Life Sciences Commons^™

Microsite Requirements For Successful Regeneration In Lowland Northern White-Cedar (Thuja Occidentalis) Forests, Jeanette Allogio

Electronic Theses and Dissertations

Declines in stands of northern white-cedar (Thuja occidentalis L., hereafter cedar) have been observed as both shifts in species composition and reductions in cedar densities, particularly those stands in lowland sites (Curtis 1946, Boulfroy 2012). While several factors inhibiting cedar regeneration have been identified, a thorough understanding of the conditions that best promote regeneration is lacking. Our objectives for the first chapter were to characterize the site conditions associated with successful regeneration in lowland cedar stands and to describe how spatial patterns of various cedar size classes relate to site preference and to regeneration dynamics. These objectives were achieved …

Nebraska Forest Action Plan - 2020, John Erixson

Nebraska Forest Service: Publications

Nebraska’s Forest Action Plan – 2020 represents a multiyear effort by Nebraska Forest Service staff to ensure trees continue to play a role in the lives of all Nebraskans. It includes assessments in locations considered to be priority forested areas; the strategies that will be implemented to address the challenges described in the preceding paragraph; and, how the agency’s resources will coalesce to bring the state’s trees and forests to a healthy and sustainable condition. Additionally, this plan maintains flexibility that allows for response to changes in the natural environment, state or federal policy, and the priorities of constituents and …

Root Phosphomonoesterase As A Vital Component Of Increasing Phosphorus Availability In Tropical Forests, Kristine Grace Manno Cabugao

Doctoral Dissertations

Tropical forests, relative to other terrestrial ecosystems, exchange the largest amount of carbon with the atmosphere and also constitute a significant carbon sink. However, nutrient limitation, particularly of phosphorus (P), could limit growth of tropical forests and their function with the global carbon cycle. Thus, understanding root mechanisms to acquire P is necessary to representing the P cycle and corresponding interactions with plant growth. A large portion of total soil P in tropical forests occurs in organic forms, only accessible through root and microbial production of phosphatase enzymes. These phosphatase enzymes mineralize organic P into orthophosphate, the form of P …

Conservation Of Terrestrial Salamanders Through Hemlock Woolly Adelgid Management In Eastern Hemlock Forests Within Great Smoky Mountains National Park, Jonathan Lawrence Cox

Masters Theses

Hemlock woolly adelgid (Adelges tsugae; HWA), an invasive aphid-like arthropod, was first documented on the east coast of the United States in the 1950s. HWA is an herbivore which primarily feeds at the needle base of hemlock tree species (Pinaceae: Tsuga). With no evolutionary defenses and few biotic controls, the eastern and Carolina hemlock (Tsuga canadensis and Tsuga carolinensis) serve as the primary diet of HWA in eastern North America. The invasive pest began to spread rapidly throughout the hemlock’s range causing defoliation and death of the trees within 4 – 10 years. With the …

Research Focus: Depaul’S Tree Whisperer

Scientia

Jalene LaMontagne, a population ecologist and associate professor of biological sciences in DePaul's College of Science and Health, is researching mast seeding of white spruce and the seed cones they produce across the 3,000-mile span of North America to understand the patter of tree behavior along the ecological dipole.

Inoculum Potential Of Pinus Edulis-Associated Ectomycorrhizal Fungi Across A Forest Extirpation Chronosequence, Annie M. Montes

Biology ETDs

Few studies have examined inoculum potential of ectomycorrhizal fungi (EMF) in the absence of plant hosts, yet persistence of these fungi may be paramount to resilience of Pinus edulis and other mycorrhizal plant species. We conducted a study in which seven sites were selected in northwestern New Mexico with known dates of P. edulis extirpation and a lack of regeneration. Age classes included: two sites extirpated 10-20 years ago, two extirpated 55-65 years ago, two extirpated 500+ years ago, and one extirpated 11,000+ years ago. At each site, two plots were paired: an extirpated plot and the nearest live adult …

Hot But Not Dry: Modest Changes In Water Relations For An Epiphytic Bromeliad In A Tropical Dry Deciduous Forest, Saúl Hernández-Robinson, Eric A. Graham, Olivia Hernández-González, Roberth Us-Santamaría, José Luis Simá, Fernando Arellano-Martín, José Luis Andrade

All Faculty Scholarship for the College of the Sciences

Premise of research. Epiphytic bromeliads endure intense seasonal environmental changes in the canopy of dry tropical deciduous forests. The analysis of the physiological responses of these epiphytes to environmental changes can be useful in assessing their plasticity, vulnerability, and adaptations to such extreme habitats.

Methodology. We measured microenvironmental variables and water relations for plants of the epiphytic bromeliad Tillandsia brachycaulos in three microhabitats within the canopy of a dry tropical forest. We measured individual plants for seasonal and spatial differences in light, leaf temperature, osmotic potential, cell wall elasticity, and relative capacitance as indications of their physiological responses …

Soil Chemistry And Enzyme Data Examining Impacts Of Callery Pear Stem Cutting, Michaela J. Woods, Grace K. Attea, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

This dataset encompasses information following the collection of soil from underneath cut and treated Callery pear stems and untreated Callery pear trees. Soil was assessed for moisture, pH, and enzyme activities.

Fostering Climate Change Resilience: A Socio-Ecological Forest Systems Approach, Alyssa R. Soucy

Electronic Theses and Dissertations

As climate change continues to impact socio-ecological systems, those that rely on natural resources are highly sensitive to climatic changes. Maine’s forest industry provides for the economic and social well-being of many residents and is especially vulnerable to climate change impacts. Changes in growing season length and timing, forest health threats imposed by insects and pathogens, extreme weather events, shifting forest composition, and changes in natural disturbance severity and frequency have already begun, and are projected to continue, to impact forest systems in the Northeastern U.S. While climate change presents a threat to forest systems, opportunities also arise due to …

Foliage Type Controls Mercury Input, Storage, And Release In The Boreal Forest, Madelaine J R Anderson

Electronic Thesis and Dissertation Repository

Mercury (Hg) is a naturally occurring element with a complex biogeochemical cycle. Forests act as net sinks for both carbon (C) and Hg as foliage accumulates Hg with time. Litterfall represents a main input of C and Hg into forest soils. My aim was to investigate how foliage type (coniferous, deciduous) governs the input of Hg into forests with a field-based study that measured Hg accumulation over a growing season, and then investigate the storage and release of Hg from foliar tissues into soil with a laboratory-based incubation experiment. Results from the field-based study demonstrate deciduous leaves have more linear …

The Impacts Of Prescribed Burning And Mechanical Thinning On Insect Communities In The Arkansas Ozarks, Aaron P. Tormanen

Theses and Dissertations from 2020

Insects are important in woodland ecosystems due to their role as pollinators and as prey for bats. My research investigated the relationships between forest management, vegetation, and insects in the Ozark National Forest in Arkansas. I selected 30 stands burned at varying frequencies in the last 12 years. Twelve of these stands were burned and mechanically thinned, 12 were only burned, and 6 were untreated. I deployed blacklight traps and malaise traps in each stand monthly from mid-March to mid- November 2019. Over 42,391 insects were collected, and Lepidoptera was the most abundant order. Insects were dried, weighed, and identified …

Ectomycorrhizal Plant-Fungal Co-Invasions As Natural Experiments For Connecting Plant And Fungal Traits To Their Ecosystem Consequences, Jason D. Hoeksema, Colin Averill, Jennifer M. Bhatnagar, Edward Brzostek, Erika Buscardo, Ko-Hsuan Chen, Hui-Ling Liao, Laszlo Nagy, Nahuel Policelli, Joanna Ridgeway, J. Alejandro Rojas, Rytas Vilgalys

Faculty and Student Publications

Introductions and invasions by fungi, especially pathogens and mycorrhizal fungi, are widespread and potentially highly consequential for native ecosystems, but may also offer opportunities for linking microbial traits to their ecosystem functions. In particular, treating ectomycorrhizal (EM) invasions, i.e., co-invasions by EM fungi and their EM host plants, as natural experiments may offer a powerful approach for testing how microbial traits influence ecosystem functions. Forests dominated by EM symbiosis have unique biogeochemistry whereby the secretions of EM plants and fungi affect carbon (C) and nutrient cycling; moreover, particular lineages of EM fungi have unique functional traits. EM invasions may therefore …

Floodplain Forest Regeneration Dynamics In The Lower Mississippi River Alluvial Valley, Whitney Anne Kroschel

LSU Doctoral Dissertations

Floodplain forest species diversity is driven, in part, by variation in disturbance regime. Flood patterns create heterogeneity in microsite quality from small differences in elevation across a floodplain which, in turn, influence flood timing and duration. Differences in species’ regeneration niches in relation to hydrologic patterns can account for long-term coexistence of various species. In the past century floodplain forests have exhibited a wide range of changes in stand development and species composition as a result of altered hydrology in rivers and floodplains. I evaluated the role of regeneration in floodplain forest systems of the Lower Mississippi River Alluvial Valley …

Quantitative And Qualitative Approaches To Assess Tree Vigor And Stand Health In Dry Pine Forests, Nancy Grulke, Craig Bienz, Kate Hrinkevich, Jason Maxfield, Kellie Uyeda

Biology Faculty Publications and Presentations

Despite a critical need to evaluate effectiveness of forest treatments in improving stand health, practitioners lack quantitative, repeatable metrics to assess tree vigor and stand health. We evaluated canopy and whole tree attributes of ponderosa pine (Pinus ponderosa Dougl. Ex Laws) related to carbon balance, water balance, and susceptibility to insects and pathogens in dry, pine-dominated forest stands during a multi-year drought, an environmental challenge to stand resilience. Metrics of trees in two unmanaged, and seven treated forested stands, in both uplands and lowlands to develop the quantitative approach. Whole tree and crown attributes including needle length and color, branchlet …

Effect Of Fire Suppression On Aquatic Invertebrates In Ephemeral Wetlands Embedded In Longleaf Pine Forests, Hailey E. Baker

Honors College Theses

It has been established for many years that longleaf pine forests require the ecological disturbance of fire in order to maintain a balanced ecosystem. However, a crucial part of these forests has become nearly excluded from prescribed burning. Ephemeral wetlands embedded within longleaf pine forests are a unique and dynamic seasonal habitat that provide homes, refuge, and breeding grounds for a large array of taxa. Past research suggests that fire suppression around ephemeral wetlands is causing harm to many species of amphibians and other herpetofauna, especially threatened species like the flatwoods salamander. However, other species have not been as well …

Modeling Species Distribution And Habitat Suitability Of American Ginseng (Panax Quinquefolius) In Virginia, Jacob D. J. Peters

Masters Theses, 2020-current

American ginseng (Panax quinquefolius) is a well-known and sought-after medicinal plant native to North America that is facing increased threat of extinction due to overharvesting, herbivory, and habitat loss. Species distribution and habitat suitability models may be valuable to landowners interested in sustainable harvest or to institutions interested in the conservation and restoration of the species. With unequal sampling efforts across a region of interest, it is likely that some locations with appropriate habitat may be misrepresented in model predictions. This study refined a state-derived species distribution model for ginseng through increased sampling effort across the Cumberland Plateau …

Shifting Public Perception: Climate Change Means Living With Fire And Smoke, Robert Froembling

Seattle Journal of Technology, Environmental & Innovation Law

The urgency to prepare for the climate crisis has never been greater. We are currently living in the sixth mass extinction and the effects are only going to accelerate. We will inherit more wildfires, larger wildfires, and more frequent wildfires.

This piece is not meant to stoke fear in its readers or be depressing, but to shift public perception on what our future holds by evaluating the laws and science presented to us. This piece will look at regional and federal regulations and assess the increased rate of forest fires and the grave public health concerns from stagnant smoke specifically …

A Comparative Ecological Study Of Limestone And Dolomite Glades In The Ozark Mountains Of Northwest Arkansas, Brittney Booth

Graduate Theses and Dissertations

Glades are one of the many habitats that exist in the Arkansas Ozarks and contribute to the overall biodiversity of the state of Arkansas. For this study, five dolomite glades and five limestone glades in the Ozarks of northwest Arkansas were studied from March to October in the years 2017 and 2018 to determine the similarities or differences that might be present. One hundred and fifteen vascular plant taxa were documented in the dolomite glades and one hundred and three vascular plant taxa were documented in the limestone glades. Forty-six vascular plant taxa were unique to the dolomite glades and …

A Comparative Taxonomic And Diversity Study Of Litter-Associated Fungi In Northwest Arkansas Forests, Rajaa Abdulrazzaq Abbas Al Aanbagi

Graduate Theses and Dissertations

Fungi are taxonomically the most species-rich group of organisms on the earth, ecologically occupy distinctive niches and interact with diverse other organisms throughout their biogeographic distributions and functionally play key roles through their various lifestyles. Plant litter, in particular, is a keystone component in ecosystems and provides heterogeneous microhabitats for the often overlooked litter-decomposing fungi and other organisms on the floor of temperate deciduous forests. Litter fungi involve indirect interactions with the plant, soil and whole food web network. However, the community structure and functions of litter-associated fungi as well as patterns of species richness distributed across various litter microhabitats …

Seed Dispersal Effectiveness In The Penobscot Experimental Forest, Gabrielle Link

Honors College

Previous studies have shown that scatter-hoarding small mammals increase seed germination success through the process of collecting and caching seeds throughout the forest. This study seeks to explore this further by examining how specific cache microsite preferences among these small mammals impacts the germination and growth of northern red oak (Quercus rubra). Seeds were planted in six different microsites across three forest treatments. Germination, seedling height, and herbivory were then monitored over time. We found that microsite did not have a significant effect on germination or height, however microsite did impact herbivory probability, and open microsites made seedlings more vulnerable …

A Floristic Survey Of Andalusia: A Historic Preservation Site In Baldwin County, Georgia, William Pharr

Biology Theses

A survey of the vascular plants of Andalusia, a historic preservation site located along Highway 441 north of Milledgeville in Baldwin County, Georgia, was conducted between August 2018 and February 2020. The site was the late home of esteemed author, Flannery O’Connor, and resides along the Georgia fall line, making it a historically significant area that could yield a unique plant community convergence, as well as rare endemic species. This floristic inventory provides baseline data on the species and plant communities of Andalusia for use in future studies regarding the flora of this area. A total of 191 vascular species …

Canopy Openness As A Predictor Of Growth For Castanea Dentata Seedlings In The Cumberland Uplands Of Tennessee, Hannah Crawford

Honors Theses

Castanea dentata growth and reproduction in the forest ecosystem is limited by light. Canopy gaps could be used for restoration efforts; however, the lack of blight resistant planting material has limited what is known about the silvicultural requirements of C. dentata. I studied the survival and growth of chestnut seedlings in various sized light gaps in the Cumberland Uplands in the 2019 season. The Tennessee Chapter of the American Chestnut Foundation previously established Eagle Point Railroad (Cumberland Plateau) and the Starr Farm (Eastern Highland Rim), and I established a site near Barker Pounds trailhead (Cumberland Plateau). Results indicate that canopy …

Correcting Tree-Ring Δ13c Time Series For Tree-Size Effects In Eight Temperate Tree Species, Matthew A. Vadeboncoeur, Katie A. Jennings, Andrew P. Ouimette, Heidi Asbjornsen

Earth Systems Research Center

Stable carbon isotope ratios (δ¹³C) in tree rings have been widely used to study changes in intrinsic water-use efficiency (iWUE), sometimes with limited consideration of how C-isotope discrimination is affected by tree height and canopy position. Our goals were to quantify the relationships between tree size or tree microenvironment and wood δ¹³C for eight functionally diverse temperate tree species in northern New England, and to better understand the physical and physiological mechanisms underlying these differences. We collected short increment cores in closed-canopy stands and analyzed δ¹³C in the most recent 5 years of growth. …

Seed Size And Germination, Meredith Cobb, Michaela J. Woods, Ryan W. Mcewan

Five Rivers MetroParks Collaboration Data Archive

This dataset encompasses information related to predictors of seed germination from the species Carya laciniosa, Juglans cinerea, and Quercus rubra. Seed sizes were recorded prior to incubation in sand, vermiculite, or without media. Seeds were then germinated with time to germination recorded in this dataset.

Chromosomal Distribution Of Genes Conferring Tolerance To Abiotic Stresses Versus That Of Genes Controlling Resistance To Biotic Stresses In Plants, Richard R.-C. Wang

Forage and Range Research Laboratory Publications

Tolerance to abiotic stresses caused by environmental conditions can prevent yield loss in crops for sustaining agricultural productivity [1]. Resistance to biotic stresses caused by diseases and insects can prevent or reduce yield loss in crops [2]. For each crop or plant species, there are many abiotic threats, such as changes in temperature, soil salinity/alkalinity, water shortage, and soil contaminants, as well as biotic challenges from pathogens (bacteria, viruses, and fungi), insects, and nematodes. Plants need to possess genes conferring tolerance to these abiotic stresses to adapt to the changing environment, due to global climate changes, in which they are …

Regional Forest Volume Estimation By Expanding Lidar Samples Using Multi-Sensor Satellite Data, Bo Xie, Chunxiang Cao, Min Xu, Barjeece Bashir, Ramesh P. Singh, Zhibin Huang, Xiaojuan Lin

Mathematics, Physics, and Computer Science Faculty Articles and Research

Accurate information regarding forest volume plays an important role in estimating afforestation, timber harvesting, and forest ecological services. Traditionally, operations on forest growing stock volume using field measurements are labor-intensive and time-consuming. Recently, remote sensing technology has emerged as a time-cost efficient method for forest inventory. In the present study, we have adopted three procedures, including samples expanding, feature selection, and results generation and evaluation. Extrapolating the samples from Light Detection and Ranging (LiDAR) scanning is the most important step in satisfying the requirement of sample size for nonparametric methods operation and result in accuracy improvement. Besides, mean decrease Gini …

Remote Sensing Monitoring Of Vegetation Dynamic Changes After Fire In The Greater Hinggan Mountain Area: The Algorithm And Application For Eliminating Phenological Impacts, Zhibin Huang, Chunxiang Cao, Wei Chen, Min Xu, Yongfeng Dang, Ramesh P. Singh, Barjeece Bashir, Bo Xie, Xiaojuan Lin

Mathematics, Physics, and Computer Science Faculty Articles and Research

Fires are frequent in boreal forests affecting forest areas. The detection of forest disturbances and the monitoring of forest restoration are critical for forest management. Vegetation phenology information in remote sensing images may interfere with the monitoring of vegetation restoration, but little research has been done on this issue. Remote sensing and the geographic information system (GIS) have emerged as important tools in providing valuable information about vegetation phenology. Based on the MODIS and Landsat time-series images acquired from 2000 to 2018, this study uses the spatio-temporal data fusion method to construct reflectance images of vegetation with a relatively consistent …

Using Dendrochronology To Create A Timescale Of Succession On Nurse Logs In The Olympic Temperate Rainforest, Sean Grealish

Summer Research

Previous work on the Olympic peninsula in Washington State has shown that recently fallen trees provide a germination location for seeds that cannot do so on the forest floor due to thick moss mats. My field work over two summers dating and surveying nurse logs yielded a crossover at ~70 years where ground mosses start to dominate over tree mosses and seedling abundance begins to decrease.

Does Masting Scale With Plant Size? High Reproductive Variability And Low Synchrony In Small And Unproductive Individuals, Michał Bogdziewicz, Jakub Szymkowiak, Rafael Calama, Elizabeth E. Crone, Josep M. Espelta, Peter Lesica, Shealyn Marino, Michael A. Steele, Brigitte Tenhumberg, Andrew Tyre, Magdalena Żywiec, Dave Kelly

Brigitte Tenhumberg Papers

Background and Aims In a range of plant species, the distribution of individual mean fecundity is skewed and dominated by a few highly fecund individuals. Larger plants produce greater seed crops, but the exact nature of the relationship between size and reproductive patterns is poorly understood. This is especially clear in plants that reproduce by exhibiting synchronized quasi-periodic variation in fruit production, a process called masting.

Methods We investigated covariation of plant size and fecundity with individual-plant-level masting patterns and seed predation in 12 mast-seeding species: Pinus pinea, Astragalus scaphoides, Sorbus aucuparia, Quercus ilex, Q. humilis …

Activity Level-Predation Risk Tradeoff In A Tadpole Guild: Implications For Community Organization Along The Hydroperiod Gradient, Nicholas C. Schiwitz, Christopher M. Schalk, Daniel Saenz

Faculty Publications

Increasing activity levels permit greater food intake for use towards growth and reproduction, consequently increasing predation risk via increased detection. Larval anurans are models to examine activity level-predation risk tradeoffs, as they occupy a variety of lentic habitats that impose constraints on the distribution and abundance of species. Ephemeral ponds have a low abundance and diversity of predators and as a result tadpole species tend to have high foraging rates for rapid development. Permanent ponds generally possess a greater diversity and abundance of predators and tadpoles inhabiting these locations tend to have low activity rates or chemical defenses to minimize …