting fish,
other aquatic organisms, and loons (Drevnick et al. 2008). Some lakes support pike with mercury
levels that exceed the Michigan advisory level by 3-fold (Swackhamer and Hornbuckle 2004).
Mercury loading itself does not explain the observed variation across lakes and species in the
park (Munthe et al. 2007), nor is it likely to explain trends through time. Other factors include:
(i) geomorphology, soils and hydrology, all of which govern mercury transport from areas of
deposition into lakes (Wiener et al. 2006), (ii) biogeochemical processes that govern the activity
of microorganisms such as sulfate-reducing bacteria which convert elemental mercury to the
bioavailable form, methyl mercury, (Gilmour et al. 1992), and (iii) food web structure that
controls biomagnification across trophic levels (Gorski et al. 2003).
3.
Monitoring of migratory birds
Currently many species of North American migratory songbirds show population losses that
have been attributed to a variety of factors, including habitat destruction in breeding and
wintering grounds, continuing use of pesticides in wintering areas, and climate change (Sauer et
al. 2007). As a pristine and isolated area, with no ongoing or neighboring changes in habitat,
other than by natural succession, Isle Royale National Park can provide an ideal laboratory to
evaluate changes in songbird numbers that may be related to changes in regions of winter habitat
and to global warming. All efforts should be taken to maintain the annual breeding bird survey
at Isle Royale (Egan 2007), perhaps standardizing its methods to the nationwide program
coordinated by the U.S. Fish and Wildlife Service.
4.
Monitoring of climate change variables with little confounding by humans
Measurements of meteorological variables (temperature, pressure, precipitation amount, etc.)
have been made at Isle Royale National Park for many years. These meteorological records
characterize the physical climatology for the region. The continued monitoring of meteorological
variables in this region with little confounding by humans will provide a rich database for
ascertaining trends in climate. For example, local and regional human activities are suspect in
declining winter precipitation on the mainland (Stottlemyer and Toczydlowski 2006), but if these
trends are observed in an isolated natural laboratory such as Isle Royale National Park, one might
be confident that ongoing global changes in climate are responsible.
5.
Current low impact of exotics
Loggers and miners inadvertently introduced non-native plants when bringing livestock to the
island; for instance, apple trees can be found near old camps (Cochrane 1990). However,
compared to many mainland locations, non-native species on Isle Royale are relatively sparse;
only 15% of the plants are exotics (Judziewicz 1995). A re-sampling of the fish communities in
the inland lakes on Isle Royale revealed remarkable stability in species assemblages that suggests
that invasions of non-native species have not been successful (Kallemeyn 2000). Because the
fish fauna appears to remain in an original state, the island's entire indigenous fish fauna should
be protected. Although gypsy moths were observed on the island in 2000, the population in 2007
proved to be all males, and there was no subsequent establishment of a reproductive population
(Alex Egan, pers. comm.). Thus, the plant and animal communities on Isle Royale may be less
susceptible to the processes of biotic homogenization that plague many other areas of the region.
On Isle Royale community dynamics can be monitored in a natural setting; however, vigilance
for detecting the potential colonization by non-native species in the future is warranted.
B.
Isle Royale as an Ideal Place to Study Fundamental Ecological Concepts
1.
Predator-prey interactions
Locally and nationally, studies of moose-wolf interactions are the basis of the Isle Royale‘s
esteemed reputation and provide fundamental understanding for a wide range of ecological
principles. This is the longest-running study of predator prey relations in the world. Ongoing
studies of predator-prey interactions between moose and wolf would benefit from a focus down
one additional level—to studies of primary production (i.e., bottom-up effects)—or perhaps two
levels to include studies of soil fertility (Ca, Na, P, etc). Such foci would allow us to: 1)
understand browsing patterns of moose by incorporating soil parameters into browse models; 2)
understand the role that browsing has on vegetation dynamics; and 3) predict forage amount and
quality on a landscape basis. The overall objective should be to understand how soils influence
plant nutritional value and forage production rate. A number of studies have indicated the need
for this approach (Sirotnak and Huntly 2000; Persson et al. 2005; Anderson et al. 2007; Brathen
et al. 2007; Persson et al. 2007; Virtanen et al. 2008), and existing Isle Royale data sets would
allow immediate investigations of soil-plant relationships.
Isle Royale National Park has a state-of-the-art soil survey that is unique in the world of soil
science owing to its fine scale and detail. The survey includes a large number of field
observations (~2000) as well as soil chemical and physical data related to modal sites. More than
600 observations by Dr. Peter Jordan of vegetation and browsing history can be matched with the
soil survey via GIS in order to develop a browsing preference by vegetation and soil type. These
data make possible a unique, long-term evaluation of browsing preferences to use as a basis for
plant and soil correlations.
Several recent studies show a link between nitrogen in browsing tissues and moose forage
preferences (Pastor et al. 1993, 1999; Persson et al. 2005, 2007). This work provides a
foundation from which to consider forage nutritive value and its relation to soils. In addition to
nitrogen, biogeochemists have long noted that many terrestrial mammals have limited supplies of
dietary sodium, which is much more concentrated in mammalian tissue than in plants. Botkin et
al. (1973) noted that the moose on Isle Royale focused their summertime feeding on aquatic
plants, which have some of the highest concentrations of sodium on the island. Isle Royale is a
unique environment where studies on this causal mechanism could be conducted, establishing
moose as an agent for upland-wetland interactions in the Park.
2.
Connections between land, wetlands and water
Pressing environmental issues ranging from nitrogen eutrophication to emerging populations of
disease vectors require scientists and managers to understand connections across the land-water
interface. Isle Royale is poised to advance ecological theory by bridging the gap between
research focused solely on terrestrial versus aquatic ecosystems. One example is studies of the
influence of beaver on wolf-moose dynamics via their role in creating wetland habitats where
moose forage for aquatic plants. Another example is effects of climate-driven changes in
hydrologic export of dissolved organic carbon that regulate many aspects of aquatic chemistry
(e.g. mercury cycling) and food web structure (Fig. 3).
Figure 3. Isle Royale has features that provide opportunities to further ecological theory. Its
remote location and pristine condition makes it valuable for understanding the effects of external
forcings such as changes in climate, atmospheric deposition of contaminants, invasive species or
disease transmission. There are strong interactions between terrestrial and aquatic systems that
can be exploited to understand landscape-level phenomena such as the effect of dissolved
organic carbon export from wetlands or moose foraging on lake trophic structure. Lower case
text and thin arrows indicate poorly understood processes that can be addressed at Isle Royale
National Park.
Many ecosystems are subject to changes among relatively stable conditions (Holling 1973), and
shifts between these relatively stable regimes may be related to changes in one or more factors
and maintained by directional feedbacks (Scheffer and Carpenter 2003). In most cases,
examinations of regime shifts have focused on anthropogenic stress (Scheffer et al. 2001). The
pristine nature of Isle Royale offers an opportunity to examine the potential influence of regime
shifts due to natural causes or indirect anthropogenic causes such as climate change.
Moose forage heavily on aquatic vegetation during the summer months. Up to 25% of their
annual consumption as adults may come from aquatic plant production (Tischler, 2004). The
removal of aquatic plants alters nutrient cycling in lakes and has the potential to influence
phytoplankton production (Genkai-Kato and Carpenter 2005) (Figure 3). Nutrients taken up by
macrophytes and stored in the associated lake sediments may be mobilized by moose grazing.
The resulting mobilization of nutrients from macrophytes to phytoplankton may increase
phytoplankton production and shift the ecosystem from a low nutrient, clear water regime to a
high nutrient, high phytoplankton (eutrophic) regime (Genkai-Kato and Carpenter 2005). The
shift from the clear water regime to high concentrations of phytoplankton may be brought about
by relatively small changes in nutrient cycling, particularly for phosphorus, which often take
years to reverse (Scheffer and Carpenter 2003).
Reports of recent phytoplankton blooms on Chickenbone and Ritchie Lakes on Isle Royale,
which are known to be used by moose, suggest that there may be a link between moose foraging
and eutrophication. The recent classification of Ritchie Lake as eutrophic by the Great Lakes
Inventory and Monitoring Network may indicate that a regime shift from a macrophytedominated phase to a phytoplankton-bloom phase has already occurred in this ecosystem.
Potential changes in water quality brought about by moose as well as the interplay between
phytoplankton dominance and nutrient cycling offer a rich set of questions that may be best
examined in a remote location such as Isle Royale. A logical extension of these questions would
also include investigations of whether wolves indirectly reduce the overall potential for the
eutrophication of aquatic ecosystems on Isle Royale via predation on moose.
Mercury levels in the biota of Isle Royale are likely to be influenced by dissolved organic carbon
(DOC) export from adjacent wetland ecosystems, sulfate deposition, and pH, as with inland lakes
in Voyageurs National Park (Wiener et al. 2006). Such connections between wetland and aquatic
biogeochemistry have been recognized relatively recently, and Isle Royale has the opportunity to
contribute to efforts worldwide aimed at solving persistent mercury contamination. Questions
that Isle Royale is well suited to address include: will the trend in declining sulfate deposition
reduce mercury methylation and, subsequently, mercury levels in fish (Drevnick et al. 2007)?
Will climate-driven trends in the timing, volume and flow paths of water discharge from Isle
Royale watersheds influence mercury loading into lakes? Do changes in aquatic food web
structure caused by moose, climate or other factors affect mercury biomagnifications? To answer
these questions, Isle Royale needs a program in mercury research that includes monitoring of
atmospheric deposition, water quality in inland lakes, watershed hydrology monitoring, and
mercury biomagnification. The presence of an existing long-term watershed hydrology
monitoring program at Wallace Lake (Appendix C) will be an asset.
3.
Studies of food web theory
In north temperate lakes, the concentrations of phytoplankton and nutrients have historically
been used to describe lake trophic status. Lakes with low phytoplankton standing stock, low
nutrient concentrations and clear water are generally considered oligotrophic, while lakes with
high phytoplankton standing stock, high nutrient concentrations and low water clarity are
considered eutrophic. In most areas, changes in factors influencing trophic status are affected by
human activities such as agriculture, water diversions by dams, and fishing pressure (Beisner et
al. 2003). The relatively pristine conditions found on Isle Royale offer a rare circumstance
where the overall influence of food web configuration on the standing stock of phytoplankton
can be examined, while nutrient inputs and fishing exploitation that typically vary extensively
with human use remain at a consistently low level.
The level of allocthonous, colored DOC found in lakes is an important variable because it can
influence the chemical conditions and light regimes that dictate aquatic processes including the
production of phytoplankton (Engstrom 1987, Gergel et al. 1999, Webster et al. 2008).
Increased DOC limits light penetration and reduces the potential for phytoplankton production
(Figure 3). As a consequence, the level of DOC in lakes is not only an indicator of the influence
of the watershed and associated wetlands on lake characteristics (Gergel et al. 1999), but also a
predictor of the potential response of primary producers in lakes to nutrient inputs, global climate
change, and ultraviolet (UV) radiation (Williamson et al. 1999).
Isle Royale contains lakes with a range in DOC concentrations and the influence of piscivorous
fish. Of the lakes surveyed for fish on Isle Royale, several contain no piscivorous fish, while
others contain one or more piscivorous species. Additionally, the wide range in DOC is
accompanied by relatively consistent phosphorus (P) levels that are generally below 17 µg/liter.
This set of natural contrasts would allow investigations of the role that DOC plays in
determining phytoplankton standing stock and production, while isolating the influence of
human-induced nutrient inputs and food web alterations.
Populations of native aquatic species found in Lake Superior waters of the Park appear to be
mostly unaffected by exotic species. One notable exception to this may be coaster brook trout
that are likely impacted by competing non-native fish species. Pacific salmon and steelhead
(rainbow) trout, which use stream and nearshore Lake Superior habitat, compete for food and
rearing areas with juvenile brook trout. Adult coaster brook trout and lake trout also compete
with non-native salmonids in nearshore and reef areas.
The only non-fish aquatic invasive species found at the Park is the spiny waterflea (Bythotrephes
longimanus), which is limited to Lake Superior waters of Isle Royale. Little is known about the
impacts of this species at the Park, but this exotic zooplanktor can compete directly with juvenile
fish for food. Due to the spiny appendage from which it gets its common name, it is usually not
a good food source for very early lifestages of many fish species.
C.
Isle Royale as an Island and Island-Archipelago
Isle Royale represents a complex system of islands within a landmass remote from the mainland.
There really is no comparable nested array of ―islands within islands‖ in temperate North
America, outside of the rainforest archipelagoes of the British Columbia coast. As such, Isle
Royale is unusual as a natural laboratory in which to study questions about the geography of
nature. Isle Royale attracts biogeographers, whose focus is the distribution of life forms as
determined by the balance of regional dispersal and local extinction processes (MacArthur and
Wilson 1967, Barbour and Brown 1974). Determination of the relative importance of both
dispersal and extinction is of central interest to ecologists wishing to explain variability in the
species diversity of a given environment and the potential changes brought about by
environmental change.
As components of a terrestrial environment, lakes and ponds are islands of water that offer an
array of habitats that differ in immigration and extinction rates for particular groups of organisms
(Magnuson 1976, Hrabik et al. 2005). The ability of organisms to disperse to new aquatic
environments is controlled by their ability to travel overland or to use the connections of the lake
or pond to others via surface drainage systems. For example, fish are largely restricted to
dispersal among lakes and ponds via surface water connections. Conversely, aquatic insects with
flying adult stages, amphibians, aquatic plants with airborne seed dispersal, and organisms
resistant to desiccation may more readily disperse among adjacent isolated lakes.
The extinction rates of organisms are most often associated with the size of the island, the
diversity of habitats found therein, the disturbance regime and the potential of the environment
for biological productivity (Rosenzweig 1995). Magnuson et al. (1998) examined the relative
influence of isolation and found that variability in fish species richness in lakes was most
associated with extinction variables (e.g., habitat severity, area and productivity). In a set of
lakes with benign conditions (no hypoxia or low pH) and contrasting levels of ground water flow
and stream connections (routes for immigration and dispersal), the richness of four taxonomic
groups including macrophytes, aquatic invertebrates, snails and fish was most strongly
influenced by variables related to extinction (Hrabik et al. 2005). The findings of each study
were consistent in identifying the importance of extinction processes on aquatic organisms and
the potential role of hydrology as a determinant of the richness of aquatic community. However,
the lakes examined in both studies have a long history of human use.
Isle Royale National Park contains a variety of lake and pond ecosystems that are much more
isolated from human activity than those found on the mainland and that may be unique in other
ways. Thus, the lakes and ponds within the Isle Royale archipelago represent an ideal laboratory
for investigations of the processes controlling dispersal and extinction that govern aquatic
communities without the confounding factors of human-aided dispersal, habitat manipulation, or
exploitation of aquatic organisms. Among the larger lakes, the ionic strength of the lakewater is
remarkably consistent and relatively high (ionic strength > 50 μS) (Kallmeyan 2000). Thus, the
geology of Isle Royale in combination with its isolated location and designation as a National
Park offers a location in which to study aquatic ecosystems where key extinction variables (e,g.,
ionic strength) and human-aided dispersal are held constant and the processes controlling
dispersal should be most apparent.
There are several prevailing questions in biogeography for which Isle Royale could serve as a
model system for inquiry. The first is diversification of life forms. Isle Royale is in many ways
an ideal place to examine microevolutionary processes given the large array of islands of
different sizes (hence effective population sizes) and degrees of isolation (hence opportunities for
migrant exchange). Moreover, the simplified communities present on Isle Royale create an
unusual opportunity to examine multiple taxa simultaneously undergoing diversification
processes and, most importantly, to understand how interactions among species mediate
evolutionary processes within lineages, a largely unexamined area of evolutionary biology.
Simplified communities in the complex geographic array also create opportunities for testing
models predicting species turnover on islands (e.g., dynamic equilibrium theory) because
relatively low diversity permits straightforward enumeration of pattern across large numbers of
variously arrayed and potentially interacting populations.
The limited extent of biological invasions in the Isle Royale system also permits understanding
biogeographical processes in an increasingly rare natural or ―uninvaded‖ biological community.
As such, Isle Royale can serve as a reference area for better understanding of invasions on the
mainland, where invasive species are far more pervasive. Given that future invasions are
inevitable, baseline biogeographical studies at Isle Royale can also create the opportunity for
studies comparing the effects of invasions in different taxonomic groups and resulting changes in
diversity at local and regional scales. Such studies would allow tests of recent hypotheses that
indicate invasive species sometimes cause very little extinction, and thus result in an increase in
local diversity. Isle Royale could also be an ideal place to understand biogeographic processes in
the context of climate change because immigration of many species to the archipelago as well as
movements within it is strongly mediated by ice cover, which is known to be changing. The
replicated array of variously distributed island populations further represents a model system to
understand disease spread/vector movement unavailable in more complex, mainland
environments.
The nested, insular nature of Isle Royale makes it a useful location to continue studies of small
population phenomena. In particular the consequences of loss of genetic variability and
inbreeding and associated inbreeding depression are important issues in conservation biology,
especially for endangered species management. Studies of inbreeding depression in captive
breeding programs suggest inverse correlation between population genetic variation and (1)
incidence of genetic defects, (2) levels of mortality, and (3) ability of wild populations to adapt
to environmental change. In contrast, theoretical models and a number of studies of wild
populations have suggested that genetic issues are often preempted by ecological problems and
demographic and environmental risks. Studies of wolves on Isle Royale are helping to resolve
differences between these two long-standing and competing perspectives about the importance of
inbreeding on population persistence. This research, if continued and profitably expanded to
other taxa, would enable Isle Royale National Park to manage rare, high profile species of much
interest to visitors (e.g., wolves, martens) while further contributing to this area of conservation
biology important to endangered species management everywhere.
1.
Do birds determine insect community composition?
Currently ecologists are devoting much attention to the importance of species diversity in
influencing ecosystem function and the provision of ecosystem services to humans. We don‘t
know, for instance, whether birds are an essential component of forest ecosystems, which would
otherwise succumb to insect attack in their absence. The diversity of small islands that are found
at Isle Royale could allow ecologists to examine whether there are fewer birds on smaller
islands, which might then harbor a relative greater abundance of insects.
2.
How fast will new species and attributes arrive with climate change?
Global climate change will likely alter the ranges of a variety of exotic and native aquatic
species. Native species may be impacted not only by the invasion of exotic species, but also
parapatric species that extend their range into new areas (Rahel et al. 2008). Intensive grazing by
herbivores may modify changes in vegetation that would be predicted solely by changes in
climate (Post and Pedersen 2008). The temperature and of the region and of Lake Superior has
changed markedly over the last two decades (Austin and Coleman 2008). With changes in local
climate, there will likely be extinctions of aquatic organisms adapted to cooler temperatures and
invasions of exotic and native organisms that are extending their ranges. Changes in the
composition and species richness of aquatic ecosystems associated with climate change may be
identified more readily on Isle Royale than on mainland areas because of its isolated nature and
unique sets of conditions. Future studies could make explicit comparisons between:
a.
b.
c.
d.
D.
Natives vs. exotic species;
Birds vs. the insects they feed upon;
Herbaceous weeds vs. tree seedlings;
Changes in vegetation vs. soil properties.
Isle Royale as a Transitional Location
1.
Sentinel species indicating ecological sensitivity to climate change
Isle Royale provides a natural laboratory to document changes in species distribution in response to
climatic change because of few confounding influences of human land-use, of the lack of exotic species,
and of its location at the transition between the temperate deciduous and boreal coniferous forest
biomes. Because of tight linkages to vegetation, many animal species show range boundaries that
coincide with vegetation. As climate warms, many of these species are expected to move northward.
Isle Royale provides a unique opportunity to document both the arrival of new species and the potential
disappearance of boreal species, such as the Mink Frog, that are rare at the southern limits of their range.
Improved understanding of the climatic responses of species at Isle Royale, in the absence of large
confounding effects of land-use change and exotic species, can be used to develop general models of
biological sensitivity to climate that may have broader applicability.
Historically, Lake Superior contained many populations of a lake-dwelling or ―coaster‖ variant
of brook trout (Salvelinus fontinalis) that provided a valued and productive sport fishery in the
late 19th and early 20th centuries. Coaster brook trout are defined as those populations that
contain individuals that spend a portion of their lives in the lake outside of natal stream habitats.
Overexploitation and habitat degradation reduced the number of viable populations to such an
extent that rehabilitation efforts are now focused on restoring this once productive fishery
(Newman et al. 2003). While coaster brook trout still exist within the lake, viable populations
are thought to persist only in a few locations in Canada and on Isle Royale (Gorman et al. 2003).
One of the primary factors that limits the recovery of coaster brook trout populations is the
availability of quality in-stream habitat for spawning and rearing young (Newman et al. 2003).
Global climate change is strongly affecting the ice cover regime and thermal budget of Lake
Superior (Austin and Colman 2007) and has the potential to influence the water level of lakes
and streams found on Isle Royale. The streams used by coaster brook trout on Isle Royale are
small and will be strongly influenced by changes in the regional climate. Monitoring of not only
the levels, but the in-stream characteristics of streams used by coaster brook trout, will be
essential to preserving these populations and to recognizing the influence of climate change.
2.
Temporal disjunctions in arrival and phenology
The success of herbivores such as moose, song birds, and plant-eating insects usually depends on the
tight linkage between availability of nutritious food and the growth and development demands of
herbivores. These links are likely to be disrupted by climate change if the plants, herbivores, and insectfeeding birds differ in their response to climate. For example, if plants leaf out and develop toxic
defenses against insect herbivores earlier than their insect herbivores, this may reduce population sizes
of these insects and the song birds that depend on them for food. Similarly, if insects and birds migrate
northward more rapidly than do plants, their cues for emergence and reproduction may differ from those
of local vegetation. Isle Royale provides the perfect laboratory to test for these ―phenological
disconnects‖ because patterns of climatically induced migration are less confounded by land-use
changes that dominate mainland ecosystems.
E.
Isle Royale as a Laboratory to Test Climate Feedbacks
Understanding the causes and consequences of climate change is one of the greatest challenges facing
humanity. There is abundant research on global patterns of climate change (IPCC 2007), but these
changes are usually substantially modified at the local scale by processes such as water and energy
exchange, particulate matter emissions, and gas-to-particle transformations, which exert their greatest
effects locally (Field et al. 2007). Local changes in these factors can either amplify or compensate for
globally-driven changes in climate (Chapin et al. 2008), although predicted patterns have rarely been
validated with observations because of the complex interactions between natural and anthropogenic
processes. Local climate determines the actual climate that society must deal with, so the ability to
project local climate is a key step in making global projections useful for policy makers and managers.
Isle Royale provides an ideal opportunity to examine these local climate feedbacks because of the
striking differences between land and the surrounding water. We highlight two research areas where Isle
Royale provides a unique opportunity to improve general understanding of local-scale climate
feedbacks.
Does the island effect on ice cover in Lake Superior influence the ―lake effect‖ on snowfall at Isle
Royale? This snowfall is important because of demands placed on winter road maintenance and because
winter snowpack strongly influences water availability the following summer. During winter the island
protects the waters north of Isle Royale from water currents that typically break up any ice that forms on
the surface of Lake Superior. This allows an ice bridge to form between the island and the mainland to
the north. Lake ice covers the surface and prevents evaporation of lake water that would fall as snow on
Isle Royale or the Upper Peninsula of Michigan (i.e., ―lake-effect‖ snow). The strong regional trend in
winter warming in the last 30 years has reduced winter ice cover on Lake Superior as a whole and in the
channel between Isle Royale and the mainland to the north. We would expect this to increase the amount
of lake-effect snow. Weather records on Isle Royale and the Upper Peninsula of Michigan of monthly
and interannual variation in snowfall could be compared with satellite records of ice cover north of Isle
Royale and for Lake Superior as a whole to test whether this local climate feedback is important.
Documentation of such an effect would improve forecasts of winter snow events and patterns of spring
flooding and summer water supply.
Does the island effect on ice cover in Lake Superior, or the successional changes in vegetation on Isle
Royale, influence the rate of winter warming at Isle Royale? Lake ice that persists long enough to
accumulate snow increases the albedo (reflectivity) of Lake Superior (replacing a dark water surface by
a more reflective ice/snow surface), which reduces energy absorption and therefore the heating of local
air (causing local climate cooling). The putative decline of winter ice cover may have already
contributed to recent increases in winter temperature. This idea could be tested by comparing warming
trends upwind of Lake Superior (e.g., northern Minnesota) with trends on Isle Royale and the Upper
Peninsula of Michigan. Regional variation in warming could be compared with patterns of lake-ice
disappearance.
The two questions above illustrate just two of many potential questions that can be addressed
through comparisons of ecological processes with remote sensing records. We strongly
recommend that Isle Royale obtain a time series of aerial photographs (e.g., 1930 to present) and
Landsat satellite images (e.g., 1970s to present) that can be compared with ground observations
of soils, vegetation, moose browsing, and other changes documented within the Park. These
records can be made available to scientists interested in long-term changes on Isle Royale.
F.
Isle Royale as a Laboratory to Study Climate Change Impacts on
Biogeochemistry
Isolation from land use change is the greatest asset of Isle Royale as a field laboratory for
measuring effects of climate change. Climate models predict that future drier conditions are
expected to prevail in this region. This appears to be happening based on recent measurements
showing warmer winters, earlier snow melt, later snow cover and reduced November
precipitation (Stottlemyer and Toczydlowski 2006). Isle Royale is well situated to define the soil
and vegetation types expected to be most sensitive to change as they react to water stress. Isle
Royale can be surveyed with respect to water-holding capacity of soils and categorized into
potentially high, medium and low soil-vegetation combinations relative to their response to
decreasing moisture and increasing evapotranspiration. Continued monitoring can ask whether
and to what degree these categories are exhibiting expected stresses.
Isle Royale is well-suited to this approach because:
1.
2.
3.
The soil survey for Isle Royale, along with the historical vegetation data
and the new monitoring effort, provides a unique database for identifying
the soil-vegetation groupings mentioned above. The Park also has a
mechanism for continued long-term monitoring of environmental change
and biotic characteristics susceptible to change through the Inventory and
Monitoring program.
These data sets can not only be used to ascertain change but are suited for
a spatial analysis over time making them unique in the world of climateeffect monitoring.
Because Isle Royale is at the interface of the boreal and temperate forest
biomes, we expect the influence of climate change to become apparent
here, and with more certainty, than in other locations deeper within the
continent.
Locally, observations of change at Isle Royale should relate directly to predicting the expected
changes in the moose-wolf relationships on Isle Royale. Nationally, the observations should be
useful to the entire scientific community in the debate on global climate change.
Soil temperature regime is another target of most climate change scenarios. Soil temperature is a
major driver in the soil biogeochemical cycle, particularly in northern climates where the annual
temperature ranges from below freezing to temperate summer readings. However, since seasonal
soil temperature is controlled by the snowpack, it is unclear in what direction winter and summer
temperatures will move with time.
If one considers winter soil temperatures, a later snowpack, as seems to be the trend at Isle
Royale (lower November precipitation and later snowpack), should induce soil freezing earlier in
the season and to a greater soil depth. An expected consequence of this would be a later spring
thaw of frozen soil; yet how this interacts with a warmer climate needs to be better modeled.
Increased soil freezing has been shown to increase soil nitrogen and phosphorus release either
from soil disturbance and death of overwintering fine roots (Fitzhugh et al. 2001; Groffman et al.
2001) or from mineralization (Callesen et al. 2007, Christopher et al. 2008). While the former
seems more in line with established theory, the question remains to be answered as to what is the
effect of soil freezing changes related to climate change. The answer, combined with the large
quantity of water available from snow melt to move released nutrient rapidly off-site, is an
important component of biogeochemical cycling in northern climates over the long-term.
Lower temperatures and deeper soil freezing will impact spring and summer soil temperatures. It
is well-known that soil temperature above freezing influences the rate of N mineralization, with
higher temperatures increasing mineralization rates (Cookson et al. 2002). What is not well
understood is the complexity of soil temperature changes induced by snowpack changes and the
resulting effect on N and P biogeochemical cycling, off-site movement of N and P, and their
influence on surface water quality. Isle Royale appears to be an ideal location to study these
changes in the absence of anthropogenic effects such as land-use change. Results from Isle
Royale studies would be directly applicable to snowpack change issues throughout the region.
Questions to ask are: How are seasonal soil temperature regimes influenced by the change in
snowpack formation? How does soil freezing degree and depth change the form and rate of
change of pools of N and P? How does snowpack hydrology move mobile and non-mobile N and
P pools to surface waters? In an increasingly warmer climate, to what degree are summer soil
temperatures and N and P mineralization influenced?
Climate change induced hydrologic and temperature changes are expected to change the organic
matter dynamics of wetlands, hence influencing associated surface waters. The connections
between wetlands and aquatic systems have already been outlined above; but the questions
related to biogeochemical cycling within wetlands are a potential feedback to climate warming
through release of GHGs as well as the movement of DOC to aquatic systems. Assuming a
climate change scenario where precipitation is reduced, models predict that CO2 from organic
matter decomposition would double as would loss of total organic matter (Clair et al. 2002). A
drier climate would result in reduced hydrologic export of DOC to aquatic systems as well as
reduced dissolved organic matter loads (Schiff et al. 1998). It is also reasonable to assume that
reduced hydroperiod accompanying a drier climate creates conditions for more organic matter
decomposition by enhancing the oxygen environment, if only seasonally. The feedbacks are
complex, making Isle Royale National Park an ideal location to study interactions between
organic matter, hydrology and temperature that are modified by a changing climate. For
example, elevated CO2 has recently been linked to increased organic matter decomposition in
wetlands mediated by O2 released from the roots of wetland plants (Wolf et al. 2007). The
questions that can be posed at Isle Royale without the interference of land use changes are: What
are the linkages between hydrology, temperature, snowpack and organic matter dynamics in
wetlands? What are the off-site effects to aquatic systems resulting from these linkages?
G.
Human Dimensions of Resource Use in the Park
Lands of the National Park Service are administered under a dual legal mandate that requires
managers to balance resource protection while providing recreation opportunities to park visitors.
In many parks, scientific research activities and recreational visitation are regarded as largely
independent, occasionally competing, and sometimes conflictive activities. Investigations of
human use often focus on visitor impacts to Park resources, as has been the case at Isle Royale
(e.g., Marion and Farrell‘s (2002) research on camping impacts on vegetation). Although
ecological research programs and the results they generate provide important materials for use in
the Park, natural interpretation programs rarely make any formal attempt to understand the nature
of interactions between research activities and overall visitor experience, which may well be
positive and synergistic.
Isle Royale is unusual within the National Park system in having substantial overlap in the
interests of scientists and wilderness recreational enthusiasts; moose and wolves are a major
draw to both tourists and scientists. What would visitation be, both in terms of quantity and
quality, at Isle Royale if not for the moose-wolf story? What are the perceptions of visitors
regarding research, researchers, and appropriate levels of research activity on the Island? Does
ongoing research in wilderness areas enhance or detract from perceptions of the ―wilderness
experience‖ of visitors? Is there a carrying capacity for research activity in a wilderness park? If
so, how much research is too much? What role should the Park Service play in promoting
research to improve visitor experience? We suggest that useful studies could use visitor surveys
to determine what influence research programs have on the experience of wilderness users and as
well as to assess visitor opinions of the role of the Park Service in facilitating research. Such
would be a contribution not only to the management of Isle Royale but also to managers
throughout the Park system who try to understand the contributions and associated costs of
scientific research and to balance resource protection with recreation opportunities for visitors.
Another productive research focus for Isle Royale in the area of human dimensions of resource
use may relate to wildlife habituation to human presence, which is an emerging issue in many
North American parks (Kloppers et al. 2005), with implications for both ecological processes
and public safety. From an ecological perspective, human-habituated wildlife can form unnatural
concentrations where they receive artificial refuge from predation, thereby altering predator-prey
relationships. From a public-safety perspective, habituation can also result in attraction of
dangerous predators to human-use areas leading to unwanted interactions with humans.
Anecdotal evidence of recent wolf-human interactions and moose use of high human occupancy
areas on Isle Royale suggests that wildlife habituation issues may be a germane focus of further
investigation. Inquiry into animal habituation at Isle Royale may be warranted given the latent
concern about the issue, the costs of not anticipating possible unwanted problems, and the need
for clear delineation of appropriate response should any undesirable interactions occur.
―Appropriate‖ response refers to ecological and social consequences for the problematic species
as well as what is ethically acceptable to the visiting public.
II.
Summary and Prioritization of Research Directions
Priorities for future research identify key contributions toward development of a more complete
functional understanding of Isle Royale as an ecosystem. Here, we list 10 questions that build on
the foundation of research and represent key opportunities for new research. These questions are
prioritized in terms of their readiness to provide insights of broad scientific importance (i.e., lowhanging fruit). Some of the questions listed later in this section would also provide significant
contributions but would entail greater effort to initiate new programs.
What explains the spatial and temporal dynamics of vegetation on Isle Royale?
Rationale: Numerous different (and largely uncoordinated) studies have collected vegetation
data on Isle Royale, resulting in a very important but untapped resource for understanding forest
dynamics. This understanding is needed for considering how the Isle Royale biota may respond
to changing climate. Interpretations to date appear to have focused almost exclusively on moose
browse—both the availability of browse and the depletion of preferred plant species. However,
the forests reflect the influences of many interacting factors, including soils, climate,
disturbances (windthrow, fire, and native pests such as spruce budworm and spruce beetle) and
the mosaic of historic land use, as well as moose herbivory. The recently flown LIDAR data
could be an important resource for understanding spatial variation in forest structure. The historic
vegetation plots could provide key long-term data on how vegetation is changing.
Strategy: If existing data were made available for analysis and synthesis, a PhD student could
develop this into a dissertation, or a postdoctoral researcher might analyze and publish these
data. In either case, direction provided by an active forest ecologist familiar with northern forests
would be key for completion. There also should be ongoing vegetation sampling. For example,
it would be ideal to have all 82 currently established FIA plots re-sampled repeatedly in the
future.
What are the implications of shorter/milder winters on the biota of Isle Royale and on
ecosystem processes such as primary production and nutrient cycling?
Rationale: Long-term climate data on Isle Royale demonstrate substantial changes in
temperature and precipitation on Isle Royale, with precipitation declining by ~15% and
temperatures increasing especially in November. Broad regional climate trends may be modified
by local climate feedbacks related to changes in albedo and lake-effect snow. The 5˚C increase
in November temperature is associated with a later-developing snowpack, and warming in early
spring is associated with earlier snowmelt and an increase in the number of days that ephemeral
streams are dry. The implications of these changes may be pronounced for biota (e.g., increased
overwinter survival of temperature-sensitive pests, increased tick loadings on moose, greater
freezing of soils, changes in hydrology, etc.). Furthermore, there may be substantial changes in
the timing of nutrient inputs to aquatic ecosystems and to rates of nutrient cycling in terrestrial
habitats.
Strategy: Assemble and maintain a time-series of environmental and biological data for Isle
Royale in a centralized database as part of the Great Lakes Inventory and Monitoring Program.
Encourage researchers, especially graduate students and postdoctoral fellows, to explore
correlations between climate and potential environmental and biotic responses. This will require
collaboration with ongoing research efforts because many of the important climate impacts may
involve complex interactions or thresholds (e.g., the winter temperature effects on moose
mediated by moose ticks).
What are the implications of its isolated location for trends in biodiversity on Isle Royale?
Rationale: Isle Royale represents a nested array of ―islands within islands‖ remote from the
mainland with simplified and largely ―uninvaded‖ biological communities. As such, the area is
highly unusual in temperate North America and holds a special attraction for biogeographers and
population biologists to focus on:
Microevolutionary processes, especially interactions among species simultaneously
undergoing diversification processes
Testing models predicting species turnover on islands
Community dynamics in a largely ―uninvaded‖ system
Biogeographic processes in the context of climate change
Consequences of loss of genetic variability and inbreeding and associated inbreeding
depression on population persistence.
Strategy: Although feasible as piece-meal studies, an omnibus research program cataloging
island-by-island distributions of an interacting assemblage of high- versus low-density, poorly
versus well-dispersing, and animal versus plant species, as well as characterizations of
population genetic structure in a subset of them, over an approximately decade-long period,
would likely generate major advances in biogeography along many of the research lines outlined
above. Isle Royale National Park might encourage a workshop or symposium attended by
researchers in these fields to initiate a program in this area.
What are the consequences of human-wildlife interactions for both the visitors and the
wildlife populations? How can the synergy between a good research program and the
visitor experience be enhanced?
Rationale: Because Isle Royale is unusual within the National Park system in having substantial
spatial and taxonomic overlap in the focal subjects of both wilderness recreational enthusiasts
and scientists, there is great opportunity to examine the nature of interactions between research
activities and overall visitor experience. Interactions between visitors and wildlife also may be
leading to mutual habituation with undesirable effects on both. Therefore productive research
lines to address these issues are as follows:
What are the perceptions of visitors regarding research and researchers and
appropriate levels of research activity?
Does ongoing research in wilderness areas enhance or detract from perceptions of the
―wilderness experience‖ of visitors?
Is there a carrying capacity for research activity in a wilderness Park?
Is wildlife habituation to human presence an emerging issue for Isle Royale? If so,
what are the costs and options for dealing with unwanted problems associated with
wildlife habituation in a manner ethically acceptable to the visiting public?
Strategy: Visitor surveys could be used to determine what influence research programs have on
the quality of experience of Park visitors and to assess visitor opinions of the role of the Park
Service in facilitating research. Wildlife habituation issues could be examined through
expansion of ongoing research on wolves, moose and loons to bring focus on their behavior and
interactions and demographic and ecological consequences in high- versus low-use visitation
areas.
How do trophic dynamics, especially moose herbivory and loon feeding affect aquatic
ecosystems?
Rationale: Several of the most successful research programs on Isle Royale have been developed
in isolation from one another and have potential to make more profound scientific contributions
if critical connections among these studies could be explored. For example, studies of wolfmoose interactions have focused primarily on terrestrial vegetation. However, fluctuations in
moose population size are likely to affect aquatic ecosystems, including wetlands and lakes,
because of direct herbivory on macrophytes and physical disturbances in the littoral and riparian
zones. The reduction in littoral vegetation and trampling of the riparian zone and near-shore
benthos can have effects that cascade through the aquatic food web and could potentially change
lake state. Similarly, the loon monitoring program has demonstrated an abundant population
nesting on numerous inland lakes, and fish consumption by loons could exert a strong top-down
influence on aquatic communities, but this connection has not yet been explored.
Strategy: Addressing these questions requires coordination and co-location of aquatic studies
with studies of moose and/or loon abundance. Tackling the effect of moose on aquatic
ecosystems would be an ideal PhD dissertation topic; the effect of loons on the inland lakes
would make a good Masters thesis.
How does water flow through the Isle Royale ecosystem, and how does hydrology act as a
master variable for both the terrestrial and aquatic ecosystems?
Rationale: Hydrology is perhaps the most fundamental variable to understand from an
ecosystem or landscape perspective. It links climate, vegetation, soils and aquatic ecosystems
and strongly regulates organisms. Climate-driven changes in hydrology will mediate many of the
effects of climate change in the region and in the park itself. At present, hydrology at Isle Royale
is not well understood and is more complex than descriptions of the park suggest. For example,
the new soil map indicates that deep soils are more extensive than previously identified, which
will influence the storage and discharge of groundwater into lakes and streams. The island
appears to have both seepage and drainage lakes, which will respond differently to climate
change. The ratio of runoff to precipitation is increasing in the Wallace Lake watershed, even as
precipitation itself is declining. Understanding the current hydrology of Isle Royale is a key
component of anticipating other ecological changes in response to climate.
Watershed monitoring can help the park understand how changes in climate will affect the water
status of forests and downstream aquatic ecosystems. The park is fortunate to have a long-term
watershed study at Wallace Lake that can help unravel causal links between climate, vegetation,
soils and aquatic ecosystems (Figure 3).
Strategy: A robust program for monitoring hydrology should include reinstating the USGS
hydrologic benchmark station at Washington Creek (station 04001000). This station
complements one of the Wallace Lake watershed monitoring studies, which will need to find
support and new collaborators in order to continue. The park can encourage Dr. Stottlemyer to
sponsor a PhD student to analyze and publish the existing data, and to make the data available to
other researchers. The USGS can be approached to cooperate with the park in funding a study of
groundwater dynamics. Additional monitoring of stream flow should include streams frequently
used by known coaster brook trout populations.
What is the biogeochemistry of mercury on the island?
Rationale: Bioaccumulation of mercury in fish and piscivorous birds (e.g., eagles and loons) is
of concern, but unraveling the cause-effect of mercury in the food chain requires going beyond
simple analyses based on deposition rates. Mercury deposition has declined, but its legacy is still
stored in the sediments. In the presence of sulfate (SO4), sulfate-reducing bacteria produce the
biologically active form of this metal, methyl-mercury. Thus, it may be the deposition of sulfate
or its continuing release from sediments or substrate that explains the ongoing bioaccumulation
of mercury. Understanding the biogeochemistry of mercury is key to managing contaminant
levels in focal species and edible fish. It will also contribute to efforts worldwide to explain
ongoing mercury cycling and bioaccumulations.
Strategy: A PhD student or post-doc with biogeochemical training could study sulfur, iron and
dissolved organic carbon chemistry on the island, its relationship to changing deposition of
mercury (both wet and dry), sulfur and sulfate, and precipitation.
How do changing amounts and sources of nitrogen (N) affect Isle Royale ecosystems?
Rationale: Long-term data indicate that total N deposition, while showing year-to-year
variability, has not changed appreciably during the past 25 years. The estimated deposition rate is
4 kg N ha-1 yr-1; however, because nitrate deposition declined following implementation of The
Clean Air Act, it is likely that ammonium deposition has increased due to intensified agricultural
activities. The long-term consequences for substantial N deposition for N and C cycling and for
the biota and aquatic ecosystems are not known.
Strategy: Measurements of meteorology, gaseous NOx, NOy, NH3, fine particulate matter, and N
wet deposition monitoring and CMAQ modeling can provide the relationships between changes
in N emissions and pollutant concentrations on atmospheric deposition.
How are “sentinel species” changing, and what factors drive changes in the presence or
abundance of these key species?
Rationale: Certain species on Isle Royale may serve as sensitive indicators of environmental
change, especially climate change because the Park is not strongly influenced by anthropogenic
influences such as land-use change or propagule pressure from non-native invasive species.
Birds and amphibians that currently reach the northern limits of their North American range are
particularly attractive candidates for study.
Strategy: Studies of sentinel species can be coordinated with ongoing monitoring efforts (e.g.,
annual bird, amphibian and loon censuses), and with the regional network of inventory and
monitoring by the Park Service. The key here is to assure rigorous data analysis and publication.
How will changes in the abundance of pests and pathogens cascade through the Isle Royale
ecosystem?
Rationale: Several native pests and pathogens are present on Isle Royale, but changes in the
frequency or severity of outbreaks would have substantial implications for the host ecosystems.
These include forest pests (e.g., spruce budworm, which is a defoliator, and spruce bark beetle,
which is a wood-boring beetle), mammalian pests (e.g., moose ticks that are having an increased
effect on moose since 2001), and others.
Strategy: Assemble and maintain a time series of species abundance data, especially for pest
species and for keystone species such as balsam fir and moose. Maintain an active monitoring
program for pest species that occur regionally, but have not yet established populations on Isle
Royale (e.g., gypsy moth). Develop action plans for addressing the arrival of potential pest
species. These action plans might range from simply monitoring impacts to active efforts to
prevent establishment of new pests, as is currently done with exotic plant species that are thought
to be transported by people.
IV. Priority Recommendations for Science Management
A. Maintain and extend critical external relationships to networks and university
researchers to draw on expertise that is currently not available at the Park. Park
personnel and lead investigators should make every effort to participate in research
networks and to advertise the availability of Isle Royale as a research site.
Partnerships between the Park and outside researchers have been a key ingredient in
leveraging long-term monitoring programs into high-impact and compelling
ecological science. The Park should be proactive in seeking new partnerships to
address the priorities identified here, and to facilitate continuity to programs as past
partners retire.
B. Maintain financial support for and expansion of ongoing studies of moose-wolf
dynamics at Isle Royale. There is no firm financial basis for the long-term
monitoring of moose and wolf populations on the Island. Research funding from the
National Science Foundation must necessarily focus on new initiatives and
hypotheses, rather than maintaining the baseline monitoring program.
C. Encourage the analysis and integration of current monitoring of changes in
vegetation. The enormous datasets from several historical and ongoing studies of
vegetation need to be synthesized, allowing insight to the role of moose, climate, and
soils in controlling the composition and dynamics of vegetation and providing a
baseline for understanding the role of moose and/or climate change in future changes
of vegetation.
D. Establish a common GIS-based database for geology, soils, vegetation (several
studies), moose population density, and other data, and acquire personnel to curate
these data. Nearly all projects would benefit from the availability of a Geographic
Information System to provide overlay maps of important environmental variables on
the Island.
E. Monitor and determine atmospheric deposition (both wet and dry) of N, S, Hg and
POPs and their impact on aquatic and terrestrial components of the Isle Royale
ecosystem. The Park needs to reestablish its historical measurements of atmospheric
deposition of key constituents and to monitor concentrations of toxic substances in
key populations.
F. Synthesize studies of loon population dynamics for developing and revising best
management practices for this species. Several intensive studies of loon populations
and trends in their body burdens of mercury are in need of synthesis and publication.
G. Synthesize and publish the long-term hydrology and biogeochemistry data sets from
Wallace Lake watershed. Give particular attention to the influence of climate
variability and implications for watershed-level changes due to climate change.
Develop a strategy for long-term support of the watershed monitoring effort and its
integration with complementary research at ISRO such as mercury cycling and moose
foraging in wetlands.
H. Develop synergies within monitoring programs by encouraging co-location of
ongoing monitoring efforts to the extent possible so that opportunities for
correlational analysis among monitored indicators are enhanced. Many research
projects would benefit from the results of parallel studies if the data were gathered at
common, spatially explicit sites.
I. Fund several Isle Royale postdoctoral scholars to help spearhead science synthesis of
Park data. Several existing datasets, especially of vegetation and Wallace Lake
watershed biogeochemistry, are ripe for synthesis and publication by doctoral-level
personnel.
J. Identify or build partnerships that can supply basic statistical/biometric expertise to
all projects. Long-term studies of climate, vegetation, and other environmental
variables need sophisticated statistical examination through trend and intervention
analysis, which should be available and applied to many of the studies being
conducted on the Island.
K. Organize regular meetings of Isle Royale investigators to share progress and ideas
and to promote synthesis of well-established projects. All Long-Term Ecological
Research (LTER) sites organize periodic meetings of cooperating investigators to
share their excitement of new findings and ideas for integration and future research.
L. Establish a standing Research Advisory Committee (RAC)
1.
To help screen unsolicited research proposals
2.
To help identify critical new members of the Isle Royale research team—
the need to be proactive, not just reactive
3.
To evaluate research priorities and progress on an ongoing basis
4.
Establish mandate for publication of previous Park-sponsored research in
peer-reviewed outlets as criterion for consideration for future sponsoring.
M. Establish a Friends of Isle Royale National Park (FIRNP), as supporters and donors to
the research program on the Island. This program could be run by volunteers who
could organize a program of speakers on research at Isle Royale to visit major cities
(e.g., Chicago, Minneapolis, Duluth), where there is likely to be a large base of
philanthropically-minded people.
Appendix A. References and selected important peer-reviewed scientific publications on Isle
Royale National Park
Anderson, T.M., M.E. Ritchie, E. Mayemba, S. Eby, J.B. Grace and S.J. McNaughton. 2007.
Forage nutritive quality in the Serengeti ecosystem: the role of fire and herbivory. American
Naturalist 170:343-357.
Aneja, V.P., W.H. Schlesinger, and J.W. Erisman, 2008. Farming Pollution. Nature Geoscience
1: 409-411.
Austin, J. A. and S. M. Coleman. Lake Superior summer water temperatures are increasing more
rapidly than regional air temperatures: a positive ice-albedo feedback. Geophysical Research
Letters 34:1-5.
Barbour, C.D. and J.H. Brown. 1974. Fish species diversity in lakes. American Naturalist 108:473489.
Biesner, B.E., C.L. Dent, S.R. Carpenter. 2003. Variability in lakes on the landscape: the roles
of phosphorus, food webs and dissolved organic carbon. Ecology 84:1563–1575
Botkin, D.B., P.A. Jordan, A.S. Dominski, H.S. Lowendorf and G.E. Hutchinson. 1973. Sodium
dynamics in a northern ecosystem. Proceedings of the National Academy of Sciences, U.S.A.
70: 2745-2748.
Brathen, K.A., R.A. Ims, N.G. Yoccoz, P. Fauchald, T. Tveraa, and V.H. Hausner. 2007.
Induced shift in ecosystem productivity? Extensive scale effects of abundant large herbivores.
Ecosystems 10:773-789.
Bryant, J.P., F.D. Provenza, J. Pastor, P.B. Reichardt, T.P. Clausen, and J.T. du Toit. 1991.
Interactions between woody plants and browsing mammals mediated by secondary metabolites.
Annual Review of Ecology and Systematics 22:431-446.
Byun, D.W. and L.K. Schere. 2006. Review of the Governing Equations, Computational
Algorithms, and Other Components of the Models-3 Community Multiscale Air Quality
(CMAQ) Modeling System. Applied Mechanics Reviews 59:51-77.
Callesen, I., W. Borken, K. Kalbitz, and E. Matzner. 2007. Long-term development of nitrogen
fluxes in a coniferous ecosystem: Does soil freeazing trigger nitrate leaching. Journal of Plant
Nutrition and Soil Science 170:189-196.
Carpenter S. R. and J. F. Kitchell. 1988. Consumer control of lake productivity. Bioscience 38:
764-769.
Carpenter, S. R., and J. F. Kitchell. 1993. The trophic cascade in lakes. Cambridge University
Press, Cambridge, UK.
Clair, T.A., P. Arp, T.R. Moore, M. Dalva, and F.R. Meng. 2002. Gaseous carbon dioxide and
methane, as well as dissolved organic carbon losses from a small temperate wetland under a
changing climate. Environmental Pollution 116S:143-148.
Chapin, F.S., J.T. Randerson, A.D. McGuire, J.A. Foley, and C.B. Field. 2008. Changing
feedbacks in the climate-biosphere system. Frontiers in Ecology and the Enviornment 6:313320.
Christopher, S.F., H. Shibata, M. Ozawa, Y. Nakagawa, M.J. Mitchell. 2008. The effect of soil
freezing on N cycling: Comparison of two headwater subcatchments with different vegetation
and snowpack conditions in the northern Hokkaido Island of Japan. Biogeochemistry 88:15-30.
Cochrane, T. 1990. Michigan history online.
http://michiganhistorymagazine.com/features/discmich/isleroyale.html
Cookson, W.R., I.S. Cornforth, and J.S. Rowarth. 2002. Winter soil temperature (2-15 degrees
C) effects on nitrogen transformations in clover green manure amended or unamended soils: A
laboratory and field study. Soil Biology and Biochemistry 34:1401-1415.
Czuczwa, J.M., B.D. McVeety, and R.A. Hites. 1984. Polychlorinated dibenzo-p-dioxins and
dibenzofurans in sediments from Siskiwit Lake, Isle Royale. Science 226:568-569.
Drevnick, P.E., D.E. Canfield, P.R. Gorski, A.L.C. Shinneman, D.R. Engstrom, D.C.G. Muir,
G.R. Smith, P.J. Garrison, L.B. Cleckner, J.P. Hurley, R.B. Nobel, R.R. Otter and J.T. Oris.
2007. Deposition and cycling of sulfur controls mercury accumulation in Isle Royale fish.
Environmental Science and Technology 41:7266-7272.
Drevnick, P.E., A.P. Roberts, R.R. Otter, C.R. Hammerschmidt, R. Klaper, and J.T. Oris. 2008.
Mercury toxicity in livers of northern pike (Esox lucius) from Isle Royale, USA. Comparative
Biochemistry and Physiology 147C:331-338.
Egan, A. 2007. Draft 2007 Breeding Bird Survey, Isle Royale National Park, Michigan.
Resource Management Report 07-1, Isle Royale National Park, Houghton, Michigan.
Engstrom, D.R. 1987. Influence of vegetation and hydrology on the humus budgets of Labrador
lakes. Canadian Journal of Fisheries and Aquatic Sciences 44:1306–1314.
Field, C.B., D.B. Lobell, H.A. Peters, and N.R. Chiariello. 2007. Feedbacks of terrestrial
ecosystems to climate change. Annual Review of Ecology and Environment 32:1-29.
Fitzhugh, R.D., C.T. Driscoll, P.M. Groffman, G.L. Tierney, T.J. Fahey, and J.P. Hardy. 2001.
Effects of soil freezing disturbance on soil solution nitrogen, phosphorus, and carbon chemistry
in a northern hardwood ecosystem. Biogeochemistry 56:215-238.
Flakne, R. 2003. The Holocene vegetation history of Isle Royale National Park, Michigan,
USA. Canadian Journal of Forest Research 33:1144-1166.
Genkai-Kato, M., and S. R. Carpenter. 2005. Eutrophication due to phosphorus recycling in
relation to lake morphometry, temperature and macrophytes. Ecology 86:210–219.
Gergel, S.E., M.E. Turner, T.K. Kratz. 1999. Dissolved organic carbon as an indicator of scale
of watershed influence on lakes and rivers. Ecological Applications 9:1377–1390
Gilmour, C.C., E.A. Henry, and R. Mitchell. 1992. Sulfate stimulation of mercury methylation
in freshwater sediments. Environmental Science and Technology 26:2281-2287.
Gorman, O.T., S.A. More, A. J. Carlson and H. R. Quinlan. 2008. Nearshore habitat and fish
community associations of coaster brook trout in Isle Royale, Lake Superior. Transactions of the
American Fisheries Society 137:1252-1267.
Gorski, P.R., L.B. Cleckner, J.P. Hurley, M.E. Sierszen, and D.E. Armstrong. 2003. Factors
affecting enhanced mercury bioaccumulation in inland lakes of Isle Royale National Park, USA.
Science of the Total Environment 304:327-348.
Groffman, P.M., C.T. Driscoll, T.J. Fahey, J.P. Hardy, R.D. Fitzhugh, and G.L. Tierney. 2001.
Effects of mild winter freezing on soil nitrogen and carbon dynamics in a northern hardwood
forest. Biogeochemistry 56:191-213.
Guinand, B., K.T. Scriber, K.S. Page, and M.K. Burnham-Curtis. 2002. Genetic variation over
space and time: Analysis of extinct and remnant lake trout populations in the upper Great Lakes.
Proceedings of the Royale Society of London 270B:425-433.
Holling, C.S. 1973. Resilience and stability of ecological systems. Annual Review of Ecology
and Systematics 4:1–23.
Hrabik, T.R., B.K. Greenfield, D. B. Lewis, A.I. Pollard, K.A. Wilson and T.K. Kratz. 2005.
Landscape scale variation in taxonomic diversity in four groups of aquatic organisms: The
influence of physical, chemical and biological properties. Ecosystems 8:301-317.
IPCC (Intergovernmental Panel on Climate Change). 2007. Climate Change 2007. The
Physical Science Basis. Contribution of Working Group 1 to the Fourth Assessment.
Cambridge University Press, Cambridge.
Judziewicz, E.J. 1995. Survey of non-native (exotic) vascular plant species of campgrounds
developed areas, and Passage Island lighthouse and trail, at Isle Royale National Park, Michigan,
1994. National Park Service, Houghton, MI. 60 pp.
Kallemeyn, L. W. 2000. A comparison of fish communities from 32 inland lakes in Isle Royale
National Park, 1929 and 1995-1997. U.S. Geological Survey, Washington, DC. Biological
Science Report USGS/BRD/BSR-2000-0004.
Kloppers, E.L., C.C. St. Clair, and T.E. Hurd. 2005. Predator-resembling aversive conditioning
for managing habituated wildlife. Ecology and Society 10(1):Article 31.
MacArthur, R.H. and E.O. Wilson. 1967. The theory of island biogeography. Monographs in
population biology. Princeton University Press, Princeton, N.J.
Magnuson J.J. 1976. Managing with exotics - a game of chance. Transactions of the American
Fisheries Society 105:1-9.
Magnuson, J.J, W.M. Tonn, A Banerjee J.Toivonen, O. Sanchez, M.Rask. 1998. Isolation vs.
extinction in the assembly of fishes in small northern lakes. Ecology 79:2941-2956.
Marion, J.L. and T.A. Farrell. 2002. Management practices that concentrate visitor activities:
Camping impact management at Isle Royale National Park, USA. Journal of Environmental
Management 66:201-212.
McLaren, B.E., and R.O. Peterson. 1984. Wolves, moose, and tree rings on Isle Royale. Science
266:1555-1558.
Meeker, J., A. Harris, V. Hofman, E. Judziewicz, and J. Marr. 2007. Assessment of Wetland
Communities at Isle Royale National Park. Great Lakes Network Report GLKN-2007-04.
Munthe, J., R.A. Bodaly, B.A. Branfireun, C.T. Driscoll, C.C. Gilmour, R. Harriss, M. Horvat,
M. Lucotte , and O. Malm. 2007. Recovery of mercury-contaminated fisheries. Ambio 36:3344.
National Park Service U.S. Department of the Interior. 1999. General Management Plan and
Impact Statement Isle Royale National Park, Michigan. Isle Royale National Park, Houghton,
MI.
Newman, L. E., R. B. DuBois and T. N. Halpern, Editors. 1997. A brook trout rehabilitation
plan for Lake Superior. Great Lakes Fishery Commission, Ann Arbor, Michigan.
Pastor, J., B. Dewey, R.J. Naiman, P.F. McInes, and Y. Cohen. 1993. Moose browsing and soil
fertility in the boreal forests of Isle Royale National Park. Ecology 74:467-480.
Pastor, J., K. Standke, K. Farnsworth, R. Moen, and Y. Cohen. 1999. Further development of
the Spalinger-Hobbs mechanistic foraging model for free-ranging moose. Canadian Journal of
Zoology 77:1505-1512.
Pergams, O.R.W. and P.A. Zaradic. 2008. Evidence for a fundamental and pervasive shift away
from nature-based recreation. Proceedings of the National Academy of Sciences 105:2295-2300.
Persson, I.L., K. Danell, and R. Bergstrom. 2005. Different moose densities and accompanied
changes in tree morphology and browse production. Ecological Applications 15:1296-1305.
Persson, zI.L., R. Bergstrom, and K. Danell. 2007. Browse biomass production and regrowth
capacity after biomass loss in deciduous and coniferous trees: Responses to moose browsing
along a productivity gradient. Oikos 116:1639-1650.
Post, E., and C. Pedersen. 2008. Opposing plant community responses to warming with and
without herbivores. Proceedings of the National Academy of Sciences, US 105:12353-12358.
Rosenzweig, M.L. 1995. Species diversity in space and time. University Press, Cambridge.
Sauer, J.R., J.E. Hines, J. Fallown. 2007. The North American Breeding Bird Survey, Results
and Analysis 1996-2006. Version 10.13.2007. U.S.G.S. Patuxent Wildlife Research Center,
Laurel, Maryland
Scheffer, M. and S.R. Carpenter. 2003. Catastrophic regime shifts in ecosystems: linking theory
to observation. Trends in Ecology and Evolution 18:648-656.
Scheffer, M., S. Carpenter, J. A. Foley, C. Folke, and B. Walker. 2001. Catastrophic shifts in
ecosystems. Nature 413:591–596.
Schiff, S., R. Aravena, E. Mewhinney, R. Elgood, B. Warner, P. Dillon, and S. Trumbore. 1998.
Precambrian shield wetlands: Hydrologic control of the sources and export of dissolved organic
matter. Climatic Change 40:167-188.
Shapiro, J. and D. I. Wright. 1984. Lake restoration by biomanipulation: Round Lake,
Minnesota the first two years. Freshwater Biology 14:371-383.
Sirotnak, J.M. and N.J. Huntly. 2000. Direct and indirect effects of herbivores on nitrogen
dynamics: Voles in riparian areas. Ecology 81:78-87.
Stottlemyer, R. and D. Toczydlowski. 1999a. Nitrogen mineralization in a mature boreal forest,
Isle Royale, Michigan. Journal of Environmental Quality 28:709-720.
Stottlemyer, R. and D. Toczydlowski. 1999b. Seasonal relationships between precipitation,
forest floor, and streamwater nitrogen, Isle Royale, Michigan. Soil Science Society of America
Journal 63:389-398.
Stottlemyer, R. and D. Toczydlowski. 2006. Effect of reduced winter precipitation and
increased temperature on watershed solute flux, 1988-2002, northern Michigan.
Biogeochemistry 77:409-440.
Stottlemyer, R., D. Toczydlowski, and R. Herrman. 1998. Biogeochemistry of a mature boreal
ecosystem: Isle Royale National Park, Michigan. Scientific Monograph 98-01, National Park
Service, Washington, DC.
Swackhamer, D. L. and K. C. Hornbuckle. 2004. Assessment of Air Quality and Air Pollutant
Impacts in Isle Royale National Park and Voyageurs National Park. Report to the National Park
Service, xiv pp.
Swackhamer, D.L., B.D. McVeety, and R.A. Hites. 1988. Deposition and evaporation of
polychlorobiphenyl congeners to and from Slakiwit Lake, Isle Royale, Lake Superior.
Environmental Science and Technology 22:664-672.
Tischler, K. A. 2004. Aquatic plant nutrient quality and contribution to moose diets at Isle
Royale National Park. MSc. Thesis. Michigan Technological University, Houghton, MI.
Tonn, W. M., J. J. Magnuson, M. Rask, and J. Toivonen. 1990. Intercontinental comparison of
small-lake fish assemblages: The balance between local and regional processes. American
Naturalist 136:347-375.
Virtanen, R., J. Salminen and R. Strommer. 2008. Soil and decomposer responses to grazing
exclusion are weak in mountain snow beds. Acta Oecologica 33:207-212.
Vucetich, J.A. and R.O. Peterson. 2004. The influence of prey consumption and demographic
stochasticity on population growth rate of Isle Royale wolves, Canis lupus. Oikos 107:309-320
Vucetich, J.A., R.O. Peterson, and C.L. Schaefer. 2002. The effect of prey and predator
densities on wolf predation. Ecology 83:3003-3013.
Webster, K.E., P.A. Soranno, K.S. Cheruvelil, M.T. Bremigan, J.A. Downing, P.D. Vaux, T.R.
Asplund, L.C. Bacon, and J. Connor. 2008. An empirical evaluation of the nutrient-color
paradigm of lakes. Limnology and Oceanography 53(3):1137-1148.
Vaux, T. R. Asplund, L. C. Bacon, and J. Connor. 2008. An empirical evaluation of the
nutrient-color paradigm for lakes. Limnology and Oceanography 53:1137-1148.
Wiener, J.G., B.C. Knights, M.B. Sandheinrich, J.D. Jeremiason, M.E. Brigham, D.R. Engstrom,
L.G. Woodruff, W.F. Cnnon, and S.J. Balogh. 2006. Mercury in soils, lakes, and fish in
Voyageurs National Park (Minnesota): Importance of atmospheric deposition and ecosystem
factors. Environmental Science and Technology 40:6261-6268.
Williamson C E., D.P. Morris, M.L. Pace and O.G. Olson. 1999. Dissolved organic carbon and
nutrients as regulators of lake ecosystems: Resurrection of a more integrated paradigm.
Limnology and Oceanography 44:795–803.
Wilmers, C.C., E. Post, P.O. Peterson, and J.A. Vucetich. 2006. Predator disease out-break
modulates top-down, bottom-up and climatic effects on herbivore population dynamics.
Ecology Letters 9:383-389.
Wolf, A.A., B.G. Drake, J.E. Erickson, J.P. Megonigal. 2006. An oxygen-mediated positive
feedback between elevated carbon dioxide and soil organic matter decomposition in a simulated
anaerobic wetland. Global Change Biology 13:2036-2044.
Appendix B. List of outside grants for research in Isle Royale National Park, 1998-2008
Principal Investigator
Blob, Rick
Clements, Will
Cuthbert, Francie
Pastor, John
Current Home Institution
Clemson University
Colorado State University
Universtiy of Minnesota-St. Paul
Resource Systems Group, Inc.,
Burlington,Vermont
University of Minnesota-Duluth, NRRI
Kaplan, J. and K. Tischler
Common Coast Research and Conservation Common Loon Population Dynamics
NPS, Canon Grant
Majewsky, M. and C. Paulson
US Forest Service
USFS
Edlund, Mark
Science Museum of Minnesota
Jordan, Peter
Soil Survey
NPS
Coaster Brook Trout Population Dynamics
Tree Coring
Hg in fish tissue
Mustelid Distribution and Abundance
Status of American Marten
USFWS
Michigan Technological University, USDA
EPA
NPS
NPS
Beaver Population Cenus
Isle Royale Natural History Association, NPS
Inventory of Nearshore Fish Communitiies
NPS
Gorman, O., Maki, R. and L. Kallemeyn
University of Minnesota-St. Paul
Natural Resources Conservation Service,
Marquette, MI
US Fish and Wildlife Service, Ashland, WI
Michigan Technological University
Woods Hole Oceanographic Institution
Isle Royale National Park
Isle Royale National Park
University Of Virginia-Wise, Yellowstone
National Park
US Geological Survey-Great Lakes Science
Center, Ashland, WI
USGS, Voyaguers National Park
FIA, Forest Inventory and Analysis
Collection and Analysis of Sediment CoresDiatoms
Moose Herbivory
NPS
Gorman, O. Quinlan, H. and W. Stott
USGS, UFWS
Smith, D. and J. Buskirk
Williams College, Maryland
Institute of Zoology, University of Zurich,
Switzerland
Michigan Technological University
Northland College
University of Wisconsin-Stevens Point
Isle Royale National Park
Michigan Technological University
Great Lakes Ecological Services, LLC,
Slinger, WI
Comparison of small lake fish communities
Inventory of Remnant Coaster Brook Trout
Populations
Chorus frog monitoring
Lawson, Steve
Carey, Lawrence
Quinlan, Henry
Janowiak, Maria
Drevnick, Paul
Romanski, Mark
Romanski, Mark
Shelton, P., Smith, D., Peterson, R., and M.
Romanski
Gorman, O.
Buskirk, J.
Peterson, R. and J. Vucetich
Meeker et al.
Judeiwicz
Mayo-Kiely, A, and D. Newland
Peterson, R.
Casper, G.
Li, An
University of Illinois at Chicago
Edwards, Joan
Williams College, Maryland
Stottlemyer, R. and D. Toczydlowski
USGS/Michigan Technological University
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
Funding in $1000s (25.5 = $25,500)
10 yr Total
1.0
1.0
50.0 50.0 49.0
149.0
2.5
2.5
5.0
Project
Antler Stiffness in Moose
PAH in Sediments
Colonial Waterbird Surveys
Funding Sources
NSF, Clemson University
NPS
USFWS
Stated Choice Survey-Computer Modeling
NPS
15.0
15.0
Moose Browse-Soil Fertility-Plant Growth
NSF
60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0
660.0
28.0 34.5 35.5 25.0 39.0 41.5
University of Minnesota, NPS
Amphibian and Reptile Inventory
NPS
Nutrient Cylcling In Watersheds
8.9
8.9
8.9
8.9
8.5
8.5
8.5
9.5
8.5
247.0
8.9
8.9
8.9
8.9
8.9
97.9
15.0 15.0
20.8 20.8 20.8 20.8 20.8 20.8 20.8 20.8 20.8
719.3
36.2 22.2 21.2 30.4 29.0 22.2 21.2 27.2 31.2 32.2 27.3
2.5
37.0 37.0 37.0
24.5 24.5
17.5
300.3
2.5
111.0
49.0
17.5
2.0
2.0
2.0
2.0
5.5
5.5
7.5
35.6 35.6 35.6 35.6 35.6
26.5
178.0
5.3
21.4 21.4 21.4 21.4
5.3
85.6
5.5
5.5
5.5
5.5
9.0
5.5
5.5
9.0 19.0 39.0 59.0
2.0
2.0
2.0
2.0
3.0
3.0
4.0
4.0
168.0
22.0
115.0 108.0 118.0 107.0 103.0 118.5 163.0 135.0 153.6 183.6 183.6
5.3
24.8 23.6
68.0 68.0 68.0
1488.3
0.0
5.3
48.4
204.0
0.0
EPA, NIOSH
Williams College, NSF
30.0
187.2
3.5 186.7 153.9 165.2 210.0
USGS, NPS
Wolf/moose-predator/prey
Aquatic Plant Inventory
Rare Plant monitoring
Pristine Zone Camping Impacts Monitoring
Moose herbivory effects on fire regime
Chronology of PBDE air deposition from
sediments
Artic Disjunct Plant Communities, Plant
movements
8.9
NPS
Australian Research Council
Swiss National Science Foundation, University of
Melbourne, Australia
NSF
NPS
NPS
NPS
NPS
Aeshna monitoring project (Dragonfly)
8.9
16.0
8.0
8.0
8.0
8.0
16.0
8.0
8.0
8.0
8.0
8.0 34.3 34.3
DOI Climate Change Program, USGS, Michigan
50.0 50.0 50.0 50.0 50.0 50.0 20.0 20.0 20.0 20.0 20.0
Tech Fund
Annual Total 338.9 319.9 399.9 458.6 458.7 465.7 494.2 633.3 553.4 605.5 651.6
Combined 10 yr Total
In most cases, overhead is included in these numbers
In most multi year studies, amount spread across years, not a detailed account, unless it was given
140.6
400.0
5379.7
5379.7
Appendix C.
Category
Fisheries
Annotated list of long-term data sets for ecosystem conditions at Isle Royale
National Park.
Description
Fishes including Coaster Brook
Trout
Invasive Species Gypsy Moth Trapping
Vegetation
Vegetation
Forest Inventory
Moose Exclosure Experiment
Variables
Start
End
Investigators
population size, reproduction
1997
ongoing
FWS
presence, population size
1998
ongoing
NPS, USFS
structure, biomass
structure, biomass
2000
1948
ongoing
ongoing
Notes
USFS
Sampling intensity has varied from 26
plots to 82 plots, and has currently
fallen to the 26 plot minimum.
NPS, John Pastor
This study has contributed signficantly
to the ecological science in the area
of plant-animal interactions. It is one
of several examples of profitable
partnerships between ISRO staff and
academic scientists. ISRO staff have
maintained the study and John Pastor
has led the science program. The
study has had NSF-LTREB funding.
John Pastor is ending his work at
ISRO, so ongoing collaboration will
require collaborating with a new
academic partner.
Vegetation
Forest Monitoring, Moose Browse structure, biomass
1963
ongoing
Peter Jordan
Water
Washington Creek Hydrologic
Benchmark Station 04001000
discharge, water quality
1964
2003
USGS
Water
Monitoring 9 "Index" Lakes
water quality
2007
ongoing
NPS
This study is a valuable long-term
record of forest structure that
complements the wolf-moose studies.
It has been run by Peter Jordan since
1964. The sampling scheme since
1980 consists of 12 cross-island
clusters, most with about 10 plots.
Peter Jordan is Emeritus at the
University of Minnesota, so ISRO will
need to establish a new collaboration
in order to maintain this long-term
data set.
Considered a major loss because
Washington Creek drains much of
ISRO. Includes Wallace Lake study
site.
These lakes are part of the Great
Lakes Inventory and Monitoring
Network (GLKN). Using other ISRO
long-term studies as a model, the
NPS should consider establishing
collaborations with academic
scientists to analyze and publish the
data.
Water
Wallace Lake Watershed
hydrology, chemistry
1982
ongoing
Wildlife
Wildlife
Wildlife
Common Loon Census
Breeding Bird Survey
Frog and Toad Survey
population size, reproduction
diversity, population size
diversity, population size
1985
1994
1996
ongoing
ongoing
2006
Wildlife
Aerial Beaver Census
population size
1960
ongoing
This long-term study has proved
useful for understanding the influence
of climate on ecosystem processes
and biogeochemical cycles. ISRO will
need to work with Robert Stottlemyer
Robert Stottlemyer to plan for continuity in this data set.
Current sampling protocols followed
NPS, Joe Kaplan since 1999.
NPS
NPS
NPS, Phil Shelton, This is the longest running dataset of
Doug Smith
its kind.
ongoing
Thus study is a gold-standard
example of how long-term monitoring
can inform basic science, and the
ability of ISRO in-kind support to
leverage top-tier research that is
useful for managing the Park.
Collaborators at Michigan Tech
University have leveraged NPS base
support to attract NSF-LTREB funding
and private donations. The long-term
viability of this study is quite secure
since MTU hired John Vucetich, who
John Vucetich, Rolf is interested in carrying the project
Peterson
forward after Rolf Peterson retires.
Wildlife
Wolf-Moose Monitoring
population size, many others
1958
Appendix D.
List of the ―Blue Ribbon‖ Panel with affiliations
William H. Schlesinger, Cary Institute of Ecosystem Studies, Millbrook, NY (Chair)
Viney P. Aneja, Department of Marine, Earth, and Atmospheric Sciences, North Carolina State
University, Raleigh
F. Stuart Chapin III, Institute of Arctic Biology, University of Alaska, Fairbanks
Nicholas Comerford, North Florida Research and Education Center, Department of Soil and
Water Science, University of Florida, Quincy
James P. Gibbs, College of Environmental Science and Forestry, State University of New York
at Syracuse
Thomas Hrabik, Biology Department, University of Minnesota, Duluth
Patrick Megonigal, Smithsonian Environmental Research Center, Edgewater, Maryland
Monica G. Turner, Department of Zoology, University of Wisconsin, Madison
John Whitaker, Department of Ecology and Organismal Biology, Indiana State University, Terre
Haute
Acknowledgements
The Blue Ribbon Panel thanks the following for their help in the committee‘s deliberations, its
trip to Isle Royale National Park and the preparation of this report:
Alex Egan, Isle Royale National Park
Phyllis Green, Superintendent of Isle Royale National Park
Margaret Gale, Dean, School of Forestry, Michigan Technological University
Ann Mayo-Kiely, Isle Royale Institute, Houghton, Michigan
Mark Romanski, Natural Resources, Isle Royale National Park
Cindy Glase, Isle Royale Institute, Houghton, Michigan
We thank the DeVlieg Foundation, the National Park Service, Michigan Technological
University, and the University of Minnesota at Duluth for financial support of the Blue Ribbon
Review Panel.