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Full-Text Articles in Earth Sciences

Plastic Storage In River Sediments Across An Urbanization Gradient In The Ipswich Watershed In Massachusetts, Jackie L. Harris Jan 2023

Plastic Storage In River Sediments Across An Urbanization Gradient In The Ipswich Watershed In Massachusetts, Jackie L. Harris

Honors Theses and Capstones

The importance of plastic pollution research has become apparent as plastic pollution has increased exponentially since its introduction in the 1950s. Plastics mechanically break down into minuscule particles called microplastics, which are plastic particles with a size range of 0.1 micrometers (μm) to 5 millimeters (mm). Most of the research on microplastic pollution has centered around marine ecosystems rather than freshwater ecosystems. More freshwater microplastic research to date is emerging but is still nascent and sparse. Furthermore, the idea that rivers are merely conduits of microplastics to the ocean is even more limited and ignores microplastic loading and retention in …


The Role Of Small Reservoirs In Reducing Reactive N Export Via Denitrification, Margaret Phillips, Wil Wollheim Jan 2019

The Role Of Small Reservoirs In Reducing Reactive N Export Via Denitrification, Margaret Phillips, Wil Wollheim

Honors Theses and Capstones

Reactive nitrogen (N), which harms ecosystem health, has been increasing in the biosphere, leading to higher N export to coastal ecosystems. Although man-made reservoirs can be significant sources of greenhouse gases, they can also retain N, thus reducing N export. Because many dams are relics from industrial hydropower, their removal is becoming increasingly common. It is therefore crucial to understand the ecological tradeoffs of man-made reservoirs. While previous studies have examined nutrient budgets and denitrification at inputs and outputs of large reservoirs, small reservoir dynamics remain understudied. In this study, we measured inputs and outputs of NO3 and N …


Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik Jan 2017

Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik

Honors Theses and Capstones

The expansion of local agriculture in the New England region is putting increased pressure on farmers to expand their arable land base. While clear-cutting is a traditional method of converting forested land to agriculture, it is known for having adverse ecological impacts. To minimize these impacts, farmers can create a silvopasture which incorporates a portion of the original forest canopy into pastures or crop fields. This study evaluates the impact of land-use changes for agriculture on soil nitrogen (N) retention. In particular, this study investigates the differences in soil N turnover, gaseous loss, and aqueous loss among an established forest, …


Global And Regional Assessments Of Unsustainable Groundwater Use In Irrigated Agriculture, Danielle S. Grogan Jan 2016

Global And Regional Assessments Of Unsustainable Groundwater Use In Irrigated Agriculture, Danielle S. Grogan

Doctoral Dissertations

Groundwater is an essential input to agriculture world-wide, but it is clear that current rates of groundwater use are unsustainable in the long term. This dissertation assesses both current use of groundwater for country- to global-scale agriculture, and looks at the future of groundwater. The focus is on 1) quantifying food directly produced as a result of groundwater use across spatially-varying agricultural systems, 2) projecting future groundwater demands with consideration of climate change and human decision-making, and 3) understanding the system dynamics of groundwater re-use through surface water systems. All three are addressed using a process-based model designed to simulate …


Fine-Scale Plant Species Identification In A Poor Fen And Integration Of Techniques And Instrumentation In A Classroom Setting, Dylan Schiff Jan 2015

Fine-Scale Plant Species Identification In A Poor Fen And Integration Of Techniques And Instrumentation In A Classroom Setting, Dylan Schiff

Honors Theses and Capstones

Refining carbon flux measurements in the carbon cycle is an ongoing challenge. This study attempted to identify plant species in Sallie’s Fen, a nutrient-poor fen in Barrington, New Hampshire, at a fine scale in order to better model and understand carbon exchange between plants and the atmosphere in this type of ecosystem. A protocol for estimating percent cover of species in plots via ground measurements was developed. The next stage of this project was to compare these measurements with measurements derived from spectral images using ImageJ computer software. Statistical tests of the ground measurement data revealed that patterns of seasonal …