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Physical and Environmental Geography Commons

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2020

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Articles 31 - 60 of 94

Full-Text Articles in Physical and Environmental Geography

Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa May 2020

Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Primary productivity (PP) has been recently investigated using remote sensing-based models over quite limited geographical areas of the Red Sea. This work sheds light on how phytoplankton and primary production would react to the effects of global warming in the extreme environment of the Red Sea and, hence, illuminates how similar regions may behave in the context of climate variability. study focuses on using satellite observations to conduct an intercomparison of three net primary production (NPP) models--the vertically generalized production model (VGPM), the Eppley-VGPM, and the carbon-based production model (CbPM)--produced over the Red Sea domain for the 1998-2018 time period. …


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 …


Lightning Activity In The Continental United States On An Enso Time Scale, 2002-2015, Tyler M. Gingrich May 2020

Lightning Activity In The Continental United States On An Enso Time Scale, 2002-2015, Tyler M. Gingrich

Senior Honors Projects, 2020-current

This investigation examined the frequency and spatial pattern of lightning in the continental United States from 2002 to 2015. Before analysis, flashes were grouped based on their El Niño Southern Oscillation (ENSO) phase and Spatial Synoptic Classification (SSC) type for the winter season (December, January, and February). The purpose of this study is to better understand the relationship between planetary teleconnections, synoptic scale air masses, and micro scale phenomena, specifically lightning, in the continental United States. Evidence suggests ENSO cold phase flashes tend to have a lower frequency in number of flashes and flash days, as well as a northward …


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 …


How Much Variation In Land Surface Phenology Can Climate Oscillation Modes Explain At The Scale Of Mountain Pastures In Kyrgyzstan?, Monika A. Tomaszewska, Geoffrey M. Henebry May 2020

How Much Variation In Land Surface Phenology Can Climate Oscillation Modes Explain At The Scale Of Mountain Pastures In Kyrgyzstan?, Monika A. Tomaszewska, Geoffrey M. Henebry

NASA Land-Cover Land-Use Change Data Sets

Climate oscillation modes can shape weather across the globe due to atmospheric teleconnections. We built on the findings of a recent study to assess whether the impacts of teleconnections are detectable and significant in the early season dynamics of highland pastures across five rayons in Kyrgyzstan. Specifically, since land surface phenology (LSP) has already shown to be influenced by snow cover seasonality and terrain, we investigated here how much more explanatory and predictive power information about climatic oscillation modes might add to explain variation in LSP. We focused on seasonal values of five climate oscillation indices that influence vegetation dynamics …


A 30-Yr Climatology Of Meteorological Conditions Associated With Lightning Days In The Interior Western United States, Dmitri Alexander Kalashnikov, Paul Loikith, Arielle J. Catalano, Duane E. Waliser, Huikyo Lee, John T. Abatzoglou May 2020

A 30-Yr Climatology Of Meteorological Conditions Associated With Lightning Days In The Interior Western United States, Dmitri Alexander Kalashnikov, Paul Loikith, Arielle J. Catalano, Duane E. Waliser, Huikyo Lee, John T. Abatzoglou

Geography Faculty Publications and Presentations

A 30-yr climatology of lightning days and associated synoptic meteorological patterns are characterized across the interior western United States (WUS). Locally centered composite analyses show preferred synoptic meteorological patterns with positive 500-hPa geopotential height anomalies located to the northeast and negative sea level pressure anomalies to the northwest and collocated with local lightning days. Variations in preferred patterns for local lightning days are seen across the interior WUS. Areas not commonly affected by the North American monsoon system including the western Great Basin and northern Rocky Mountains show higher-amplitude anomalies of geopotential height, moisture, and midtropospheric instability patterns suggesting the …


Spatial Analysis Of Soil Creep Rates On Mount Sequoyah, Fayetteville Arkansas, Amy Suzanne Morris May 2020

Spatial Analysis Of Soil Creep Rates On Mount Sequoyah, Fayetteville Arkansas, Amy Suzanne Morris

Graduate Theses and Dissertations

Mount Sequoyah in Fayetteville, Arkansas, is a part of the Boston Mountains, which are considered a deeply dissected plateau. The area is prone to mass wasting, which is the general downslope movement of sediments, soils, and rock through different processes that cause instabilities along a hillslope, and in its soil and loose rubble mantle. For this study, we looked at soil creep, which is the small-scale movement of soil downhill because of gravity, wetting and drying cycles, and heating and cooling cycles.

By measuring the tilt of utility poles, we determined multiple causes of soil creep. The variables that are …


A Tale Of Two Species: Black-Tailed And White-Tailed Prairie Dog Biogeography From The Last Interglacial To 2070, April Dawn Bledsoe May 2020

A Tale Of Two Species: Black-Tailed And White-Tailed Prairie Dog Biogeography From The Last Interglacial To 2070, April Dawn Bledsoe

Electronic Theses and Dissertations

Ecological niche models (ENMs) were created for White-tailed and Black-tailed prairie dogs and projected into the Last Interglacial (LI), the Last Glacial Maximum (LGM), and mid-Holocene (mid-H) to discern possible past suitable habitat for both species. Additionally, ENMs were projected into the future year 2070 representative concentration pathways (RCPs) 2.6 and 8.5 to discern how climate change may affect future habitat suitability. Kernel density estimations, minimum convex polygons, and median distribution centers of White-tailed and Black-tailed occurrence records were examined between time-periods to discern the effects of anthropogenic westward expansion on both species’ distributions. Current ENMs were constructed from commonly …


216— Using Rochester’S Family Public Housing In The “Crescent Of Poverty” As A Catalyst For A Solar Initiative, Christopher Miller Apr 2020

216— Using Rochester’S Family Public Housing In The “Crescent Of Poverty” As A Catalyst For A Solar Initiative, Christopher Miller

GREAT Day Posters

Both the climate crisis and poverty rates in US cities have increased rapidly, with few solutions. This research examines the relative solar potential in public housing developments in Rochester, NY, specifically in the area of concentrated poverty called the “Crescent of Poverty.” Also examined are societal benefits that an inclusive solar/sustainability movement provides for Rochester. Rochester is a mid-sized, diversely populated city with an overall poverty rate >30% and a childhood poverty rate >50% (Murphy, 2018). These alarming rates have contributed to the creation of the “Crescent of Poverty”, where the majority of family public housing developments are located. Solar …


Crude Oil Spill Response In The Great Lakes Region: Before And After The 2010 Kalamazoo River Enbridge Oil Spill, Marshall Kim Apr 2020

Crude Oil Spill Response In The Great Lakes Region: Before And After The 2010 Kalamazoo River Enbridge Oil Spill, Marshall Kim

Honors Theses

Pipeline infrastructure is a particularly sensitive and unique energy transport mode. Pipelines carry gas, biofuels and liquid petroleum throughout the United States (U.S. Department of Transportation, 2019). These pipelines stretch beneath sensitive ecological areas, lakes, rivers and streams, and our homes and businesses. According to the Pipeline and Hazardous Materials Safety Administration (PHMSA) (2018), between all of the states in the Great Lakes region (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and New York) there is a cumulative 801,718 miles of pipeline. This includes interstate and intrastate, natural gas and petroleum pipelines. 9,556.9 miles of this is the interstate …


Analyzing Climate Risk To Maritime Cypress Swamps And Pine Savannas Of The Gulf Of Mexico Coastal Plain, Clay Stephens Tucker Apr 2020

Analyzing Climate Risk To Maritime Cypress Swamps And Pine Savannas Of The Gulf Of Mexico Coastal Plain, Clay Stephens Tucker

LSU Doctoral Dissertations

As sea levels rise, coastal trees are increasingly stressed by saltwater inundation, and stressed trees are ideal for studying changes in the environment through time. Dendrochronology has been used for more than a century to explain changes in past environments using tree rings. Using ring widths and stable isotopes from coastal trees, the effects of tropical cyclones and freshwater moisture availability are shown in regard to tree growth and ultimately are discussed in terms of change to the environment as a whole. Changes in tree growth as they relate to various climate parameters are measured using superposed epoch analysis, moving-window …


Automatic Features Extraction From Time Series Of Passive Microwave Images For Snowmelt Detection Using Deep-Learning – A Bidirectional Long-Short Term Memory Autoencoder (Bi-Lstm-Ae) Approach., Bienvenu Sedin Massamba Apr 2020

Automatic Features Extraction From Time Series Of Passive Microwave Images For Snowmelt Detection Using Deep-Learning – A Bidirectional Long-Short Term Memory Autoencoder (Bi-Lstm-Ae) Approach., Bienvenu Sedin Massamba

LSU Master's Theses

The Antarctic surface snowmelt is prone to the polar climate and is common in its coastal regions. With about 90 percent of the planet's glaciers, if all of the Antarctica glaciers melted, sea levels will rise about 58 meters around the planet. The development of an effective automated ice-sheet snowmelt monitoring system is therefore crucial.

Microwave remote sensing instruments, on the one hand, are very sensitive to snowmelt and can see day and night through clouds, allowing us to distinguish melting from dry snow and to better understand when, where, and for how long melting has taken place. On the …


University Of North Florida: Measuring And Mapping The Footprint Of Growth Over Time, Cheyenne Black, Autumn Cummings, Caroline Howard, Monica Murray, Evelyn Thorpe, Chris Baynard Apr 2020

University Of North Florida: Measuring And Mapping The Footprint Of Growth Over Time, Cheyenne Black, Autumn Cummings, Caroline Howard, Monica Murray, Evelyn Thorpe, Chris Baynard

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

This study analyzes remotely sensed aerial imagery in 5-7 year increments to determine land use change of the University of North Florida from 1970 to 2017. By geo-referencing, digitizing, and examining land-use data, we will map and measure the expansion of infrastructure as well as the loss of natural areas. We will compare the imagery of the original 1972 master plan to the current 2015-2025 master plan.


Land Surface Phenology In The Highland Pastures Of Montane Central Asia: Interactions With Snow Cover Seasonality And Terrain Characteristics, Monika A. Tomaszewska, Lan H. Nguyen, Geoffrey Henebry Apr 2020

Land Surface Phenology In The Highland Pastures Of Montane Central Asia: Interactions With Snow Cover Seasonality And Terrain Characteristics, Monika A. Tomaszewska, Lan H. Nguyen, Geoffrey Henebry

NASA Land-Cover Land-Use Change Data Sets

Many studies have shown that high elevation environments are among very sensitive to climatic changes and where impacts are exacerbated. Across Central Asia, which is especially vulnerable to climate change due to aridity, the ability of global climate projections to capture the complex dynamics of mountainous environments is particularly limited. Over montane Central Asia, agropastoralism constitutes a major portion of the rural economy. Extensive herbaceous vegetation forms the basis of rural economies in Kyrgyzstan. Here we focus on snow cover seasonality and the effects of terrain on phenology in highland pastures using remote sensing data for 2001–2017. First, we describe …


The Belknap Campus And Metro Louisville Urban Heat Island Effect: Air And Ground Surface Temperature Analysis, Kenyetta Johnson Apr 2020

The Belknap Campus And Metro Louisville Urban Heat Island Effect: Air And Ground Surface Temperature Analysis, Kenyetta Johnson

Undergraduate Arts and Research Showcase

Numerous studies show that urban morphologies and land covers generate excess heat emissions and retain heat relative to surrounding rural areas, known as the Urban Heat Island (UHI) effect. Urban fabrics paved by concretes and asphalts absorbs solar radiation during solar peak then radiates heat after sundown. This study investigates temperature distribution data related to the UHI effect on the Belknap campus at the University of Louisville, which represents a small aerial sample of the Louisville metropolitan UHI effect. The objective of this study is to measure the reflectivity of ground surfaces and air temperatures on the Belknap campus during …


Creating A Distribution Model Of Invasive Rusty Crayfish (Faxonius Rusticus) In Michigan Streams Using Publically Accessible Data, Robert C. Homan Apr 2020

Creating A Distribution Model Of Invasive Rusty Crayfish (Faxonius Rusticus) In Michigan Streams Using Publically Accessible Data, Robert C. Homan

Masters Theses

The purpose of this thesis is to create a predictive model of habitat suitability for the invasive rusty crayfish (Faxonius rusticus) throughout the state of Michigan. F. rusticus often outcompete and extirpate native crayfish species, so understanding their habitats of success is instrumental in monitoring vulnerable ecosystems. Michigan State University and the Michigan DNR conducted extensive field surveys across 461 streams sites from 2014-2016. This project compares this field data set to data from publicly available national datasets with the purpose of revealing the ecosystems most vulnerable to the introduction of F. rusticus. The pattern of F. rusticus …


Agritourism Development In Southwest Michigan: Motivations Of Agritourists And Operators, Esther Akoto Amoako Apr 2020

Agritourism Development In Southwest Michigan: Motivations Of Agritourists And Operators, Esther Akoto Amoako

Masters Theses

National agricultural statistics show that the number of agritourism farms and the proportion of agritourism related revenues in the United States has steadily increased during the last ten years, especially among small family farms. The recent growth in agritourism is both demand - and supply-driven. However, there are limited studies that explore agritourism motivations from both the visitors' and operators’ perspectives. This study examines what the agritourists' and operators’ motivations are and the challenges facing the industry to provide information for those currently involved and those wanting to include agritourism in their operations. Online and in-person surveys and unstructured interviews …


Dead Wolf To Red Wolf: Virginia Reintroduction Habitat Suitability, Hector Gomez Apr 2020

Dead Wolf To Red Wolf: Virginia Reintroduction Habitat Suitability, Hector Gomez

Environmental Studies Senior Seminar Projects

Red wolves (Canis Rufus) are the most endangered species of wolves. All red wolves currently in the wild are in the Albemarle Peninsula in North Carolina. Red wolf population in the Albemarle decreased from a peak of around 113-149 wolves in 2014 to 15-17 wolves in 2021. Most red wolf mortalities for this wild population occurred from anthropogenic causes such as accidental shooting, poaching, and vehicle strikes. The purpose of this study is to assess the suitability of the Delmarva Peninsula as a potential reintroduction site for another red wolf population. To do so I analyzed the land cover, deer …


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 …


Legal Geographies And Political Ecologies Of Water Allocation In Maui, Hawai'i, Alida Cantor, Kelly Kay, Chris Knudson Mar 2020

Legal Geographies And Political Ecologies Of Water Allocation In Maui, Hawai'i, Alida Cantor, Kelly Kay, Chris Knudson

Geography Faculty Publications and Presentations

Throughout the Hawaiian Islands, sugar plantations have controlled a large proportion of water resources for over a century, often leaving little water in streams to support ecosystems or Native Hawaiian cultural and agricultural practices. Recently, in Maui, Hawai‘i, community activists and lawyers representing Native Hawaiian and environmental interests have successfully reclaimed water resources for instream flow utilizing legal processes and tools such as Hawai‘i’s public trust doctrine, which has plural roots in both Hawaiian and Western legal traditions. In this paper, we use qualitative fieldwork, including interviews, participant observation, and archival data collection, to explore two recent and ongoing legal …


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 …


Population Collapse And Retreat To Fire Refugia Of The Tasmanian Endemic Conifer Athrotaxis Selaginoides Following The Transition From Aboriginal To European Fire Management, Andres Holz, Samuel W. Wood, Carly Ward, Thomas T. Veblen, David M.J.S. Bowman Mar 2020

Population Collapse And Retreat To Fire Refugia Of The Tasmanian Endemic Conifer Athrotaxis Selaginoides Following The Transition From Aboriginal To European Fire Management, Andres Holz, Samuel W. Wood, Carly Ward, Thomas T. Veblen, David M.J.S. Bowman

Geography Faculty Publications and Presentations

Untangling the nuanced relationships between landscape, fire disturbance, human agency, and climate is key to understanding rapid population declines of fire‐sensitive plant species. Using multiple lines of evidence across temporal and spatial scales (vegetation survey, stand structure analysis, dendrochronology, and fire history reconstruction), we document landscape‐scale population collapse of the long‐lived, endemic Tasmanian conifer Athrotaxis selaginoides in remote montane catchments in southern Tasmania. We contextualized the findings of this field‐based study with a Tasmanian‐wide geospatial analysis of fire‐killed and unburned populations of the species. Population declines followed European colonization commencing in 1802 ad that disrupted Aboriginal landscape burning. Prior to …


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 …


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 …


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 …


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 …


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 …