Browsing by Subject "ecology"

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Biotic Guild Diversity with Varying Stream Parameters
(2010-03-16) Rittenhouse, David; Gasteiger, Autumn; Greenfield, Morgan; Thomes, Reggie
The River Continuum Concept is a model that provides a framework for predicting many characteristics of a river or stream based off of its order. We examined three streams, the Mississippi River headwaters, a creek emerging from Mark Lake, and a iron spring that flows into Elk Lake, all with varying characteristics, but all headwaters of a streams found within Itasca State Park, MN. Physical properties of each stream were measured along with an assessment of the stream’s species richness found by looking at the richness of the biotic guilds of anuran, terrestrial invertebrates, benthic invertebrates, aquatic vegetation, emergent vegetation, and riparian vegetation. We found the Mississippi headwaters to have the highest species richness in all guilds but riparian vegetation, leading us to believe it to be a middle-order stream based of the characteristics described in the River Continuum Concept.
Comparison of Two Small Streams in Itasca State Park with the River Continuum Concept
(2010-03-11) Petitti, James; Jewett, Erin; Reddy, Priyanka; Shimp, Adam
The river continuum concept (RCC) first proposed by Vannote et al. (1980) has widely been accepted as the general template for characterizing the ecology of streams and rivers as water travels from the headwaters to much larger bodies of water. We tested the RCC on two small streams, Mary Creek and Chambers Creek in Itasca State Park. The streams chosen were both small with lentic sources, however physically the streams differ greatly in the variables we examined. We examined variables including substrate type, flow, canopy coverage, depth, width, pH and macro-invertebrate functional feeding groups to test if the two streams would fit the concept of low order streams. We found that the two streams are significantly different from each other and that Chambers varies somewhat from the RCC. Mary Creek fits the characteristics of a low order stream while Chambers Creek fits the physical characteristics of a mid order stream with some of the community composition of a low order stream. Mary Creek’s characteristics that classify it as a low order stream are the almost complete canopy coverage, narrow average width of 2.5m, shallow depth of 19cm, and substrate of rock and sand. Whereas, the characteristics that make Chambers Creek a mid order stream are little to no canopy coverage, mid size width averaging 10m, depth of 70cm, and a substrate of silt and sand. The organic matter at each location also differs, Mary Creek is comprised of coarse particulate organic matter (CPOM) and Chambers Creek is comprised of mostly fine particulate organic matter (FPOM). This organic matter is the primary nutrient source for different functional feeding groups.
Ecology and Geology of the Mississippi River Gorge
(1998) Brewer, Aaron
Ecology Of Influenza A Virus In Avian Species In Minnesota
(2018-02) Guo, Xi
The fall introductions of Influenza A virus (IAV) to turkey flocks in Minnesota (MN) have occurred annually since 1982 with very few exceptions. These cases were associated with outdoor production of turkeys and their exposure to wild birds during migration. Since 2007, there has been an emerging trend of Spring introductions (SIs) of IAV in MN. The subtypes associated with SIs includes H3, H4, H7, H9, and highly pathogenic avian influenza (HPAI) H5N2 which were all avian-origin strains. Outdoor production practices were stopped in 1998 eliminating direct links between wild birds and domesticated turkeys. The factors that drive the Spring seasonality of IAV introductions has never been studied. The goal of this study is to identify these factors. We hypothesized that SIs of IAVs are driven by two synergistic factors, i.e. the presence of sufficient quantities of IAVs that can infect domesticated turkeys, and farm practices that link the flocks with a virus source. The approaches include to characterize the climate conditions, to investigate the epidemiological factors and to evaluate the virological basis. The findings demonstrate that these two factors work synergistically and were not deterministic to the occurrence of SIs. By detecting the viral persistence under SI related temperatures and by measuring the infectious dose of IAVs in turkeys, we show that IAV has long-term persistence under the temperature of both SI-years and non-SI years. Sufficient quantity of IAVs are necessary to drive SIs. By investigating risks associated with farm practices during 2014 – 2016, we illustrate that on-site mortality disposal and the activities of farm workers are critical factors that drive SIs. Improving the current understanding of SIs requires effective surveillance on the natural hosts of SIs. To control and prevent SIs in the future, on farm practices need to be adjusted for Spring conditions and to address risk factors like on site mortality disposal.
Effects of environmental factors on pathogen exposure and transmission in wild rodent populations
(2023-08) Mistrick, Janine
Anthropogenic land-use change is altering ecosystems across the globe and has been implicated as a major factor increasing the spillover of zoonotic diseases from wildlife into human populations. Wild rodents are of particular importance for spillover as they host the largest diversity of zoonotic pathogens of any mammalian order. Moreover, rodent hosts of zoonotic pathogens have been found to increase in abundance in anthropogenic landscapes. In my dissertation, I investigate the effects of environmental factors related to anthropogenic land-use change on pathogen prevalence and transmission in wild rodent populations. Using an observational field study across landscape and habitat types, I broadly investigate the effects of anthropogenic development on the prevalence of zoonotic bacterial pathogens in wild Peromyscus mice (Chapter 1). I then turn to finer spatial scales to consider how spatial overlap can be used to approximate transmission in wildlife populations (Chapter 2). Using wild bank voles (Clethrionomys glareolus) as a model system, I leverage a replicated, experimental field study to quantify the effects of food supplementation and helminth macroparasite removal on vole space use and spatial overlap to approximate transmission opportunities (Chapter 3). Finally, I test how spatial overlap predicts infection of an endemic viral pathogen and examine whether the relationship between spatial overlap and infection is influenced by food abundance and macroparasite infection (Chapter 4). My research indicates that agricultural development may increase the prevalence of zoonotic bacterial pathogens in wild rodents. Further, I show that environmental factors alter the space use of wild rodents and that both environmental conditions and host traits are important to predict how spatial overlap affects transmission of an endemic pathogen. As such, my dissertation research has contributed empirical evidence that shows how environmental conditions alter zoonotic pathogen prevalence and transmission in wild rodent populations. This represents an important step forward in our ability to quantify the effects of anthropogenic land-use change on disease dynamics in wildlife, advancing our ability to understand and predict transmission dynamics and control spillover potential from wildlife into human populations.
Effects of Plains Pocket Gopher (Geomys bursarius) Disturbances in a Mixed Prairie in Northwestern Minnesota
(2010-03-11) Adams, Nicole; Fillmore, Megan; Frost, Mark; Sinton, Christopher
Our objective was to determine what effect plains pocket gophers (Geomys bursarius) and their mounds have on plant diversity within Frenchman’s Bluff Scientific and Natural Area (SNA), located in northwestern Minnesota. Our predictions were threefold. First, we predicted increased plant diversity in areas on and immediately surrounding gopher mounds in accordance with the Intermediate Disturbance Hypothesis. Second, we predicted that biomass in the areas on and around gopher mounds would decrease when compared to control areas where there were no gopher mounds. Lastly, we predicted that yellow sweet clover (Melitotus officinalis) will be more abundant on and around the disturbed mounds than in areas where there is no gopher disturbance. The experiment was performed in one afternoon at Frenchman’s Bluff by creating a 100x100 meter grid and assessing plant diversity and coverage in twenty 2x2 meter randomly selected control plots and comparing with twenty 2x2 meter plots that contained gopher mounds created by G. bursarius. Analysis of percent coverage of yellow sweet clover, biomass and species diversity between the gopher mound and control plots all proved to be statistically insignificant, but are all nearing significance. Given the number of experimental difficulties experienced and the limited scope of this study, it is likely that future research into the effects of the plains pocket gopher activity on plant diversity at the Frenchman’s Bluff SNA will realize conclusive and significant results that correlate with the predictions of this study.
Evaluating Landscape and Local Drivers of Pollination in Melittophilous Tallgrass Prairie Forbs: Effects of Surrounding Land-use on Pollen Limitation of Chamaecrista fasciculata & Prescribed Burning on Flowering and Pollination of Dalea purpurea
(2020-01) Ritchie, Alan
Tallgrass prairies are one of the most endangered ecosystems in North America. Habitat loss and degradation of remaining prairies threaten both the biodiversity and functioning of these ecosystems. At the landscape scale, loss and fragmentation of existing prairie may limit regional pools of species and abundance of individuals, hampering movement of plants and animals between suitable habitats. At the local scale, degradation of prairies has been exacerbated by loss of native grazers and suppression of fire, the major ecological forces that historically shaped prairie species and communities. While the impacts of these factors on biodiversity in prairies is well-established, little is known about the role of these factors on plant-pollinator interactions, an important ecological process for many prairie forbs. As restoration of prairie habitats is one of the chief means of protecting prairie habitats and biodiversity, evaluating the roles of these factors in mediating ecological processes such as pollination will be critical to their reconstruction. Within this thesis, I explore how two important aspects of habitat restoration management, landscape context and prescribed burning, influence pollination in two common, widespread prairie forbs reliant on insects, namely bees, for pollination. The findings of these studies serve as initial assessments of two under-explored topics with relevance to tallgrass prairie conservation: how placement of a restoration effects recruitment of pollinators and the pollination they provision a habitat, and how animal-mediated pollination influences prescribed burning’s effects on plant reproduction.
Evaluating regeneration and stand dynamics in tamarack stands impacted by eastern larch beetle in northern Minnesota, USA
(2022-06) Shaunette, Amy
Tamarack (Larix laricina DuRoi K. Koch) forests in Minnesota are currently threatened by a landscape-level outbreak of eastern larch beetle (ELB) (Dendroctonus simplex LeConte), a native bark beetle. Since 2001, ELB has impacted 816,833 acres of tamarack forest over 20 consecutive years. This has resulted in many management questions related to stand development, especially in terms of regeneration. To explore how ELB has influenced stand structure and composition, 33 sites across a gradient of ELB damage severity and outbreak timing in north-central Minnesota were sampled. Older mortality sites had the highest overstory tree density, driven largely by a high volume of standing dead tamarack. On average, regeneration exceeded a commonly used standard of 600 trees per acre in older high mortality stands only and was below the suggested stocking level in recent high mortality and low mortality stands. Tree ring analysis of 150 tamarack tree cookies revealed understory tamarack saplings aged 9 to 82 years old, suggesting tamarack may have more robust shade tolerance than previously believed. Tamarack established consistently throughout a period of 64 years, suggesting advance regeneration is a part of tamarack stand dynamics. Finally, we identified temporal differences in establishment periods in stands with varying levels of ELB impacts. The combined results of this work highlight complex and understudied dynamics related to tamarack regeneration. Regeneration may take 10 to 15 years to establish after an ELB outbreak. However, it is not only new germinants present in the seedling, sapling, and small tree layer but also advance regeneration.
Friends of the Vermillion River Water Trail Study
(2005) Ochs, Christopher
Interview with Margaret Davis
(University of Minnesota, 1999-10-14) Davis, Margaret; Pflaum, Ann M.
Ann Pflaum interviews Regents Professor Margaret Davis of the College of Biological Sciences.
Investigating collective action as a scaffold for eco-evolutionary feedbacks
(2021-12) Wang, Pu
Eco-evolutionary feedbacks involve situations where environmental conditions influence evolutionary changes, which, in turn, feedback to the environment. Such interactions between ecological and evolutionary processes are prevalent in many biological systems from phage and bacteria to forests and animals. An increasing number of research projects address the significant impact of eco-evolutionary feedbacks in shaping the diversity of living organisms and their living niche, in many ecosystems in the modern world. Furthermore, interactions between ecology and evolution are taking place all the time. Thus, eco-evolutionary feedbacks would have significantly impacted the evolutionary history of life. The evolution of collective action also has significantly changed the form of life, by changing the way selection worked on organisms. Multicellularity, one example of the collective action of cells, is considered as one of the major transitions of life. The significance of such a major transition has been addressed more from promoting new organization or functions. However, the other, even more impactful, aspect of influencing the entire community via eco-evolutionary feedbacks has been less emphasized. Populations experiencing major transitions could alter the environments innovatively that would feedback on the subsequent evolutionary changes. In my thesis research, I addressed this impactful but less emphasized aspect of a major transition’s significance, by investigating the effect of eco-evolutionary feedbacks via collective actions. My projects demonstrated collective action is a scaffold for eco-evolutionary feedbacks from three perspectives. Firstly, I documented the evolutionary process of collective action. Then I created a predator-prey microcosm to describe how eco-evolutionary interactions occur along with the emergence of collective action. Lastly, I used genome sequencing techniques to investigate how eco-evolutionary interactions influence the entire communities including unevolved ones. I took the experimental evolution approach with different microbial systems to address each perspective. My research provided an empirical basis for investigating the important, yet less addressed aspect of the impact of major transitions. The effect of major transitions affected the evolving organism itself as well as the rest of the community by shaping the environment with new structures and functions. It also provides insights into the impact of eco-evolutionary feedbacks in the history of life.
New Rules for Simulation and Analysis in Ecology, Epidemiology, and Elsewhere
(2012-06-13) Lehman, Clarence; Keen, Adrienne
An invisible "phase change" has recently re-shaped computation, in only a few years. Vast memories allow new modeling methods–still being invented and deployed. We apply such methods to epidemiology and ecology, outlined here.
Quantitative Ecology: A New Unified Approach
(University of Minnesota Libraries Publishing, 2019-07) Lehman, Clarence; Loberg, Shelby; Clark, Adam
Quantitative Ecology introduces and discusses the principles of ecology from populations to ecosystems including human populations, disease, exotic organisms, habitat fragmentation, biodiversity and global dynamics. The book also reformulates and unifies ecological equations making them more accessible to the reader and easier to teach.
Snapshot Safari Educational Materials
(2020-11-16) Palmer, Meredith S; Dewey, Jessica; Huebner, Sarah; palme516@umn.edu; Palmer, Meredith S; University of Minnesota Lion Research Center
Snapshot Safari (www.snapshotsafari.org) is a cross-continental network of biodiversity monitoring programs run by the University of Minnesota Lion Center (www.lioncenter.umn.edu/snapshot-safari). To address the urgent need for accurately assessing vulnerable wildlife populations, we deployed over two dozen camera trap surveys distributed in protected areas across Africa. We rely on the help of online volunteers ("citizen scientists") to help classify animals captured in our millions of camera trap images. The citizen science platform provides a novel opportunity for public engagement and science education, and we have created educational multimedia based on the Snapshot Safari citizen science experience to promote these learning opportunities. Here, we present activities and videos aimed at a middle school-level audience that use our camera trap images to teach ecological and conservation principles.
Time, Ecology And The Graphics Of The Borgia Group Of Codices
(2024-07) Nair, Sreekishen
This dissertation examines a selection of beautifully illustrated almanacs found in the Borgia Group of Codices: a set of sacred manuscripts drafted in Central Mexico by Indigenous scribes during the 14th-15th centuries ce (the Late Postclassic Period). A growing body of research demonstrates that these calendrical tools were used, in part, to record, organize, and tabulate data about seasonal ecology and the environment, here understood as vitally dynamic and intrinsically sacred. The information was archived through a sophisticated mode of visual communication, unique to Central Mexico, that combines glyphic, notational and pictographic signs with illustration. Contemporary studies have partially reconstructed this visual language using bilingual documents prepared by Indigenous scribes during 16th century, which incorporate both alphabetic Spanish and native glyphic entries. Drawing from these lines of research, I discuss Borgia Group almanacs whose graphical contents address agriculture, weather, and astronomy in terms of sacred calendrical cycles. I examine both the internal logic of their graphical language, and the external environment they describe, combing both inquiries with ethnohistoric data to construct a hypothesis for the social lives of the almanacs in their native contexts. I propose that priestly specialists compiled their ecological and astronomical observations into graphical archives that were referenced for managing vital civic concerns, such as agriculture or periodic environmental crises (e.g. drought or pestilence). Notable similarities among almanacs from different regions suggest that communities were sharing such data across wide geographies. The function of the ancient almanacs parallels governmental bulletins published in 18th century Guatemala that were compiled to manage potential locust outbreaks, researched by Martha Few (2013). This discussion contextualizes the sacred almanacs within Mexico’s Indigenous scientific scholarship as expressed through art, architecture, and landscape management. As sacred dossiers for ecological data, the almanacs in the Borgia Group comprise an archive that explains how their ancient authors experienced their environments. They thus enhance contemporary understandings of climate patterns, and present a sample of the rich, polyvocal scholarship that flourished in ancient Mesoamerica. This study is submitted in honor of the Indigenous authors of that archive, as well as their contemporary descendants.
Top-down Trophic Cascades in Three Meromictic Lakes
(2010-03-11) Kraft, Tanner; Newman, Caitlin; Smith, Michael; Spohr, Bill
Projections of tropic cascades from a top-down model suggest that biotic characteristics of a lake can be predicted by the presence of planktivorous fish. From the same perspective, the presence of planktivorous fish can theoretically be predicted based off of the sampled biotic factors. Under such theory, the presence of planktivorous fish contributes to low zooplankton abundances, increased zooplankton predator-avoidance techniques, and subsequent growth increases of algae. Lakes without planktivorous fish would theoretically experience zooplankton population booms and subsequent decreased algae growth. These assumptions were used to describe the tropic interactions of Arco, Deming, and Josephine Lakes; three relatively similar meromictic lakes differing primarily from their absence or presence of planktivorous fish. Due to the presence of several other physical, chemical, and environmental factors that were not sampled, these assumptions did not adequately predict the relative abundances of zooplankton and algae in a lake based solely on the fish status. However, the theory did successfully predict the depth preferences of zooplankton based on the presence or absence of fish.
Water clarity in Lake Itasca: Bottom-up vs. Top-down theory
(2010-03-11) Dube, Mark; Strelow, Desiree; Woods, Rachel
Lake Itasca is clearer than normal for spring and expected to become less clear as the summer progresses, due to algal growth. Our research investigated the main factor that controls water clarity in Lake Itasca based on two different theoretical concepts: Bottom-up versus Top-down effects. Ultimately, we inferred that the top-down theory was the main influence, in which food web interactions were the largest driver of water clarity. We examined the abundance of zooplankton, hatching of yellow perch larvae, and algal levels in conjunction with nutrient levels to support our hypothesis. The zooplankton population declined in correlation to the presence of larval yellow perch, along with growth in the amount of chlorophyll at each site, presented evidence in food web change. Nitrate levels showed consistency and no pattern of change, further providing support towards our hypothesis. These results of our research supported our hypothesis in that the Top-down theory was the main controller on water clarity in Lake Itasca.
Water Resources Administration in Minnesota, 1972
(Water Resources Research Center, University of Minnesota, 1972-04) Walton, William C.
In 1970. Minnesota’s State government contained at least 21 departments, agencies, boards, commission, committees, etc. with which water and related land resources responsibilities. Expenditures by these organizations increased from $5.7 million in 1950 to $31.9 million in 1970. About 86% of expenditures were made by the Department of Conservation. Total State agency staff complements increased from 1,100 in 1960 to 1,400 in 1970. Prime responsibility for water and related land resources programs rested in 3 Committees of the Senate and 2 Committees in the House. The Governor’s and Legislature’s control of the State’s administrative apparatus is hampered through fragmented organization. A recommended plan of reorganization centers on consolidation of major functions within and Department of Natural Resources. There is need for the Legislature to enunciate a comprehensive environmental policy for the State. In 1970, there were 5 international, 5 regional, 3 interstate, and 4 Federal-State organizations with programs in the State. Federal responsibilities in water and related land resources planning, development and management in Minnesota was divided among 30 units in 8 executive departments and agencies; 6 independent agencies; 6 units in the executive office of the President; 9 other boards, committees, councils and commissions; and 1 quasi-official agency. In fiscal Year 1970, Federal outlays for water and related land resources activities in the State totaled about $75 million or 2.3 percent of total Federal outlays in Minnesota of about $3.3 billion. There were about 1,300 Federal employees residing in Minnesota in fiscal year 1970 with assignments pertaining to water and related land resources. In 1971, there were at least 49 Interest groups in Minnesota with major water and related land resources programs, 4 Leagues and Associations with minor water and related land resources programs, at least 80 organizations that tend to have a continuing interest in water related land resources issues, and at least 150 National organizations concerned with water and related land resources programs which have or could have members in the State. The Minnesota Senate 1971 registration files for lobbyists listed 110 lobbyists in the field of water and related land resources; the House files listed 138 lobbyists. Of the 53 Interest groups (49 Interest group sand 4 Leagues and Associations mentioned above), 40 were conservation-preservation oriented, 8 had the word environmental in their name, and 5 were development and management oriented. Taking into consideration multiple memberships, it is estimated that approximately 25,000 citizens in Minnesota were members of the 53 interest groups in 1971. Membership in individual Interest groups ranged from 13 to 12,000. Expenditures in 1971for water and related land resources programs of the 53 Interest groups probably totaled in excess of $250,000. Annual expenditures by individual Interest groups ranged from $100 to in excess of $35,000. These figures do not include the thousands of hours of volunteer time by members. The sources of income were dues, contributions, donations, and grants. The affairs of 45 of the 53 Interest groups were under the direction of Officers; 8 Interest groups had Boards; and 14 Interest groups had staffs. It is estimated that the number of water and related land resources Interest groups increased from about 16 in 1950 to 25 in 1960 to 33 in 1965 to 53 in 1971. In the past, there has been considerable activity in Minnesota associated with the development and management of water and related land resources. For example, water-supply and sewage treatment plants have been constructed at most cities and villages as well as by many industries. Water-oriented recreation facilities have been provided in connection with parks, waysides, reserves, and monuments, etc. scattered throughout the State. Fish management programs have been extended to many areas and hundreds of wildlife management areas have been developed. Wetland waterfowl production areas being managed. Agricultural lands have been drained in extensive areas and farmers have made considerable progress in the installation of conservation practices to reduce and control soil erosion. Some flood control and prevention have been accomplished as soil and water conservation projects of the U.S. Army Corps of Engineers. Extensive improvements of rivers and harbors for navigation are located along the Mississippi River and in the Duluth-Superior area. Past development and management practices, as substantial as they are, have not kept pace with the steadily growing demands placed upon water and related land resources. Not only does Minnesota have catch up problems to contend with in the future, continuing pressures and demands for enhancement of the enivironemnt and improved economic well-being can be expected to create steadily growing demands for water and related land resources. There exists many water and related land resource problems associated with such matters as: pollution of streams, lakes and groundwater; water-oriented recreation; water supply; flooding; navigation; and land use. Responsibilities for water and related land resources data acquisition and handling in Minnesota are shared among many Federal, State, local and private organizations. The diffusion of responsibility makes it difficult to launch a comprehensive attack on environmental and other problems. Divided responsibility means that some needed data acquisition and handling programs slip between the cracks and disappear from view. One such program is the development of a statewide water and related land resources data system. A statewide water and related land resources - data system is needed to improve the coordination of data acquisition and handling responsibilities, to improve the efficiency of data programs, and to upgrade and fill deficiencies in data programs. Institutional arrangements must be devised to design the system. A State Environmental Policy Bill, H.F. No. 2405, introduced by Messrs. Dunn, Norton, Becklin, Munger and Knutson passed the House on May 21, 1971 with a vote of yeas 117 and nays 12. A companion bill, S.F. 2048, introduced by Messrs. Gage, Gustafson, and Popham and referred to the Committee on Civil Administration was not reported out-of-Committee. H.F. No. 2405, passed by the House, was introduced in the Senate on May 22, 1971. The bill was never read for the third time, thus, it never came up for vote in the Senate. This bill addressed itself to many existing water and related land resources planning policy questions as did a report approved by the Land and Water Resource s Committee, House of Representatives on November 30, 1970. During 1971 and 1972, several Subcommittees of Committees of the State Senate and House held joint hearings on water and related land resources issues. Governor Anderson in April 1972 established an Environmental Quality Council with a Citizens Advisory Committee. These actions could lead to the passage of a State Environmental Policy Act during the 1973 Session of the Legislature and to the improvement of government for water and related land resources programs in Minnesota.

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