Ecology and Evolutionary Biology Commons^™

Field Journal: The Excluded Middle, Carrie E. Kouts

Masters Theses

What does it look like to engage with organisms and landscapes at the periphery of anthropocentric value structures? How does one break the internalized myth that the “built” environment is excluded from the natural world? When does a hyper-mobile and hyper-commodified society confront the exponential crisis of animal death? Within this series of journal entries, field notes, collection observations, weird prose, and sensory musings, one will find questions on the nature of being human and the complex narratives of care we encounter in a world shared with more-than-humans. Each handwritten vignette and photograph from daily life weaves a non-linear and …

Sexual And Vegetative Recruitment Of Trembling Aspen Following A High-Severity Boreal Wildfire, Denyse A. Dawe, Ellen Whitman, Michael Michaelian, Alan J. Tepley, Marc-André Parisien

Aspen Bibliography

Background High-severity fire is rare in trembling aspen-dominated forests of the boreal region. The post-fire recruitment strategy of aspen, by either vegetative suckering or sexually (i.e., by seed), has considerable implications for subsequent forest structure, genetic diversity, and ecological resilience to shifting climatic and disturbance regimes. In this study, we take advantage of the unique opportunity provided by the Chuckegg Creek Wildfire Fire (310,000 ha) in northern Alberta, Canada, which burned at high severity through aspen stands before and after spring green-up, to document how phenology, fire severity, and stand characteristics affect recruitment one year following the fire.

Results We …

Factors Impacting The Variability Of Post-Fire Forest Regeneration In Central European Pine Plantations, Florent Jouy, Maren Schüle, Yojana Adhikari, Anja Binder, Danica Clerc, Werner Gerwin, Thilo Heinken, Thomas Raab, Frank Repmann, Susanne Rönnefarth, Marina Schirrmacher, Marie-Therese Schmehl, Jens Schröder, Pierre L. Ibisch

Aspen Bibliography

Fire is increasingly posing a risk to forests and plantations, even in the temperate latitudes of central Europe. Little is known about fire ecology in this region, and therefore, appropriate approaches for the management and reforestation of burned sites are mostly lacking. In a Scots pine plantation region in Brandenburg (northeast Germany), the early tree regeneration of two nearby areas that burned 1 year apart was investigated. We observed that 3 years after the fire events, the forest in one study area showed a relatively high regeneration with a mean density of 7765 saplings/ha, clearly dominated by European aspen (93%); …

Pollinator Plant Communities Within Restored Montane Longleaf Pine Ecosystems, Hanen Van Rossem

Master's Theses

Historically the fire-dependent and biodiverse longleaf pine (Pinus palustris) ecosystem was the dominant ecosystem of the Southeastern US. This ecosystem’s range was massively reduced due to land conversion and fire exclusion, causing the decline of many native species. Efforts to restore and protect longleaf pine stands are now ongoing with the goal of expanding habitat and refuge for threatened species. Differences in restoration practices and prior land use may influence the extent to which restored habitat patches can support pollinators and their plants. This study compared pollinator plant biodiversity between restored neighboring montane longleaf pine stands that differed in …

Causes Of Heterozygosity Excess: The Case Of Mexican Populations Of Populus Tremuloides, Javier Hernández-Velasco, José Ciro Hernández-Díaz, Sergio Leonel Simental-Rodríguez, Juan P. Jaramillo-Correa, David S. Gernandt, José Jesús Vargas-Hernández, Ilga Porth, Roos Goessen, M. Socorro Gonzáles-Elizondo, Matthias Fladung, Cuauhtémoc Sáenz-Romero, José Guadalupe Martínez-Ávalos, Artemio Carrillo-Parra, Eduardo Mendoza-Maya, Arnulfo Blanco-García, Christian Wehenkel

Aspen Bibliography

The presence of heterozygous individuals in a population is crucial for maintaining genetic diversity, which can positively affect fitness and adaptability to environmental changes. While inbreeding generally reduces the proportion of heterozygous individuals in a population, polyploidy tends to increase the proportion. North American Populus tremuloides is one of the most widely distributed and ecologically important tree species in the Northern Hemisphere. However, genetic variation in Mexican populations of P. tremuloides, including the genetic signatures of their adaptation to a variety of environments, remains largely uncharacterized. The aim of this study was to analyze how inbreeding coefficient (F …

Monitoring Mangrove Dynamics And Evaluating Future Afforestation Potential In The Egyptian Red Sea, Rasha M. Abou Samra, Mansour Almazroui, Wenzhao Li, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Mangrove forests are vital for ecosystem services and coastal management but face stressors from anthropogenic activities and climate change. This study estimates the extent and afforestation potential of mangroves along the Egyptian Red Sea coast from 1984 to 2022 using NDVI derived from Landsat-5 and Sentinel-2 data in Google Earth Engine. Aboveground biomass (AGB), belowground biomass (BGB), carbon (C) stock, and CO₂ sequestration potential were evaluated using Sentinel-2 and elevation data. Future afforestation suitability (2020–2050) under SSP2-4.5 and SSP5-8.5 scenarios was assessed with the MaxEnt model. Mangrove area increased from 0.95 km² in 1984 to 1.46 km^{2 …}

Genomic Structure Among Populations Of A Regionally Rare Perennial Plant Indicates The Need For Reevaluation Of Management Units, Cheyenne Moore, Angela J. Mcdonnell, Scott Schuette, Christopher T. Martine

Faculty Journal Articles

Conservation of rare species often relies on the delineation of management units and genomic tools can now be applied for this purpose. However, this is not as common on a local scale, where populations are often small and fragmented, despite the utility of informing conservation and management practice at the regional level. We use a genotyping by sequencing (GBS) approach to assess the perennial riparian plant species Baptisia australis (Fabaceae) in Pennsylvania, where the taxon is at the edge of its natural distribution and considered threatened. In this system, we investigate whether sampled subpopulations exhibit genetic structure. We find that …

A Tale Of Two Asters: Resolving The Plant And Microbial Community Structure Of An Invasive And Native Forb, William Cartelli

Theses, Dissertations and Culminating Projects

Old fields dominated by flowering forbs are frequent targets for ecological restoration, particularly because they are often inhabited by invasive species whose ecological effects remain context dependent and widely debated. While native plants are typically favored in restoration efforts, and invasive species viewed as threats to biodiversity, such classifications may oversimplify ecological function. This study investigates two dominant genera of the Asteraceae family —Centaurea stoebe (L) (non-native) and Solidago spp. (S. rugosa and S. canadensis, both native)—to examine whether biogeographic origin or ecological strategy more strongly influences their impact on above and below ground community structure. Despite their contrasting origins, …

Chromosome Evolution Model Reveals Hidden Variation In Karyotype-Driven Speciation In Ferns, Thomas Buchloh

All Theses

Because karyotype change commonly generates reproductive isolation between diverging species, rapid karyotype evolution, like that seen in plants, may increase the total rate of diversification. However, few studies have investigated this predicted relationship. Tests of this prediction have identified a positive correlation between the rate of karyotype change (specifically whole genome duplications) and diversification, but tests have been restricted to relatively small and young clades. Fortunately, novel macroevolutionary models have recently become available to investigate patterns of karyotype evolution in large phylogenies, providing new opportunity to investigate variation in karyotype driven diversification. Ferns are one of the most karyotype rich …

Modifying The Comb, Rethinking The Install: Integrated Approaches To Honey Bee Colony Establishment And Winter Survival, Shelby A. Kittle

Department of Entomology: Dissertations, Theses, and Student Research

The European, or Western honey bee (Apis mellifera L.) plays a vital role in global ecosystems and agriculture, providing essential pollination services and producing valuable hive products. However, honey bee colony losses have escalated worldwide, but particularly across the United States due to various stressors, including biotic and abiotic factors, mismanagement, and environmental challenges. This thesis investigates key challenges in honey bee management and explores solutions aimed at improving colony health and productivity.

Chapter 1 provides an overview of the beekeeping industry, detailing its economic importance, services, and products, as well as the many challenges faced by beekeepers. It …

Landscape Effects On The Beneficial Arthropod Community In Agriculturally Dominated Environments, Hannah E. Stowe

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

Ecosystem services in agriculturally dominated regions rely, at least in part, on arthropods. Environment and biodiversity influence beneficial arthropods in population size, community structure, diversity, and ecosystem service provisioning. Predation is among the most important services provided by arthropods in agroecosystems. Understanding what alters predation and predator activity can support the successful application of biological control and, more broadly, integrated pest management. Land use and edge adjacency, field characteristics, landscape, seasonality, and diel period all alter predatory behavior. Crop fields dominate Nebraska agroecosystems, although interspersed perennial grasslands persist through the Conservation Reserve Program (CRP). Such grasslands supply crucial resources and …

Assessing Phenotypic Variation Across Generations Of Iberodes Littoralis Under Climate Change, Mariangel M. Fernandez Silva

Electronic Theses, Projects, and Dissertations

The consequences of climate change and anthropogenic activity have decreased wildlife biodiversity. Plants are particularly vulnerable to climate change due to their large biomass on the planet and sessile nature. A particularly useful method for plants to cope with environmental changes is phenotypic plasticity. Adjusting morphological traits through plasticity can help plants cope with environmental changes. Furthermore, plastic responses can be passed down through methods such as changes in DNA sequence or epigenetic modifications.

Our research project focuses on an herb, Iberodes littoralis, a species of concern native to the Siberian Peninsula with approximately thirteen extant populations. The data that …

The Impacts Of Management Practices On Industrial Hemp Chemistry, Physiology, And Microbiome Ecology., Allison Marie Rietman

Electronic Theses and Dissertations

Agroecology incorporates ecology and agronomy to inform crop management. Industrial hemp (Cannabis sativa L.) is a prime system to investigate agroecological questions because it has only recently been authorized for commercial cultivation and its sensitivity to biotic and abiotic stressors is unresolved. Here, I investigate how some conventional management choices, including the application of fungicide, plastic mulch, and irrigation, impact the physiology, chemistry, and microbial ecology of industrial hemp. Overall, I found that industrial hemp can be both resilient and resistant to these stressors, an important development for the industry. In Chapter II, I tested the impacts of fungicide application …

Patterns Of Fire History And Vegetation Changes In The Last 5000 Years: A Paleoecological Study Of Iquitos, Annabel Zwarts

Theses and Dissertations

The vegetation of the Amazonian rainforest is hypothesized to have been shaped by pre-Columbian activities, such as burning and palm management to various extents. Management of palms is hypothesized to have caused some of the most useful species to become hyperdominant in Amazonia. This study investigated the extent to which human activities over the past 5000 years affected palm abundances in mature lowland rainforests near Iquitos, Peru. I used phytoliths and charcoal from soil cores to determine the history of local floras, and modern palm surveys to compare modern phytolith occurrence with modern vegetation. Because pre-Columbian activity clustered along the …

Below-Ground Carbon Gradients Surrounding Saskatchewan's Native Agricultural Copses, Andrea V. Cline, Colin P. Laroque

Aspen Bibliography

As carbon markets develop, understanding the carbon storage capabilities of agricultural land is imperative to maximizing carbon storage. Ecosystems store two-thirds of their carbon below ground. Shrubland and shelterbelt carbon storage have been well documented in agricultural settings, yet little is known about the carbon stored under the native woody vegetation scattered across the Prairies. This study aims to be the first to quantify the below-ground carbon under and around these native trembling aspen (Populus tremuloides) copses in the Canadian Prairies. For this study, the leaf, fibric, humic layer (LFH) and soil samples up to 60cm were collected …

Restoring Exotic Cool-Season Grass Dominated Landscapes With Clethodim And Glyphosate, Eleanor J. Muzzy, Joshua D. Wiese, Abraham J. Kanz

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

A major threat to grasslands around the world is the spread of exotic cool-season grasses (ECSG). ECSG dominate vegetative communities and degrade critical habitats. One of the most common methods to treat ECSG is herbicide. To compare how the widely-used, non-specific herbicide glyphosate compared to the grass-specific herbicide clethodim, we conducted a fall spray in November 2023 at two different sites located in the Central Platte River Valley of Nebraska. The following June, we used a modified Daubenmire frame sampling method to gather data on relative cover, species richness, and community composition. After analysis, glyphosate appeared to be more effective …

Effectiveness Of Silvicultural Options In Renewal Of Trembling Aspen–Jack Pine Mixedwood Stands, 21 Years After Treatment, Rongzhou Man

Aspen Bibliography

Regenerating conifers after harvest through planting and postharvest broadcast application of herbicide is effective in ensuring the survival and growth of seedlings, but faces challenges in meeting broad social and ecological objectives of forest management. This study reports the effectiveness of alternative options in regenerating jack pine (Pinus banksiana Lamb.), 21 years after harvest of trembling aspen (Populus tremuloides Michx.)-dominated boreal mixedwood stands. The treatment options included (i) preharvest spray—aerial broadcast spray prior to harvest, (ii) postharvest partial spray—ground herbicide application in strips, (iii) partial harvest in strips, (iv) postharvest aerial broadcast, and (v) uncut reference. Twenty-one years …

Life After Death: Investigating The Resistance And Recovery Of Fungal Communities To Foundation Tree Mortality, Jessie F. Marlenee

Biology ETDs

Tree mortality can have cascading effects on the composition and resilience of interacting fungal communities. Yet, little is known about the impact tree mortality, distinct from abiotic drivers (i.e., drought), has on these communities. This dissertation focuses on the resilience of fungal communities to experimental tree mortality in a piñon-juniper woodland. In chapter one, I found that piñon mortality reduced piñon fine root biomass and piñon mycorrhizal fungal diversity, whereas juniper mycorrhizal fungi were unaffected by juniper mortality. In chapter two, I revealed that piñon mortality altered the composition and spatial structure of mycorrhizal and saprotrophic fungi in the soil, …

17 - Mapping The Spatial Distribution Of Submerged Aquatic Vegetation Using Commercial Satellite Imagery, Brandon Watson

Undergraduate Research Symposium

Seagrass in the Chesapeake Bay has seen an increase due to restoration efforts since the 90s, but with the extreme change of climate, we are unsure if the seagrass will thrive or perish, and where it will occur in the bay. Seagrass stabilizes coastal sediments, reducing erosion and protecting shorelines. It provides crucial habitats and nursery grounds for a diverse range of marine species, supporting both biodiversity and fisheries. Additionally, they play a significant role in carbon sequestration, which mitigates the effects of climate change. This study specifically looked at the area from the mouth of the Rappahannock River up …

05 - Freeze Severity And Black Mangrove Growth: Influence Of Plant Origin On Side Shoot Development, Kathryn Bourlier, Katelyn Overstreet, Erik Yando

Undergraduate Research Symposium

Despite a reduction in freeze events and subsequent expansion in the southeastern US, freeze impacts still play a critical role in mangrove morphology and local range limits. Freeze events can impair growth, limit survival, and commonly prompts side shoot development. This study examines the relationship between plant origin, freeze severity, and side shoot development in black mangroves. Our findings show that plants from each location exhibited distinct morphological responses, with similarities more closely linked to environmental conditions rather than geographic proximity. Our work offers insights into thermal tolerance thresholds and implications for mangrove stature in coastal wetlands.

Plant Biodiversity Of Short-Grass Prairie On An Eastern Colorado Cattle Ranch From 1988-2024, Emilee D. Cole, Zoey E. Daniels-Sneed, Matthew Galliart, Sarah Elzay

SACAD: Scholarly Activities

This survey examined the possible effects that rotational grazing and large-scale beef cattle production has on plant diversity in short-grass prairie rangeland. The survey was conducted on the Frasier Ranch, a working cattle ranch in eastern Colorado. Plant diversity was measured via species richness, ratio of cool to warm season grasses, and Shannon-Weiner Diversity Index. In this case study, it was determined that plant diversity did not change significantly in recorded years from 1988-2024.

Ecological Restoration And Ecosystem Memory Of Wildlife Forage And Understory Diversity In A Young Pine Monoculture Plantation In Central-Interior British Columbia, Julia Claire Bizon

Aspen Bibliography

Ecological restoration has recently taken center stage in the rehabilitation of degraded forest ecosystems to improve multifunctionality, biodiversity, and wildlife habitat conservation. The research summarized herein assessed the efficacy of variable stand density thinning (200, 400, and 600 stems/ha) and artificial canopy gaps (0.2, 0.5, 1.0, 2.0 ha in size) as potential restoration treatments to enhance wildlife forage and native biodiversity in a young lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Wats.) forest in central-interior British Columbia. Field data collection was conducted from May-August, 2023 to assess the early response (1-3 years post-treatment) of the forest …

How The Biotic And Abiotic Factors In The Belle Forest Cave And Arboretum Soil Dictates Tree Species Prevalence, Amya A. Bingham

SPARK Symposium Presentations

A plethora of factors in the soil impact a plant’s health, including the presence of different biotic and abiotic factors. These include things like temperature, elevation, pH, microbial respiration and the presence of water, clay, loam, silt, sand, nitrogen, potassium, and phosphorus. Different soils will have varying amounts of these, which may dictate what is able to grow in them, and therefore also the surrounding area. This research project explores how the aforementioned biotic and abiotic factors affect the soil at the Belle Forest Cave and Arboretum. Three samples will be taken from four spots along a transect at this …

Lawn Nutrient Availability And Run-Off During Establishment Under Enhanced Biodiversity, Masami S. Kanyuk

Environmental Studies Honors Theses

Biodiversity has consistently been found to have positive ecosystem effects, including erosion mitigation and stability of nutrient cycling. For lawns, this can translate to reducing the need for fertilizer application, and reducing soil loss and leaching that can impact water quality. This paper investigates the effects of biodiversity and plant community establishment in a lawn ecosystem on soil erosion, nitrate leaching via porewater sampling, and plant available nitrogen.

In the first growing season of PLEDGE (the Pastures and Lawns Enhanced Drought and Global-Change Experiment), we hypothesized that three-species lawns (tall fescue, dwarf white clover, and creeping thyme) would experience higher …

Aspen Health On National Forests In The Northern Rocky Mountain Region (2008/2009 To 2024), James T. Blodgett, Kurt K. Allen, Megan Wilson, Bradley Lalande

Aspen Bibliography

Quaking aspen (Populus tremuloides) is a widely distributed species in the western United States, but in the northern Rocky Mountain Region it is a rare forest component. In national forests (NF) of the northern Rocky Mountain Region this species comprises only 1% of the Bighorn, 3% of the Black Hills, and 1% of the Shoshone cover types (DeBlander 2002, Menlove 2008, Witt 2008). Since aspen forests provide increased species richness, support wildlife, are an important component of watersheds, and have aesthetic value, there are concerns regarding the health of this relatively rare forest cover type.

Contrasting Effects Of Climate Warming On Hosts And Parasitoids: Insights From Rocky Mountain Aspen Leaf Miners And Their Parasitoids, Alisha A. Shah, Emily Hamant, Juan G. Rubalcaba, Beau Larkin, Andrew A. Forbes, H. Arthur Woods

Aspen Bibliography

Because temperature has pervasive effects on biological rates, climate warming may alter the outcomes of interactions between insect hosts and their parasitoids, which, for many host species, constitute the single largest source of mortality. Despite growing interest in parasitoid-host responses due to climate change, there are few empirical tests of thermal tolerance differences between non-model lepidopteran hosts and their parasitoids and almost none from mountain ecosystems where warming is occurring more rapidly. We examined the thermal ecology of a host–parasitoid interaction in the Rocky Mountains using the wild populations of the aspen leaf miner (Phyllocnistis populiella) and a …

Draft Genome Data Including Functional Annotation Of An Emerging Fungal Pathogen (Neodothiora Populina) Causing A Canker Disease Of Trembling Aspen In Interior Alaska, Ursel M. E. Schütte, Mace Wages, Aaron Buechlein, Jorda P. Kovash, Danielle C. Wrenn, Tereza Smrhova, Andrea Zubrova, Doug B. Rusch, Loretta M. Winton, Gerard C. Adams, Roger W. Ruess, Mary Beth Leigh, Devin M. Drown

Aspen Bibliography

Neodothiora populina is a black yeast-like fungus in the family Dothioraceae. It causes an aggressive canker disease of trembling aspen that results in widespread mortality of aspen across the boreal forest of Interior Alaska. Here we report a high-quality draft genome including functional annotation of this emerging fungal pathogen based on Oxford Nanopore Technologies long-read sequences. Our initial genome assembly totaled 23,960,169 bp and contained 18 contigs, and we identified 7,343 genes. This resource announcement provides new genomic data that are useful long term for improving our understanding of forest health in Alaska.

Bryce Canyon Aspen: Recent Trends, Future Actions, Paul C. Rogers

Aspen Bibliography

In cooperation with Bryce Canyon National Park, we undertook a survey of quaking aspen (Populus tremuloides Michx.) conditions throughout the Park with the intention of better understanding conditions and prescribing corrective measures where needed. There are clear disparities within the Park between sustainable aspen conditions and failing stands. Based on condition of mature trees, but most importantly regeneration and recruitment of juvenile stems, most aspen forests within Bryce Canyon are in poor condition. Aspen recruitment—generally sapling-sized trees that have survived browsing ungulates—is the most important metric of future stand resilience and here we found 83% of all aspen sample …

Changing Fire Regimes In The Great Basin Usa, Eva K. Strand, Kori Blankenship, Corey Gucker, Mark Brunson, Eugénie Montblanc

Aspen Bibliography

Wildfire is a natural disturbance in landscapes of the Western United States, but the effects and extents of fire are changing. Differences between historical and contemporary fire regimes can help identify reasons for observed changes in landscape composition. People living and working in the Great Basin, USA, are observing altered fire conditions, but spatial information about the degree and direction of change and departure from historical fire regimes is lacking. This study estimates how fire regimes have changed in the major Great Basin vegetation types over the past 60 years with comparisons to historical (pre-1900) fire regimes. We explore potential …

Occurrence Of Spotted Wing Drosophila (Drosophila Suzukii) In Wild Berries In Forested Areas Of Marquette And Keweenaw Counties, Upper Peninsula Of Michigan, Alexis M. Shatrau, Erika I. Hersch-Green

The Great Lakes Entomologist

Spotted-wing Drosophila (SWD, Drosophila suzukii Matsumura, Diptera: Drosophilidae) is an invasive fly that targets unripe soft-fruits causing premature ripening, dehiscence, and rotting. While the presence of SWD in agricultural systems is well-documented, much less is known about the host range of SWD in wild areas, especially in more northern latitudes where colder temperatures and short summers are thought to restrict their life-cycles and limit population growth. In 2019 and 2020, we collected wild berries from two counties in the Upper Peninsula of Michigan, with long, cold winters, to determine the prevalence, host range, and seasonal/temporal variation of SWD. We found …