Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 3271 - 3300 of 19698

Full-Text Articles in Entire DC Network

Relationships Between Watershed Factors And Community Size Spectra Of The Fish And Macroinvertebrate Communities Of Mid-Appalachian Streams, Jarrett Hunter Landreth Jan 2023

Relationships Between Watershed Factors And Community Size Spectra Of The Fish And Macroinvertebrate Communities Of Mid-Appalachian Streams, Jarrett Hunter Landreth

Graduate Theses, Dissertations, and Problem Reports (ETD)

Freshwater lotic communities are complex, dynamic, and quick to respond to changes to their environment. However, some of the specific mechanisms driving those changes are yet to be fully understood. Here, I will use the community size spectrum (CSS) approach to assess how the CSS slope, elevation, and food chain length of the fish and macroinvertebrate assemblages as well as the combined CSS of 15 mid-sized (2nd-4th order) streams in north-central West Virginia respond across gradients of watershed factors (drainage area, mean drainage slope, mean drainage elevation, drainage % forest, and stream specific conductance). Field sampling was carried out in …


Investigating Dormancy And Germination Characteristics To Promote Restoration Success In The Northern Great Plains, Gregory A. Cooper Jan 2023

Investigating Dormancy And Germination Characteristics To Promote Restoration Success In The Northern Great Plains, Gregory A. Cooper

Electronic Theses and Dissertations

Failures in seed-based restoration can be partially attributed to a lack of knowledge on seed dormancy. Dormancy is beneficial for plant establishment in unpredictable environmental conditions, but a lack of uniform germination can hinder restoration efforts. The purpose of this research was to gain a better understanding of dormancy displayed by select forbs of the northern Great Plains. The first data chapter attempted to identify and break dormancy class. Seeds were treated with scarification, smoke, and fertilizer pretreatments in an attempt to break seed dormancy. Seeds were also placed in spring and summer temperatures to identify how seasonal phenology influenced …


C3 And C4 Grass Dominated Plant Communities Differ In Response To Future Larger And Less Frequent Rainfall, Zigeng Chen Jan 2023

C3 And C4 Grass Dominated Plant Communities Differ In Response To Future Larger And Less Frequent Rainfall, Zigeng Chen

Electronic Theses and Dissertations

Climate change is leading to larger and less frequent rainfall in the Northern Great Plains (NGP). We ask if this change in rainfall would influence carbon (C) and nitrogen (N) cycling in the NGP. First, we collected soils from C3 and C4 grass dominated plant communities from western South Dakota and conducted an incubation experiment to explore the effects of soil water content (SWC) and temperature on soil respiration (Rs) and N mineralization rate (ΔIN). Second, we conducted a three-year rainfallmanipulation (RaMP) experiment with two distinct rainfall regimes (frequent/small and infrequent/large events with constant total monthly precipitation) and two grasses …


Ecological Impacts Of Anthropogenic Chemicals On Non-Target Species And The Role Of Plant Diversity In Ecosystem Restoration And Resilience, Shiva Torabian Jan 2023

Ecological Impacts Of Anthropogenic Chemicals On Non-Target Species And The Role Of Plant Diversity In Ecosystem Restoration And Resilience, Shiva Torabian

Electronic Theses and Dissertations

Understanding ecosystem processes in rangelands is of paramount importance for ensuring global food security, given their pivotal role in sustaining forage and livestock production. Central to this understanding are fundamental processes such as nutrient cycling, decomposition, and plant biomass dynamics. However, the use of anthropogenic chemicals in agricultural practices has the potential to exert significant influence on these critical ecosystem functions. A pivotal factor in this context is the plant diversity inherent to these rangeland ecosystems. Plant diversity not only provides essential ecosystem functions but also enhances them with the capacity to withstand and recover from perturbations. Ecosystems characterized by …


Effects Of Agricultural Chemicals On Native Plants Of The Northern Great Plains, Gabrielle Bolwerk Jan 2023

Effects Of Agricultural Chemicals On Native Plants Of The Northern Great Plains, Gabrielle Bolwerk

Electronic Theses and Dissertations

Agricultural chemicals are ubiquitous on the Northern Great Plains landscape and have negative impacts on non-target plant communities, even at small doses. Northern Great Plains grassland plant communities may experience herbicide drift from agricultural fields or be subject to livestock pharmaceuticals in grazing lands. My research objective was to evaluate if and how native plants are affected by agricultural chemical presence at different concentrations. In Chapter 2, I studied the effect of different concentrations of three common agricultural herbicides (2,4-D, atrazine, and trifluralin) on the germination, emergence, and growth of native plant species of the Northern Great Plains. I performed …


"Our Loons": Participant Attachments And Motivations Within A Community-Based Monitoring Program, Taylor Tewksbury Jan 2023

"Our Loons": Participant Attachments And Motivations Within A Community-Based Monitoring Program, Taylor Tewksbury

Graduate Student Theses, Dissertations, & Professional Papers

Organizations can benefit from understanding person-place relationships and volunteer motivations as they recruit and sustain involvement in their community-based monitoring (CBM) programs. Place attachment, or the bond between people and their meaningful environments, is one lens through which to explore these relationships. Past studies have associated place attachment with environmentally responsible behaviors (ERB), such as CBM involvement. However, few studies have explored the relationship between place attachment and CBM in the context of volunteers’ attachment to the species of study.

The purpose of this research study was to explore the place-based relationships and motivations among volunteers of the Loon Preservation …


Hide And Seek: An Exploration Of Antipredator And Predator Avoidance Mechanisms In Orthopodomyia Signifera In Response To Predation From Toxorhynchites Rutilus, Nathaniel Dahlberg Jan 2023

Hide And Seek: An Exploration Of Antipredator And Predator Avoidance Mechanisms In Orthopodomyia Signifera In Response To Predation From Toxorhynchites Rutilus, Nathaniel Dahlberg

Master's Theses

There have been many observations of larval Orthopodomyia signifera coexisting with the predator Toxorhynchites rutilus. There are three hypotheses that could explain how Or. signifera resists predation from Tx. rutilus. The first hypothesis states that larvae adapt behavioral changes that limit predation. The second hypothesis states thoracic setae serve as a physical defense that prevents Tx. rutilus from grasping Or. signifera. The third hypothesis states Or. signifera possess a chemical defense indicated by aposematic coloration. To test the first hypothesis larval Or. signifera were exposed to conspecific and heterospecific predation cues and their behavior was observed. Both cues …


Proposing An Rna Interference (Rnai)-Based Treatment For Human Immunodeficiency Virus (Hiv) By Analyzing The Post-Transcriptional Gene Targeting Of Sars-Cov-2, Hepatitis C Virus, And A549 Lung Cancer Cells, Arjun Jagdeesh Jan 2023

Proposing An Rna Interference (Rnai)-Based Treatment For Human Immunodeficiency Virus (Hiv) By Analyzing The Post-Transcriptional Gene Targeting Of Sars-Cov-2, Hepatitis C Virus, And A549 Lung Cancer Cells, Arjun Jagdeesh

UROP Posters

Human Immunodeficiency Virus (HIV) is a retrovirus that infects CD4+ T cell lymphocytes in humans, leading to the development of Acquired Immunodeficiency Syndrome (AIDS) if left untreated. While current treatment methods, including antiretroviral combination treatments, effectively limit HIV replication, HIV can evade these treatments due to its high mutation rate. Long-term antiretroviral treatment can also be toxic to patients, meaning patients would benefit from a new mechanism of HIV treatment. RNA interference (RNAi) is an antiviral pathway found in mammals, plants, and insects that involves a small-interfering RNA that is incorporated into a protein complex called the RNA-induced Silencing Complex …


Developing Best Practices For The Propagation Of Spartina Alterniflora For Use In Salt Marsh Restortaion, Justin Hinson Jan 2023

Developing Best Practices For The Propagation Of Spartina Alterniflora For Use In Salt Marsh Restortaion, Justin Hinson

College of Graduate Studies: Theses & Dissertations

Coastal salt marshes are valuable ecosystems under threat from climate change and sea level rise. Living shorelines offer a promising solution, often incorporating the foundational salt marsh species Spartina alterniflora due to its ability to tolerate natural stressors and maintain sediment stability. However, research suggests that seed-based propagation protocols should be developed on a local scale due to the genetic heterogeneity within and between S. alterniflora populations. Here, we attempt to contribute to the development of one such protocol for coastal Georgia S. alterniflora.

In Fall 2021, seeds were collected bi-monthly from four marshes of varying ocean proximity and …


Reconstructing The Ecological Relationships Of The Latest Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced Diet And Ecological Niche Among Basal Ornithopod Dinosaurs, Ian Broxson Jan 2023

Reconstructing The Ecological Relationships Of The Latest Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced Diet And Ecological Niche Among Basal Ornithopod Dinosaurs, Ian Broxson

EWU Masters Thesis Collection

Of the final three connected Gondwanan landmasses, the dinosaur fossil record of Antarctica in the Cretaceous is the least complete. Most dinosaur faunas in this time period (145 Ma to 66.0 Ma) are widely separated geographically and temporally from one another by million years. However, a group of non-avian dinosaurs from the James Ross Basin (JRB) of the Antarctic Peninsula, composed of two elasmarians, a parankylosaurian ankylosaur, a hadrosaur and a suspected megaraptor, all are represented by fragmentary remains have emerged from the same horizon of the Sandwich Bluff Member (SBM) of the López de Bertodano Formation and were thus, …


Measuring The Production Of Migratory Westslope Cutthroat Trout In Tributaries To Priest River, Idaho, Collin J. Hendricks Jan 2023

Measuring The Production Of Migratory Westslope Cutthroat Trout In Tributaries To Priest River, Idaho, Collin J. Hendricks

EWU Masters Thesis Collection

Iteroparous salmonids that exhibit a migratory life history are essential to functioning metapopulations. They are demographically important as migratory females produce more eggs than non-migratory individuals. Additionally, they provide genetic support through gene flow, resulting in more robust, genetically diverse populations. The lower Priest River flows into the Pend Oreille River in the panhandle of northern Idaho and is a system susceptible to degrading conditions due to increasing water temperature. It is also, a significant contributor of migratory Westslope Cutthroat Trout Oncorhynchus clarkii lewisi (WCT) in the Clark- Fork Pend Oreille Basin (CFPOR). The goal of our study was to …


Fairy Shrimp (Anostraca) In The Vernal Pools Of Eastern Washington, Megan Garvey Jan 2023

Fairy Shrimp (Anostraca) In The Vernal Pools Of Eastern Washington, Megan Garvey

EWU Masters Thesis Collection

Vernal pools are ephemeral wetlands that retain water annually from winter and spring precipitation and snowmelt but are dry the rest of the year. Though important habitats and sources of freshwater biodiversity, they are little accounted for in wetland conservation and restoration practices. Like much of the world’s wetlands, they have seen a significant decline from anthropogenic impacts and conversion for alternative land use. Pools are also at significant risk due to the impacts of climate change and invasive species. These small temporary water bodies perform vital ecosystem services and are host to rare and endemic species. Anostraca, or fairy …


Evolution Of The Diets Of Australian Possums (Marsupialia: Phalangeriformes) From The Etadunna Formation In The Lake Eyre Basin, South Australia, Theodore C. Wheat Jan 2023

Evolution Of The Diets Of Australian Possums (Marsupialia: Phalangeriformes) From The Etadunna Formation In The Lake Eyre Basin, South Australia, Theodore C. Wheat

EWU Masters Thesis Collection

The Lake Eyre Basin in South Australia holds Australia’s oldest known fossil marsupials representing both extant and extinct families in the Etadunna Formation, a formation that spans nearly two million years from 23.3 to 25 MA. During that two-million-year period, the terrestrial herbivorous marsupials present in the area underwent a dramatic transition both taxonomically and dentally, likely brought on by a changing environment caused by a warming climate. However, it is unknown whether a similar change occurred to the marsupials like possums that live up in the canopy. Understanding this could help determine how extensively this change in the environment …


Using Micro Satellites To Assess The Impact Of Algae Growth On Global Warming, Hursh, Vanessa Jan 2023

Using Micro Satellites To Assess The Impact Of Algae Growth On Global Warming, Hursh, Vanessa

Student Works

Data gathered from microsatellites can inform policymakers and environmental agencies about the impact of algae on global warming. It can guide the development of strategies to mitigate or harness the potential benefits of algae growth.


Plant Sentience Revisited: Sifting Through The Thicket Of Perspectives, Paco Calvo, Miguel Segundo-Ortin Jan 2023

Plant Sentience Revisited: Sifting Through The Thicket Of Perspectives, Paco Calvo, Miguel Segundo-Ortin

Animal Sentience

In our target article (Segundo-Ortin & Calvo 2023), we proposed the intriguing possibility of plant sentience, drawing parallels with non-human animal studies. This response aims to sift through the rich thicket of perspectives offered by our commentators. To do so, we assess the risks of employing double standards, as well as the tendencies of anthropomorphizing and zoomorphizing in plant studies. We also emphasize the need for clarity in linguistic and conceptual terms, examine the neurophysiological evidence for plant sentience, and discuss the ethical implications of such recognition.


Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo Jan 2023

Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo

Animal Sentience

A growing number of non-human animal species are being seriously considered as candidates for sentience, but plants are either forgotten or explicitly excluded from these debates. In our view, this is based on the belief that plant behavior is hardwired and inflexible and on an underestimation of the role of plant electrophysiology. We weigh such assumptions against the evidence to suggest that it is time to take seriously the hypothesis that plants, too, might be sentient. We hope this target article will serve as an invitation to investigate sentience in plants with the same rigor as in non-human animals.


Potential Effects Of Road Proximity On Zooplankton Communities And Water Quality In Lakes In The Northwest Territories, Marie N. Hannan Jan 2023

Potential Effects Of Road Proximity On Zooplankton Communities And Water Quality In Lakes In The Northwest Territories, Marie N. Hannan

Theses and Dissertations (Comprehensive)

Studies conducted along Canada’s Dempster Highway in the Northwest Territories have shown that road dust can affect water quality in roadside lakes, leading to higher calcium, conductivity, and pH levels. These water quality changes have the potential to affect important members of the lower aquatic food web, such as zooplankton.

For my thesis research, I had two main objectives: 1) To determine if changes in water chemistry caused by deposition of road dust affects zooplankton communities; and 2) To examine if the type of roadside vegetation influences the effects of road dust on aquatic habitats. To achieve these objectives, I …


Discerning Friend From Foe: Systematic Revision Of Cuscuta L. Section Indecorae Using A Combined Ecological, Morphometric, And Phylogenetic Approach., Corey Burt Jan 2023

Discerning Friend From Foe: Systematic Revision Of Cuscuta L. Section Indecorae Using A Combined Ecological, Morphometric, And Phylogenetic Approach., Corey Burt

Theses and Dissertations (Comprehensive)

The genus Cuscuta (Dodder; Convolvulaceae) are obligate parasitic plants. In one clade known as section Indecorae, there are species which are considered pests that pose significant threats to agricultural crop production, while other species are rare or known only from historical records. Section Indecorae contains three species: C. coryli, C. warneri, and C. indecora (the latter with three infraspecific taxa: var. indecora, var. longisepala, and var. attenuata). The systematics of section Indecorae are not currently resolved. Cuscuta indecora has a long and complicated taxonomic history with many infraspecific varieties described, and …


Differences In Drifting Invertebrate Communities Across Arctic Ecozones And The Influence On Potential Growth Of Grayling (Thymallus Arcticus), Charles Chanyi Jan 2023

Differences In Drifting Invertebrate Communities Across Arctic Ecozones And The Influence On Potential Growth Of Grayling (Thymallus Arcticus), Charles Chanyi

Theses and Dissertations (Comprehensive)

Invertebrate drift is a key process that potentially affects multiple levels of food web organization within stream environments. However, our understanding of the mechanistic drivers of drift in high latitude streams and subsequent bottom-up control that drift may have on fish predators in these environments remains understudied. This project aimed to gain the baseline knowledge of how drift functions across two major high latitude ecozones, the boreal forest and tundra, and how those possible differences in drifting community characteristics may impact drift-feeding Arctic grayling (Thymallus arcticus). These objectives were accomplished by characterizing stream environments across both ecozones, sampling …


Investigating The Effects Of Disturbance And Competition On Establishment, Growth, And Reproduction Of The Endangered Ripariosida Hermaphrodita, Daniel Engelking Jan 2023

Investigating The Effects Of Disturbance And Competition On Establishment, Growth, And Reproduction Of The Endangered Ripariosida Hermaphrodita, Daniel Engelking

Theses and Dissertations (Comprehensive)

Ripariosida hermaphrodita (Virginia Mallow) is a perennial riparian plant with broad, maple-like leaves. It grows up to three meters high and is often found in large clonal patches, but sexually reproduces readily. While this plant may seem like a redoubtable competitor when growing in large colonies, it is declining across its range in North America. The only known occurrences in Canada are in southern Ontario. Prior to this study, no new populations had been recorded even though one of the known populations produces copious amounts of viable seed with potential to disperse. There are many hypotheses for its rarity, but …


Natural Variation In Temperature-Modulated Immunity To Pseudomonas Syringae Pv. Tomato (Pst Dc3000) In Arabidopsis Thaliana Plants, Christina A. M. Rossi Jan 2023

Natural Variation In Temperature-Modulated Immunity To Pseudomonas Syringae Pv. Tomato (Pst Dc3000) In Arabidopsis Thaliana Plants, Christina A. M. Rossi

Theses and Dissertations (Comprehensive)

Studies conducted on the model plant-pathogen system Arabidopsis thaliana-Pseudomonas syringae pv. tomato (Pst) showed that elevated temperature suppresses the pathogen-induced production of salicylic acid (SA), which is a key plant defence hormone. This increased host vulnerability at higher temperatures is due to downregulated expression of CALMODULIN BINDING PROTEIN 60-LIKE G (CBP60g) and SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1), which encode master regulators of SA production. Collectively, these previous studies only focused on one natural accession of Arabidopsis called Columbia-0 (Col-0). However, the intraspecific variation in Arabidopsis immunity phenotypes under elevated temperature remains unknown. To fill this critical knowledge gap, my …


Nicotiana Glauca Graham (Solanaceae) Bioactivity And Toxic Effects On Mortality, Feeding Behavior And Pupation Choice Of Drosophila Melanogaster Larvae (Diptera: Drosophilidae), Abir Bouzar, Sarra Habbachi, Ibtissem Samai, Makarem Rahat, Nour El Imene Boublata, Saadane Fatma Zohra, Wafa Habbachi, Benhissen Saliha, Abdelkrim Tahraoui Dec 2022

Nicotiana Glauca Graham (Solanaceae) Bioactivity And Toxic Effects On Mortality, Feeding Behavior And Pupation Choice Of Drosophila Melanogaster Larvae (Diptera: Drosophilidae), Abir Bouzar, Sarra Habbachi, Ibtissem Samai, Makarem Rahat, Nour El Imene Boublata, Saadane Fatma Zohra, Wafa Habbachi, Benhissen Saliha, Abdelkrim Tahraoui

Journal of Bioresource Management

Nicotiana glauca is a medicinal plant used by traditional healers as antibacterial, antifungal, antiviral and anti-inflammatory medicines. The leaves of N. glauca are very rich in indolic alkaloids which give it a larvicidal power which allows us to use it as a bio-insecticide.In the present study we were perfomed in the direct (mortality) and indirect (food attractiveness and pupation) toxic effects of the aqueous extract of N. glauca on the mortality and feeding behavior of the fruit fly Drosophila melanogaster. The treatment was administered to 2nd instar larvae (L2) and the mortality rate was monitored for 15 days. Similarly we …


Diet Of The Golden Jackal (Canis Aureus) And Silver-Backed Jackal (Canis Mesomelas) In The Southern Part Of The Serengeti Ecosystem, Tanzania: A Comparative Study, Steven E. Temu, Cuthbert L. Nahonyo, Marion L. East, Patricia D. Moehlman Dec 2022

Diet Of The Golden Jackal (Canis Aureus) And Silver-Backed Jackal (Canis Mesomelas) In The Southern Part Of The Serengeti Ecosystem, Tanzania: A Comparative Study, Steven E. Temu, Cuthbert L. Nahonyo, Marion L. East, Patricia D. Moehlman

Tanzania Journal of Science

Habitat and food resource partitioning are predicted to facilitate the coexistence of similar-sized carnivores. The golden jackal (Canis aureus) and silver-backed jackal (Canis mesomelas) are similar-sized canids that respectively inhabit grassland and woodland in the Serengeti ecosystem, Tanzania. As information on the diet and food-intake of these two species in this ecosystem is limited, we aimed to compare the diet and food-intake of these canids in the wet and dry seasons, using data from focal samples of foraging behaviour and scat analysis. We predicted dietary differences between these species, seasonal differences within species and peak food intake when breeding. Result …


Ecological Diagnosis And Diversity Structure Of The Forest Birds Community In Machroha Forest (Souk Ahras – Northeastern Algeria), Abdelhak Boucif, Mouslim Bara, Moussa Houhamdi Dec 2022

Ecological Diagnosis And Diversity Structure Of The Forest Birds Community In Machroha Forest (Souk Ahras – Northeastern Algeria), Abdelhak Boucif, Mouslim Bara, Moussa Houhamdi

Journal of Bioresource Management

Machroha forest is a large hot spot of biodiversity of northeastern region of Algeria. It is dominated by several species of oak tree that can contribute to the conservation of many animals such as birds. Our study was carried out from February 2019 to July 2021, in order to diagnosis the ecological status of forest birds and their dynamics. Our results reported that this forest was including 19.21% of the Algerian avifauna diversity. We recorded 78 species of birds classified in 32 families. The main species were sedentary with an insectivorous trophic categories and terrestrial guild. Three species observed in …


A Comparison Of Seasonal Reproductive Pattern In Two Sympatric Darters Of The Simoperca Clade, Etheostoma Duryi And Etheostoma Simoterum, Tiffany Bell, Elizabeth Cantrell, Bruce Stallsmith Dec 2022

A Comparison Of Seasonal Reproductive Pattern In Two Sympatric Darters Of The Simoperca Clade, Etheostoma Duryi And Etheostoma Simoterum, Tiffany Bell, Elizabeth Cantrell, Bruce Stallsmith

Southeastern Fishes Council Proceedings

We present results from an examination of the seasonal reproductive patterns of two closely related sympatric darter species of the Simoperca clade, Etheostoma duryi and Etheostoma simoterum. Most members of the genus Etheostoma exhibit striking sexual dimorphism, making reproductive strategy a logical point of study. Monthly collections of specimens over a one-year period were performed at a single site on the Flint River near Huntsville, Alabama. Standard length and gross somatic mass were measured for all individuals. Sex ratio was examined for possible skew. Measures of reproductive effort were monthly means of gonadosomatic index of both sexes, total oocyte count, …


Isolation And Characterization Of Cellulose Degrading Microorganisms Generating Electricity Using Microbial Fuel Cell, Lama Fayad, Rania Amer, Ahmad Abd El Nabi, Ali Hammoud, Hoda Yusef Dec 2022

Isolation And Characterization Of Cellulose Degrading Microorganisms Generating Electricity Using Microbial Fuel Cell, Lama Fayad, Rania Amer, Ahmad Abd El Nabi, Ali Hammoud, Hoda Yusef

BAU Journal - Science and Technology

Global warming and the accumulation of organic waste constitute a serious environmental problem. Therefore, microbial fuel cells (MFC) are an eco-friendly device that have significant capability for the production of electricity using biodegradable waste as fuel. Microorganisms used as catalysts in the anode compartment, execute a principal function in operating MFCs. The present study was conducted to isolate and to screen potential bioelectricity generating microorganisms from dumpsite soil samples and also to construct a domestic dual-chambered microbial fuel cell (MFC). Streptomyces fimicarius was found to be the best isolate for the degradation of cellulose and the production of bioelectricity. The …


Tree Biomass – A Fragile Carbon Storage In Old-Growth Birch And Aspen Stands In Hemiboreal Latvia, Laura Ķēniņa, Didzis Elferts, Ieva Jaunslaviete, Endijs Bāders, Guntars Šņepsts, Āris Jansons Dec 2022

Tree Biomass – A Fragile Carbon Storage In Old-Growth Birch And Aspen Stands In Hemiboreal Latvia, Laura Ķēniņa, Didzis Elferts, Ieva Jaunslaviete, Endijs Bāders, Guntars Šņepsts, Āris Jansons

Aspen Bibliography

Birch (Betula pendula Roth, Betula pubescens Ehrh.) and European aspen (Populus tremula L.) stands dominate the deciduous forests of Northern Europe. Due to increasing forest protections, more deciduous stands will reach the old-growth stage. Thus, data on the carbon storage potential in such areas are essential. We aimed to establish a benchmark for carbon stocks of the main carbon pools in old-growth deciduous hemiboreal stands. Carbon pools were calculated from measurements in forty old-growth (104–148 years-old) deciduous stands in forests on fertile mineral soil. The carbon stock in these stands is distributed across tree biomass (~ 60%), mineral soil (~ …


Effects Of Riverine Barriers On Avian Evolution In The Amazon Basin, Andre Eugene Moncrieff Dec 2022

Effects Of Riverine Barriers On Avian Evolution In The Amazon Basin, Andre Eugene Moncrieff

LSU Doctoral Dissertations

The high biodiversity found in the Amazon Basin has long captivated the attention of naturalists and evolutionary biologists seeking to explain its origins. Early observations by Alfred Wallace highlighted the role of rivers in delimiting the geographic ranges of many species; furthermore, where rivers narrow towards their headwaters, he noted that some species cross rivers freely. A major goal of this dissertation is to investigate how these and other observations about riverine barriers might inform our understanding of how speciation unfolds in Amazonia. My approach involved generating genomic data with dense geographic sampling for manakins in the genus Lepidothrix, …


Methods For Drone Trajectory Analysis Of Bottlenose Dolphins (Tursiops Truncatus), Jillian D. Bliss Dec 2022

Methods For Drone Trajectory Analysis Of Bottlenose Dolphins (Tursiops Truncatus), Jillian D. Bliss

Theses and Dissertations

With the increase in the use of UAS (Unmanned Aerial Systems) for marine mammal research, there is a need for the development of methods of analysis to transform UAS high resolution video into quantitative data. This study sought to develop a preliminary method of analysis that would quantify and present a way to visualize the dynamics and relative spatial distribution and changes in distribution of bottlenose dolphins (Tursiops truncatus) in the waters of Turneffe Atoll, Belize. This approach employs a previously developed video tracking program ‘Keypoint Tracking’ that enables manual tracking of individual dolphins and the creation of …


Aspen Leaves As A "Chemical Landscape" For Fungal Endophyte Diversity - Can Nitrogen And Herbivory Shape The Community Composition In Controlled Conditions?, Johanna Witzell, Vicki Huizu Guo Decker, Marta Agostinelli, Carmen Romeralo Tapia, Michelle Cleary, Benedicte Riber Albrectsen Dec 2022

Aspen Leaves As A "Chemical Landscape" For Fungal Endophyte Diversity - Can Nitrogen And Herbivory Shape The Community Composition In Controlled Conditions?, Johanna Witzell, Vicki Huizu Guo Decker, Marta Agostinelli, Carmen Romeralo Tapia, Michelle Cleary, Benedicte Riber Albrectsen

Aspen Bibliography

The endophytic microbiome may influence the ecological performance of plants, including forest trees. Various abiotic and biotic factors may shape the endophyte communities directly but also indirectly, by modifying the quality of host plants as a substrate. We hypothesized that potentially antifungal or fungistatic condensed tannins (CTs) would determine the quality of aspen (Populus tremula) leaves as a substrate for endophytic fungi. By subjecting the plants to nitrogen fertilization (N) or herbivory (H; leaf beetles) we aimed to change the internal “chemical landscape”, especially the CT levels, in aspen leaves. We expected that this would lead to changes in the …