Characterization of legacy organic carbon in a culturally eutrophic lake : the role of the historic carbon deposition in the time course and extent of lake recovery

The time course of lake recovery after a reduction in external loading of nutrients is often controlled by conditions in the sediment. Remediation of eutrophication is hindered by the presence of legacy organic carbon deposits, that exert a demand on the terminal electron acceptors of the lake and contribute to problems such as internal nutrient recycling, absence of sediment macrofauna, and flux of toxic metal species into the water column. Being able to quantify the timing of a lake’s response requires determination of the magnitude and lability, i.e., the susceptibility to biodegradation, of the organic carbon within the legacy deposit. This characterization is problematic for organic carbon in sediments because of the presence of different fractions of carbon, which vary from highly labile to refractory. The lability of carbon under varied conditions was tested with a bioassay approach. It was found that the majority of the organic material found in the sediments is conditionally-labile, where mineralization potential is dependent on prevailing conditions. High labilities were noted under oxygenated conditions and a favorable temperature of 30 °C. Lability decreased when oxygen was removed, and was further reduced when the temperature was dropped to the hypolimnetic average of 8° C . These results indicate that reversible preservation mechanisms exist in the sediment, and are able to protect otherwise labile material from being mineralized under in situ conditions. The concept of an active sediment layer, a region in the sediments in which diagenetic reactions occur (with nothing occurring below it), was examined through three lines of evidence. Initially, porewater profiles of oxygen, nitrate, sulfate/total sulfide, ETSA (Electron Transport System Activity- the activity of oxygen, nitrate, iron/manganese, and sulfate), and methane were considered. It was found through examination of the porewater profiles that the edge of diagenesis occurred around 15-20 cm. Secondly, historical and contemporary TOC profiles were compared to find the point at which the profiles were coincident, indicating the depth at which no change has occurred over the (13 year) interval between core collections. This analysis suggested that no diagenesis has occurred in Onondaga Lake sediment below a depth of 15 cm. Finally, the time to 99% mineralization, the t99, was viewed by using a literature estimate of the kinetic rate constant for diagenesis. A t99 of 34 years, or approximately 30 cm of sediment depth, resulted for the slowly decaying carbon fraction. Based on these three lines of evidence , an active sediment layer of 15-20 cm is proposed for Onondaga Lake, corresponding to a time since deposition of 15-20 years. While a large legacy deposit of conditionally-labile organic material remains in the sediments of Onondaga Lake, it becomes clear that preservation, mechanisms that act to shield labile organic carbon from being degraded, protects this material from being mineralized and exerting a demand on the terminal electron acceptors of the lake. This has major implications for management of the lake, as it defines the time course of lake recovery following a reduction in nutrient loading.

Radical Verses: Aku Päiviö's Literary Influence on the Finnish Working-Class

Aku Päiviö was one of the most influential voices of the Finnish labor movement in North America—a poet who also wrote plays and novels, and an editor who worked for a variety of newspapers across the United States and Canada. During the height of the Finnish socialist movement from around 1904-1916, Päiviö published a number of poems that identified with the actions and ideologies of the working-class. He also edited for newspapers such as Kansan Lehti and Raivaaja, further extending his literary reach. Despite his prodigious publications and influence, however, little of Päiviö’s writing has been translated into English. This paper celebrates Päiviö’s legacy with some English translations of his poems, specifically those commemorating the 1913-14 Michigan Copper Strike, and illuminates how various thematic and structural relationships in these poems relate to the ideologies and movements of the time.

Exhibit: "Michigan-I-O": Alan Lomax and the 1938 Library of Congress Folk-Song Expedition"

In 1938, a young folk music collector named Alan Lomax—destined to become one of the legendary folklorists of the 20th century recorded Michigan’s richly varied folk music traditions for the Archive of American Folk-Song at the Library of Congress. Michigan in the 1930s was experiencing a golden age of folksong collecting, as local folklorists mined the trove of ballads remembered by aging lumbermen and Great Lakes schoonermen. In addition to the ballads of these north woods singers, Lomax recorded a vibrant mix of ethnic music from Detroit to the western Upper Peninsula. The multimedia performance event Folksongs from Michigan-i-o combines live performance with historic images, color movie footage, and recorded sound from the Great Depression. Some of these materials haven’t been heard or seen by the general public for more than seven decades. The traveling exhibition Michigan Folksong Legacy: Grand Discoveries from the Great Depression brings Alan Lomax’s 1938 field trip to life through words, song lyrics, photographs, and sound recordings. Ten interpretive banners explore themes and each panel contains a QR code that links to related sound recordings from the Alan Lomax Collection at the American Folklife Center, Library of Congress.

Exhibit: "Michigan-I-O": Alan Lomax and the 1938 Library of Congress Folk-Song Expedition"

In 1938, a young folk music collector named Alan Lomax—destined to become one of the legendary folklorists of the 20th century recorded Michigan’s richly varied folk music traditions for the Archive of American Folk-Song at the Library of Congress. Michigan in the 1930s was experiencing a golden age of folksong collecting, as local folklorists mined the trove of ballads remembered by aging lumbermen and Great Lakes schoonermen. In addition to the ballads of these north woods singers, Lomax recorded a vibrant mix of ethnic music from Detroit to the western Upper Peninsula. The multimedia performance event Folksongs from Michigan-i-o combines live performance with historic images, color movie footage, and recorded sound from the Great Depression. Some of these materials haven’t been heard or seen by the general public for more than seven decades. The traveling exhibition Michigan Folksong Legacy: Grand Discoveries from the Great Depression brings Alan Lomax’s 1938 field trip to life through words, song lyrics, photographs, and sound recordings. Ten interpretive banners explore themes and each panel contains a QR code that links to related sound recordings from the Alan Lomax Collection at the American Folklife Center, Library of Congress.

Exhibit: "Michigan-I-O": Alan Lomax and the 1938 Library of Congress Folk-Song Expedition

In 1938, a young folk music collector named Alan Lomax—destined to become one of the legendary folklorists of the 20th century recorded Michigan’s richly varied folk music traditions for the Archive of American Folk-Song at the Library of Congress. Michigan in the 1930s was experiencing a golden age of folksong collecting, as local folklorists mined the trove of ballads remembered by aging lumbermen and Great Lakes schoonermen. In addition to the ballads of these north woods singers, Lomax recorded a vibrant mix of ethnic music from Detroit to the western Upper Peninsula. The multimedia performance event Folksongs from Michigan-i-o combines live performance with historic images, color movie footage, and recorded sound from the Great Depression. Some of these materials haven’t been heard or seen by the general public for more than seven decades. The traveling exhibition Michigan Folksong Legacy: Grand Discoveries from the Great Depression brings Alan Lomax’s 1938 field trip to life through words, song lyrics, photographs, and sound recordings. Ten interpretive banners explore themes and each panel contains a QR code that links to related sound recordings from the Alan Lomax Collection at the American Folklife Center, Library of Congress.

Characterizing the effects of turbulence on sediment oxygen and sediment nitrate demand using flow-through reactors

Onondaga Lake has received the municipal effluent and industrial waste from the city of Syracuse for more than a century. Historically, 75 metric tons of mercury were discharged to the lake by chlor-alkali facilities. These legacy deposits of mercury now exist primarily in the lake sediments. Under anoxic conditions, methylmercury is produced in the sediments and can be released to the overlying water. Natural sedimentation processes are continuously burying the mercury deeper into the sediments. Eventually, the mercury will be buried to a depth where it no longer has an impact on the overlying water. In the interim, electron acceptor amendment systems can be installed to retard these chemical releases while the lake naturally recovers. Electron acceptor amendment systems are designed to meet the sediment oxygen demand in the sediment and maintain manageable hypolimnion oxygen concentrations. Historically, designs of these systems have been under designed resulting in failure. This stems from a mischaracterization of the sediment oxygen demand. Turbulence at the sediment water interface has been shown to impact sediment oxygen demand. The turbulence introduced by the electron amendment system can thus increase the sediment oxygen demand, resulting in system failure if turbulence is not factored into the design. Sediment cores were gathered and operated to steady state under several well characterized turbulence conditions. The relationship between sediment oxygen/nitrate demand and turbulence was then quantified and plotted. A maximum demand was exhibited at or above a fluid velocity of 2.0 mm•s-1. Below this velocity, demand decreased rapidly with fluid velocity as zero velocity was approached. Similar relationships were displayed by both oxygen and nitrate cores.

Retention of canopy trees as biological legacies for balancing woody biomass production and biodiversity in managed aspen forests of the Great Lakes Region

Green-tree retention under the conceptual framework of ecological forestry has the potential to provide both biomass feedstock for industry and maintain quality wildlife habitat. I examined the effects of retained canopy trees as biological legacies (“legacy trees”) in aspen (Populus spp.) forests on above-ground live woody biomass, understory plant floristic quality, and bird diversity. Additionally, I evaluated habitat quality for a high conservation priority species, the Golden-winged Warbler (Vermivora chrysoptera). I selected 27 aspen-dominated forest stands in northern Wisconsin with nine stands in each of three legacy tree retention treatments (conifer retention, hardwood retention, and clearcuts or no retention) across a chronosequence (4-36 years post-harvest). Conifer retention stands had greater legacy tree and all tree species biomass but lower regenerating tree biomass than clearcuts. Coniferous but not hardwood legacy trees appeared to suppress regenerating tree biomass. I evaluated the floristic quality of the understory plant assemblage by estimating the mean coefficient of conservatism (C). Mean C was lower in young stands than in middle-age or old stands; there was a marginally significant (p=0.058) interaction effect between legacy tree retention treatment and stand age. Late-seral plant species were positively associated with stand age and legacy tree diameter or age revealing an important relationship between legacy tree retention and stand development. Bird species richness was greatest in stands with hardwood retention particularly early in stand development. Six conservation priority bird species were indicators of legacy tree retention or clearcuts. Retention of legacy trees in aspen stands provided higher quality nest habitat for the Golden-winged Warbler than clearcuts based on high pairing success and nesting activity. Retention of hardwoods, particularly northern red oak (Quercus rubra), yielded the most consistent positive effects in this study with the highest bird species richness and the highest quality habitat for the Golden-winged Warbler. This treatment maintained stand biomass comparable to clearcuts and did not suppress regenerating tree biomass. In conclusion, legacy tree retention can enhance even-aged management techniques to produce a win-win scenario for the conservation of declining bird species and late-seral understory plants and for production of woody biomass feedstock from naturally regenerating aspen forests.

Economic sustainability of the Flambeau Mine Ladysmith, Wisconsin

Today sustainable development is a very pertinent issue. Communities do not want companies, specifically mining companies, to deplete a natural resource and leave. The goal is to minimize the negative impacts of mining and the boom/bust cycles of natural resource extraction. In this study a three part framework was developed to analyze the sustainability of the Flambeau Mine in Ladysmith, Wisconsin. The first and second part dealt with an in-depth local and regional analysis and whether the community was developing within its own vision. The third part used nine sustainability measures including: 1. Need Present Generation 2. Future Need 3. Acceptable Legacy 4. Full-Cost 5. Contribution to Economic Development 6. Equity 7. Consent 8. Respect for Ecological Limits, Maintenance of Ecological Integrity and Landscape Requirements 9. Offsetting Restoration This study concluded that the Flambeau Mine was sustainable relative to the first two criteria and that it can be considered mostly sustainable relative to the nine criteria. Overall it can be stated that the Flambeau Mine was a beneficial project to the Ladysmith Wisconsin area. Additionally it appeared to decrease the public’s negative perception of mining. Recommendations for future analytical work are made. Suggestions are made as to how mining companies could increase the potential for the attainment of sustainability in projects. It is recommended that this framework be used by other industries.

Planting and production of switchgrass (Panicum virgatum L.) as a bioenergy crop in Michigan's Upper Peninsula

Switchgrass (Panicum virgatum L.) is a perennial grass holding great promise as a biofuel resource. While Michigan’s Upper Peninsula has an appropriate land base and climatic conditions, there is little research exploring the possibilities of switchgrass production. The overall objectives of this research were to investigate switchgrass establishment in the northern edge of its distribution through: investigating the effects of competition on the germination and establishment of switchgrass through the developmental and competitive characteristics of Cave-in-Rock switchgrass and large crabgrass (Digitaria sanguinalis L.) in Michigan’s Upper Peninsula; and, determining the optimum planting depths and timing for switchgrass in Michigan’s Upper Peninsula. For the competition study, a randomized complete block design was installed June 2009 at two locations in Michigan’s Upper Peninsula. Four treatments (0, 1, 4, and 8 plants/m2) of crabgrass were planted with one switchgrass plant. There was a significant difference between switchgrass biomass produced in year one, as a function of crabgrass weed pressure. There was no significant difference between the switchgrass biomass produced in year two versus previous crabgrass weed pressure. There is a significant difference between switchgrass biomass produced in year one and two. For the depth and timing study, a completely randomized design was installed at two locations in Michigan’s Upper Peninsula on seven planting dates (three fall 2009, and four spring 2010); 25 seeds were planted 2 cm apart along 0.5 m rows at depths of: 0.6 cm, 1.3 cm, and 1.9 cm. Emergence and biomass yields were compared by planting date, and depths. A greenhouse seeding experiment was established using the same planting depths and parameters as the field study. The number of seedlings was tallied daily for 30 days. There was a significant difference in survivorship between the fall and spring planting dates, with the spring being more successful. Of the four spring planting dates, there was a significant difference between May and June in emergence and biomass yield. June planting dates had the most percent emergence and total survivorship. There is no significant difference between planting switchgrass at depths of 0.6 cm, 1.3 cm, and 1.9 cm. In conclusion, switchgrass showed no signs of a legacy effect of competition from year one, on biomass production. Overall, an antagonistic effect on switchgrass biomass yield during the establishment period has been observed as a result of increasing competing weed pressure. When planting switchgrass in Michigan’s Upper Peninsula, it should be done in the spring, within the first two weeks of June, at any depth ranging from 0.6 cm to 1.9 cm.

Promoting Biodiversity in Forest Ecosystems Using Ecological Forestry

A subset of forest management techniques, termed ecological forestry, have been developed in order to produce timber and maintain the ecological integrity of forest communities through practices that more closely mirror natural disturbance regimes. Even though alternative methods have been described and tested, these approaches still need to be established and analyzed in a variety of geographic regions in order to calibrate and measure effectiveness across different forest types. The primary objective of this research project was to assess whether group selection combined with legacy-tree retention could enhance mid-tolerant tree recruitment in a late-successional northern hardwood forest. In order to evaluate a novel alternative regeneration technique, 49 group-selection openings in three size classes were created in 2003 with a biological legacy tree retained in the center of each opening. Twenty reference sites, managed using single-tree selection, were also analyzed for comparison. The specific goals of the project were to: 1) determine the fate and persistence of the openings and legacy trees 2) assess the understory response of the group-selection openings versus the single-tree selection reference sites, and 3) evaluate the spatial patterns of yellow birch (Betula alleghaniensis Britt.) and eastern hemlock (Tsuga canadensis (L.) Carr.) in the group-selection openings. The results from 8-9 years post-study implementation and the changes that have occurred between 2004/5 and 2011/12 are discussed. The alternative regeneration technique developed and assessed in this study has the potential to enrich biodiversity in a range of forest types. Projected group-selection opening persistence rates ranged from 41-91 years. Openings from 500-1500 m2 are predicted to persist long enough for mid-tolerant tree recruitment. The legacy trees responded well to release and experienced a low mortality rate. Yellow birch (the primary shade mid-tolerant tree in the study area) densities increased with opening size. Maples surpassed all other species in abundance. In the sapling layer, sugar maple (Acer saccharum Marsh.) was 2 to over 300 times more abundant in the group-selection openings and 2 to 3 times more abundant in the references sites than all other species present. Red maple (Acer rubrum L.) was the second most abundant species present in the openings and reference sites. Spatial patterns of yellow birch and eastern hemlock in the openings were mostly aggregated. The southern edges of the largest openings contained the highest magnitude of yellow birch and eastern hemlock per unit area. Continued monitoring and additional treatments will likely be necessary in order to ensure underrepresented species successfully reach maturity.

TIME LAPSE SEISMIC OBSERVATIONS AND EFFECTS OF RESERVOIR COMPRESSIBILITY AT TEAL SOUTH OIL FIELD

One of the original ocean-bottom time-lapse seismic studies was performed at the Teal South oil field in the Gulf of Mexico during the late 1990’s. This work reexamines some aspects of previous work using modern analysis techniques to provide improved quantitative interpretations. Using three-dimensional volume visualization of legacy data and the two phases of post-production time-lapse data, I provide additional insight into the fluid migration pathways and the pressure communication between different reservoirs, separated by faults. This work supports a conclusion from previous studies that production from one reservoir caused regional pressure decline that in turn resulted in liberation of gas from multiple surrounding unproduced reservoirs. I also provide an explanation for unusual time-lapse changes in amplitude-versus-offset (AVO) data related to the compaction of the producing reservoir which, in turn, changed an isotropic medium to an anisotropic medium. In the first part of this work, I examine regional changes in seismic response due to the production of oil and gas from one reservoir. The previous studies primarily used two post-production ocean-bottom surveys (Phase I and Phase II), and not the legacy streamer data, due to the unavailability of legacy prestack data and very different acquisition parameters. In order to incorporate the legacy data in the present study, all three poststack data sets were cross-equalized and examined using instantaneous amplitude and energy volumes. This approach appears quite effective and helps to suppress changes unrelated to production while emphasizing those large-amplitude changes that are related to production in this noisy (by current standards) suite of data. I examine the multiple data sets first by using the instantaneous amplitude and energy attributes, and then also examine specific apparent time-lapse changes through direct comparisons of seismic traces. In so doing, I identify time-delays that, when corrected for, indicate water encroachment at the base of the producing reservoir. I also identify specific sites of leakage from various unproduced reservoirs, the result of regional pressure blowdown as explained in previous studies; those earlier studies, however, were unable to identify direct evidence of fluid movement. Of particular interest is the identification of one site where oil apparently leaked from one reservoir into a “new” reservoir that did not originally contain oil, but was ideally suited as a trap for fluids leaking from the neighboring spill-point. With continued pressure drop, oil in the new reservoir increased as more oil entered into the reservoir and expanded, liberating gas from solution. Because of the limited volume available for oil and gas in that temporary trap, oil and gas also escaped from it into the surrounding formation. I also note that some of the reservoirs demonstrate time-lapse changes only in the “gas cap” and not in the oil zone, even though gas must be coming out of solution everywhere in the reservoir. This is explained by interplay between pore-fluid modulus reduction by gas saturation decrease and dry-frame modulus increase by frame stiffening. In the second part of this work, I examine various rock-physics models in an attempt to quantitatively account for frame-stiffening that results from reduced pore-fluid pressure in the producing reservoir, searching for a model that would predict the unusual AVO features observed in the time-lapse prestack and stacked data at Teal South. While several rock-physics models are successful at predicting the time-lapse response for initial production, most fail to match the observations for continued production between Phase I and Phase II. Because the reservoir was initially overpressured and unconsolidated, reservoir compaction was likely significant, and is probably accomplished largely by uniaxial strain in the vertical direction; this implies that an anisotropic model may be required. Using Walton’s model for anisotropic unconsolidated sand, I successfully model the time-lapse changes for all phases of production. This observation may be of interest for application to other unconsolidated overpressured reservoirs under production.

Reclaiming Indigenous Narratives through Critical Discourses and the Autonomy of the Trickster

How do prevailing narratives about Native Americans, particularly in the medium of film, conspire to promote the perspective of the dominant culture? What makes the appropriation of Indigenous images so metaphorically popular? In the past hundred years, little has changed in the forms of representation favored by Hollywood. The introductory chapter elucidates the problem and outlines the scope of this study. As each subsequent chapter makes clear, the problem is as relevant today as it has been throughout the entire course of filmic history. Chapter Two analyzes representational trends and defines each decade according to its favorite stereotype. The binary of the bloodthirsty savage is just as prevalent as it was during the 1920s and 30s. The same holds true for the drunken scapegoat and the exotic maiden, which made their cinematic debuts in the 1940s and 50s. But Hollywood has added new types as well. The visionary peacemaker and environmental activist have also made an appearance within the last forty years. What matters most is not the realism of these images, but rather the purposes to which they can be put toward validating whatever concerns the majority filmmakers wish to promote. Whether naïvely or not, such representations continue to evacuate Indigenous agency to the advantage of the majority. A brief historical overview confirms this legacy. Various disciplines have sought to interrogate this problem. Chapter three investigates the field of postcolonial studies, which makes inquiry into the various ways these narratives are produced, marketed, and consumed. It also raises the key questions of for whom, and by whom, these narratives are constructed. Additional consideration is given to their value as commodities in the mass marketplace. Typically the products of a boutique-multiculturalism, their storylines are apt to promote the prevailing point of view. Critical theory provides a foundational framework for chapter four. What is the blockbuster formula and how do the instruments of capital promote it? Concepts such as culture industry and repressive tolerance examine both the function and form of the master narrative, as well as its use to control the avenues of dissent. Moreover, the public sphere and its diminishment highlight the challenges inherent in the widespread promotion of an alternative set of narratives. Nonetheless, challenges to prevailing narratives do exist, particularly in the form of Trickster narratives. Often subject to persistent misrecognition, the Trickster demonstrates a potent form of agency that undeniably dismantles the hegemony of Western cinema. The final chapter examines some of the Trickster's more subtle and obscure productions. Usually subjugated to the realm of the mystical, rather than the mythical, these misinterpreted forms have the power to speak in circles around a majority audience. Intended for an Other audience, they are coded in a language that delivers a type of direction through indirection, promoting a poignant agency all their own.