Biology Commons^™

Quantifying The Ecological Effects Of Salix Fragilis On Riparian Habitat In Kittitas County, Washington, Landon Shaffer

All Master's Theses

Invasive species threaten plant community structure and function globally. Riparian areas, the zone near streams where water influences vegetation, are especially sensitive to invasive species colonization, suffering large-scale shifts in community composition. Salix fragilis (crack willow) is a nonnative riparian species abundant in the lower elevation tributaries of central Washington. Some speculate whether this willow should be listed as invasive in Washington, despite a lack of regional supporting evidence. I studied riparian communities dominated by either S. fragilis or native species in the Kittitas Valley and measured biodiversity, quantified differences in solar attenuation, and compared leaf decomposition rates to learn …

Environmental Biology Masters Capstone, Antonio Gonzalez-Pita

Regis University Student Publications (comprehensive collection)

Human wildlife interactions (HWI) pose a complex challenge for wildlife managers. Human encroachment into wildlife habitat and the growing number of outdoor recreationists are increasing the frequency of contact and conflict, especially in regions such as the Front Range of Colorado. Geographic information systems (GIS), which use a combination of remote sensing and environmental survey data, allow for predictive spatial analyses of where human wildlife interactions are likely to occur. I used publicly reported observations of moose to create spatial predictive maps in a species distribution model framework. Slope and elevation were shown to be the strongest predictors of HWI, …

Welcome, Audrey E. Mcgowin

Runkle Woods Symposia

The introduction to the 6th Annual Runkle Woods Symposium given by Audrey McGowin.

Woods Symposium 2023 Program, Wright State University

Runkle Woods Symposia

The program for the 6th annual Wright State University Runkle Woods Symposium that took place on November 17, 2023

The Impact Of Soil Disturbance On Soil Bacterial Community Composition, Marie A. Rodriguez, Mark Peach, Timothy D. Trott

Research in Biology

Soil bacterial communities are an important part of terrestrial ecosystems due to their roles in biogeochemical cycling processes. Consequently, understanding how soil disturbance affects the soil bacterial diversity is vital to understanding the entire ecosystem. In this study we examined the effects of soil disturbance (by mining) on the soil bacterial community composition from three sites on Bauxite Ridge in Southeast Tennessee compared to three undisturbed sites in a nearby location. The soil bacterial community was analyzed by 16S rDNA amplicon sequencing of total DNA extracted from the soil samples collected from each of the six sites. Characterization of the …

Evidence Of Competitive Release Following Overstory Mortality In A Semi-Arid Piñon-Juniper Woodland, Corrie D. Gonzalez

Biology ETDs

Extreme temperatures and severe drought events have led to widespread tree mortality worldwide. In semi-arid regions of the Southwest United States, these events pose a significant threat to piñon-juniper (PJ) woodlands. We studied the effects of piñon and juniper mortality on the growth and physiology of existing saplings in PJ woodlands by analyzing water status, photosynthetic activity, and tissue chemistry to gain insights into these impacts. Juniper saplings exhibited improved water status and water use efficiency in response to overstory mortality, whereas piñon saplings did not. Additionally, both piñon and juniper saplings exhibited increased photosynthetic rates, increased photosynthetic capacity, and …

Comparing Fungal Communities In Tsuga Heterophylla Seedling Roots Across Nurse Log Decay Stages And The Forest Floor, Ellie Olpin, Reisha Foertsch

Summer Research

Nurse logs are fallen, decaying trees that have been shown to facilitate the survival, establishment, and growth of tree seedlings, therefore making vital contributions to forest regeneration. Plant-fungi interactions may play a role in influencing seedling survival across nurse log decay and the forest floor. We sought to examine how fungal communities in seedling roots change between nurse logs and forest floor as well as across nurse log decay stages. To study this, we collected western hemlock (Tsuga heterophylla) seedlings (5-10 cm) from nurse logs of each decay stage and the forest floor at three field sites on the Olympic …

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

Fine Characterization Of Leafing Phenology In The Brazilian Atlantic Forest By Optical And Microwave Remote Sensing, James B. Bell

Dissertations and Theses

Tropical forests provide important ecosystem functions in the global biosphere, but they remain among the most poorly understood elements of land surface models, especially with regard to their seasonal dynamics. For instance, in seasonally dry forests, the pattern of the annual green-up in their canopies closely follows annual patterns of rainfall. The same, however, does not occur in wet forest canopies which are dominated by evergreen trees. In the latter, water is not scarce enough to limit leaf photosynthetic function. Canopy leafing phenology in these forests is therefore poorly characterized by optical remote sensing methods which are not sensitive to …

Assessing The Recovery Of Forest Understory Vegetation After Clearcut Logging Across A 445-Year Chronosequence, Molly Smith Metok

Cal Poly Humboldt theses and projects

The conversion of natural forested lands to managed forests has reduced the amount of older, structurally diverse forests worldwide. In conifer forests of the Pacific Northwest (USA) – where the understory plant communities comprise only 1% of forest biomass but represent 90% of the plant species richness – the long-term impacts of timber harvesting are not fully understood. I used a chronosequence of forests in southwestern Oregon that ranged from 25 to 445 years of age to compare changes in plant communities in logged (i.e., managed) stands with that of stands in late succession and old growth conditions. The chronosequence …

Territory Inheritance And The Evolution Of Cooperative Breeding In The Acorn Woodpecker, Walter D. Koenig, Joseph Haydock, Hannah L. Dugdale, Eric L. Walters

Biological Sciences Faculty Publications

There are two main hypotheses for why offspring in cooperatively breeding taxa delay dispersal and remain on their natal territory rather than disperse. First, ecological constraints may force offspring to remain on their natal territory until a reproductive opportunity presents itself in an otherwise saturated habitat. Alternatively, delaying dispersal and helping kin may increase an offspring's inclusive fitness. One means by which offspring might enhance their direct fitness by delaying dispersal is by inheriting breeding status on their natal territory. Such territory inheritance regularly occurs in acorn woodpeckers, Melanerpes formicivorus, a species whose social groups consist of a cooperatively …

Callery Pear Allelopathy Study, Michaela J. Woods, Jonathan T. Bauer, Dena Schaeffer, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

No abstract provided.

Wetlands In Our Backyard: A Review Of Wetland Types In Virginia State Parks, Kirsten Bauer, Benjamin K. Campbell

Virginia Journal of Science

Wetlands constitute a significant component of Virginia’s natural resources and heritage. Though historically they have been discounted—and often denigrated—the exceptional value of wetlands is currently growing in recognition and appreciation. In addition to the value provided by extracted resources and ecological regulation, wetlands also offer people the opportunity to enrich themselves through cultural, educational, and recreational pursuits. The state parks of Virginia provide access to a variety of ecosystems, including a wide array of wetland types. In this review, we document the diversity of wetlands in Virginia State Parks through a typology that groups wetland systems into the three principal …

Relating Occupancy Patterns To Multi-Life-History Scales For Pond-Breeding Anurans In Eastern Virginia, Patrick A. Hardner

Undergraduate Honors Theses

Amphibians are experiencing population declines worldwide due to a multitude of factors, including habitat loss. Therefore, assessments of breeding habitat occupancy are important to determine which environmental characteristics are crucial for conservation of amphibians. While most research assesses habitat conditions at the breeding site (i.e., pond or wetland), for many species this misrepresents annual habitat use as many migrate to terrestrial habitats once breeding is completed. To provide a comprehensive assessment of annual habitat use, we evaluated how anuran (i.e., frog and toad) breeding site occupancy related to three life-history scales: breeding, migration and dispersal. Basically, the three scales define …

Leaf Phenology Of Callery Pear: Fall, Margaret E. Maloney, Abby Hay, Eric B. Borth, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

This dataset is one of three affiliated with the paper "Leaf phenology and freeze tolerance of the invasive tree Pyrus calleryana Roseaceae) and potential native competitors."

The other two datasets are:

• Leaf Phenology of Callery Pear: Spring
• Leaf Phenology of Callery Pear: Frost Damage

Leaf Phenology Of Callery Pear: Frost Damage, Margaret E. Maloney, Abby Hay, Eric B. Borth, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

This dataset is one of three affiliated with the paper "Leaf phenology and freeze tolerance of the invasive tree Pyrus calleryana Roseaceae) and potential native competitors."

The other two datasets are:

• Leaf Phenology of Callery Pear: Spring
• Leaf Phenology of Callery Pear: Fall

Leaf Phenology Of Callery Pear: Spring, Margaret E. Maloney, Abby Hay, Eric B. Borth, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

This dataset is one of three affiliated with the paper "Leaf phenology and freeze tolerance of the invasive tree Pyrus calleryana Roseaceae) and potential native competitors."

The other two datasets are:

• Leaf Phenology of Callery Pear: Fall
• Leaf Phenology of Callery Pear: Frost Damage

Callery Pear Removal Experiment: Trees-Sprouting (Stillwater Conservation Area), Margaret E. Maloney, Eric B. Borth, Grace Dietsch, Mary C. Lloyd, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

The invasive tree Callery pear (Pyrus calleryana) is problematic in open habitats in the American Midwest. We investigated the efficacy of various control techniques on P. calleryana invasion in grasslands. Treatments were applied to P. calleryana stems that had experienced mowing annually for several years and were sprouting (n = 100 stems) and response of those stems was measured.

Callery Pear Removal Experiment: Trees-Intact (Medlar Conservation Area), Margaret E. Maloney, Eric B. Borth, Grace Dietsch, Mary C. Lloyd, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

The invasive tree Callery pear (Pyrus calleryana) is problematic in open habitats in the American Midwest. We investigated the efficacy of various control techniques on P. calleryana invasion in grasslands. Treatments were applied to P. calleryana stems that were single-stemmed trees (around 7 years; n = 40 stems), and response of those stems was measured.

Poor Acclimation To Experimental Field Drought In Subalpine Forest Tree Seedlings, Alex Goke, Patrick H. Martin

Biological Sciences: Faculty Scholarship

The ability of tree species to acclimate and tolerate projected increases in drought frequency and intensity has fundamental implications for future forest dynamics with climate change. Inquiries to date on the drought tolerance capacities of tree species, however, have focused almost exclusively on mature trees with scant in situ work on seedlings, despite the central role that regeneration dynamics play in forest responses to changing conditions. We subjected naturally established seedlings of co-dominant subalpine conifer species (Abies lasiocarpa and Picea engelmannii) in the southern Rocky Mountains to 2 years of in situ summer precipitation exclusion, simulating summer drought …

Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier

Theses and Dissertations

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem functioning after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether LiDAR-derived canopy structures as material legacies drive 3-year responses of NPP to a range of disturbance severity levels. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances at a range of …

Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey

Theses and Dissertations

Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rs is linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through …

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield

Electronic Theses and Dissertations

As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …

Frayed Connections: How Long-Term Nitrogen Additions Disrupt Plant-Soil Interactions And The Carbon Cycle Of A Temperate Forest, Brooke A. Eastman

Graduate Theses, Dissertations, and Problem Reports

Forests are expected to mitigate some of the negative effects of climate change by sequestering anthropogenic carbon (C) from the atmosphere, but the degree to which they drawn down C will depend on the availability of key nutrients, such as nitrogen (N). There is a fair amount of uncertainty in the future of the forest C sink, mostly owing to the fate of soil organic matter (SOM) and soil heterotrophic respiration to future conditions. In N limited systems, plants allocate a significant amount of their photosynthate belowground for the acquisition of nutrients, but under conditions of chronic N deposition, plants …

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 …

Seed Rain–Successional Feedbacks In Wet Tropical Forests, Nohemi Huanca Nuñez, Robin L. Chazdon, Sabrina E. Russo

School of Biological Sciences: Faculty Publications

Abstract

Tropical forest regeneration after abandonment of former agricultural land depends critically on the input of tree seeds, yet seed dispersal is increasingly disrupted in contemporary human-modified landscapes. Here, we introduce the concept of seed rain–successional feedbacks as a deterministic process in which seed rain is shaped by successional dynamics internal to a forest site and that acts to reinforce priority effects. We used a combination of time series and chronosequence approaches to investigate how the quantity and taxonomic and functional composition of seed rain change during succession and to evaluate the strength of seed rain–successional feedbacks, relative to other …

Focus Stacking Images Of Morphological Character States For Differentiating The Adults Of Ixodes Affinis And Ixodes Scapularis (Acari: Ixodidae) In Areas Of Sympatry, Robyn M. Nadolny, Marcée Toliver, Holly D. Gaff, John G. Snodgrass, Richard G. Robbins

Biological Sciences Faculty Publications

Adult females and males of Ixodes affinis and Ixodes scapularis are illustrated by focus stacking image photography, and morphological character states are described that reliably differentiate the two species. In conjunction with other environmental cues, such as the questing phenology of adults, these characteristics will enable the rapid identification of adults of either sex along the southern Coastal Plain of the United States, where these species are sympatric.

The Interspecific Growth–Mortality Trade-Off Is Not A General Framework For Tropical Forest Community Structure, Sabrina E. Russo, Sean M. Mcmahon, Matteo Detto, Glenn Ledder, S. Joseph Wright, Richard S. Condit, Stuart J. Davies, Peter S. Ashton, Sarayudh Bunyavejchewin, Chia-Hao Chang-Yang, Sisira Ediriweera, Corneille E.N. Ewango, Christine Fletcher, Robin B. Foster, C.V. Savi Gunatilleke, I.A.U. Nimal Gunatilleke, Terese Hart, Chang-Fu Hseih, Stephen P. Hubbell, Akira Itoh, Abdul Rahman Kassim, Yao Tze Leong, Yi Ching Lin, Jean-Remy Makana, Mohizah Bt. Mohamad, Perry Ong, Anna Sugiyama, I-Fang Sun, Sylvester Tan, Jill Thompson, Takuo Yamakura, Sandra L. Yap, Jess K. Zimmerman

School of Biological Sciences: Faculty Publications

Resource allocation within trees is a zero-sum game. Unavoidable trade-offs dictate that allocation to growth-promoting functions curtails other functions, generating a gradient of investment in growth versus survival along which tree species align, known as the interspecific growth–mortality trade-off. This paradigm is widely accepted but not well established. Using demographic data for 1,111 tree species across ten tropical forests, we tested the generality of the growth–mortality trade-off and evaluated its underlying drivers using two species-specific parameters describing resource allocation strategies: tolerance of resource limitation and responsiveness of allocation to resource access. Globally, a canonical growth–mortality trade-off emerged, but the trade-off …

Seedling Growth And Soil Chemistry In A Chronosequence Of Forest Restoration From Agriculture, Michaela J. Woods, Sarah J. Frankenberg, Joseph R. Juodvalkis, Mary C. Lloyd, Meredith Cobb, Ryan Mcewan

Five Rivers MetroParks Collaboration Data Archive

Soils were collected from forest restorations that were 0, 7, 10, 50 and 100 years old and assessed for soil nutrients, chemistry, and enzymatic activity. Quercus macrocarpa seedlings were planted in each soil type, after 5 months of growth seedlings were destructively harvested. Seedling mass and the colonization rate of their roots by ectomycorrhizal fungi are reported.

The photo accompanying this data collection is of the researchers' germinating Quercus macrocarpa seeds.

Wildlife Forage Recovery Following Boreal Wildfire, Alexis Jorgensen, Jennifer Baltzer

Theses and Dissertations (Comprehensive)

Climate change is altering the boreal wildfire regime through increases in the extent and severity of burning and reductions in fire return intervals. These changes can alter the regeneration trajectory of canopy species and ground vegetation, with implications for wildlife habitat. There is some uncertainty about the timelines of when different animal species will use burned areas as their preferred forage taxa recover following fire, and how such recovery is mediated by environmental factors. Here, we aim to address these knowledge gaps through the following questions: 1) What are the main forage types consumed by boreal wildlife and how much …