Digital Commons Network^™

Geography, Income, And The Incidence Of A Massachusetts Carbon Tax, Susan Stratton Sayre

Economics: Faculty Publications

I use spatial microsimulation to estimate the geographic incidence of the consumer-facing portion of various revenue-neutral carbon tax designs in Massachusetts. I identify a substantial urban-rural disparity in impacts that is reduced, but not eliminated, by proposed revenue-targeting mechanisms. I further demonstrate that seemingly small variations in the definition of rural households can have substantial impacts on urban-rural equity and the distribution of gains and losses. Proposed policies are highly progressive in the aggregate with most low-income households receiving more in rebates than they pay in taxes, but notable numbers of low-income households are likely to experience significant losses. Methodologically, …

Low Methane Emissions From Nutrient-Rich Former River Channels In A Hydrologically Managed Dryland Delta, Siena Stassi, Jude A. Benavides, Chu-Lin Cheng, Marcelo Gomes Da Silva, Nicholas E. Ray, Nathan O. Barros, Rafael M. Almeida

School of Earth, Environmental, & Marine Sciences Faculty Publications

Anthropogenic stresses in dryland regions can alter hydrology, salinization, and biogeochemical processes. How these pressures influence methane (CH4) cycling and emissions from aquatic ecosystems remains poorly understood. Over the course of 1 year, we measured diffusive and ebullitive CH4 emissions from resacas—shallow, hydrologically managed distributary channels prevalent throughout the Lower Rio Grande Valley along the US–Mexico border. Despite warm, nutrient-rich waters, CH4 emissions from resacas were low, and more comparable to rates observed in estuarine systems. CH4 fluxes were positively related to temperature but negatively related to salinity and rainfall. Elevated salinity, driven by evaporation and source water from the …

Ecological Insights And Management Implications Of The Global Migratory Connectivity Of Green Turtles, Jaime Restrepo, Dina Nisthar, Harris Wei-Khang Heng, Lily K. Bentley, Corrie Curtice, Sarah Deland, Ei Fujioka, Patrick N. Halpin, Sarah K. Poulin, Roldán A. Valverde

School of Earth, Environmental, & Marine Sciences Faculty Publications

Aim

Green turtles are a widely distributed and highly migratory species; despite extensive data on their movement, there is no species-specific global synthesis on the subject. Based on three decades of published literature and building on previous global analyses, we developed a global network model of migratory connectivity for green turtles to better understand their spatial biology.

Location

Global.

Time Period

1990–2022.

Major Taxa Studied

Green Sea Turtle (Chelonia mydas).

Methods

We conducted a structured literature review extracting georeferenced information on the movement of green turtles from 1990 to 2022, aggregating this information into a single connectivity model, …

Microplastic Composition And Exposure Pathways In Freshwater Systems: A Multi-Matrix Comparison Between Streams And Retention Ponds In Hamilton County, In, Mya Whaley

All-Inclusive List of Electronic Theses and Dissertations

Since the early 1900s, the use of plastics has increased exponentially. The breakdown of plastic materials has exposed all ecosystems to microplastics (small particles of plastic < 5 mm), which are now ubiquitous in natural settings. Microplastics have a relatively large surface area, and many chemicals adsorb to these small particles, impacting their fate and transport of pollution. While microplastics have been found in virtually every setting on Earth, research is necessary to understand their impact on freshwater ecosystems and biogeochemical cycles. The focus of this research was to investigate microplastic compositions in crayfish, sediments, and water samples collected in streams and retention ponds. We analyzed trends in microplastic counts across different land-cover classes, waterbody types, and species, and compared concentrations among matrices to improve our understanding of microplastic exposure pathways in freshwater ecosystems. As a secondary objective, lead and arsenic concentrations were analyzed from sediment samples to investigate metal burdens and compare them to microplastic concentrations. Our findings revealed that, in general, urban streams had the highest microplastic concentrations within land cover categories, and retention ponds had higher microplastic counts than streams. Crayfish, such as F. rusticus had higher microplastic concentrations than F. virilis and F. propinquus, although these results may be influenced by study design. The most common microplastic type was fibers, and most common color was transparent. There was no significant correlation between microplastic and metal concentrations in sediments. We found crayfish to be adequate bioindicators of microplastic pollution, because they were less impacted by environmental variability than sediment and water samples. This research presents the first evidence of microplastics in our study species, F. propinquus, F. rusticus, and F. virlis. This work presents new evidence of microplastic accumulation in crayfish, sediments, and water from freshwater systems in the Midwestern United States. Microplastics were found in every sample type—crayfish, water, and sediment—across urban, rural, and forested landscapes, highlighting their pervasive distribution. The findings provide foundational data for assessing emerging ecological and human-health risks and emphasize the importance of sustained monitoring and research on MP contamination in freshwater environments.

Regional Assessment Of South Texas Wells Produced Water, Hunter T. Barnett

Water Resources Science and Technology Theses and Graduate Research Reports (Archived)

This study presents a regional assessment of produced water (PW) quality from oil and gas wells in South Texas, with a focus on variability and its implications for treatment and reuse. As oil and gas production continues to expand, PW waste streams will continue to grow. With a focus on the Eagle Ford Shale, understanding the chemical composition is critical for effective PW management. A total of 28 PW samples were collected from wells located in Pleasanton, Jourdanton, and Tilden, Texas. Samples were analyzed for key parameters including total dissolved solids (TDS), chloride, total hardness, and calcium. The results showed …

Low Climate Benefit Of Nordic Coastal Marshes: Site Conditions Outweigh Grazing Effects And Shape Trade-Offs Between Carbon Storage And Its Stability, Carmen Leiva-Dueñas, T. Banta, Christoffer Boström, Franziska Eller, Johan Eklöf, Line Holm Andersen, Kai Jensen, Marianna Lanari, Ella Logemann, Pere Masque, Thomas Ostertag, Christoph Reisdorff, Anaïs Richard, Anu Vehmaa, Jukka Alm, Mikael Von Numers, Dorte Krause-Jensen

Research outputs 2022 to 2026

Coastal marshes, recognized as effective organic carbon (OC) sinks, have gained attention for their potential contribution to climate mitigation through protection and restoration. However, the climate mitigation potential of Nordic coastal marshes remains understudied, likely due to their heterogeneous and often non-tidal nature. To fill this gap, we examined soil OC storage and accumulation rates, and the effects of grazing, a common management practice, across eight Nordic coastal marsh areas spanning broad climate and environmental gradients. We also assessed soil methane emissions in selected areas. The Nordic marshes studied store a median of 7 kg OC m⁻² (interquartile range, …

Draft Final Annual Operations And Maintenance (O&M) Report: Butte Treatment Lagoon (Btl) System – 2025, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Final Silver Bow Creek Conservation Area Materials Management Plan, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Final Revised Silver Bow Creek Conservation Area (Sbcca) Construction Quality Assurance Plan (Cqap), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

2024 Annual Operations And Maintenance Report 2024 Bres Annual Summary Report For Work Completed In Quadrant 4, Butte-Silver Bow Department Of Reclamation And Environmental Services

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Draft Final 2026 Interim Site-Wide Groundwater Monitoring Quality Assurance Project Plan, Woodard & Curran

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Foraging Plasticity And Mercury Contamination In Red-Legged Kittiwakes: A Multiple Stressor Perspective, Sam E. Clay

All-Inclusive List of Electronic Theses and Dissertations

Arctic seabirds are facing increasing stress from climate change, yet the interactive effects of multiple stressors on behavior remain poorly understood. Adopting a multiple stressor perspective promises to advance understanding of avian behavioral responses to climate change, as climate change is exposing Arctic and subarctic animals to a complex set of stressors rather than a single stressor in isolation. Using the red-legged kittiwake (Rissa brevirostris) as a model, I examined how multiple stressors, including mercury (Hg) exposure, shifting wind conditions, and varying foraging conditions linked to sea surface temperature (SST) may interact to constrain behavioral plasticity and energetically expensive behavior …

Dendroclimatic Response Of The Wet Miombo Woodland Species: A Case Study Of Mufulira District, Copperbelt Province, Zambia, Collins Chibuye Malubeni

All-Inclusive List of Electronic Theses and Dissertations

Zambia is a tropical, landlocked country that lies in the South-Central part of Africa. The climate in Zambia includes distinct dry and rainy seasons, mainly influenced by the north-south movement of the Intertropical Convergence Zone (ITCZ), which shifts seasonally. This research is focused on understanding the relationship between tree growth and climate using dendrochronology. Forty-nine tropical species, including Julbernardia paniculata, Brachystegia longifolia, and Pericopsis angolensis, were analysed for dendroclimatic potential, and 70% showed clear ring formation, indicating that trees in this locality produce distinct annual ring boundaries. For the single species chronology, thirteen cores from eight trees that were initially …

Ai-Driven Multispectral Drone Monitoring For Afforestation In Arid Environments, Hesham Morgan, Ali Elgendy, Brandon Tran, Tamer Ismail, Mohamed M. Moursy, Yehya Kh. Shehadeh, Ahmed Elgharib, Ahmed Abdullah Al-Dughairi, Ali El Mubarak, Khaled Allam Harhash, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Monitoring large-scale afforestation projects in arid and semi-arid environments requires accurate, high-resolution, and repeatable methods to assess tree survival and growth. In this study, we integrated unmanned aerial vehicle (UAV) multispectral imaging with an advanced object detection framework to evaluate vegetation establishment in the Shuayb Al-Budai afforestation site, part of the Imam Turki bin Abdullah Royal Natural Reserve, Kingdom of Saudi Arabia (KSA). Multispectral datasets were acquired using a MicaSense Altum-PT sensor and processed through a masked Region-based Convolutional Neural Network (RCNN) with two backbone architectures: ResNet-101 and VGG19-BN. The Mask R-CNN–ResNet-101 model achieved superior performance, with an overall accuracy …

Vulnerability Of Bass Populations To Our Changing Climate In The Mississippi River, Cameron Schreifels

Celebrating Scholarship and Creativity Day (2018-)

Climate change is altering habitats and damaging bass populations throughout the Mississippi. The main factors of climate change affecting bass are shifts in water quality and significant weather events, which have increased bass vulnerability. With rising temperatures and eutrophication changing the way these bass hunt for their prey, it has made it easier for other non-native species to encroach on their habitat, which has led to bass further encroaching on other species due to climate change.  Given their economic importance and cultural significance, better management practices are needed to find new ways to protect them and ensure they remain a …

Aquatic Invasive Species Control: Minnesota’S Herbicide Problem, Adam Novak

Celebrating Scholarship and Creativity Day (2018-)

Minnesota lakes have an invasive species problem: invasives are outcompeting our native plants and causing ecological degradation. Herbicides are used in Minnesota to help alleviate the stress that invasive plants put on the ecosystem, but continued use of herbicides has its own environmental downside. An analysis of five common aquatic herbicides including, diquat, endothall, 2,4-D, fluridone, and copper-based solutions was completed to find specific ecological downsides. Sediment degradation, effects on various fish life stages, zooplankton, and other non-target organisms were analyzed. This study offers alternative managements strategies and presents a decision tree to help lake associations manage invasive plants.

Tour Geography Of Bad Bunny Compared With Hispanic Demographics In The United States, Arabella Fuzak

Celebrating Scholarship and Creativity Day (2018-)

This project looks at how the distribution of Bad Bunny’s tour locations has changed over time and how they relate to concentrations of the Hispanic/Spanish-speaking population in the United States. The first map visualizes the tour stops (across all of the tours Bad Bunny has made in the United States, which were found by social media posts), along with how many shows he has done in each state. The second map looks at the percent of residents per county in the United States who are Hispanic. The third map looks at the percent of residents per county in the United …

Apparent Hack’S Law In River Deltas, Tian Y. Dong, Lawrence Vulis, Hongbo Ma, Alejandro Tejedor, Timothy A. Goudge

School of Earth, Environmental, & Marine Sciences Faculty Publications

River deltas are densely populated, ecologically vital landscapes threatened by rising sea levels. Distributary channel networks disperse sediment to build deltaic land, yet the relationship between the network organization and land building remains elusive. Inspired by Hack’s law, which shows that watershed drainage area scales with channel length in tributary networks, we analyzed a global dataset of distributary networks and found a nearly identical scaling relationship between distributary channel length and nourishment area, the land-building counterpart to drainage area. Despite this apparent global scaling, we further identified two distinct local land-building patterns: uniform delta networks consistently follow Hack’s law, whereas …

Warming Climate Amplifies Vapor Pressure Deficit Limits On Gross Primary Productivity, Shiqin Xu, Nate G. Mcdowell, Tim R. Mcvicar, Diego G. Miralles, Stephen Sitch, Pablo Sanchez-Martinez, Joshua B. Fisher, Pierre Friedlingstein, Hylke E. Beck, Matthew F. Mccabe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ongoing climate warming may profoundly impact terrestrial gross primary productivity (GPP), a key component of the global carbon cycle. However, uncertainty in the relative roles of atmospheric water demand (vapor pressure deficit, VPD) and root-zone soil moisture (SM) limits predictions of drought impacts on GPP. Here, we show that growing-season GPP was more strongly constrained by VPD than SM globally, based on observation-constrained model estimates, satellite retrievals and Dynamic Global Vegetation Model simulations. The importance of VPD increased with higher temperatures and more severe and prolonged droughts. This pattern reflects VPD’s critical role in regulating stomatal conductance and plant hydraulic …

Geospatial Assessment Of Agrivoltaic Opportunities And Land Use Requirements In Nigeria, Ifeoluwa Ezekiel Babarinde, Bashir Salisu, Jude A. Benavides, Engil Pereira, Steven M. Grodsky, Rafael M. Almeida

School of Earth, Environmental, & Marine Sciences Faculty Publications

Agrivoltaics, the co-location of agriculture and solar photovoltaic (PV) infrastructure, can deliver co-benefits like reduced plant drought stress and improved yields of shade-tolerant crops, particularly in water-scarce regions. Despite growing global interest, the technical potential and opportunities for agrivoltaics remain poorly understood in many regions facing both food and energy insecurity, such as sub-Saharan Africa. Here we provide a spatial assessment of agrivoltaic opportunities in Nigeria by integrating cropland distribution, solar resources, and water stress. We find that northern states—where cropland is abundant and water-stressed, solar irradiance is high, and electricity access remains low—offer the greatest potential for agrivoltaic systems …

Re: Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) Final Unreclaimed Sites Field Sampling Plan (Fsp) Package #7: Ur-01, Ur-12, Ur-03, Ur-04, Ur-15, And Ur-17 Amendment (Dated April 28, 2026), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Re: Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Joesphine Shaft (Bres No. 37) – Remedial Action Work Plan (Rawp) (Dated March 24, 2026), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Re: Comment Letter For The Draft Final Butte Priority Soils Operable Unit (Bpsou) Insufficiently Reclaimed Sites Bres No. 30 – Atlantic 1 Remedial Action Work Plan (Rawp) (Dated March 24, 2026), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Re: Comment Letter For Draft Final 2026 Interim Site-Wide Groundwater Monitoring Quality Assurance Project Plan (Dated April 17, 2026), Emma Rott

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Butte Priority Soils Operable Unit (Bpsou) Final Unreclaimed Sites Field Sampling Plan (Fsp) Package #7: Ur-01, Ur-12, Ur-03, Ur-04, Ur-15, And Ur-17 Amendment, Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Final Unreclaimed Sites Quality Assurance Project Plan (Qapp), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Final Insufficiently Reclaimed Sites Quality Assurance Project Plan (Qapp), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Evaluation Of Sirna-Mediated Knockdown Of Heat Shock Protein 16.2 In Adult Acropora Cervicornis, Edward P. Gniffke, Benjamin D. Young, Keir J. Macartney, Michael S. Studivan, Ian C. Enochs, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Acropora cervicornis is a critically endangered Caribbean coral species facing a precipitous decline due to disease and thermal bleaching. To combat the loss of ecologically important reef-building corals, novel molecular approaches can be used to understand mechanisms of resilience and ultimately provide a means to modulate coral performance. In this study, we tested a recently developed method for gene knockdown in adult corals that utilizes short interfering RNAs (siRNAs) and the RNA interference pathway. The Heat Shock Protein 16.2 (HSP16.2) gene in fragments of adult A. cervicornis was targeted for knockdown using a single siRNA construct. RT-qPCR analysis of HSP16.2 …

Re: Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) Draft Final Whitehall Borrow Submittal #3 (Dated March 27, 2026), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.