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Landscape Scale: Inter- And Intraspecific Variation In Plant Interactions Along A Stress Gradient In The Sheep Range Of Nevada, Jordan Dowell Dec 2019

Landscape Scale: Inter- And Intraspecific Variation In Plant Interactions Along A Stress Gradient In The Sheep Range Of Nevada, Jordan Dowell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Impending threats to shrubland ecosystems, posed by climate change, necessitate niche modeling efforts to project vegetation range shifts. However, efforts often remain unguided by individual-scale interspecific plant interactions. The stress gradient hypothesis posits that facilitation should increase in areas of high abiotic stress, only if the individuals are able to ameliorate the surrounding area via functional traits. The Sheep Range of Nevada was used to assess the role of functional traits as predictors of plant association. Larrea tridentata, Coleogyne ramosissima, and Artemisia nova were selected as shrubs with variable life history strategies and ranges in order to identify general patterns ...


Watching Grass Grow: How Soil Moisture Affects Vesicular-Arbuscular Mycorrhizae And Growth In Little Bluestem, Laura M. Jones Dec 2019

Watching Grass Grow: How Soil Moisture Affects Vesicular-Arbuscular Mycorrhizae And Growth In Little Bluestem, Laura M. Jones

Honors Scholar Theses

Vesicular-arbuscular mycorrhizae (VAM) are an ancient mutualism in which soil-dwelling fungi enhance plant absorption of phosphorus and nitrogen in exchange for photosynthates. VAM are sensitive to changes in soil moisture and nutrient content, fluctuating between mutualism and parasitism depending on conditions of drought stress and nutrient deficiency. Understanding how VAM respond to precipitation changes is crucial for both conservation and agricultural purposes. To test how soil moisture changes the effects of VAM colonization and growth in little bluestem (Schizachyrium scoparium), a common prairie grass, I planted 300 seeds in a greenhouse in sterilized soil and soil inoculated with VAM fungi ...


Diffuse Light And Wetting Differentially Affect Tropical Tree Leaf Photosynthesis, Z. Carter Berry, Gregory R. Goldsmith Aug 2019

Diffuse Light And Wetting Differentially Affect Tropical Tree Leaf Photosynthesis, Z. Carter Berry, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

‐Most ecosystems experience frequent cloud cover resulting in light that is predominantly diffuse rather than direct. Moreover, these cloudy conditions are often accompanied by rain that results in wet leaf surfaces. Despite this, our understanding of photosynthesis is built upon measurements made on dry leaves experiencing direct light.

‐Using a modified gas exchange setup, we measured the effects of diffuse light and leaf wetting on photosynthesis in canopy species from a tropical montane cloud forest.

‐We demonstrate significant variation in species‐level response to light quality independent of light intensity. Some species demonstrated 100% higher rates of photosynthesis in diffuse ...


Herbarium Records Reveal Earlier Bloom Times In Three Southern Appalachian Plant Species, Melanie Flood, Mark Davis, Ashlee Mccaskill Aug 2018

Herbarium Records Reveal Earlier Bloom Times In Three Southern Appalachian Plant Species, Melanie Flood, Mark Davis, Ashlee Mccaskill

Georgia Journal of Science

Plant phenology, especially the onset of flowering in angiosperms, is a useful tool for studying the effects of climate change on native flora because it is influenced by temperatures. Numerous studies in different biomes have provided evidence of earlier bloom times in response to increasing temperatures. We examined herbarium specimen data to determine whether three spring-blooming species (Sanguinaria canadensis, Iris cristata, and Trillium rugelii) at the southern terminus of the Appalachians exhibit a similar change in onset of flowering over several decades. All three species exhibited significantly earlier flower onset during the past 120 years, a change that could have ...


A Quantitative Analysis Of The Effects Of Urbanization, Mesophication And Prescribed Burns On Oak Woodlands In The Chicago Metropolitan Area, Chad Populorum May 2018

A Quantitative Analysis Of The Effects Of Urbanization, Mesophication And Prescribed Burns On Oak Woodlands In The Chicago Metropolitan Area, Chad Populorum

Celebration of Learning

Urban expansion has had devastating impacts on forest ecosystems, especially within the past century. Human attempts to dominate nature have diminished natural disturbance regimes, which have maintained the biodiversity and historic composition of these ecosystems. Fires have been a prominent force in maintaining the structure of oak, hickory and other heliophytic (sun loving and fire-adapted) forest systems. Human induced fire suppression has led to mesophication across North America. Mesophication is the transition from drier conditions with open canopies to wetter conditions with closed canopies. These new conditions decrease the survival rates of these important species and begin to favor mesophytic ...


Drivers Of Post-Fire Vascular Plant Regeneration In The Conifer-Dominated Boreal Forest Of Southern Northwest Territories, Alison White Jan 2018

Drivers Of Post-Fire Vascular Plant Regeneration In The Conifer-Dominated Boreal Forest Of Southern Northwest Territories, Alison White

Theses and Dissertations (Comprehensive)

In recent years, climate warming has led to an increase in the severity and frequency of naturally occurring fires in boreal ecosystems globally. In 2014, an unprecedented 3.4 million hectares of boreal forest burned in the Northwest Territories (NWT). While much research has focused on post-fire succession of serotinous tree species such as Picea mariana (black spruce) and Pinus banksiana (jack pine), the understory community of vascular plants play an important role in ecosystem functioning but less is known about the response of this component of the system to changing fire regimes. Regeneration strategies such as the ability to ...


Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis Mar 2017

Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis

Seaver College Research And Scholarly Achievement Symposium

Between 2012-2016, southern California experienced unprecedented drought that caused dieback in Malosma laurina, a keystone species of chaparral shrub communities. Dieback was especially severe in coastal exposures of the Santa Monica Mountains, leading to whole plant mortality exceeding 50% at some sites. We hypothesized that the endophytic fungus causing the dieback, Botryosphaeria dothidea, was successful in invading the xylem tissue of M. laurina because of protracted water stress, carbon starvation, or a combination of the two. We tested these possibilities in a controlled pot experiment by comparing three treatments, each inoculated with the fungus: (1) irrigated controls (2) non-irrigated (water ...


Political Ecology Of Medicinal Plant Use In Rural Nepal: Globalization, Environmental Degradation, And Cultural Transformation, Emily Dovydaitis Jan 2017

Political Ecology Of Medicinal Plant Use In Rural Nepal: Globalization, Environmental Degradation, And Cultural Transformation, Emily Dovydaitis

Honors Undergraduate Theses

Prior to the advent of biomedicine, rural communities in Nepal relied on phytochemically active compounds in medicinal plants as their primary source of medicine; however, ethnobotanical practices have shifted over time due to economic, environmental, and sociocultural stimuli. Findings from 2016 fieldwork conducted in Dumrikharka, Nepal and Tutung, Nepal are compared to existing literature to describe the political ecology of medicinal plants in rural Nepal.

Anthropogenic climate change threatens individual plant species and ecosystem biodiversity. Globalized markets unabated by weak conservation programs place increasing demands on medicinal plants. As indigenous plants become overharvested and more difficult to access, Nepalis incorporate ...


Long-Term Sandhills Prairie Responses To Precipitation, Temperature, And Cattle Stocking Rate, John A. Guretzky, Cheryl Dunn, Heidi L. Hillhouse Jun 2016

Long-Term Sandhills Prairie Responses To Precipitation, Temperature, And Cattle Stocking Rate, John A. Guretzky, Cheryl Dunn, Heidi L. Hillhouse

Agronomy & Horticulture -- Faculty Publications

Understanding of Sandhills prairie, the most expansive sand dune region stabilized by perennial grasses in the Western Hemisphere, is limited by lack of long-term vegetation data. We used a 26-year dataset to evaluate Sandhills prairie responses to yearto- year variation in precipitation, temperature, and cattle stocking rate. Basal cover, a measurement that is constant seasonally and used to detect long-term changes in bunchgrass vegetation, was measured in 38–40 permanent plots positioned along four transects spanning 769 ha from 1979 to 2007. Across this period, total basal cover averaged 2.4 % and was dominated by warm-season grasses (81.1 %). Schizachyrium ...


Enhancement Of The Role Of Spatial Planning In Climate Change Adaptation By Long Term Modelling Of Land Use Change In Hungary, Krisztián Schneller, Erzsébet Vajdovich Visy, Vilja Vaszócsik Jan 2016

Enhancement Of The Role Of Spatial Planning In Climate Change Adaptation By Long Term Modelling Of Land Use Change In Hungary, Krisztián Schneller, Erzsébet Vajdovich Visy, Vilja Vaszócsik

Proceedings of the Fábos Conference on Landscape and Greenway Planning

The purposeful formation of land use significantly contributes to the moderation of the adverse impact of climate change. Since spatial planning plays a fundamental role in the formation of land use, therefore it is essential to integrate climate adaptation goals into the planning process (Biesbroek, G.R. et al., 2009). Spatial plans primarily assist the achievement of adaptation purposes by the delimitation and protection (primarily against urban sprawl) of areas (as zones, such as ecological corridors) which are important in adaptation and risk prevention. In Hungary at present the spatial planning system already contribute to the above mentioned objectives, but ...


Sustainable Urban Planning And Climate Change Scenarios: An Investigation Of Staten Island's Urban Planning, Melissa Wagner, Lauren E. Gentile, Joanna Merson, Elizabeth Wentz Jan 2016

Sustainable Urban Planning And Climate Change Scenarios: An Investigation Of Staten Island's Urban Planning, Melissa Wagner, Lauren E. Gentile, Joanna Merson, Elizabeth Wentz

Proceedings of the Fábos Conference on Landscape and Greenway Planning

Recent events like Hurricane Sandy, which struck Staten Island, NY on October 29, 2012, serve as a costly reminder of how unsustainable designs and mounting social pressures can contribute to extensive structural damage and subsequent financial cost, from storm surge inundation and coastal flooding. It is unlikely that Hurricane Sandy was a one-time event but rather a warning of what can occur over the next century without proper mitigation strategies. Based on climate change projections, such extreme events are expected to become more frequent and intense due to warmer sea surface temperatures and rising sea levels (Emmanual, 2005; Kirtman et ...


Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez Jan 2016

Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez

Agronomy & Horticulture -- Faculty Publications

It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize–soybean rotation offers multiple potential benefits that can reduce the impacts of higher temperatures and more variable rainfall; some of the anticipated changes for the Midwest. In this experiment we used the Agricultural Production Systems sIMulator (APSIM) to understand how winter rye cover crops impact crop production and environmental outcomes, given future climate change. We ...


Investigating The Effects Of Short- And Long-Term Climatic Variation On The Water Use Of Three Northern Hardwood Tree Species, Alex R. Collins Jan 2015

Investigating The Effects Of Short- And Long-Term Climatic Variation On The Water Use Of Three Northern Hardwood Tree Species, Alex R. Collins

Dissertations, Master's Theses and Master's Reports - Open

Many tree species are expected to decline in the northern Midwestern United States due to climate change increasing annual temperature 3-5º C by 2100. Sugar maple (Acer saccharum), an economically important timber and syrup species, is not expected to be sustainable in its current range under projected future climate, while trembling aspen (Populus tremuloides) and red maple (Acer rubrum) are expected to react more favorably to climate change. The success of individual tree species is dependent on how climate change will alter a species environment in regards to water use. Climate change could potentially reduce available soil moisture, reducing potential ...


Limited Alpine Climatic Warming And Modeled Phenology Advancement For Three Alpine Species In The Northeast United States, Michael L. Davis, Kenneth D. Kimball, Douglas M. Weihrauch, Georgia L. D. Murray, Kenneth Rancourt Sep 2014

Limited Alpine Climatic Warming And Modeled Phenology Advancement For Three Alpine Species In The Northeast United States, Michael L. Davis, Kenneth D. Kimball, Douglas M. Weihrauch, Georgia L. D. Murray, Kenneth Rancourt

Ecology Center Publications

  • Premise of the study: Most alpine plants in the Northeast United States are perennial and flower early in the growing season, extending their limitedgrowing season. Concurrently, they risk the loss of reproductive efforts to late frosts. Quantifying long-term trends in northeastern alpine flower phenology and late-spring/early-summer frost risk is limited by a dearth of phenology and climate data, except for Mount Washington, New Hampshire (1916 m a.s.l.).
  • Methods: Logistic phenology models for three northeastern US alpinespecies (Diapensia lapponica, Carex bigelowii and Vaccinium vitis-idaea) were developed from 4 yr (2008–2011) of phenology and air temperature measurements from ...


Monteverde: Ecology And Conservation Of A Tropical Cloud Forest - 2014 Updated Chapters, Nalini M. Nadkarni, Nathaniel T. Wheelwright Jan 2014

Monteverde: Ecology And Conservation Of A Tropical Cloud Forest - 2014 Updated Chapters, Nalini M. Nadkarni, Nathaniel T. Wheelwright

Bowdoin Scholars' Bookshelf

The Monteverde Cloud Forest Reserve has captured the worldwide attention of biologists, conservationists, and ecologists and has been the setting for extensive investigation over the past 40 years. Roughly 40,000 ecotourists visit the Cloud Forest each year, and it is often considered the archetypal high-altitude rain forest. “Monteverde: Ecology and Conservation of a Tropical Cloud Forest”, edited by Nalini Nadkarni and Nathaniel T. Wheelwright (Oxford University Press, 2000 and Bowdoin’s Scholar’s Bookshelf. Book 1 ), features synthetic chapters and specific accounts written by more than 100 biologist and local residents, presenting in a single volume everything known in ...


Assessment Matrix Based Evaluation Of Ecosystem Services In Relation To Land Use Change Scenarios, Gergő Gábor Nagy, Veronika Magyar, Sándor Jombach, László Kollányi, Balázs Duray Jan 2013

Assessment Matrix Based Evaluation Of Ecosystem Services In Relation To Land Use Change Scenarios, Gergő Gábor Nagy, Veronika Magyar, Sándor Jombach, László Kollányi, Balázs Duray

Proceedings of the Fábos Conference on Landscape and Greenway Planning

The ecosystem services are natural assets and services, which are used by humans directly or indirectly over their respective lifetimes (MEA, 2005). Several authors and organizations describe these goods of nature in different ways. Some authors use ecological concepts as the basis for categorization (Norberg, 1999), others concentrate on different human needs (Wallace, 2007), however the most common categories are based on some functional distinction (MEA, 2005; de Groot, 2006; Hein et al., 2006). Authors representing this latter group usually mention the following classification: provisioning, regulating, supporting and cultural services. The provisioning services like water, wood or timber are used ...


Effects Of Detention For Flooding Mitigation Under Climate Change Scenarios— Implication For Landscape Planning In The Charles River Watershed, Massachusetts, Usa, Chingwen Cheng, Elizabeth A. Brabec, Yi-Chen E. Yang, Robert L. Ryan Jan 2013

Effects Of Detention For Flooding Mitigation Under Climate Change Scenarios— Implication For Landscape Planning In The Charles River Watershed, Massachusetts, Usa, Chingwen Cheng, Elizabeth A. Brabec, Yi-Chen E. Yang, Robert L. Ryan

Proceedings of the Fábos Conference on Landscape and Greenway Planning

Climate change has posed increased risks to environmental hazards (e.g., flooding, droughts, hurricanes) in addition to new challenges under climate change impacts (e.g., early snow melt, sea level rises, heat waves). Floods are omnipresent in almost every city in the United States and account for the most economic losses than any other single geophysical hazard (White and Haas 1975). Previous climate change studies have suggested promising trends of increasing temperature and changing precipitation patterns as well as increased intensity and duration of storm events that are likely to result in more flooding events in the Northeast region. Flooding ...


A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur Jan 2013

A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur

Dissertations & Theses

This study investigated a terrestrial climate proxy, phytoliths, as a complimentary approach to documenting the dynamics of present and past vegetation on Sanak Island, the largest island in a small island group in the eastern Aleutian archipelago, and as a new basis by which to interpret Holocene environmental variability in Alaska. A phytolith reference collection was established from 59 selected plant species of maritime tundra belonging to 27 families. The grass species and a sedge species produced abundant phytolith forms whereas the majority of dicotyledons in this study were trace producers of phytoliths. A paleoenvironmental reconstruction from fossil phytoliths recovered ...


Greenways In Strategies Of Mitigation And Adaption To Climate Change: Case Study Of State Of Maryland, Usa, David Myers Jan 2010

Greenways In Strategies Of Mitigation And Adaption To Climate Change: Case Study Of State Of Maryland, Usa, David Myers

Proceedings of the Fábos Conference on Landscape and Greenway Planning

This paper, using the State of Maryland, USA as a case study, draws connections between greenway contributions to the Greenprint Program in MD and the rapidly expanding work on the use of green infrastructure to address climate change. It focuses on recent initiatives that could support the role of greenways in mitigating and adapting to climate change. Maryland established the Climate Change Commission in April 2007 by executive order to develop a plan for reducing the state’s vulnerability to sea level rise and other impacts of climate change. The Maryland Climate Change Commission's Climate Action Plan documented fortytwo ...


Blueprints For Green Communities: Climate Change Visioning And Participatory Landscape Planning For Resilient Low-Carbon Communities, David N. Flanders, Stephen R.J. Sheppard, Ellen Pond, Sarah Burch, Alison Shaw, Stewart Cohen Jan 2010

Blueprints For Green Communities: Climate Change Visioning And Participatory Landscape Planning For Resilient Low-Carbon Communities, David N. Flanders, Stephen R.J. Sheppard, Ellen Pond, Sarah Burch, Alison Shaw, Stewart Cohen

Proceedings of the Fábos Conference on Landscape and Greenway Planning

Emerging 3D visualization tools and future visioning methods offer new ways to make climate change impacts and potential responses explicit, and accelerate holistic solutions. Previous research at UBC’s Collaborative for Advanced Landscape Planning (CALP) and elsewhere confirms that 4D visioning processes using landscape visualizations of recognizable places under alternative future conditions can improve community engagement and awareness on complex environmental and planning issues (Tress and Tress, 2002; Sheppard and Meitner, 2005; Schroth, 2007). This paper examines a visioning process (Sheppard, 2008) that applies visualization and other landscape planning methods to explore high and low-carbon futures of the affluent, sub-urban ...