Physical Sciences and Mathematics Commons^™

Lethal And Sublethal Effects Of Beauveria Bassiana On Maine Ticks Across Soil Ph, Alexander Mahar

Honors College

Ticks are obligate parasite arthropods that are becoming increasingly common in northern regions of the United States. Ticks such as the black-legged tick (Ixodes scapularis) and the American dog tick (Dermacentor variabilis) are vectors for pathogens that cause a wide range of diseases, and as these ticks increase their exposure to humans, the diseases they transmit become more prevalent. This upward trend in cases of tick-borne illnesses has necessitated the pursuit of tick control methods that can be used across the diverse environments that are present in tick habitat ranges. One such control method is the fungal biological control, Beauveria …

Root Biomass And Other Soil Properties Affecting The Co2 Flush From Laboratory Dried And Rewetted Soils, Audrey E. Laffely

Electronic Theses and Dissertations

Soil that has been dried and rewetted has been observed to release a ‘burst’ or ‘flush’ of carbon dioxide (CO 2 ) upon rewetting. This CO 2 flush has been proposed as an indicator of soil health. This may be a valuable indicator of soil health, however the CO 2 flush has yet to be fully evaluated. Roots and root exudates influence the soil in a variety of ways that may impact the CO 2 flush, such as increasing aggregation, organic carbon (C), and microbial biomass. We conducted both field and greenhouse experiments to elucidate the relationship of root biomass …

Nitrogen Cycling During A Period Of Environmental Change, Kaizad Patel

Electronic Theses and Dissertations

Natural and anthropogenic disturbances have altered the N cycle on the regional to global scale. Although numerous studies have examined the effects of chronic atmospheric N deposition on ecosystem processes, less is known about intra-annual variability of these processes, or how these responses might be altered under conditions of changing climate. The work described in this dissertation focuses on the effects of a changing chemical and physical climate, particularly terrestrial N processes (a) during Maine’s changing winters, and (b) in response to chronic elevated N additions.

Subnivean winter soil processes were examined at the Dwight B. DeMerritt Forest (DBDF) and …

Utilizing Ground-Penetrating Radar In The Delineation And Cultural Resource Management Of Eroding Maine Coastal Shell Middens, Jacquelynn F. Miller

Electronic Theses and Dissertations

Shell middens along the Maine coast archive up to 5000 years of cultural and climatic change, but the record is continually and rapidly lost to the sea through climate-driven coastal erosion and sea-level rise. These sites were constructed by the ancestors of Maine Tribes, and are composed of centimeters to meters of clam (Mya arenaria) and/or oyster (Crassostrea virginica) shells, other faunal remains, and cultural materials. Shell middens record human interaction with the environment and early coastal occupation and adaptation. The faunal remains reflect paleoenvironmental conditions and the distribution of extinct and extant forage-species along the western Gulf of Maine. …

Reducing Tillage In Small-Scale Permanent Bed Organic Vegetable Production Systems, Jeremiah D. Vallotton

Electronic Theses and Dissertations

The response of field-grown vegetable crops to reduced tillage and mulching in permanent beds was evaluated through measuring crop yields, weed pressure, earthworm counts, and soil basal respiration. Two vegetable crops (“Bush Delicata” squash and “Farao” cabbage) were started in April and May of 2016 and 2017 respectively, transplanted in late June, and harvested on 15-Sep-2016 and 25-Aug-2017. Fruit number and weight of squash, and head weight and feeding damage of cabbage were measured. These results suggest that intensive tillage (8” rototill every year) can be successfully reduced to alternating years of shallow (2”) rototilling and a less intensive form …

Influence Of Common Bean (Phaseolus Vulgaris) Grown In Elevated Co2 On Apatite Dissolution, Brian Matthew Morra

Electronic Theses and Dissertations

Elevated concentrations of atmospheric CO₂ brought about by human activity creates changes in plant morphology, growth rate and exudate production. Our study sought to understand the effect of these changes on soil mineral weathering using plants grown under two conditions, ambient CO₂ (400ppm) and elevated CO₂ (1000ppm). Phaseolus vulgaris (common beans) were grown in flow-through microcosms consisting of a mixture of quartz and apatite sands. Plant growth was sustained by a nutrient solution devoid of calcium (Ca) and phosphorous (P). Using Atomic Adsorption Spectroscopy and colorimetry, Ca and P content of the leachate and plant tissue served …

Modeling And Measurement Of Evaporation From Frequently Tilled Sandy Soils, Nicholas R. Lawson

Electronic Theses and Dissertations

Moisture observation and control is the single largest factor that controls the mechanical properties of sand based surfaces used for thoroughbred horse racing. Currently the moisture content is estimated based on the experience and expertise of the superintendent and water is added as needed based on experience. While extensive modelling has been done on moisture loss from a range of soils with crop covers in agronomy, currently no method exists to estimate the evaporation from a surface that is tilled many times a day and remains in a partially compacted state. This thesis develops an evaporation model based on real …

Mr447: Seasonal Water Table And Temperature Relationships In Calcareous Till And Residual Soils Of Central Maine, David E. Turcotte, Christopher C. Dorion, Nicholas R. Butler, Ivan J. Fernandez

Miscellaneous Reports

Water table depths and soil temperatures were monitored for four growing seasons in six calcareous till pedons developed on gently rolling to level till plains in Corinth and Exeter, Maine. These soils are part of a new catena that supports potato production in southeastern Penobscot County. Three of these coarse-loamy to fine-loamy pedons are moderately well drained Oxyaquic Eutrudepts taxadjuncts in potato fields, and three are somewhat poorly drained Aquic Dystric Eutrudepts in predominantly deciduous forest. Soil morphology, hydrologic data, and a,a dipyridyl applications support the described subgroup classification of each pedon, along with the udic moisture regime. Despite a …

Collaborative Research: Interactive Effects Of Chronic N Deposition, Acidification, And Phosphorus Limitation On Coupled Element Cycling In Streams, Kevin S. Simons, Ivan J. Fernandez, Stephen A. Norton

University of Maine Office of Research Administration: Grant Reports

The overarching goal of this project is to understand how chronic acidification and nitrogen enrichment of watersheds influences coupled biogeochemical cycling in streams. Embedded in the project were two primary research elements: 1) examining nitrogen satuartion and the extent of coupling between nitrogen and phosphorus cycling and 2) resolving the interactions among acidification, phosphorus bioavailability and biotic demand for nitrogen and phosphorus. The research involved a series of stable isotope tracer experiments to document nitrogen uptake under ambient and elevated phosphrous conditions and examination of a suite of key microbial processes (denitrification, decomposition, microbial enzyme activity) at two whole-watershed experiment …

Ltreb: Biogeochemical Mechanisms Of Response In The Third Decade Of Whole-Ecosystem Experimental Manipulations At The Bear Brook Watershed In Maine (Bbwm), Ivan J. Fernandez, Stephen A. Norton, Lindsey E. Rustad

University of Maine Office of Research Administration: Grant Reports

This grant will support the Bear Brook Watershed in Maine (BBWM) where research has been conducted for approximately 20 years on the effects of atmospheric sulfur and nitrogen deposition on forests. The research is conducted on two watersheds, each drained by a first order stream. One is treated bimonthly by helicopter to simulate atmospheric deposition of sulfur and nitrogen. Over the past 20 years, this research has identified and verified key factors governing forest response to air pollution, and also revealed major gaps in our understanding that are critical to determining the success of current and potential future regulations under …

Tb202: Composition And Biomass Of Forest Floor Vegetation In Experimentally Acidified Paired Watersheds At The Bear Brook Watershed In Maine, Peter Kenlan, G. B. Wiersma, A. S. White, I. J. Fernandez

Technical Bulletins

The percentage cover (abundance), frequency of occurrence, biomass, species richness, and species diversity of understory herbs was measured on a paired watershed ecosystem in eastern Maine, USA. This paired watershed site (Bear Brook Watershed in Maine, BBWM) has had the West Bear Brook Watershed treated bi-monthly with granular ammonium sulfate at a rate of 28.8 kg S ha-1 yr-1 and 25.2 kg N ha-1 yr-1 since 1989. East Bear Brook Watershed serves as the reference site. More than 100 plots were randomly located across the two watersheds. The data suggest that there is generally a lower frequency of occurrence of …

Tb200: Carbon And Nutrients In Maine Forest Soils, Ivan J. Fernandez

Technical Bulletins

Recent public concerns surrounding climate change and greenhouse gas emissions have resulted in a lively debate about approaches to fossil fuel offsets and carbon (C) sequestration in forests. The forest community sees opportunities for the intensification of the use of forests for markets ranging from forest products, such as fuel or fuel feedstock, to a range of new bioproducts. This report provides initial insights from an ongoing effort to synthesize forest soils data for Maine. The specific objectives presented here were (1) to develop descriptive statistics for C and measures of available forms of the essential nutrients N, P, and …

Methodology And Assessment Of The Susceptibility Of Potato Genotypes To Phytophthora Erythrosetpica Causal Organism Of Pink Rot, Erica Fitzpatrick-Peabody

Electronic Theses and Dissertations

Phytophthora erythroseptica Pethyb., causal organism of potato (Solanum tuberosum L.) pink rot is a soil-borne ubiquitous oomycete pathogen that can cause severe losses in both the field prior to harvest and during storage. The efficacy of the most effective fungicide, mefenoxam for control of P. erythroseptica is in jeopardy due to the widespread development of resistance in the US. Cultivar resistance may provide the best option for management of P. erythroseptica in the future. Recently published reports of cultivars susceptible to P. erythroseptica are based on evaluation techniques involving detached tubers and nontuber germplasm rather than field evaluations. Screening detached …

Tb196: Temperature, Soil Moisture, And Streamflow At The Bear Brook Watershed In Maine (Bbwm), Ivan J. Fernandez, Joseph E. Karem, Stephen A. Norton, Lindsey E. Rustad

Technical Bulletins

The Bear Brook Watershed in Maine is a whole-ecosystem chemical manipulation initiated in 1987 to study the effects of acid deposition on forests and surface waters. The focus of this research was to understand the biogeochemical response of watersheds with emphasis on chemistry and hydrology. In 2001 a program was initiated to provide more detailed measurements of temperature and moisture to examine critical linkages amongst chemical, biological, and physical processes that ultimately work together to define ecosystem function. The purpose of this publication is to provide data from the initial phase of soil temperature, air temperature, and soil moisture measurements …

Collaborative Research: Mechanisms Of Abiotic Immobilization Of Nitrate In Temperate Forest Soils, David B. Dail

University of Maine Office of Research Administration: Grant Reports

Atmospheric deposition of nitrogen to temperate forests has increased in recent decades as a result of increased combustion of fossil fuels. Knowing how nitrogen in air pollution is retained within forests will improve the ability of scientists to anticipate interactions among efforts to mitigate human alterations of regional and global cycles of carbon and nitrogen. For example, the way that forests retain nitrogen affects the ability of forests to help mitigate expected global warming due to increased carbon gases in the atmosphere. Because nitrogen often limits rates of plant growth, increased nitrogen inputs could affect forest growth and health. Most …

Tb195: Element Concentrations In Maine Forest Vegetation And Soils, Chandra J. Mcgee, Ivan J. Fernandez, Stephen A. Norton, Constance S. Stubbs

Technical Bulletins

Bioaccumulation of trace metals in plant tissues can present a health risk to wildlife, and potentially to humans. The Passamaquoddy Tribe in Maine was concerned about health risks of cadmium (Cd) because of a health advisory for moose liver and kidney consumption due to high Cd levels. In addition to Cd, this study evaluated concentrations of aluminum (Al), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), nickel (Ni), phosphorus (P), lead (Pb), and zinc (Zn) in four common terrestrial moose-browse species, associated forest soils, and two species of aquatic vegetation on Passamaquoddy tribal land in eastern …

Climatic And Lithogenic Controls On Soil Organic Matter-Mineral Associations, Rota Wagai

Electronic Theses and Dissertations

Interactions of organic matter (OM) with soil mineral phases strongly affect the storage and dynamics of soil OM as well as other ecosystem processes. This study examined aspects of organo-mineral associations in soils at different scales. First, I assessed the potential controls of climate and parent rock type on organo-mineral associations using two sets of undisturbed tropical forest soils developed on two contrasting rocks along an altitudinal gradient in Borneo, Southeast Asia. Density fractionations showed that OM stored in surface mineral soils partitioned towards plant detritus fraction under cooler climates on both rock types. Thus climate exerted stronger control on …

Soil Solution Dynamics In Response To Elevated Nitrogen And Sulfur Treatments At The Bear Brook Watershed In Maine, Johanna Szillery

Electronic Theses and Dissertations

Base cation depletion in forest soils of northeastern North America is a continuing concern because of the ongoing elevated deposition of sulfur (S) and nitrogen (N), intensive-management practices, and the often poorly understood implications of land-use history on modem ecosystem function. At the Bear Brook Watershed in Maine (BBWM), one of two paired, forested watersheds has been subjected to experimental additions of S and N for over a decade. Treatments consist of 28.8 kg S ha-' yr-' and 25.2 kg N ha-' yr-' in the form of granular (NH&SO4 applied bimonthly by helicopter. Ceramic cup tension lysimeters were used to …

The Effect Of Nitrogen Loading On An Estuarine Faunal Community: A Stable Isotope Approach, Rachel A. Keats

Electronic Theses and Dissertations

Coastal ecosystems worldwide face increased nutrient enrichment from shoreline and watershed development and atmospheric pollution. To gain an understanding of the effects of nitrogen loading on the natural faunal community of Ruppia maritima beds in Northeast Creek estuary (Acadia National Park, Maine, USA), we (1) assessed the response of the faunal community to increased nitrogen loading using an in situ enrichment experiment during the summer growing season of 2001 (Chapter I), and (2) completed a description of the natural macroinvertebrate community in the estuary in 2001 with qualitative (May-July) and quantitative (August-October) monthly sample collections (Chapter 2). This study formed …

The Role Of Forest Soils In A Northern New England Effluent Management System, Leslie B. Nelson

Electronic Theses and Dissertations

The Carrabassett Valley Sanitary District in Carrabassett Valley, Maine has utilized both a forest spray irrigation system and a Snowfluent™ system for the treatment of their wastewater effluent. This study was designed to evaluate potential changes in soil properties after approximately 20 years of treatment in the forested spray irrigation site and three years of treatment in the field Snowfluent™ site. In addition, grass yield and composition were evaluated on the field study sites. After treatment with effluent or Snowfluent™, soils showed an increase in soil exchangeable Ca, Mg, Na, and K, base saturation, and pH. While most constituents were …

Decadal Responses In Soil N Dynamics At A Paired Watershed Experiment In Maine, Sultana Sarvatara Shah

Electronic Theses and Dissertations

Nitrogen is commonly thought of as the most limiting nutrient to plant growth, yet elevated N deposition can result in N accumulating in excess of biotic demand, a condition known as 'TI Saturation." Excess N can perturb soil microbial N transformations and may cause initial increases in net N mineralization rates followed by decreases in net N mineralization with concomitant increases in net nitrification. Along with increases in net nitrification and N loss, N saturation is often associated with a loss of forest productivity. Understanding nitrogen dynamics in soil under enhanced N deposition is key to predicting future forest health. …

Early Stage Humification During Amendment Decomposition And Its Influence On Cu-Binding Capacity Of Dissolved Organic Carbon, Karen A. Merritt

Electronic Theses and Dissertations

This thesis monitored the progression of early-stage humification during the decomposition of four soil amendments and analyzed the effect of hurnification on the copper (Cu) binding capacity of amendment-derived dissolved organic carbon (DOC). Amendments chosen for the 8-week incubation were: wheat straw (Triticum aestivium L.), crimson clover (Trifolium incamaturn L.), a primary papermill residue (PPR), and a primary papermill residue mixed with secondary wastewater treatment sludge (PPR+SS). Specific attention was given to the