Life Sciences Commons^™

Developing Novel Food Packaging Products With High Barrier Properties, Enabled By Cnf, Nabanita Das

Electronic Theses and Dissertations

In recent times, plastic has become a highly favored choice for packaging due to its exceptional microbial, damage, and water-resistant properties. However, the alarming rise in plastic usage has led to adverse environmental pollution. This study aims to develop innovative food packaging solutions using renewable and compostable cellulose nanofibrils (CNFs). This thesis comprises two related studies on the barrier performance of novel food packaging materials, including oxygen barrier and oil/grease barrier properties. The goal of the first study was to enhance the mechanical and barrier properties of the cellulose nanofibril (CNF) films by inducing fibrils orientation for food packaging applications. …

Regeneration Response To Salvage Logging Following Tornado Disturbance, Colby K. Bosley-Smith

Electronic Theses and Dissertations

In an era of increasing natural disturbances, successful tree regeneration has grown more difficult to achieve. Salvage logging, a common management response to disturbance, may further impede regeneration success, although published literature currently remains inconclusive. In 2013, a rare tornado in northcentral Maine, USA, and subsequent salvage operation created three clear ‘treatments’ for evaluation of post-disturbance regeneration: blowdown, blowdown followed by salvage logging and an undisturbed control. In the summers of 2022 and 2023, (nine and ten) years post-tornado, we revisited this site to examine regeneration outcomes.

During the summer of 2022, we evaluated stand structure and regeneration success of …

Integrating Remote Sensing And Machine Learning To Assess Forest Health And Susceptibility To Pest-Induced Damage, Rajeev Bhattarai

Electronic Theses and Dissertations

Spruce budworm (Choristoneura fumiferana; SBW) outbreaks are cyclically occurring phenomena in the northeastern USA and neighboring Canadian provinces. These outbreaks are often of landscape level causing impaired growth and mortality of the host species namely spruce (Picea sp.) and balsam fir (Abies balsamea (L.) Mill.). Acknowledging the recent SBW outbreak in Canadian provinces like Quebec and New Brunswick neighboring the state of Maine, our study devised comprehensive techniques to assess the susceptibility of Maine forests to SBW attack. This study aims to harness the power of remote sensing data and machine learning algorithms to model and map the susceptibility of …

Mobilizing Indigenous Research Methodologies And Wabanaki Knowledge In Biophysical Research To Restore Wabanaki Sweetgrass Harvesting In Acadia National Park And Identify Basket Quality Black Ash Habitat For Emerald Ash Borer (Agrilus Planipennis) Preparedness, Suzanne Greenlaw

Electronic Theses and Dissertations

Black ash (wikpiyik/Fraxinus nigra) and sweetgrass (suwitokolasol/Anthoxanthum nitens) are two culturally important species to Wabanaki (Passamaquoddy, Penobscot, Maliseet, Mi’kmaq, and Abenaki) people, and to many other Native American tribes across the species’ ranges. Wabanaki relationships with black ash and sweetgrass include creation stories, generational stewardship practices, important economic markets, and cultural identity. Land use patterns, changes in access, invasive species, and climate change are negatively affecting both the health of black ash and sweetgrass and Wabanaki people’s relationship to these species. This dissertation consists of five chapters that mobilize Wabanaki knowledge and address Wabanaki access to sweetgrass and an invasive …

Forest Management In A Changing Climate: Integrating Social And Biopysical Sciences To Inform Adaptive Responses To Future Uncertainty, Peter Breigenzer

Electronic Theses and Dissertations

Forests provide numerous ecological and socio-economic benefits, yet climate change is creating novel and extreme conditions that threaten forests and disrupt traditional management practices. To address future uncertainty about how to manage forests amid a rapidly changing climate, researchers have developed adaptive management strategies that move away from using historical ecological baselines as management goals. However, despite increases in adaptive forest management frameworks, there are still concerns that private woodland owners (PWOs; also known as family forest owners or non-industrial private landowners) are not adopting beneficial practices. Additionally, since tree canopies often buffer understory microclimates (i.e., fine scale variation in …

Barriers To Use Of Cross-Laminated Timber In Maine, Shane R. O'Neill

Forest Resources Faculty Scholarship

To increase understanding of both the adoption rate and in-state manufacturing of mass timber In Maine, the 131^st Legislature and Governor Mills passed LD 881, a resolve directing a study of the barriers facing cross-laminated timber In Maine and provide recommendations to promote their use in construction. This study was developed in response to the resolve. The study engaged 108 unique participants to define available training, education, and experiences across the stakeholders throughout the building lifecycle process in the state.

From this information, the following five recommendations are proposed:

1. Understand the policies and initiatives of other states to develop …

Climate Interactions Drive Tree Physiology And Growth In A Northeastern Forest Ecotone, Alexandra M. Barry

Electronic Theses and Dissertations

Climate change is a threat to global forest ecosystems. In the northeastern United States, forest trees are facing rising temperatures and increasingly inconsistent moisture regimes. In addition to long-term changes in climate conditions, there is concern about the potential for more frequent and intense climate extremes, which can have severe and rapid negative effects on tree physiology and growth. Further, climate extremes may co-occur to produce a greater magnitude of effect than the sum of their parts, with a prominent example being hot droughts, which are increasing in occurrence and severity. The impact of these and other extreme climate interactions …

Cellulose Nanocrystals/Polydimethylsiloxane Composite Membranes For Air Dehydration With The Aim Of Energy-Use Reduction In Wood Kiln Drying, Nasim Alikhani

Electronic Theses and Dissertations

This dissertation project addressed the manufacture and evaluation of a small polydimethylsiloxane (PDMS) hollow fiber membrane system in the kiln drying of lumber in an attempt to explore air dehydration and reduced energy usage. Temperature and vacuum pressure exert the most pronounced influence on membrane efficiency. Under optimal conditions, the PDMS membrane module demonstrates a remarkable 66% efficiency in removing water vapor from a moist air stream. Based on the parameters of the lab system and its operational performance, a finite element model was developed to simulate its scaleup for a lab-scale lumber drying kiln to remove moisture from the …

Effects Of Large Wood Additions On Basal Resources, Macroinvertebrates, And Ecosystem Processes In The Narraguagus River, Maine, Val Watson

Electronic Theses and Dissertations

Ecological restoration is an increasingly common practice across ecosystems, and current practices aim to restore the biological and physical processes underlying ecosystem function, often for the sake of endangered higher-level consumers. Studies of restoration outcomes often report few or inconsistent ecological changes, and monitoring of restoration projects rarely measures ecological processes. Monitoring also usually measures outcomes at a single scale, despite the prevalence of scale- dependent phenomena across ecosystems. My thesis uses measurements of ecological processes to assess restoration response and evaluates responses across multiple scales. I focus here on a long-term large wood addition project on the Narraguagus River …

Long-Term Influence Of Commercial Thinning On Spruce-Fir Forests, Bishnu H. Wagle Mr.

Electronic Theses and Dissertations

This study investigates long-term influences of pre-commercial thinning (PCT) and commercial thinning (CT) treatments in spruce-fir forests, a key forest type in northeastern North America. Utilizing repeated measurements from replicated experimental research sites (n=15) in Maine, both stand- and tree-level responses to contrasting CT with and without prior PCT (NoPCT) have been quantified. In addition, an in-depth economic analysis, exploring the impact of different thinning treatments, associated costs, merchantability specifications, varying timber and carbon prices, and discount rates, on net present value (NPV) has been carried out using both measured and projected data. Thinning treatments at nine PCT sites combined …

Influence Of Biochar As A Soil Amendment On Soil Water Content And Wild Blueberry Physiology, Abigayl Novak

Electronic Theses and Dissertations

Maine wild (or lowbush) blueberries (Vaccinium angustifolium Ait.) continue to face challenges imposed by climate change. Reduced frequency of precipitation and increased drought conditions have negatively impacted this crop since it resides in sandy soils with limited retention of water and nutrients. The wild blueberry plants growing in water- and nutrient-poor sandy soils are likely to have poor resilience to drought, resulting in a decline in berry yield during drought years. Thus, there is an urgent need to find a drought management solution for wild blueberries. Compared with other drought management practices, such as irrigation systems, mulching, and adopting drought-resistant …

Developing An Enhanced Forest Inventory In Maine Using Airborne Laser Scanning: The Role Of Calibration Plot Design And Data Quality, Stephanie Willsey

Electronic Theses and Dissertations

Forests provide essential ecosystem services such as carbon sequestration, clean water, lumber, and more. It is important that foresters be able to collect accurate forest inventories, especially in a changing climate. Foresters need to know what is in the forest not only to manage for the economic benefits, but also to manage for social acceptability and ecological soundness to prevent further degradation of these ecosystem services. One way to collect accurate and precise forest inventories is through the utilization of remote sensing products. These enhanced forest inventories (EFIs) can be done at varying resolutions that are contingent on the plot …

New Office Supports Maine Climate Action, Parker Gassett, Ivan Fernandez

Maine Policy Review

Expanding and expediting access to climate change information can improve collective action outcomes. Accordingly, the Maine Climate Action Plan called for the creation of an information-coordinating hub, to enable effective and efficient use of climate information in Maine’s climate change response. To aid that need, the University of Maine created the Maine Climate Science Information Exchange (MCSIE) office as a gateway to information about climate-relevant research, the scientists conducting that research, and the most recent data and applied science efforts relating to Maine’s climate change strategies. The office was established in 2023, after a year of developing prototypes of the …

Quantitative Silviculture Of Northern Conifers, David G. Ray

Electronic Theses and Dissertations

Quantitative tools used to guide the management of important northern conifer species require updating and refinement to address changes in the contemporary resource and evolving objectives of ownership. This work builds on an extensive body of knowledge about stand density management and innovates some new approaches. In sum, the three chapters presented herein: 1) seek to strengthen and more fully articulate arguments for adopting relative density as a primary metric of stand density assessment, 2) quantify minimum stand densities to achieve full site occupancy and argue for more parity with treatment of maximum stand density, and 3) present an empirically …

Carbon Dioxide Emissions From Deadwood In Forests Of The Northeastern United States, Zoe Read

Electronic Theses and Dissertations

As the climate changes, understanding the sources and sinks of greenhouse gases such as carbon dioxide (CO₂) is increasingly important. However, several components of the carbon cycle within forests remain poorly understood. For example, knowledge gaps exist in our understanding of CO₂ emissions from coarse woody material (CWM; logs and stumps), including how emissions change over time, how they are influenced by environmental variables, and how they compare to soil and ecosystem-level CO₂ emissions.

To fill these knowledge gaps, we examined CO₂ emissions from CWM at three sites. We sampled 18 red spruce (Picea …

Form And Risk Class Distribution And Its Effect On Estimated Product Ratios In Commercial Species Commonly Found In Northeastern Forests And A Comparative Analysis Of Contrasting Field Inventory Methodologies, Ryan Smith

Electronic Theses and Dissertations

Estimating product ratios in hardwood forests is difficult due to the highly complex stem forms and diverse growth and regeneration strategies found in hardwood species. This is of particular concern for landowners with large ownerships requiring robust product potential estimates as part of both short-term tactical harvest planning and long-term growth and yield projections. Hardwood-dominated forests are generally managed for high-value sawlog and veneer products. This makes it increasingly important to identify strategies for improving hardwood management to meet economic (maximizing sawlog recovery) and ecological (maintaining healthy and diverse forests) goals.

This study seeks to achieve two primary goals. The …

Bibliography Of Mountain Biking Research: 1990-2021, Katelyn P. Kuklinski, Kimberly J. Coleman, Jessica E. Leahy, Elizabeth E. Perry, Emily Reinhardt, Luke Briccetti

Non-Thesis Student Work

Since the 1980s, mountain biking as an outdoor recreation activity has grown rapidly worldwide. Research on mountain biking is growing across many academic disciplines, from medicine to outdoor recreation and tourism research. This bibliography includes peer-reviewed research published on mountain biking within the context of natural resource management from 1990-2021.

Northern White-Cedar Stand Structure, Composition, And Ecophysiology: Implications For Management And Climate Change Resilience, Katlyn Schulz

Electronic Theses and Dissertations

Low rates of regeneration and recruitment for northern white-cedar (Thuja occidentalis) have been observed in lowland forests in some parts of its range, especially in comparison to its main tree competitor, balsam fir (Abies balsamea). In addition, climate projections suggest that suitable habitat conditions for the two species will decline in the northeastern United States and adjacent Canada due to widespread warming and increased variation in the timing and amount of precipitation. As such, future climate conditions may alter the competitive dynamics of these two species, which poses a major challenge for mitigating the negative effects of climate change through …

Contact Dewatering Of Cellulose Nanofibers For Biopolymer Composite Applications, Alexander Collins

Electronic Theses and Dissertations

Cellulose Nanofibrils (CNFs) are promising materials for reinforcement of polymer matrices attributable to their impressive physical and mechanical properties, as well as their biodegradability. However, the utilization of these materials in composites is made challenging by the water content of CNF slurries, the tendency of CNFs to agglomerate as they dry, and incompatibility between hydrophilic CNFs and hydrophobic polymer matrices. The most commercially viable drying methods to produce small-scale dry CNFs, such as spray drying, are very energy intensive, can only dry the materials down to micron-scale agglomerates, and do not preserve fibrillar aspect ratios. “Contact dewatering,” or the removal …

Quantifying Spatial Heterogeneity Of Wild Blueberries And Crop Water Stress Monitoring Using Remote Sensing Technologies, Kallol Barai

Electronic Theses and Dissertations

The wild blueberry is one of the major crops of Maine, with significant economic value and potential health benefits. Due to global climate change, drought impacts have been increasing significantly in recent years in the northeast region of the USA, causing significant economic losses in the agricultural sectors. It has been predicted to increase further in the future. Changing patterns of the elevated atmospheric temperatures, increased rainfall variabilities, and more frequent drought events have made the wild blueberry industry of Maine vulnerable, suggesting the adoption of novel approaches to mitigate the negative impacts of global climate changes. Also, wild blueberry …

Sustainability In Forest Operations: Harvesting On Fragile Ground, Best Management Practices Assessment, Perspectives On Forest Certification, And Life Cycle Assessment Of Forest Products, Alex Kunnathu George

Electronic Theses and Dissertations

Sustainably managed forest and forest products are at the center as the world move toward a green economy. Sustainable forest management (SFM) cannot be possible without sustainability in forest operations, which includes quality optimization and ergonomics along with environment, economics, and people. To excel in the above-mentioned performance areas, all tools need to be employed to generate knowledge that enables forest managers and policymakers to preserve forests as a renewable resource. Machine cost and productivity estimation, forest growth modeling (Forest Vegetation Simulator), soil erosion modeling (Universal Soil Loss Equation), forestry best management practices (BMP) assessment, questionnaire survey, and life cycle …

Comparative Life Cycle Assessment Of Embodied Carbon And Operational Energy Of Different Building Systems, Marilia Hellmeister

Electronic Theses and Dissertations

Due to human activity, the levels of carbon emissions found in the atmosphere have reached its highest concentration and therefore it is necessary to find solutions to reduce, mitigate and adapt to a more sustainable pattern of development. The substitution of fossil fuel-dependent materials with renewable materials which exhibit lower embodied carbon is an option to be considered in the design phase of a building. Engineered wood product innovations over the past twenty years, coupled with design innovation and building code modifications have demonstrated their viability in multi-story construction (18 stories). The goals of this project are to 1) estimate …

Linkind Deadwood Inhabiting Fungi To Carbon Dioxide Flux Of Decomposing Coarse Woody Debris, Elyse Daub

Honors College

The decomposition of wood is driven by a combination of abiotic and biotic factors, the most influential of them all are fungi. These decomposer fungi use the wood for food, digesting woody material to absorb nutrients and release carbon dioxide. Fungi are the primary drivers of decomposition in most terrestrial ecosystems; thus, the rate and degree of decomposition are greatly dependent on the community of fungi found on woody debris. However, little is known about which fungi decompose woody debris most efficiently. This study aims to investigate the decomposer fungi in the Bear Brook Watershed via molecular techniques and quantify …

Yield And Mechanical Properties Of Veneer From Maine-Grown Eastern Spruce And Balsam Fir, Marshal Bertrand

Electronic Theses and Dissertations

This research focused on the utilization of Maine Eastern spruce and balsam fir for veneer production. Maine currently has no manufacturers of or products using structural veneer. The diversification of markets for Maine’s softwoods has been identified as a route to increase the resilience of the forest-based economy. Veneer production technology has improved significantly since the last look at Maine spruce veneer (1969), justifying the reinvestigation of Maine spruce-fir veneer. The objective of this research was to provide information on the yield of processing veneer and the quality of said veneer. A sample size of 37 Eastern spruce and 38 …

Development And Production Of Cellulose Nanocrystal Fillers, Pva Fibers And Composite Pva/Cnc Fibers With Electro-Spray/Spinning For Application In Thermoplastic Reinforcement, J. Elliott Sanders

Electronic Theses and Dissertations

The work within this dissertation involved the production and utilization of cellulose nanomaterials within the context of electrospraying and electrospinning. The production of nano-dimension cellulose nanocrystal (CNC) powders was a novel contribution to the multi-decade efforts surrounding the drying of CNC suspensions, and the powders were produced by electrospraying reduced surface tension suspensions at room temperature. The CNC powders were used as a control for comparison with electrospun fibers in thermoplastic composites. Nano-diameter (submicron) fibers generated most of the work outlined in this dissertation and were produced using a water-soluble, sustainably derived, poly (vinyl alcohol) (PVA). The CNC suspension was …

Assessing The Long-Term Effects Of Natural Disturbance-Based Silvicultural On The Avian Assemblage At The Acadian Forest Ecosystem Research Program, Carl Pohlman

Electronic Theses and Dissertations

Active forest management alters the resources available to forest-obligate species. Large-scale intensive management practices where timber production is the primary objective can lead to notable ecological changes in forest ecosystems. A key concept of ecological forestry is to design forest management activities to emulate natural disturbance regimes as a way to maintain the ecological integrity of forests. The Acadian Forest Ecosystem Research Program (AFERP) was undertaken as an experimental demonstration of management reflective of the region’s disturbance regime, which typically produces small canopy gaps. AFERP includes nine research areas assigned to three silvicultural treatments: unharvested control, small gap (expanding-group selection …

Rusty Blackbird Use Of Commercial Spruce-Fir Forests Of Northern New England, Luke M. Douglas

Electronic Theses and Dissertations

The Rusty Blackbird (Euphagus carolinus) has experienced a steep population decline since the 1970s, with qualitative accounts suggesting that the species’ numbers have been falling prior to the 1950s. The reason for this decline is still not fully understood, though recent work suggests that habitat destruction and disturbance in the breeding and wintering ranges are likely causes. The species is a habitat specialist that relies on spruce-fir stands located near wetlands for breeding in the boreal and Acadian forests of North America. Historically, the natural disturbance regime in the Acadian region included biotic agents such as beaver and …

Mp765: Creating The Orono Bog Boardwalk: A Facility For Education, Research, And Recreation, Ronald B. Davis

Miscellaneous Publications

A memoir by Dr. Ronald Davis detailing the creation of the Orono Bog Boardwalk. The Orono Bog Boardwalk is a premier destination in the Bangor/Orono area for persons wishing to experience the beauty and fascinating plants and animals of a Maine bog. The 1-mile boardwalk loop trail begins at the forested wetland edge in the Bangor City Forest, and after 800 feet crosses the Orono town line into the portion of the Orono Bog owned by the University of Maine. Along the way the boardwalk passes through a wide range of changing vegetation and environments on its way to the …

College Of Natural Sciences, Forestry, And Agriculture (University Of Maine) Records, 1885-2003, Special Collections, Raymond H. Fogler Library, University Of Maine

Finding Aids

The College of Natural Sciences, Forestry, and Agriculture was established in 1996 as part of a University of Maine restructure. Many of the individual schools and units within the college had formerly been in the College of Natural Resources, Forestry and Agriculture which itself was established in 1993 following the merger of the College of Forest Resources and College of Applied Sciences and Agriculture. The first dean of the College of Natural Sciences, Forestry, and Agriculture was G. Bruce Wiersma.

The record group includes copies of College of Natural Sciences, Forestry, and Agriculture and individual unit publications; photographs and negatives …

Soil Organic Carbon In Maine, Its Responses To Biochar Addition, And Climate Change, Xue Bai

Electronic Theses and Dissertations

Soil organic carbon (SOC), as one of the largest C pools in terrestrial ecosystems, plays a key role in governing soil ecosystem processes and climate regulation. Climate change concerns have resulted in a rapidly growing interest in understanding the potential for natural climate solutions (NCS) that include enhancing SOC sequestration and reduce net atmospheric greenhouse gas (GHG) emissions. This research focused on addressing information needs about SOC in Maine, specifically in evaluating available soil databases to accurately quantify SOC density and concentration, and study the response of selected representative Maine soils to biochar amendments under a changing climate.

Maine SOC …