Ecology and Evolutionary Biology Commons^™

Lmpact Of Salmonella Enterica Effector Proteins On Plant Physiology And Immunity, Sara Qader

Honors Theses

Salmonella enterica serovar Typhimurium are primarily recognized as pathogens associated with foodborne illnesses in humans. Salmonella also can colonize plant tissue effectively. The pathogen relies on type III secretion systems (T3SS) to infect mammals and plants successfully and counteract the immune response. Understanding the molecular mechanisms underlying Salmonella’s interactions with plants is essential for developing effective strategies to reduce its impact on human health and agriculture. Effector proteins, known for their role in modulating host-pathogen interactions, have been implicated in the virulence and pathogenicity of Salmonella. However, their specific functions and contributions to Salmonella’s interactions with plants remain largely unknown. …

First Record Of The Invasive Chenopodium Aphid, Hayhurstia Atriplicis (Linnaeus, 1761) (Hemiptera: Aphididae), In Colombia, Takumasa Kondo, Roberto Rosero, Jackeline Gaviria

Insecta Mundi

The chenopodium aphid, Hayhurstia atriplicis (Linnaeus, 1761) (Hemiptera: Aphididae), is reported for the first time in Colombia. The aphid was found on the aerial parts of the quinoa plant, Chenopodium quinoa Willd. (Amaranthaceae), especially on the leaves, in five municipalities in the department of Cauca, Colombia. Brief information on its natural enemies, distribution and biology is provided. This is the only aphid in Colombia known to cause malformations on the leaves of quinoa plants. In South America, this aphid has been found previously only in Ecuador, where it was reported for the first time in 2023 based on specimens collected …

Relationships, Species Boundaries, And Speciation Of Piper Section Enckea, Cara Jean Hastings

Boise State University Theses and Dissertations

Species are fundamental biological units but defining what constitutes a species has been debated by biologists, philosophers, and other scholars. Our concept of what constitutes a species has evolved over time, reflecting progress and advances in technology and types of data available as well as increased understanding of the complexity of the speciation process. To understand how extant species evolved, it is useful to evaluate their relationships using molecular data in a phylogenetic framework. By pairing phylogenetic data with other types of data including morphological and fossil data as well as topographical and climatic history, we can gain understanding of …

Cross-Pollination: Building A Co-Taught Course To Examine Art And Sex Through The Lens Of Botany, Christopher T. Martine, Diamanda A. Zizis, Anna K. Kell

Faculty Journal Articles

Driven by overlapping interests in plants, art, and diversity in sex expression, Anna Kell (Department of Art and Art History) and Chris Martine (Department of Biology) developed a course that integrates the perspectives of a visual artist and a botanist. Art & Sex Through the Lens of Botany seeks to impart the importance of making connections across disciplines and the value of visual literacy across academic lines. The course introduces foundational concepts in each field and encourages students to integrate and explore these different systems of knowledge and their intersections. In addition to developing fluencies related to both general botany …

Identifying Grassland Cores In The Southeast: Relating Spatial Covariance To Avian Communities And Vegetation Structure, Lauren L. Berry

Graduate Theses and Dissertations

Globally, grasslands are declining in range, which is leading to a decline in grassland-dependent taxa. These declines can be attributed to a variety of issues, a major one being the encroachment of woody species into historic grasslands. There is a new framework for strategizing grassland management, referred to as “Defend the Core,” which calls for proactive management of intact grasslands, meaning conserving remaining grasslands by preventing woody encroachment in the first place. To successfully defend the core, it is imperative that we develop rapid methods to identify intact grassland cores for management priority. One method that can be used for …

Reconnecting With Nature One Classroom At A Time, Bianca Apuzzo

Senior Honors Projects

Environmental science is more important to today’s society than it has ever been, and developing basic ecoliteracy is the easiest way we can work towards a more sustainable future. Ecoliteracy allows us to connect deeper to nature and provides us with the information needed to protect and restore our beautiful planet. We are rolling downhill, picking up speed as we go, through a silent mass extinction. The scariest part of it all: nobody seems to care.

In response to the lack of environmental education provided to today’s students, I have created a syllabus for a high school level science course …

Threads Of Connection: An Offering To Re-Tangle Humanity And Nature With The Patterns Of Our World, Emily Shelton

Graduate Theses

In our world there are patterns of self-similarity that serve as evidence of the interconnectedness between humankind and the rest of the natural world. They are reflected in our bodies, behaviors, and environments, both natural and manmade, and can be found throughout systems at every scale, micro through macro. These organic, linear motifs branch into smaller iterations that seem to shape our existence on this planet as we gravitate towards experiences that echo these patterns. During everyday acts like shopping in a grocery store or a crowd at a concert, we unconsciously participate in self-similar collective movements as we navigate …

Plant-Plant Interaction In Early- Vs. Late-Successional Varieties Of The Hawaiian Landscape-Dominant Tree, Metrosideros Polymorpha, Tomoko Sakishima

UNLV Theses, Dissertations, Professional Papers, and Capstones

Plant-plant interactions play an important role in assembling plant communities. Interactions between neighboring plants can vary as a result of the genetic relatedness of neighbors, impacting rates of growth and patterns of resource allocation. When growing alongside close relatives, some species decrease their growth in a form of cooperation, while others grow faster through facilitation. A complication of plant interaction studies arises because decreased growth in the presence of close relatives can also be due to competition for resources, which increases with phenotypic similarity. Further complicating matters, mycorrhizal fungi, through their connections with plant roots, may strongly influence plant interactions. …

Seasonal Climate And Environmental Conditions Associated With Physiological Variations Of Southwestern United States Pines, Taylor Brewer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Juvenile and adult conifers in the southwestern United States are vulnerable to a range of different abiotic and biotic factors, yet it is unclear how their stress tolerance varies across environments. Predicted increases in the frequency and intensity of disturbance as well as greater climate and weather variability across the region highlight the potential for differential physiological responses across tree species and populations. This thesis focuses on two physiologic mechanisms, hydraulic vulnerability and mortality, that could be altered by climate change in two broadly distributed southwestern United States conifers: ponderosa pine and pinyon pine.

In chapter 2, I measured the …

Mapping Quaking Aspen Using Seasonal Sentinel-1 And Sentinel-2 Composite Imagery Across The Southern Rockies, Usa, Maxwell Cook, Teresa Chapman, Sarah Hart, Asha Paudel, Jennifer Balch

Aspen Bibliography

Quaking aspen is an important deciduous tree species across interior western U.S. forests. Existing maps of aspen distribution are based on Landsat imagery and often miss small stands ( < 0.09 ha or 30 m²), which rapidly regrow when managed or following disturbance. In this study, we present methods for deriving a new regional map of aspen forests using one year of Sentinel-1 (S1) and Sentinel-2 (S2) imagery in Google Earth Engine. Using observed annual phenology of aspen across the Southern Rockies and leveraging the frequent temporal resolution of S1 and S2, ecologically relevant seasonal imagery composites were developed. We derived spectral indices and …

Ecosystem Response To Increasing Hurricane Disturbance: Comparing Nutrient Cycling Dynamics Associated With Early- And Late-Successional Tree Species In A Wet Tropical Forest, Miriam Kleit

Biology Honors Projects

Puerto Rico has seen changes in the frequency and severity of disturbances in recent years as hurricanes become more frequent and more intense under climate change. In ecosystems experiencing increasing disturbances, we expect that species composition will shift as early successional trees become more common. These changes to species composition and community ecology are likely to affect terrestrial nutrient cycling both directly and indirectly, and it is still not well understood how shifting community composition may alter ecosystem functioning. To address this gap, I measured carbon (C) and nitrogen (N) variables in soils, microbial biomass, roots, leaves, and soil greenhouse …

Sustainability And Drivers Of Populus Tremuloides Regeneration And Recruitment Near The Southwestern Edge Of Its Range, Connor D. Crouch, Nicholas P. Wilhelmi, Paul C. Rogers, Margaret M. Moore, Kristen M. Waring

Aspen Bibliography

Quaking aspen (Populus tremuloides Michx.) ecosystems are highly valued in the southwestern United States because of the ecological, economic, and aesthetic benefits they provide. Aspen has experienced extensive mortality in recent decades, and there is evidence that many areas in Arizona, United States lack adequate recruitment to replace dying overstory trees. Maintaining sustainable levels of regeneration and recruitment (i.e. juveniles) is critical for promoting aspen ecosystem resilience and adaptive capacity, but questions remain about which factors currently limit juvenile aspen and which strategies are appropriate for managing aspen in an increasingly uncertain future. To fill these critical knowledge gaps, …

Spring Burns And Its Effects On Vernal Forbs, Liam Poitra, Miriam Gieske, Stuart Wagenius

Undergraduate Research Symposium 2024

Grasslands are the least protected ecosystem on earth. In North America, protected native grasslands are typically burned in the spring, when native warm-season grasses are dormant, to reduce growth of invasive cool-season grasses; burn seasons historically included summer burns. This study aims to find how spring burns affect early spring flowering forbs (non-woody, non-grass plants).

Continuous Mowing Differentially Affects Floral Defenses In The Noxious And Invasive Weed Solanum Elaeagnifolium In Its Native Range, Alejandro Vasquez, Alexa Alaniz, Robert K. Dearth, Rupesh R. Kariyat

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

In weeds, disturbance has been found to affect life history traits and mediate trophic interactions. In urban landscapes, mowing is an important disturbance, and we previously showed that continuous mowing leads to enhanced fitness and defense traits in Solanum elaeagnifolium, Silverleaf Nightshade (SLN). However, most studies have been focused on foliar defenses, ignoring floral defenses. In this study we examined whether continuous mowing affected floral defenses in SLN using mowed and unmowed populations in South Texas, their native range. We found flowers of mowed SLN plants larger but lighter than unmowed plants. Additionally, flowers on plants that were mowed …

Predicting The Potential Distribution Of Pseudococcus Longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) In South Korea Using A Climex Model, Su Bin Kim, Soo-Jung Suh

Insecta Mundi

Pseudococcus longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) is a widely-distributed pest that feeds on many economically important hosts, particularly tropical fruits and ornamentals. The potential distribution of this mealybug pest in South Korea remains a primary concern because of its high incidence of interceptions screened during inspection. Hence, this species prompted a modelling effort to assess its potential risk of introduction. Potential risk maps were developed for this pest with a CLIMEX model based on occurrence records under environmental data. The potential distribution of these pests in South Korea in the 2020s, 2050s and 2090s was projected based on the RCP 8.5 …

The Genus Centris Fabricius In Cuba, With A New Record And The Description Of A New Species (Hymenoptera: Apoidea: Anthophila), Julio A. Genaro, Dayron Breto

Insecta Mundi

Members of the genus Centris Fabricius (Hymenoptera: Apoidea: Anthophila) constitute a significant component of the Neotropical (including insular) bee fauna, exhibiting high species richness, a moderate to large body size, and extensive interactions with various important plant groups. Females of most species possess specialized morphology adapted for collecting oils from flowers. This study documents the presence of the genus in Cuba, recognizing six species: C. aethiops Cresson, C. cornuta Cresson, C. fulviventris Cresson, C. poecila Lepeletier, C. taina Genaro and Breto new species, and C. tarsata F. Smith. Detailed information is provided for …

Diagnosis Of Spilococcus Pacificus (Borchsenius, 1949) And An Updated List Of Scale Insects (Hemiptera: Coccomorpha) On Pears (Pyrus L.: Rosaceae) In South Korea, Jungyoun Ji, Soo-Jung Suh

Insecta Mundi

Pears, Pyrus pyrifolia (Burm.f.) Nak. (Rosaceae) are one of the most widely grown fruit trees in South Korea. Approximately 11% of the total pear production in 2022 was exported to countries such as the United States and Vietnam. Exported pears must be free of pest species that are considered of quarantine importance by the importing countries. Herein, a list of scale insects (Hemiptera: Coccomorpha) associated with pear trees is updated. Additionally, Spilococcus pacificus (Borchsenius) is added to the list of mealybugs affecting pears in South Korea and is briefly diagnosed based on non-type specimens and illustrated using photographs. Information on …

Settling Preference Of Nipponaclerda Biwakoensis (Hemiptera: Aclerdidae) On Phragmites Australis Stems, Alexia Catherine Desoto

LSU Master's Theses

Phragmites australis, a wetland grass that stabilizes the Louisiana coastline, has been undergoing a major die-off near the Mississippi River Delta (MRD) since the autumn of 2016. One suspected cause for this plant decline is the attack of an invasive scale insect, Nipponaclerda biwakoensis. We lack information on the host preference of the crawlers, the life stage that decides where to settle and when to start feeding on the plant. The objectives of this study were to identify what positions along the vertical stem N. biwakoensis prefers to settle and what host-plant traits may be influencing this choice. We recorded …

Where Have All The Flowers Gone? A Call For Federal Leadership In Deer Management In The United States, Bernd Blossey, Darragh Hare, Donald M. Waller

Aspen Bibliography

Forests in the United States continue to lose biodiversity and many fail to regenerate due to high deer (family Cervidae) abundance. Declines in biodiversity and overall ecosystem health due to high deer populations increases prevalence of wildlife and human diseases associated with increasing tick abundances and decreases forest resilience and the ability to deliver benefits provided by healthy ecosystems. In the eastern and midwestern United States, white-tailed deer (Odocoileus virginianus) are the main stressor, while in the western U.S. elk (Cervus elaphus) and black-tailed and mule deer (Odocoileus hemionus) can become equally problematic. Federal …

Vascular Epiphyte Population Dynamics Within Human-Modified Landscapes Of Guadalupe, Cerro Punta, Chiriquí, Panamá, Lucine Tashjian

Independent Study Project (ISP) Collection

Epiphytes are plants that grow on other plants non-parasitically, and globally, epiphytes compose a very large and diverse group. They are especially abundant and species-rich in the tropics- particularly, in tropical montane forest ecosystems. Human population growth in the tropics, however, has resulted in significant declines in forest cover with land being converted largely for agricultural purposes. Studies on epiphytes have traditionally been undertaken in pristine, undisturbed forest ecosystems, yet terrestrial land conversion has increased the need to understand the value of human-modified ecosystems for epiphytic populations and biodiversity conservation. This study sought to understand the relationship between human modification …

The Role Of Geomorphological Context In Vegetative Succession Within The Breiðamerkurjökull Glacial Foreland, Lucas Nerbonne

Independent Study Project (ISP) Collection

As glaciers retreat worldwide at an accelerating pace, understanding primary succession in these newly exposed landscapes becomes increasingly critical. This study examines the initial vegetative colonization patterns in glacial forelands, focusing on the influence of geomorphological formations of resulting plant communities. By analyzing vegetative communities in glaciofluvial and push moraine deposits, this study highlights how the more varied, channelized morphologies of fluvial deposits create potential microclimates better conducive to heterogenous plant colonization than the homogenous terrain of the nearby push moraine. Vegetative coverage, sediment size, and species abundance was collected at 480 sites across 6 different historical glacial extents across …

The Virginia Academy Of Science: A Scholarly Forum Over Decades For Students Of A Plant Ecologist, Stewart Ware

Virginia Journal of Science

As a newcomer to Virginia in 1968, I learned that annual meetings of the Virginia Academy of Science (VAS) were regarded as an excellent place for students to have their first experience giving a talk about their research to fellow scientists, and a place for faculty to get to know other Virginia scientists in their fields. Over the next four decades William and Mary students (undergraduate and graduate) and I were presenters or co-authors of 42 talks or posters at VAS annual meetings, 29 of them based on studies of plant ecology across Virginia. Two were talks by colleagues with …

Interacting Effects Of Nutrient Availability And Environmental Change On Grassland Plant Communities, George Robert Wheeler

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The availability of nutrients plays an important role in shaping the composition, productivity and diversity of plant communities. Such effects are particularly well documented in grassland ecosystems, where both independent studies and collaborations such as the Nutrient Network consistently show increasing productivity and decreasing diversity with the addition of limiting nutrients. The specifics of this pattern, however, vary widely from site to site, and within a single site, they may shift with changes in environmental conditions and disturbance regimes.

My research at Cedar Creek Ecosystem Science Reserve (Minnesota, USA), documents such a pattern through resampling of a long-term experiment on …

Variations In Salinity And Forest Structure Between Marginal And Cloistered Mangrove Forests In Boca Del Drago, Bocas Del Toro, Panama, Mary Elizabeth Hodge

Independent Study Project (ISP) Collection

Mangroves are incredibly important ecosystems that have an outsized impact on their surroundings, providing crucial ecosystem services like carbon sequestration and coastal protection. At the same time, mangroves are some of the most threatened habitats due to their valuable position along tropical coastlines. Globally, mangrove forests are deforested and degraded by aquaculture, tourism developments, urbanization, and overharvesting. Due to high rates of mangrove loss, mangrove deforestation is now illegal in Panama, though this legislation is inconsistent and allows for exceptions, especially in tourism developments. This study aims to probe the impacts of localized coastal developments on a small mangrove forest …

Eurasian Aspen (Populus Tremula L.): Central Europe's Keystone Species 'Hiding In Plain Sight', Antonín Kusbach, Jan Šebesta, Robert Hruban, Pavel Peška, Paul C. Rogers

Aspen Bibliography

Knowledge of Eurasian aspen’s (Populus tremula L.) ecological and growth characteristics is of high importance to plant and wildlife community ecology, and noncommercial forest ecosystem services. This research assessed these characteristics, identified aspen’s habitat optimum, and examined causality of its current scarce distribution in central Europe. We analyzed a robust database of field measurements (4,656,130 stands) for forest management planning over 78,000 km² of the Czech territory. Our analysis we used GIS techniques, with basic and multivariate statistics such as general linear models, ordination, and classification. Results describe a species of broad ecological amplitude that has heretofore attracted …

Envisioning Transition From Open Landscapes To Forested Landscapes In The Routt National Forest, Colorado, United States, Brice B. Hanberry, Jacob M. Seidel

Aspen Bibliography

Globally, in remaining wildlands, tree densities and forested cover have increased in grasslands and open forests since European settlement. In the southern Rocky Mountains of Colorado, United States, we determined tree composition and tree cover from historical (years 1875 to 1896) surveys and compared them to current (2002 to 2011) tree composition and current (year 2016) forested land cover for 500,000 ha of the Routt National Forest. Additionally, we examined whether changes in precipitation occurred. Regarding composition, pine (primarily lodgepole pine; Pinus contorta) decreased from 65% to 32% of all trees, with increased subalpine fir (Abies lasiocarpa) …

Pollinator Communities And Their Ecosystem Services At Conservation Grasslands And Adjacent Croplands, Araceli Gomez Villegas

Department of Entomology: Dissertations, Theses, and Student Research

Pollinators are intrinsically linked to the success of unmanaged and managed ecosystems by providing pollination services that aid in the reproduction of wildflowers and many crops. Land use change, habitat loss, fragmentation, and related landscape-level phenomena (for example, increased pesticide exposure) threaten pollinators and have been associated with population declines. In the Midwestern region of the United States, land conversion of native prairies and grasslands to row-crop agriculture has been one of the largest contributors to pollinator habitat loss. Conservation programs, such as the Conservation Reserve Program, have worked towards removing environmentally sensitive lands from agriculture production and enrolling them …

Can The Impact Of Gravel Roads On Organic Layer Thickness Explain The Distribution Of Populus Tremuloides Along Road Networks In The Boreal Forest Of Eastern Canada?, Mathilde Marchais, Dominique Arseneault, Yves Bergeron

Aspen Bibliography

Roads are known to alter environmental conditions and the composition of road edge plant communities, particularly when exogenous materials are used as road surfacing. In this study, we evaluate the impact of gravel roads on the organic layer thickness (OLT) and aspen distribution in a boreal forest landscape of Eastern Canada. The OLT and aspen distribution were compared at different distances from the roads (0 m, 10 m, and >10 m) to determine whether a reduction in the OLT along the roads could explain the distribution of aspen along the road network, and in particular the role of the roads …

Oystershell Scale (Hemiptera: Diaspididae) Population Growth, Spread, And Phenology On Aspen In Arizona, Usa, Connor D. Crouch, Richard W. Hofstetter, Amanda M. Grady, Nylah N.S. Edwards, Kristen M. Waring

Aspen Bibliography

Oystershell scale (OSS; Lepidosaphes ulmi L.) is an invasive insect that threatens sustainability of aspen (Populus tremuloides Michx.) in the southwestern United States. OSS invasions have created challenges for land managers tasked with maintaining healthy aspen ecosystems for the ecological, economic, and aesthetic benefits they provide. Active management is required to suppress OSS populations and mitigate damage to aspen ecosystems, but before management strategies can be implemented, critical knowledge gaps about OSS biology and ecology must be filled. This study sought to fill these gaps by addressing 3 questions: (i) What is the short-term rate of aspen mortality in …

Pile Burning After Conifer Removal From Aspen Stands Affects Tree Mortality, Regeneration, And Understory Recovery, John-Pascal Berrill, Christa M. Dagley, Yoon G. Kim, J. Morgan Varner

Aspen Bibliography

Quaking aspen (Populus tremuloides Michx.) stands throughout the western United States provide valuable ecosystem services but can be lost via succession from aspen to conifer. Forest managers are cutting conifers, but disposal of cut wood can be challenging in remote or sensitive areas. Piling and burning is being tested within aspen stands but ecosystem responses to this treatment are understudied. We assessed aspen tree mortality, tree regeneration, and understory vegetation after forest restoration thinning followed by pile burning in seven aspen-conifer stands around Lake Tahoe, California and Nevada, USA. Pile burning was conducted after cut wood had dried (1.5–7.5 …