Life Sciences Commons^™

Sixty Years Of Change In Picea Rubens (Red Spruce) Forests Of Coastal Maine, U.S.A., Camilla Seirup

Electronic Theses and Dissertations

Picea rubens is a cold-adapted, sub-boreal species whose existence along Maine’s coast is enabled by the moderating effect of the Gulf of Maine. Picea rubens, and the larger spruce-fir forest type, are highly vulnerable to climate change with studies predicting near complete loss of P. rubens suitable habitat in the USA as early as 2060. However, despite these dire future predictions, P. rubens populations have recently seen positive trends across a range of metrics. In addition, coastal Maine may have served as a refugium for P. rubens during the mid-Holocene warming, remaining cooler and wetter than inland regions. Therefore, …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Economics And Operational Decision Constraints Of Small-Diameter Tree Harvesting, Libin Thaikkattil Louis

Electronic Theses and Dissertations

Sustainably managed forests are crucial in balancing trade-off between various ecosystem functions and optimum product utilization. Improving the utilization of these renewable resources through diversified forest wood products faces various socio-economic, ecological, and cultural challenges. A major challenge faced by forest managers in the Northeastern United States is overstocked stands dominated by small-diameter trees (SDT). Major woody portion of the harvested residues is constituted by SDT and are typically of low value. Data from the national inventory indicates a high number of SDT in Northeastern forests such that the average size of all trees in the region is less than …

The Future Of Maine's Forests Under Alternative Socioeconomic, Climate And Conservation Pathways, Jianheng Zhao

Electronic Theses and Dissertations

Maine is a historically important timber supply region in North America and understanding the potential change in forestlands and their product industries affected by climate change and various socio-economic conditions can better improve the forest healthy and sustain a sustainable product industry. A statistical harvest choice model for the state of Maine was developed in chapter 1. It was estimated using a multinomial logit model of two products, under varying management intensities, and ownership classifications across varying market conditions. Results indicate that stumpage prices have a significant effect on forest landowners' harvest decisions and that the expansion of conservation land …

Fostering Climate Change Resilience: A Socio-Ecological Forest Systems Approach, Alyssa R. Soucy

Electronic Theses and Dissertations

As climate change continues to impact socio-ecological systems, those that rely on natural resources are highly sensitive to climatic changes. Maine’s forest industry provides for the economic and social well-being of many residents and is especially vulnerable to climate change impacts. Changes in growing season length and timing, forest health threats imposed by insects and pathogens, extreme weather events, shifting forest composition, and changes in natural disturbance severity and frequency have already begun, and are projected to continue, to impact forest systems in the Northeastern U.S. While climate change presents a threat to forest systems, opportunities also arise due to …

Exploring The Social Effects Of Increased Hiker Use At The Northern Terminus Of The Appalachian Trail, Leah Beck

Electronic Theses and Dissertations

The increase of tourism and outdoor recreation popularity has produced a field of research revolved around the social and environmental impacts of visitors. Past research has shown that understanding visitor use and behavior is essential for influencing management strategies. This study focused on understanding the crowding perceptions and experiences of hikers who summit Maine’s tallest mountain, Mount Katahdin. Katahdin is designated as the northern terminus of the Appalachian Trail (AT) which has seen a notable increase in use from long distance hikers in the last 25 years. Increased long-distance AT hikers, and documented issues with hiker behavior in Baxter State …

Spruce Budworm Defoliation Dynamics And Its Influence On The Acadian Forest, Cen Chen

Electronic Theses and Dissertations

Spruce budworm (SBW; Choristoneura fumiferana (Clem.)) is the primary forest defoliator in North America. SBW defoliation has affected tens of millions ha of forests during its periodic outbreaks and caused severe growth reduction and mortality of spruce-fir (Picea-Abies) species. Evaluating these damaging effects of SBW defoliation requires understandings of the variation and dynamics of defoliation, as well as trees' variable responses to defoliation in consideration of various tree- stand-, and site-level factors. In this dissertation, we developed statistical models to 1) evaluate influences of SBW defoliation on spruce-fir stand dynamics of annual volume net growth, mortality, …

Understory Response To Gap-Based, Multi-Aged Silviculture, Maggie R. Mansfield

Electronic Theses and Dissertations

The ubiquity of managed forests has created a demand for management practices that simultaneously meet traditional management goals and maintain biodiversity. Ecological forestry, which emulates the outcomes of natural disturbances, is assumed to enhance native species survival by creating conditions similar to those under which species have long survived. We assessed this assumption by exploring the herbaceous plant community response to 20 years of gap-based, multi-aged silviculture treatments. Additionally, we assessed the ability of the treatments to meet silvicultural objectives by exploring trends in tree regeneration. The Acadian Forest Ecosystem Research Project (AFERP) is a replicated study established in 1995 …

Productivity, Costs, And Best Management Practices For Major Timber Harvesting Frameworks In Maine, Harikrishnan Soman

Electronic Theses and Dissertations

Though the timber harvesting industry in Maine ranges over two centuries, the state has more forest cover than a century ago. Currently, some of the crucial challenges faced by the forest management industry in Maine and elsewhere in the northeastern US are increasing costs of forest operations, diminishing monetary returns and falling markets.

The major goal of this study was to evaluate the production economics of timber harvesting frameworks under different silvicultural prescriptions common to the region. For which, two field studies were conducted at two different locations in Maine, US. The first field study (Study I) was conducted in …

Improving Conservation Of Declining Young Forest Birds Through Adaptive Management, Anna Buckardt Thomas

Electronic Theses and Dissertations

Early successional forest and shrubland habitats are collectively called young forest. Changes in disturbance regimes and land use conversion resulted in declines of young forest and associated wildlife across eastern North America. Conservation of declining young forest birds relies on the maintenance and creation of young forest habitats used for breeding. American Woodcock (AMWO; Scolopax minor) and Golden-winged Warbler (GWWA; Vermivora chrysoptera) are two declining young forest species. Conservation plans for both species use an adaptive management framework, which is an iterative process of planning, management actions, and monitoring and evaluation, in the context of species conservation goals. Adaptive management …

Associations Between Avian Spruce-Fir Species, Harvest Treatments, Vegetation, And Edges, Brian W. Rolek

Electronic Theses and Dissertations

Habitat loss is the primary cause of species loss and declines of global biodiversity. Several birds associated with the spruce-fir forest type (hereafter spruce-fir birds) have declining populations across the continent in the Atlantic Northern Forest, and the extent of coniferous forest has declined in some areas. This region is extensively and intensively managed for timber products.

To investigate the influence from harvest treatments on the spruce-fir bird assemblage during the breeding and post-breeding period in lowland conifer and mixed-wood forests, we used avian point count detection data to test for associations between avian assemblages and seven common harvest treatments. …

Drivers Of Tree Growth And Mortality In An Uneven-Aged, Mixed-Species Conifer Forest Of Northeastern United States, Erin Fien

Electronic Theses and Dissertations

Individual tree growth and mortality drive forest stand dynamics and are important, universal metrics of tree success. Studying the factors that affect growth and mortality is particularly challenging in mixed-species, uneven-aged systems due to their defining heterogeneity and strong temporal and spatial variability. However a better understanding of the factors driving growth and mortality in mixed-species, uneven-aged forest is crucial to managing and maintaining these valuable systems for the future.

The goal of this study was to determine the relative importance of individual tree attributes (e.g., species, size, neighborhood crowding, crown position) and environmental characteristics (e.g., soil moisture) in driving …

New Approaches To Mapping Forest Conditions And Landscape Change From Moderate Resolution Remote Sensing Data Across The Species-Rich And Structurally Diverse Atlantic Northern Forest Of Northeastern North America, Kasey R. Legaard

Electronic Theses and Dissertations

The sustainable management of forest landscapes requires an understanding of the functional relationships between management practices, changes in landscape conditions, and ecological response. This presents a substantial need of spatial information in support of both applied research and adaptive management. Satellite remote sensing has the potential to address much of this need, but forest conditions and patterns of change remain difficult to synthesize over large areas and long time periods. Compounding this problem is error in forest attribute maps and consequent uncertainty in subsequent analyses. The research described in this document is directed at these long-standing problems.

Chapter 1 demonstrates …

Immersed In Fire: The Use Of Virtual Reality As An Attitude Assessor And Boundary Object In Wildland Fire Management, Casey Olechnowicz

Electronic Theses and Dissertations

Interest in using prescribed burning as a forest management tool to promote forest health and regeneration is growing in Maine. The goal for this research was to better understand the way that the public perceives prescribed burning practices in wildland-urban interfaces, with an emphasis placed on how immersive imagery, closely related to virtual reality (VR), compares to traditional communication methods. We specifically focus on the social acceptability of prescribed burning and analyze how the level of immersive imagery is related to that acceptability (Ahn, 2015; Bricken, 1990; Fogg, Cuellar, and Danielson, 2009; Smith 2015; Wiederhold, Davis, and Wiederhold, 1998). The …

Big Data For Small Parks: Examining Regional Vegetation Patterns To Assess The Current Condition And Vulnerability Of Eastern National Parks To Climate Change, Kathryn M. Miller

Electronic Theses and Dissertations

The United States National Park Service mission is to preserve natural and cultural resources unimpaired for future generations. Given climate change, the paradigm of restoring natural resources to their pre-European settlement condition is no longer appropriate or achievable management. Instead, we must promote resilience and plan for adaptation. This approach poses many challenges, including knowledge gaps about the current condition of park ecosystems including wetlands, and lack of information about the matrix surrounding parks, which will strongly influence park ecosystem response to climate change. My dissertation research focused on filling these knowledge gaps to provide much needed information to managers …

Long-Term Sustainability Of Northern Mixedwood Management: Spatial And Temporal Aspects Of Forest Productivity, Bethany L. Munoz

Electronic Theses and Dissertations

Natural disturbances of moderate severity are common in northern temperate forests in Maine, USA. Given estimated return intervals of 575-1000 years for severe windstorms and 385-1200 years for severe fire events, few opportunities arise to evaluate high severity disturbances in northern mixedwood or northern conifer forests. This research evaluated 50-year results of clearcutting with whole-tree harvesting (WTH), stem-only harvesting (SOH), and stem-only harvesting with prescribed burning (SOHB) on growing stock, composition, and relationships among foliar and soil nutrient concentrations. At the other end of the disturbance spectrum, this research also investigated 60-year results of single-tree selection with a 10-year cutting …

Evaluating The Influence Of Stem Form And Vigor On Product Potential, Growth, And Survival For Northern Commercial Hardwood Species, Mark Castle

Electronic Theses and Dissertations

Northern hardwood and mixed-wood forest types occupy a considerable percentage of the forest landscape across the Northeastern United States and portions of eastern Canada. While capable of producing valuable saw timber and veneer products, hardwood species demonstrate a wide range of stem quality resulting from the large variety of stem forms and defects that these species can manifest. The effect of different stem forms and damage has largely not been accounted for in predictions of volume, growth, and mortality. In addition to potential bias in growth and yield applications, the lack of quantification of these features has left the …

The Paradigm Of Engagement: Integrating Social Science And Extension Outreach To Engage Beginning Family Forest Owners, Ian Anderson

Electronic Theses and Dissertations

Family forest owners own 36% of the forestland in the United States. These lands provide ecosystem services and natural resources to a broad community and management of these lands should be based on informed decisions. However, many family forest owners are unaware of conservation and stewardship options, and the number of unaware landowners may be increasing. A new cohort of beginning family forest owners (BFFO), who have acquired land in the past 5 years, has emerged. Programs designed to inform landowners about different management opportunities tend to attract only a small group of interested owners. In the following 2 phase …

Economic And Spatial Impacts Of A Wildlife Habitat Policy On Forest Management, Karin N. Bothwell

Electronic Theses and Dissertations

Regulations protecting habitat of forest-dwelling species often impact forest management practices. Those impacts may be mutually beneficial to both wildlife and forestry or they may lead to unanticipated negative outcomes, such as an associated economic cost compared to management free from habitat regulations. One example of a regulation that impacts forest management is the zoning of winter habitat of white-tailed deer (Odocoileus virginianus) in Maine, where deer abundance has been consistently below socially desired levels in most areas of the State since the 1970s due in part to the heavy toll of severe winter weather. To mitigate winter-related mortality, the …

Forest Products Trucking Industry In Maine: Opportunities And Challenges, Anil Koirala

Electronic Theses and Dissertations

Forest transportation from in-woods to the final point of utilization is one of the major components in forest harvesting operations in terms of economics, public visibility and safety. In many cases, the price of delivered wood products depends on the transportation distance. Transportation is also crucial in terms of ensuring the supply of demanded products on time.

Globally, road transportation being the most predominant medium for forest products transportation, majority of research are focused on this subject. These scientific researches are of diverse nature; with main emphasis on improving the supply chain issues and minimizing cost of transportation, including road …

Old-Growth Characteristics Of Northern White-Cedar Stands, Nathan Wesely

Electronic Theses and Dissertations

Northern white-cedar (Thuja occidentalis; hereafter white-cedar) communities have received relatively little research attention, and managers lack the tools used in the management of other commercial tree species. This includes the recognition of old-growth characteristics and the differentiation between old-growth and partially harvested stands, particularly in the context of Forest Stewardship Council (FSC-US) certification. Specifically, there is very little information about characteristics that define old-growth white-cedar stands despite the species’ abundance and wide distribution. Regional indices for late-successional or old-growth stands (Whitman and Hagan, 2007) do not include white-cedar. Forests dominated by white-cedar represent a type that currently lacks …

Modeling And Forecasting The Influence Of Current And Future Climate On Eastern North American Spruce-Fir (Picea-Abies) Forests, Caitlin Andrews

Electronic Theses and Dissertations

The spruce-fir (Picea-Abies) forest type of the Acadian Region is at risk of disappearing from the United States and parts of Canada due to climate change and associated impacts. Managing for the ecosystem services provided by this forest type requires accurate forecasting of forest metrics across this broad international region in the face of the expected redistribution of tree species. This analysis linked species specific data with climate and topographic variables using the nonparametric random forest algorithm, to generate models that accurately predicted changes in species distribution due to climate change. A comprehensive dataset, consisting of 10,493,619 observations …