Ecology and Evolutionary Biology Commons^™

Comparing Allelochemicals Of ​English Ivy And Native Georgia Plants​, Rebecca Senft

Symposium of Student Scholars

English Ivy (Hedera helix L.) is a common invasive plant causing biodiversity losses across the southeast and parts of the northwestern US. The mechanisms by which Ivy invades native ecosystems are not well understood but may include allelopathy, a process through which one species produces biochemicals that disrupt competitors. These biochemicals are often produced and exuded by roots into soil, making them difficult to isolate. This study used a soil-less hydroponic system and gas-chromatography mass spectroscopy to examine differences in the chemicals produced by roots of native Georgia plants and English Ivy. Our results suggest there are differences in the …

Biocontrol Of The Emerald Ash Borer: An Adapted Nicholson-Bailey Model, Michael Kerckhove, Shuheng Chen

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Basal Sprout Centered Management Of Vector-Borne Tree Diseases, Kelly Buch

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Sampling Bias Exaggerates A Textbook Example Of A Trophic Cascade, Elaine M. Brice, Eric J. Larsen, Daniel R. Macnulty

Aspen Bibliography

Understanding trophic cascades in terrestrial wildlife communities is a major challenge because these systems are difficult to sample properly. We show how a tradition of non-random sampling has confounded this understanding in a textbook system (Yellowstone National Park) where carnivore [Canis lupus (wolf)] recovery is associated with a trophic cascade involving changes in herbivore [Cervus canadensis (elk)] behaviour and density that promote plant regeneration. Long-term data indicate a practice of sampling only the tallest young plants overestimated regeneration of overstory aspen (Populus tremuloides) by a factor of 4–7 compared to random sampling because it favoured plants taller than the preferred …

Camera Trap Survey Suggests Forestry And Prescribed Burns Attract Wildlife, But May Not Enhance Diversity, Melissa S. Vilgats, Ryan Ott, Stephanie S. Coster

Virginia Journal of Science

This study explored whether habitat management techniques such as forest thinning and burning promoted biodiversity. Fifteen camera trap stations were established at Fort A.P. Hill in Bowling Green, VA across forest stands with low, medium, and high basal area. Camera traps were deployed for a total of 532 trap nights, and trap success and species diversity were calculated using Shannon’s index. At each site, the distance to trafficable roadways and water sources, vegetation composition, and the percent groundcover, canopy cover, and understory were measured. The cameras captured nine species and recorded a total of 398 trap events. Linear regression was …

Remote Detection Of Disturbance From Motorized Vehicle Use In Appalachian Wetlands, Walter Smith

Virginia Journal of Science

Wetland disturbance from motorized vehicle use is a growing concern across the Appalachian coalfields of southwestern Virginia and portions of adjacent states, particularly as both extractive industries and outdoor recreation development expand in regional communities. However, few attempts have been made in this region or elsewhere to adapt approaches that can assist researchers and land managers in remotely identifying and monitoring wetland habitats disturbed by motorized vehicle use. A comparative analysis of wetlands impacted and unimpacted by off-road vehicle activity at a public recreation area in Tazewell County, Virginia was conducted to determine if and how a common, satellite-derived index …

A Ladder Of Endemicity: A Pioneering Study Of Anuran Communities Along An Elevational Gradient In The Eastern Andean Cloud Forests, Ecuador, Ella Halbert

Independent Study Project (ISP) Collection

Per unit of area, Ecuador is home to the most herpetofauna of any region on Earth, yet many ecosystems are under researched. Positioned between the Eastern Andes and the Amazon rainforest, the Río Pastaza Basin of Ecuador has been the recent focus of anuran biodiversity surveys and is home to many endemic species. This study aimed to determine how the anuran community composition of a vertical transect in the Llanganates National Park varied between elevations. A 7-day expedition was conducted along a new trail up Abitagua Range spanning 1,050 m in elevation. Each night, visual encounter surveys were employed to …

Growth–Defense Trade-Offs Shape Population Genetic Composition In An Iconic Forest Tree Species, Olivia L. Cope, Ken Keefover-Ring, Eric L. Kruger, Richard L. Lindroth

Aspen Bibliography

All organisms experience fundamental conflicts between divergent metabolic processes. In plants, a pivotal conflict occurs between allocation to growth, which accelerates resource acquisition, and to defense, which protects existing tissue against herbivory. Trade-offs between growth and defense traits are not universally observed, and a central prediction of plant evolutionary ecology is that context-dependence of these trade-offs contributes to the maintenance of intraspecific variation in defense [Züst and Agrawal, Annu. Rev. Plant Biol., 68, 513–534 (2017)]. This prediction has rarely been tested, however, and the evolutionary consequences of growth–defense trade-offs in different environments are poorly understood, especially in long-lived species …

Towards The Identification Of The Soil Fungal Microbiome Community Associated With Longleaf Pine, Joshua Inneh, Grace Krueger, Ian Thomasson, Fletcher Moon, Geoffrey Eger

Symposium of Student Scholars

This project is part of a larger study looking at the restoration of the Longleaf Pine (LLP) ecosystem in certain Wildlife Management Areas (WMA) in Northwest Georgia. Our long-term aim is to look for potential associations between the aboveground and belowground community structures as the complex system of feedback mechanisms between the soil microbiome, the rhizosphere, and the plant communities is not yet understood.

Soil samples were collected from a total of six plots in the Sheffield WMA located in Paulding County. The samples were collected from north or south facing hillside plots except for in the savanna sites (an …

Observations Of Post-Wildfire Landcover Trends In Boreal Alaska Using A Suite Of Remote Sensing Approaches, Eric John Deutsch

Theses - ALL

Wildfires are a common occurrence in the boreal ecosystems of the Pacific Northwest. Studies suggest that anthropogenic climate change has fostered more frequent and higher severity fires in recent decades in these forests, which may result in substantial changes in vegetation structure and ecosystem functioning. However, large-scale studies examining the linkages between changing boreal wildfire regimes and vegetation structure have historically been limited in spatial scope due to the broad area and inaccessibility of many boreal regions, including the Alaskan interior. The development and advancement of satellite remote sensing instruments and geospatial analysis techniques provide researchers with unmatched abilities to …

Interspersed Denuded Zone (Idz): How Patchy Leaf Litter Dynamics In A Buckthorn-Invaded Urban Woodland Can Affect Microarthropod Species Richness, Angela Stenberg

DePaul Discoveries

Biodiversity loss may serve as a key diagnostic of the Anthropocene. An important driver of this loss is by means of invasive species. In this study of a forest preserve in Chicago, Illinois we examined Interspersed Denuded Zones (IDZs for short), which are areas of patchy leaf litter in invaded forests caused in this case by the rapid decomposition of litter from buckthorn (Rhamnus cathartica). We characterized the leaf litter mass in IDZs and enumerated litter-inhabiting microarthropod populations. We found that plots of high buckthorn density are associated with IDZs: there was significantly less leaf litter mass in …

Modeling Reproduction Influencers Of An Endangered Oak, Camila Cortez

DePaul Discoveries

The endemic oak, Quercus brandegeei has been labeled as endangered by the IUCN Red List of Endangered Species due to its limited genetic diversity and lack of regeneration. The oak (Quercus) species is a keystone species in many parts of the world and has been facing various challenges to their survival (Westwood 2017) making efforts to support and protect endemic oaks all the more ecologically and socially imperative. There are challenges to identifying threats as there are many unknown characteristics of Q. brandegeei’s biology that are essential to carrying out conservation efforts. To develop a greater understanding of …

Determining The Novel Pathogen Neodothiora Populina As The Causal Agent Of The Aspen Running Canker Disease In Alaska, Loretta M. Winton, Gerard C. Adams, Roger W. Ruess

Aspen Bibliography

Neodothiora populina Crous, G.C. Adams & Winton was determined to be a new pathogen of trembling aspen (Populus tremuloides) growing in Alaska, based on completion of Koch’s Postulates in replicated forest and growth chamber inoculation trials. The pathogen is responsible for severe damage and widespread rapid mortality of sapling to mature aspen (≥ 80 years) in the boreal forests of interior Alaska, due to large diffuse annual (1–2 years) cankers. Isolation of the pathogen was challenging, and identification based on cultural characters was difficult. Fruiting bodies were not found on wild diseased trees, but erumpent pycnidia were found …

Community Structure And Dynamics Of Benthic Macroinvertebrates In A Recreated Headwater Stream System On A Valley Fill In A Retrofitted Watershed Located In The Appalachian Coalfields Of Southeastern Kentucky (U.S.A.), Steven W. Bailey

Electronic Theses and Dissertations

The extraction of coal from steep-gradient surface mining sites such as in the Appalachian Coalfields of the U.S. produces excess debris that is often placed in adjacent valleys resulting in the creation of valley fills. Not only are headwater streams buried in the process, but watershed functions are either destroyed outright, or become fragmented and disconnected from adjacent ecosystems resulting in adverse effects to downstream biological communities. In this dissertation, the dynamics of stream macroinvertebrate community structure, composition, diversity, and biotic integrity are assessed at a “proof of concept” stream system recreated on a retrofitted valley fill. For comparison, two …

Upscaling Tree Demography To Heterogenous Landscapes Using Models And Remote Sensing, Cristina Barber

Boise State University Theses and Dissertations

Tree demography is foundational to ecology and conservation, from mass tree die-offs to forest recovery. Plot-level studies of tree demography, including field measurements of tagged individuals, have been fundamental for developing ecological theory and forest management strategies. However, the limited spatial extent of field plots impedes generalizing plot-level models for spatial predictions across heterogeneous landscapes. Novel high-spatial resolution remote sensing imagery has opened the possibility for measuring tree demographic rates with continuous spatial coverage at landscape to regional extents. Remote sensing derived measurements could address pressing research questions, including disentangling causes of high variation in natural regeneration across secondary forest …

Intensive Hunting Pressure Changes Local Distribution Of Wild Boar, Jakub Drimaj, Jiří Kamler, Radim Plhal, Přemysl Janata, Zdeněk Adamec, Miloslav Homolka

Human–Wildlife Interactions

Wild boar (Sus scrofa) is now an important species of wild ungulates in Central Europe. Next to conflicts of wild boar with agriculture, the main threat of wild boar presence lies in the expansion of African swine fever across Europe. The regulation of the wild boar population is complicated by the high reproduction rate and intelligent behavior of the species, which limits hunting effectiveness. We analyzed the spatial behavior of wild boar in an environment with a lack of natural food resources. The study area consisted of a forest complex (1,283 ha) with 2 areas. In the “risk” …

Availability And Structure Of Coarse Woody Debris In Hemiboreal Mature To Old-Growth Aspen Stands And Its Implications For Forest Carbon Pool, Silva Šēnhofa, Guntars Šnepsts, Kārlis Bičkovskis, Ieva Jaunslaviete, Līga Liepa, Inga Straupe, Āris Jansons

Aspen Bibliography

European aspen deadwood is extensively studied as a habitat for saproxylic species, while less is known of its dynamics and role in carbon sequestration. We studied unmanaged mature (41–60 years), moderately overmature (61–80 years), overmature (81–100 years), and old-growth (101–140 years) and managed mature and moderately overmature aspen stands on fertile mineral soils. In unmanaged stands, marginal mean CWD volume was from 67.3 ± 12.1 m³ ha⁻¹ in moderately overmature to 92.4 ± 5.1 m³ ha⁻¹ in old-growth stands, with corresponding marginal mean CWD carbon pool 8.2 ± 1.6 t ha⁻¹ and 12.5 ± 0.7 …

Coarse Woody Debris Decomposition Assessment Tool: Model Validation And Application, Zhaohua Dai, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, Daniel L. Lindner

Aspen Bibliography

Coarse woody debris (CWD) is a significant component of the forest biomass pool; hence a model is warranted to predict CWD decomposition and its role in forest carbon (C) and nutrient cycling under varying management and climatic conditions. A process-based model, CWDDAT (Coarse Woody Debris Decomposition Assessment Tool) was calibrated and validated using data from the FACE (Free Air Carbon Dioxide Enrichment) Wood Decomposition Experiment utilizing pine (Pinus taeda), aspen (Populous tremuloides) and birch (Betula papyrifera) on nine Experimental Forests (EF) covering a range of climate, hydrology, and soil conditions across the continental USA. …

Beaver Reintroduction And Its Potential As An Ecological Conservation Measure For At-Risk Amphibian Species In The Pacific Northwest, Danielle Schwantes

University Honors Theses

Amphibian decline is a major concern in the Pacific Northwest (PNW), with many amphibian species listed as sensitive, threatened or endangered throughout the region. Some of the predicted main causes of amphibian decline are climate change and loss of habitat. The reintroduction of beavers into ecoregions of the PNW could be an important step in the conservation of this region’s amphibians, due to the beaver’s ability to engineer and structurally manipulate forest ecosystems. Beavers are able to restore wetland quality, productivity and biodiversity, creating vital amphibian habitat. This work explored the linkage between beaver presence and wetland hydrology, geomorphology, landscape …

Tree Establishment On Post-Mining Waste Soils: Species, Density, And Mixture Effects, Degi Harja Asmara, Suzanne Allaire, Meine Van Noordwijk, Damase P. Khasa

Aspen Bibliography

Tree establishment to restore degraded boreal post-mining lands is challenged by low soil productivity, a harsh microclimate, and potentially high contaminant levels. The use of mixed vegetation can facilitate the microclimate but increase competition for soil resources. A statistical accounting of plant–plant interactions and adaptation to multispecies conditions is hard to achieve in field experiments; trials under controlled conditions can distinguish effects of planting density and species interactions in the early stages of plant establishment. A greenhouse trial was established in containers (“mesocosms”) with waste rock or fine tailings from gold mines. Pregerminated (1-week-old) seedlings (Alnus viridis subsp. crispa …

Spatial And Temporal Variation Of Epigaeic Beetle Assemblages (Coleoptera, Carabidae, Staphylinidae) In Aspen-Dominated Mixedwood Forests Across North-Central Alberta, H. E. James Hammond, Sergio García-Tejero, Greg R. Pohl, David W. Langor, John R. Spence

Aspen Bibliography

Epigaeic beetle assemblages were surveyed using continuous pitfall trapping during the summers of 1992 and 1993 in six widely geographically distributed locations in Alberta’s aspen-mixedwood forests prior to initial forest harvest. Species composition and turnover (β-diversity) were evaluated on several spatial scales ranging from Natural Regions (distance between samples 120–420 km) to pitfall traps (40–60 m). A total of 19,885 ground beetles (Carabidae) representing 40 species and 12,669 rove beetles (non-Aleocharinae Staphylinidae) representing 78 species was collected. Beetle catch, species richness, and diversity differed significantly among the six locations, as did the identity of dominant species. Beetle species composition differed …

Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Phytophthora ramorum is the causal agent of Sudden Oak death (SOD), ramorum dieback and ramorum leaf blight which affect both forest environments and nurseries. This oomycete pathogen has had a huge economic impact on the nursery and lumber industry. Forests in California have experienced substantial mortality of oaks affecting the forest dynamics and diversity. Our research investigates four native species and two ornamental cultivars of plants, which belong to the genus Arctostaphylos (manzanita) and are considered to be new hosts for P. ramorum in the chaparral ecosystem of California. Symptom expression and transmission rates were analyzed on Arctostaphylos glauca, …

Salicylic Acid Response To Simulated Herbivory In Geographically Distinct T. Heterophylla And H. Discolor Populations, Amy E. Castle

Honors Projects

It is commonly known that plants may produce salicylic acid as a chemical defense response to wounding, although the phenomenon has usually been observed with regard to insect herbivory. Stem and leaf tissue of two species, Tsuga heterophylla and Holodiscus discolor, which are often eaten by deer, were extracted in methanol and analyzed by HPLC to quantify salicylic acid concentration in experimentally wounded or control samples. No salicylic acid response was detectable in T. heterophylla, suggesting it is a less useful candidate species for future study. Some but not all H. discolorsamples had a measurable salicylic acid …

Splitting The Difference: Heterogeneous Soil Moisture Availability Affects Aboveground And Belowground Reserve And Mass Allocation In Trembling Aspen, Ashley T. Hart, Morgane Merlin, Erin Wiley, Simon M. Landhäusser

Aspen Bibliography

When exploring the impact of resource availability on perennial plants, artificial treatments often apply conditions homogeneously across space and time, even though this rarely reflects conditions in natural systems. To investigate the effects of spatially heterogeneous soil moisture on morphological and physiological responses, trembling aspen (Populus tremuloides) saplings were used in a split-pot experiment. Following the division of the root systems, saplings were established for a full year and then subjected to either heterogeneous (portion of the root system exposed to non-lethal drought) or homogeneous (whole root system exposed to non-lethal drought or well-watered) treatments. Above- and belowground …

Soil Macroinvertebrates Responses To Wildfires In The Blue Ridge Mountains, Usa, Madeline Olliff

Biology Theses

Fire has been a prevalent disturbance on Earth for millions of years. Around the globe there are several regions that have become fire adapted, including the Southeastern United States. There have been few studies examining the effects of wildland fires on soil macroinvertebrates in the Blue Ridge Mountains, in spite of the importance of these animals to soil processes and their contributions to the biodiversity of these ecosystems. During the fall of 2016, the Southeastern USA experienced numerous, large wildfires. These fires offered an opportunity to study the effects of wildland fire on soil macroinvertebrates. We sampled sites from three …

Food-Web And Functional Trait Community Structure Of Predator Assemblages In Pine Forests Under Different Management Regimes, Connor Adams

Electronic Theses and Dissertations

Anthropogenic activities can alter natural disturbance regimes in ecosystems, and thereby affect the structure and function of biological diversity. As many of the world’s ecosystems are degraded beyond natural recovery, well-defined restoration goals are necessary to maintain the ecological processes that provide valuable ecosystem services. Utilizing taxonomic, functional, and food-web approaches, I investigated the impacts of forest management practices in structuring predator communities in two pine forest systems of eastern Texas. The results of this study indicate that the increased frequency of forest management practices such as prescribed fires and thinning operations encourages predator diversity while increasing functional and trophic …

The Effects Of Late Spring Frost On Forest And Landscape Health And Recovery Of The Black Rock Forest, New York, Caroline Eco, Oliver Imhans, Aaron Davitt, Andrew B. Reinmann

Publications and Research

Projected changes in climate are expected to increase the frequency of late spring frost events in the Northeast US. Such events can be harmful to trees because freezing temperatures that occur after leaf-out can damage or kill young leaves. The resultant defoliation typically forces a second flush of leaves, but delays canopy development, which in turn delays the onset of canopy carbon uptake and alters canopy thermal properties. In this study, we analyzed a recent freeze event that occurred on 8-9 May 2020 (DOY 129-130) at Black Rock Forest (BRF), which is in the Hudson Highlands of southeastern New York …

Chloroplast Genomes In Populus (Salicaceae): Comparisons From An Intensively Sampled Genus Reveal Dynamic Patterns Of Evolution, Jiawei Zhou, Shuo Zhang, Jie Wang, Hongmei Shen, Bin Ai, Wei Gao, Cuijun Zhang, Qili Fei, Daojun Yuan, Zhiqiang Wu, Luke R. Tembrock, Sen Li, Cuiha Gu, Xuezhu Liao

Aspen Bibliography

The chloroplast is one of two organelles containing a separate genome that codes for essential and distinct cellular functions such as photosynthesis. Given the importance of chloroplasts in plant metabolism, the genomic architecture and gene content have been strongly conserved through long periods of time and as such are useful molecular tools for evolutionary inferences. At present, complete chloroplast genomes from over 4000 species have been deposited into publicly accessible databases. Despite the large number of complete chloroplast genomes, comprehensive analyses regarding genome architecture and gene content have not been conducted for many lineages with complete species sampling. In this …

Pando's Lessons: Restoration Of A Giant Aspen Clone, Paul C. Rogers, Jody Gale, Darren Mcavoy

Aspen Bibliography

A 106 acre (43 ha) aspen clone lives in the Fishlake National Forest in south-central Utah. Clones are comprised of multiple aspen stems, called ramets, which are genetically identical. This particular colony of ramets was named “Pando” (Latin for “I spread”) by researchers believing it to be the largest living organism by mass on earth. Recently, forest managers have noted a rapid dying of mature stems without recruitment of younger trees. This unsustainable situation has galvanized restoration efforts at Pando. Human interventions caused this imbalance; restoration will rely on protection, monitoring, and innovation. As a laboratory, this forest icon may …

Analysis Of The White-Tailed Deer Population Of Hobbs State Park, Jesse Morrison

Biological and Agricultural Engineering Undergraduate Honors Theses

White Tailed deer (Odocoileus virginianus) are the only deer species native to Arkansas, playing a crucial role in the ecosystem. Healthy deer populations are important for environmental and human wellbeing, and overpopulation can lead to poor herd health, overgrazing, increased vehicle collisions, and transmission of diseases. Monitoring deer populations through surveys can be a useful tool in managing wildlife and maintaining Arkansas’ natural resources.

This study analyzed trends in Hobbs State Park’s deer population and estimated the current roadside deer population of the park. Data from past surveys was analyzed for trends using a Mann-Kendall Test, and a distance sampling …