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Full-Text Articles in Physical and Environmental Geography

Use Of Unoccupied Aerial Vehicle (Drones) Based Remote Sensing To Model Platform Topography And Identify Human-Made Earthen Barriers In Salt Marshes, Joshua J. Ward Mar 2024

Use Of Unoccupied Aerial Vehicle (Drones) Based Remote Sensing To Model Platform Topography And Identify Human-Made Earthen Barriers In Salt Marshes, Joshua J. Ward

Masters Theses

Elevation is a foundational driver of salt marsh morphology. Elevation governs inundation and hydrological patterns, vegetation distribution, and soil health. Anthropogenic impacts at grand scales (e.g., rising sea levels) and local scales (e.g., infrastructure) have altered the elevation of the salt marsh surface, changing the topography and morphology of these ecosystems. This study establishes and assesses means to document and analyze these impacts using Unoccupied Aerial Vehicle (UAV) based remote sensing to model platform topography. This thesis’s first and primary study presents and compares methods of producing high-resolution digital terrain models (DTMs) with UAV-based Digital Aerial Photogrammetry (DAP) and Light …


Public-Ish, Aliah Werth Jun 2023

Public-Ish, Aliah Werth

Masters Theses

Climate change affects public space, and architecture must establish tenets that prioritize pedestrians in this difficult era. Greywater re-use can be a mechanism for creating shade, and in turn, public space.

As heat waves grow more intense, the vast swaths of asphalt that connect commercial zones pose greater risks to public health and to urban vitality. This thesis records the typical material, spatial, and lived conditions of strip malls in urban heat islands, and demands more from infrastructure in public-ish space.

Heat violence weaves through Los Angeles’ built form. Parking space minimums, required setbacks, and height restrictions pull buildings away …


Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek Apr 2023

Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek

Masters Theses

Tidal marshes serve as important “blue carbon” ecosystems that accrete large amounts of carbon with limited area. While much attention has been paid to the spatial variability of sedimentation within salt marshes, less work has been done to characterize spatial variability in marsh carbon density. Driven by tidal inundation, surface topography, and sediment supply, soil properties in marshes vary spatially with several parameters, including marsh platform elevation and proximity to the marsh edge and tidal creek network. We used lidar to extract these morphometric parameters from tidal marshes to map soil organic carbon (SOC) at the meter scale. Fixed volume …


Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson Jan 2023

Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson

Scripps Senior Theses

We are experiencing a climate crisis that must be confronted with strategic mitigation. Pomona College contributes to the climate crisis through its emissions for which there is a baseline record. However there is no baseline record of the climate mitigation currently performed by the trees on Pomona’s campus through carbon storage. This study seeks to determine a current baseline quantity of carbon stored and sequestrated by Pomona’s trees as well as possible courses of climate mitigation for Pomona College to take. Initial information gathering was conducted through interviews with several stakeholders. This study was conducted using data collected prior to …


The Human Natural Resource Endowment Of Limestone For Cement Manufacturing, Vanya Marie North Dec 2022

The Human Natural Resource Endowment Of Limestone For Cement Manufacturing, Vanya Marie North

Graduate Theses and Dissertations

This study investigates the total per-capita allocation of limestone globally. Termed the Human Natural Resource Endowment (HNRE), it is calculated by subtracting the cumulative annual production from the ultimately recoverable reserve (URR) of limestone and dividing the difference by global population. HNRE represents a unique way of visualizing resource depletion by asking how much of a given resource can be allocated to each person on earth, and how long that allocation can last given multiple population and usage scenarios. The average American, born in 2021, will use approximately 23,930 kgs of cement in their lifetime, with similar demands globally. Demand …


Local And State Climate Initiatives In Louisiana Since 2005: Content And Thematic Analyses, Jessie F. Parrott Jul 2022

Local And State Climate Initiatives In Louisiana Since 2005: Content And Thematic Analyses, Jessie F. Parrott

LSU Master's Theses

Louisiana is uniquely exposed to severe weather because of its geography and climate. Louisiana’s extreme weather is exacerbated by anthropogenic climate change, which will worsen in the future. The risks its population and environment are exposed to has generated several policies and planning documents, nine of which are analyzed in this thesis. Three plans are from the state level, three are from the parish level, and three are from the urban (New Orleans) level. These planning documents pose various adaptation and mitigation actions to ameliorate and address multiple climate issues. These actions utilize specific mitigation strategies. The content and thematic …


Multi-Criteria Evaluation Model For Classifying Marginal Cropland In Nebraska Using Historical Crop Yield And Biophysical Characteristics, Andrew Laws May 2022

Multi-Criteria Evaluation Model For Classifying Marginal Cropland In Nebraska Using Historical Crop Yield And Biophysical Characteristics, Andrew Laws

School of Natural Resources: Dissertations, Theses, and Student Research

Marginal cropland is suboptimal due to historically low and variable productivity and limiting biophysical characteristics. To support future agricultural management and policy decisions in Nebraska, U.S.A, it is important to understand where cropland is marginal for its two most economically important crops: corn (Zea mays) and soybean (Glycine max). As corn and soybean are frequently planted in a crop rotation, it is important to consider if there is a relationship with cropland marginality. Based on the current literature, there exists a need for a flexible yet robust methodology for identifying marginal land at different scales, which …


The Demotechnic Index Of Nations, 1980-2018, Camden Rainwater May 2022

The Demotechnic Index Of Nations, 1980-2018, Camden Rainwater

Geosciences Undergraduate Honors Theses

The Demotechnic Index (DI) is a non-dimensional metric that is the scalar multiple of energy consumption over and above that required for mere subsistence of a national population. Thus, the DI is a measure of energy efficiency that scales a country’s industrial energy consumption (called the total technological energy) and the energy required to meet the metabolic demand of the population (called the total metabolic energy). The DI was created by scientist John Vallentyne in 1982, refined in 1994, but never gained popularity or wide use as a sustainability metric. The objective of this thesis was to re-evaluate the DI …


Perceptions Of Historical Climate Change And Park Policy: The Impact On The Fremont Cottonwood In Zion National Park, Kathleen Kavarra Corr Mar 2022

Perceptions Of Historical Climate Change And Park Policy: The Impact On The Fremont Cottonwood In Zion National Park, Kathleen Kavarra Corr

Doctoral Dissertations

Despite its “natural” appearance and the Organic Act 1916 mandate for preservation of the natural environment in National Parks, the Virgin River as it flows through Zion National Park’s Zion Canyon was transformed through massive flood control re-engineering projects in the 1930s. The armoring of the river has had significant impacts on riparian vegetation, particularly on the stands of native Fremont Cottonwood trees that once filled the narrow valley. What was the motivation for this massive flood control project carried out in an arid region with less than 15 inches of rain per year? This dissertation explores the motivations which …


Tibetan Dust Accumulation Linked To Ecological And Landscape Response To Global Climate Change, Xianmei Huang, Xiaodong Miao, Qiufang Chang, Jiemei Zhong, Joseph A. Mason, Paul R. Hanson, Xianjiao Ou, Liubing Xu, Zhongping Lai Jan 2022

Tibetan Dust Accumulation Linked To Ecological And Landscape Response To Global Climate Change, Xianmei Huang, Xiaodong Miao, Qiufang Chang, Jiemei Zhong, Joseph A. Mason, Paul R. Hanson, Xianjiao Ou, Liubing Xu, Zhongping Lai

School of Natural Resources: Faculty Publications

The Tibetan Plateau (TP) is a hotspot of earth system research, and understanding its landscape and ecosystem evolution has been hampered by the lack of time-constrained geological records. Geochronological data from 14 loess sites covering a large region in the Tibetan interior show that the TP loess, rather than accumulating during glacial periods, began aggrading at either 13.4 ± 0.4 or 9.9 ± 0.2 ka. An ecological threshold was crossed, when warmer and wetter conditions resulted in increased vegetation cover enabling dust trapping. This dust accumulation model is out of phase with that of the Chinese Loess Plateau (CLP) where …


Evaluating Urban Parks Accessibility And Equity: A Case Study Of Hartford, Ct And New Haven, Ct, Natalie Roach, Mara Tu May 2021

Evaluating Urban Parks Accessibility And Equity: A Case Study Of Hartford, Ct And New Haven, Ct, Natalie Roach, Mara Tu

Honors Scholar Theses

Public parks provide cities with environmental benefits, positive health effects, recreational opportunities, community building, educational spaces, and public amenities. However, certain populations have been systematically denied their fair share of these benefits because of unjust practices in the creation and maintenance of urban parks. With a lens of environmental justice, the goal of this research was to assess park quality and accessibility of two Connecticut cities, Hartford and New Haven, by gathering publicly available information as well as using GIS tools.

The Trust for Public Land (TPL) has an existing ParkScore rating system that evaluates the quality of a city’s …


Protocol For Monitoring Fish Communities In Small Streams In The Heartland Inventory And Monitoring Network, Version 2.0, Hope R. Dodd, David G. Peitz, Gareth Rowell, Janice A. Hinsey, David E. Bowles, Lloyd W. Morrison, Michael D. Debacker, Jennifer L. Haack-Gaynor, Jeffrey M. Williams Mar 2021

Protocol For Monitoring Fish Communities In Small Streams In The Heartland Inventory And Monitoring Network, Version 2.0, Hope R. Dodd, David G. Peitz, Gareth Rowell, Janice A. Hinsey, David E. Bowles, Lloyd W. Morrison, Michael D. Debacker, Jennifer L. Haack-Gaynor, Jeffrey M. Williams

United States National Park Service: Publications

Executive Summary

Fish communities are an important component of aquatic systems and are good bioindicators of ecosystem health. Land use changes in the Midwest have caused sedimentation, erosion, and nutrient loading that degrades and fragments habitat and impairs water quality. Because most small wadeable streams in the Heartland Inventory and Monitoring Network (HTLN) have a relatively small area of their watersheds located within park boundaries, these streams are at risk of degradation due to adjacent land use practices and other anthropogenic disturbances. Shifts in the physical and chemical properties of aquatic systems have a dramatic effect on the biotic community. …


Ecological Risk Assessment Of Managed Relocation As A Climate Change Adaptation Strategy, Aviv Karasov-Olson, Mark W. Schwartz, Julian D. Olden, Sarah Skikne, Jessica J. Hellmann, Sarah Allen, Christy Brigham, Danielle Buttke, David J. Lawrence, Abraham J. Miller-Rushing, Jeffrey T. Morisette, Gregor W. Schuurman, Melissa Trammell, Cat Hawkins Hoffman Mar 2021

Ecological Risk Assessment Of Managed Relocation As A Climate Change Adaptation Strategy, Aviv Karasov-Olson, Mark W. Schwartz, Julian D. Olden, Sarah Skikne, Jessica J. Hellmann, Sarah Allen, Christy Brigham, Danielle Buttke, David J. Lawrence, Abraham J. Miller-Rushing, Jeffrey T. Morisette, Gregor W. Schuurman, Melissa Trammell, Cat Hawkins Hoffman

United States National Park Service: Publications

Executive Summary

Changing climate and introduced species are placing an increasing number of species at risk of extinction. Increasing extinction risk is increasing calls to protect species by relocating, or translocating, them to locations with more favorable biotic or climatic conditions. Managed relocation, or assisted migration, of species entails risks to both the conservation target organisms being moved as well as the recipient ecosystems into which they are moved.

Recognizing this risk, calls have been made for practitioners interested in considering a managed relocation project to engage in a serious risk assessment prior to advancing a project. We engaged a …


Protocol For Monitoring Aquatic Invertebrates Of Small Streams In The Heartland Inventory & Monitoring Network, Version 2.1, David E. Bowles, Michael H. Williams, Hope R. Dodd, Lloyd W. Morrison, Janice A. Hinsey, J. Tyler Cribbs, Gareth A. Rowell, Michael D. Debecker, Jennifer L. Haack-Gaynor, Jeffrey M. Williams Feb 2021

Protocol For Monitoring Aquatic Invertebrates Of Small Streams In The Heartland Inventory & Monitoring Network, Version 2.1, David E. Bowles, Michael H. Williams, Hope R. Dodd, Lloyd W. Morrison, Janice A. Hinsey, J. Tyler Cribbs, Gareth A. Rowell, Michael D. Debecker, Jennifer L. Haack-Gaynor, Jeffrey M. Williams

United States National Park Service: Publications

Executive Summary

The Heartland Inventory and Monitoring Network (HTLN) is a component of the National Park Service’s (NPS) strategy to improve park management through greater reliance on scientific information. The purposes of this program are to design and implement long-term ecological monitoring and provide information for park managers to evaluate the integrity of park ecosystems and better understand ecosystem processes. Concerns over declining surface water quality have led to the development of various monitoring approaches to assess stream water quality. Freshwater streams in network parks are threatened by numerous stressors, most of which originate outside park boundaries. Stream condition and …


A Karst Feature Prediction Model For Prince Of Wales Island, Alaska Based On High Resolution Lidar Imagery, Alexander Lyles Jan 2021

A Karst Feature Prediction Model For Prince Of Wales Island, Alaska Based On High Resolution Lidar Imagery, Alexander Lyles

Master's Theses

Investigation into surface karst formation is significant to hazard prediction, hydrogeologic drainage, and land management. Southeast Alaska contains over 600,000 acres of mapped carbonate bedrock, and some of the fastest recorded karst dissolution in the world. The objectives of this study are to develop and compare multiple semi-automated models to map and delineate karst features from bare-earth LiDAR imagery using ArcGIS Desktop 10.7, and to apply a preliminary geostatistical analysis of sinkhole morphometric parameters to highlight potential spatial patterns of karst evolution on Prince of Wales Island, Alaska. A semi-automated approach of mapping karst features provides a dataset that minimizes …


Applying The Food-Energy-Water Nexus Approach To Urban Agriculture: From Few To Fewp (Food-Energy- Water-People), Silvio Caputo, Victoria Schoen, Kathrin Spect, Baptiste Grard, Chris Blythe, Nevin Cohen, Runrid Fox-Kämper, Jason Hawes, Joshua Newell, Lidia Poniży Dec 2020

Applying The Food-Energy-Water Nexus Approach To Urban Agriculture: From Few To Fewp (Food-Energy- Water-People), Silvio Caputo, Victoria Schoen, Kathrin Spect, Baptiste Grard, Chris Blythe, Nevin Cohen, Runrid Fox-Kämper, Jason Hawes, Joshua Newell, Lidia Poniży

Publications and Research

Many studies examine the correlation between the use of resources such as water, energy and land, and the production of food. These nexus studies focus predominantly on large scale systems, often considering the social dimensions only in terms of access to resources and participation in the decision- making process, rather than individual attitudes and behaviours with respect to resource use. Such a concept of the nexus is relevant to urban agriculture (UA), but it requires customisation to the particular characteristics of growing food in cities, which is practiced mainly at a small scale and produces not only food but also …


Agate Fossil Beds National Monument, Paleontological Resources Management Plan (Public Version), Scott Kottkamp, Vincent L. Santucci, Justin S. Tweet, Jessica De Smet, Ellen Stark Sep 2020

Agate Fossil Beds National Monument, Paleontological Resources Management Plan (Public Version), Scott Kottkamp, Vincent L. Santucci, Justin S. Tweet, Jessica De Smet, Ellen Stark

United States National Park Service: Publications

Executive Summary

Since Agate Springs Ranch was founded by James H. Cook in 1887, exquisite examples of transitional Miocene mammalian fauna have been found along this stretch of the Niobrara River valley. Collectively these paleontological discoveries, along with the existing archeological and historical Native American collection, were the basis for establishing Agate Fossil Beds National Monument (AGFO) as a unit of the National Park System (NPS). The fossil remains from the Harrison and Anderson Ranch formations span a short, but important, time period within the Miocene Epoch. AGFO has provided science with an intimate look into North American mammalian evolution …


Rfia: An R Package For Estimation Of Forest Attributes With The Us Forest Inventory And Analysis Database, Hunter Stanke, Andrew O. Finley, Aaron S. Weed, Brian F. Walters, Grant M. Domke Jun 2020

Rfia: An R Package For Estimation Of Forest Attributes With The Us Forest Inventory And Analysis Database, Hunter Stanke, Andrew O. Finley, Aaron S. Weed, Brian F. Walters, Grant M. Domke

United States National Park Service: Publications

Forest Inventory and Analysis (FIA) is a US Department of Agriculture Forest Service program that aims to monitor changes in forests across the US. FIA hosts one of the largest ecological datasets in the world, though its complexity limits access for many potential users. rFIA is an R package designed to simplify the estimation of forest attributes using data collected by the FIA Program. Specifically, rFIA improves access to the spatiotemporal estimation capacity of the FIA Database via space–time indexed summaries of forest variables within user-defined population boundaries (e.g., geographic, temporal, biophysical). The package implements multiple design-based estimators, and has …


Development Of A Modified Floristic Quality Index As A Rapid Habitat Assessment Method In The Northern Everglades, Rebakah E. Gibble, Donatto D. Surratt May 2020

Development Of A Modified Floristic Quality Index As A Rapid Habitat Assessment Method In The Northern Everglades, Rebakah E. Gibble, Donatto D. Surratt

United States National Park Service: Publications

Floristic quality assessments (FQA) using floristic quality indices (FQIs) are useful tools for assessing and comparing vegetation communities and related habitat condition. However, intensive vegetation surveys requiring significant time and technical expertise are necessary, which limits the use of FQIs in environmental monitoring programs. This study modified standard FQI methods to develop a rapid assessment method for characterizing and modeling change in wetland habitat condition in the northern Everglades. Method modifications include limiting vegetation surveys to a subset of taxa selected as indicators of impact and eliminating richness and/or abundance factors from the equation. These modifications reduce the amount of …


Fire Monitoring Handbook May 2020

Fire Monitoring Handbook

United States National Park Service: Publications

Fire is a powerful and enduring force that has had, and will continue to have, a profound influence on National Park Service (NPS) lands. Fire management decisions within the National Park Service require information on fire behavior and on the effects of fire on park resources. With good reason, the public is holding park management increasingly accountable, especially in the area of fire management. Federal and state agencies are instituting progressively more stringent guidelines for burning, monitoring, and evaluation. The impetus behind these guidelines and the purpose of this handbook are to ensure that management objectives are being met, to …


Acoustically Advertising Male Harbour Seals In Southeast Alaska Do Not Make Biologically Relevant Acoustic Adjustments In The Presence Of Vessel Noise, Leanna P. Matthews, Michelle E.H. Fournet, Christine Gabriele, Holger Klinck, Susan E. Parks Mar 2020

Acoustically Advertising Male Harbour Seals In Southeast Alaska Do Not Make Biologically Relevant Acoustic Adjustments In The Presence Of Vessel Noise, Leanna P. Matthews, Michelle E.H. Fournet, Christine Gabriele, Holger Klinck, Susan E. Parks

United States National Park Service: Publications

Aquatically breeding harbour seal (Phoca vitulina) males use underwater vocalizations during the breeding season to establish underwater territories, defend territories against intruder males, and possibly to attract females. Vessel noise overlaps in frequency with these vocalizations and could negatively impact breeding success by limiting communication space. In this study, we investigated whether harbour seals employed anti-masking strategies to maintain communication in the presence of vessel noise in Glacier Bay National Park and Preserve, Alaska. Harbour seals in this location did not sufficiently adjust source levels or acoustic parameters of vocalizations to compensate for acoustic masking. Instead, for every 1 dB …


Carnivore Population Structure Across An Urbanization Gradient: A Regional Genetic Analysis Of Bobcats In Southern California, Julia G. Smith, Megan K. Jennings, Erin E. Boydston, Kevin R. Crooks, Holly B. Ernest, Seth Riley, Laurel E. K. Serleys, Shaelynn Sleater-Squires, Rebecca L. Lewison Mar 2020

Carnivore Population Structure Across An Urbanization Gradient: A Regional Genetic Analysis Of Bobcats In Southern California, Julia G. Smith, Megan K. Jennings, Erin E. Boydston, Kevin R. Crooks, Holly B. Ernest, Seth Riley, Laurel E. K. Serleys, Shaelynn Sleater-Squires, Rebecca L. Lewison

United States National Park Service: Publications

Context In human-dominated landscapes, habitat fragmentation and barriers to movement can interrupt gene flow. While often considered at a local extent, regional analyses are also needed to reveal broader landscape-mediated population processes.

Objectives To explore the relationship between patterns of gene flow and fragmentation resulting from urbanization across southern California, we used the bobcat as an indicator species. We assembled data for a landscape level genetic analysis across southern California from both archived and new samples, including two northern Californian populations for comparison, to identify local and regional areas affected by isolation.

Methods Our regional analyses focused on a dataset …


Asynchronous Carbon Sink Saturation In African And Amazonian Tropical Forests, Wannes Hubau, Simon L. Lewis, Et. Al. Authors Mar 2020

Asynchronous Carbon Sink Saturation In African And Amazonian Tropical Forests, Wannes Hubau, Simon L. Lewis, Et. Al. Authors

United States National Park Service: Publications

Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 percent of 1–3 anthropogenic carbon dioxide emissions. Climate-driven vegetation models 4,5 typically predict that this tropical forest ‘carbon sink’ will continue for decades . Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to …


Problematic Plant Monitoring In Homestead National Monument Of America, 2006–2017, Craig C. Young Mar 2020

Problematic Plant Monitoring In Homestead National Monument Of America, 2006–2017, Craig C. Young

United States National Park Service: Publications

Abstract

Managers are challenged with the impact of problematic plants, including exotic, invasive, and pest plant species. Information on the abundance, distribution, and location of these plants is essential for developing risk-based approaches to managing these species. Based on surveys conducted in 2006, 2009, 2013, and 2017, Heartland Inventory and Monitoring Network staff and contractors identified a cumulative total of 20 potentially problematic plant species in Homestead National Monument of America (NMA). Of the 13 species found in 2017, we characterized 4 as very low frequency, 4 as low frequency, 2 as medium frequency, and 3 as high frequency. Only …


Problematic Plant Monitoring In Tallgrass Prairie National Preserve, 2006–2018, Craig C. Young Mar 2020

Problematic Plant Monitoring In Tallgrass Prairie National Preserve, 2006–2018, Craig C. Young

United States National Park Service: Publications

Abstract

Managers are challenged with the impact of problematic plants, including exotic, invasive, and pest plant species. Information on the abundance, distribution, and location of these plants is essential for developing risk-based approaches to managing these species. Based on surveys conducted in 2006, 2010, 2014, and 2018, Heartland Inventory and Monitoring Network staff and contractors identified a cumulative total of 33 problematic plant species in Tallgrass Prairie National Preserve. Of the 27 species found in 2018, we characterized 14 as very low frequency, 9 as low frequency, 4 as medium frequency, and 0 as high frequency. Only 4 (14.8%) of …


Estimation Of Available Epinephrine Dose In Expired And Discolored Autoinjectors Via Quantitative Smartphone Imaging, Amirus Saleheen, Bill M. Campbell, Rebecca A. Prosser, Christopher A. Baker Feb 2020

Estimation Of Available Epinephrine Dose In Expired And Discolored Autoinjectors Via Quantitative Smartphone Imaging, Amirus Saleheen, Bill M. Campbell, Rebecca A. Prosser, Christopher A. Baker

United States National Park Service: Publications

Epinephrine autoinjectors (EAIs) are important first aid medications for treating anaphylaxis. A 10-fold price increase over the past 12 years and evidence that expired EAIs may still contain significant doses of available epinephrine have motivated interest in the efficacy of expired EAIs as treatments of last resort. Degradation of expired EAIs, which can be caused by improper storage conditions, results in various degrees of discoloration of the epinephrine solution. Previous studies have determined that significant epinephrine remains available in expired EAIs, but these have only considered EAIs that show no discoloration. Here, we investigate the potential for colorimetric estimation of …


Nurse Rock Microclimates Significantly Buffer Exposure To Freezing T Temperature And Moderate Summer Temperature, Joshua L. Conver, Elliott Yarwood, Lucas D. Hetherington, Don E. Swann Feb 2020

Nurse Rock Microclimates Significantly Buffer Exposure To Freezing T Temperature And Moderate Summer Temperature, Joshua L. Conver, Elliott Yarwood, Lucas D. Hetherington, Don E. Swann

United States National Park Service: Publications

Nurse tree canopies mitigate exposure to freezing temperatures that could result in injury or mortality to the saguaro cactus (Carnegiea gigantea). Abiotic objects have been hypothesized to provide similar beneficial microclimates. We used data loggers at 11 nurse rock sites to record daily daytime summer maximum and winter nighttime minimum temperatures at Saguaro National Park, Arizona, to examine the effectiveness of rocks to moderate seasonal temperature extremes in the microclimate. Temperatures at rock sites averaged 2 °C warmer than exposed open control sites in winter. We found that the efficiency of rocks to act as insulators significantly increased as temperature …


Effects Of Culling White-Tailed Deer On Tree Regeneration And Microstegium Vimineum, An Invasive Grass, John Paul Schmit, Elizabeth R. Matthews, Andrejs Brolis Feb 2020

Effects Of Culling White-Tailed Deer On Tree Regeneration And Microstegium Vimineum, An Invasive Grass, John Paul Schmit, Elizabeth R. Matthews, Andrejs Brolis

United States National Park Service: Publications

Reduction of forest regeneration due to overbrowsing by white-tailed deer is a growing concern for land managers. Abundant deer can impede forest regeneration through direct predation on tree seedlings. Additionally high deer density can facilitate the establishment of a dense understory of browse tolerant plant species that shades seedlings and persists even in the absence of deer. In response to these challenges, land managers have sought to reduce deer herds to restore tree regeneration, but few studies have evaluated the effectiveness of this management. Our study took place in Catoctin Mountain Park, a US National Park Service unit with a …


Implications Of Organic Mass To Carbon Ratios Increasing Over Time In The Rural United States, W.C. Malm, B.A. Schichtel, J.L. Hand, A.J. Prenni Feb 2020

Implications Of Organic Mass To Carbon Ratios Increasing Over Time In The Rural United States, W.C. Malm, B.A. Schichtel, J.L. Hand, A.J. Prenni

United States National Park Service: Publications

The thermal evolution procedure used by most monitoring programs in the United States to determine carbonaceous aerosol concentrations is referred to as the thermal‐optical reflectance method, where an aerosol sample that has been collected on a quartz filter is heated and evolved carbon is characterized as either organic (OC) or light absorbing carbon (LAC). Evolved carbon assigned to OC is multiplied by a factor, Roc, to achieve an estimate of organic mass. Over the last 10–15 years, Roc, estimated through multiple linear regression analysis of data collected in the Interagency Monitoring of Protected Visual Environments (IMPROVE) program, has increased at …


Beryllium-7 Elucidate Sediment Dynamics Of The Branford River Estuary, Connecticut, Usa, Gaboury Benoit, Matthew Hirschbeck, Beth Bisson Feb 2020

Beryllium-7 Elucidate Sediment Dynamics Of The Branford River Estuary, Connecticut, Usa, Gaboury Benoit, Matthew Hirschbeck, Beth Bisson

United States National Park Service: Publications

Berrylium-7 elucidates sediment dynamics (i.e., sources, sinks, deposition, and resuspension) in a Connecticut estuary. Average 7 −2−1 annual atmospheric deposition of Be is 290 mBq cm year. Sediment samples from 43 locations within the estuary show that 7Be deposition is spatially complex, but were statistically indistinguishable a year apart. Weekly time series of sediments indicate 7 that levels are nearly constant on this shorter time scale on ceradio active decay is taken into account. Be levels in sediments area balance between steady losses through radioactive decay and periodic pulse inputs following rainstorms. The water column was measured intensively during three …