Natural Resources Management and Policy Commons^™

Forest Management In The Context Of Global Change: Impacts Of Disturbance, Adaptive Management, And Invasive Species On Northeastern Forests, Jennifer Santoro

Graduate College Dissertations and Theses

Climate change is predicted to have variable and uncertain effects on forested ecosystems globally. In the northeastern US, natural disturbances have historically been a central driver of forest successional dynamics, but as climate warming is projected to alter the frequency and severity of these events, post-disturbance management strategies to sustain biodiversity and ecosystem services must adaptively change to promote forest resilience. A suite of adaptive silvicultural actions has been proposed to promote forest resilience in the face of uncertainty, but due to the multi-decadal scale of forest management, initial field experiments are only beginning to show results. To address these …

Revealing The Direct And Indirect Effects Of Climate Change On Soil Nutrient Dynamics And Forage Resources In Mountain Ecosystems, Kenna Elizabeth Rewcastle

Graduate College Dissertations and Theses

Modern climate change is already altering the structure and function ofecosystems around the world in nontrivial ways. Mountain ecosystems in particular will continue to experience a greater magnitude and rate of climatic warming than the global average, threatening the stability of key ecosystem processes like nutrient cycling as well as the supply of benefits from ecosystem services provided by mountains. While significant advancements have been made to address the direct effects of rising temperatures on nutrient cycling dynamics, our understanding of the synergies between the direct effects of warming and the indirect effects of climate change, mediated by the response …

Changing Environmental Conditions And The Response And Potential Adaptability Of Freshwater Whitefishes, Taylor R. Stewart

Graduate College Dissertations and Theses

Changes in winter conditions, such as increased temperatures and decreased ice coverage, have been observed worldwide. The responses of many lake fish populations to changing winters are projected to be inadequate to counter the speed and magnitude of climate change. Such environmental changes have been hypothesized to explain the low recruitment observed in freshwater whitefishes (Salmonidae Coregoninae). My research focused on measuring the impact changing winter conditions may have on coregonine reproductive phenology and developmental and morphological traits to better predict changes in coregonine populations as a result of climate change.

I used experimental incubation methods and modeling to explore …

Shaping Soil: Examining Relationships Between Agriculture And Climate Change, Lindsay Barbieri

Graduate College Dissertations and Theses

As the ripple-effects of a changing climate shape our planet, understanding relationships between agriculture and climate change is critical. With agricultural practices shaping soils on over a third of the earth’s land surface, the soils and lands where food is produced are integral grounds for examining these relationships. While not all humans practice agriculture in similar or damaging ways, nevertheless, dominant agricultural practices are displacing beings and ecosystems and perturbing global nutrient cycles across the planet. These entwined imbalances of dominance and nutrients result in flows of excess nitrogen, phosphorus, and carbon that are responsible for nearly three-fourths of the …

Factors Affecting The Adoption Of Automated Wood Pellet Heating Systems In The Northeastern Us And Implications For The Transition To Renewable Energy, Laura Edling

Graduate College Dissertations and Theses

Public and private incentive programs have encouraged conversions to high efficiency, low emissions wood heating systems as a strategy to promote renewable energy and support local economies in the Northeastern US. Despite these efforts, the adoption of these systems remains slow. The study that is the subject of this dissertation examines several social, economic, policy and environmental factors that affect the decisions of individuals and small-scale institutions (local business and community facilities) to transition to automated wood pellet boilers and furnaces (AWPH) utilizing local fuel sources. Due to the complexity and risk associated with conversion, the transition to these systems …

Uncovering The Drivers Of Non-Native Plant Invasions Using Ecological Data Synthesis, Marina Golivets

Graduate College Dissertations and Theses

Understanding what promotes invasiveness of species outside their native range and predicting which ecosystems and under which conditions will be invaded is an ultimate goal of the field of invasion ecology. Obtaining general answers to these questions requires synthesis of extensive yet heterogeneous empirical evidence, coupled with a solid theoretical background. In this dissertation, I sought to provide insight into the drivers of non-native plant invasions through combining and synthesizing ecological data from various sources using advanced statistical techniques. The results of this work are presented as three independent research studies.

In the first study, I aimed to understand what …

Tools For Landscape-Scale Automated Acoustic Monitoring To Characterize Wildlife Occurrence Dynamics, Cathleen Michelle Balantic

Graduate College Dissertations and Theses

In a world confronting climate change and rapidly shifting land uses, effective methods for monitoring natural resources are critical to support scientifically-informed management decisions. By taking audio recordings of the environment, scientists can acquire presence-absence data to characterize populations of sound-producing wildlife over time and across vast spatial scales. Remote acoustic monitoring presents new challenges, however: monitoring programs are often constrained in the total time they can record, automated detection algorithms typically produce a prohibitive number of detection mistakes, and there is no streamlined framework for moving from raw acoustic data to models of wildlife occurrence dynamics. In partnership with …

Physicochemical Properties Of Residuals From Anaerobic Digestion Of Dairy Manure And Food Waste: Nutrient Cycling Implications And Opportunities For Edible Mushroom Cultivation, Brendan J. O'Brien

Graduate College Dissertations and Theses

Organics recycling is increasing in New England as multiple states have enacted laws to divert organic materials, including food scraps and food processing residuals, away from landfills. Anaerobic digesters on dairy farms represent an attractive approach to food waste recycling because existing infrastructure is in place and co-digestion of dairy manure with food waste can increase renewable biogas production. In addition, anaerobic digestion results in effluents that can be separated into solid and liquid residual materials, or 'digestates'. Screw-press separated solids consist of lignocellulosic biomass resistant to microbial degradation during anaerobic digestion. These separated solids are typically recycled on farms …

Regeneration Responses To Management For Old-Growth Characteristics In Northern Hardwood-Conifer Forests, Aviva Joy Gottesman

Graduate College Dissertations and Theses

Silviculture practices interact with multiple sources of variability to influence regeneration trends in northern hardwood forests. There is uncertainty whether low-intensity selection harvesting techniques will result in desirable tree regeneration. Our research is part of a long-term study that tests the hypothesis that a silvicultural approach called "structural complexity enhancement" (SCE) can promote accelerated development of late-successional forest structure and functions. Our objective is to understand the regeneration dynamics following three uneven-aged forestry treatments modified to increase postharvest structural retention: single-tree selection, group selection, and SCE. In terms of regeneration densities and composition, how do light availability, competition, seedbad, and …

Early Feeding In Lake Trout Fry (Salvelinus Namaycush) As A Mechanism For Ameliorating Thiamine Deficiency Complex, Carrie L. Kozel

Graduate College Dissertations and Theses

Recruitment failure of lake trout (Salvelinus namaycush) in the Great Lakes has been attributed in part to the consumption of alewife (Alosa pseudoharengus) by adult lake trout, leading to Thiamine Deficiency Complex (TDC) and early mortality in fry. The current understanding of thiamine deficiency in lake trout fry is based on information from culture and hatchery settings, which do not represent conditions fry experience in the wild and may influence the occurrence of TDC. In the wild, lake trout fry have access to zooplankton immediately following hatching; previous studies found that wild fry begin feeding before complete yolk-sac absorption. However, …

Lasting Legacies Of Hurricane, Harvesting, And Salvage Logging Disturbance On Succession And Structural Development In An Old-Growth Tsuga Canadensis-Pinus Strobus Forest, Emma Sass

Graduate College Dissertations and Theses

Disturbance events affect forest composition and structure across a range of spatial and temporal scales, and forest development may differ after natural, anthropogenic, or compound disturbances. Following large, natural disturbances, salvage logging is a common yet controversial management practice around the globe. While the short-term impacts of salvage logging have been studied in many systems, the long-term effects remain unclear. Further, while natural disturbances create many persistent and unique microsite conditions, little is known about the long-term influence of microsites on forest development. We capitalized on over eighty years of data on stand development following the 1938 hurricane in New …

Importance Of Agricultural Systems As Multifunctional Landscapes, Flavio Sutti

Graduate College Dissertations and Theses

Agricultural landscapes provide our society with many benefits. While food production is the primary role of these landscapes, sociocultural and ecological benefits are also provided. However, the full scope of benefits that we obtain from agricultural landscapes are not always taken into account, and with the intensification of agricultural activities, more complex multifunctional landscapes are converted into simpler and less-functional landscapes. I used a heterogeneous agricultural landscape, the Champlain Valley of Vermont, as a case study to examine the interactions between landscape structure and the provision of landscape functions and services.

I analyzed sociocultural and production functions indices obtained via …

Long-Term Forest Carbon Storage And Structural Development As Influenced By Land-Use History And Reforestation Approach, Andrea Rose Urbano

Graduate College Dissertations and Theses

Temperate forests are an important carbon sink, yet there is uncertainty regarding land-use history effects on biomass accumulation and carbon storage potential in secondary forests. Understanding long-term biomass dynamics is important for managing forests as carbon sinks and for co-benefits such as watershed protection and biodiversity. However there are many unanswered questions regarding these dynamics in northeastern U.S. forests: How have secondary forests of the U.S. Northeast recovered post nineteenth century agricultural abandonment? How has the region's extensive land-use history influenced long-term structural development and aboveground carbon storage? To answer these questions, we employed a longitudinal study based on twelve …

Edge-Of-Field Water And Phosphorus Losses In Surface And Subsurface Agricultural Runoff, Laura B. Klaiber

Graduate College Dissertations and Theses

Quantifying effectiveness of soil management practices on surface and subsurface water quality at the field scale is becoming increasingly important in the Lake Champlain Basin and other agricultural watersheds. During 2012 and 2013, field plots (22.9 x 45.7 m) were established at the Lake Alice Wildlife Area in Chazy, NY to begin a long-term water quality monitoring study. Plots were established in a cool season grass field (1 ha) leased and managed by the William H. Miner Agricultural Research Institute in Chazy, NY. The soil type transitions from an excessively drained outwash soil on the upslope to a very poorly …

Lidar Remote Sensing Of Forest Canopy Structure: An Assessment Of The Accuracy Of Lidar And Its Relationship To Higher Trophic Levels, Christopher Felix Hansen

Graduate College Dissertations and Theses

Light detection and ranging (LiDAR) data can provide detailed information about three-dimensional forest horizontal and vertical structure that is important to forest productivity and wildlife habitat. Indeed, LiDAR data have been shown to provide accurate estimates to forest structural parameters and measures of higher trophic levels (e.g., avian abundance and diversity). However, links between forest structure and tree function have not been evaluated using LiDAR. This study was designed and scaled to assess the relationship of LiDAR to multiple aspects of forest structure and higher trophic levels (arthropod and bird populations), which included the ground-based collection of percent crown and …

The Impact Of Engagement With Community Supported Agriculture On Human Attitude Towards The Sustainable Food Movement, Ariana Margarita Cano

Graduate College Dissertations and Theses

With a total of 164 community supported agriculture programs (CSA), Vermont is leading the "locavore" movement in the United States, ranked number one in the country with the most CSAs and Food Hubs per capita. ("Locavore Index," 2013)

CSAs have a large positive impact on reducing carbon emissions, advancing local economic growth, and promoting healthy lifestyles of consumers. The purpose of this study is to explore the overall experience of individuals in comparison to their current social norm, individual attitudes, identity, and intentions of change, and understand any change overtime in their individual attitude and behavior.

Attitude change was measured …