Life Sciences Commons^™

Quantitative Silviculture Of Northern Conifers, David G. Ray

Electronic Theses and Dissertations

Quantitative tools used to guide the management of important northern conifer species require updating and refinement to address changes in the contemporary resource and evolving objectives of ownership. This work builds on an extensive body of knowledge about stand density management and innovates some new approaches. In sum, the three chapters presented herein: 1) seek to strengthen and more fully articulate arguments for adopting relative density as a primary metric of stand density assessment, 2) quantify minimum stand densities to achieve full site occupancy and argue for more parity with treatment of maximum stand density, and 3) present an empirically …

Effects Of Prescribed Fire Regimes On White-Tailed Deer (Odocoileus Virginianus) Browse, Forage, And Nutrient Availability In The Pineywoods Ecoregion Of Texas, Wyatt L. Bagwell

Electronic Theses and Dissertations

Fire is a management tool for white-tailed deer (Odocoileus virginianus) habitat, influencing browse availability, herbaceous production, and nutrient content. In 2020 and 2021, this study utilized 46 plots across East Texas to assess these habitat components. A stem count index survey method was used to assess browse utilization prior to April in both years, and preferred browse species were clipped and analyzed for nutrient availability, and herbaceous production was also measured. Additionally, white-tailed deer population data, browse survey data, and recent fire history were obtained from five different wildlife management areas to examine their relationship. Deer had preferences …

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 …

Laguncularia Racemosa Top-Layer Sediment Microorganism Makeup In Relation To Differing Levels Of Perceived Anthropogenic Impact In Bocas Del Drago, Bocas Del Toro, Panama, Gabrielle Glendening

Independent Study Project (ISP) Collection

As mangrove forests are destroyed by human factors across the earth, many crucial ecological processes that take place in these systems of trees are obstructed. One of the most important roles played by mangroves is their ability to sequester carbon in the sediment, as this storage of carbon helps diminish atmospheric warming. Many sediment microorganisms help in this process of carbon sequestration and play various other vital roles in mangrove ecosystems. Microorganisms in marine sediments can be used to assess the health of the surrounding environment. Past research has found significant differences in sediment microorganism composition, abundance, and diversity in …

Observational Study Of Woolly Monkey Behavior And Vocalizations: Behavioral Time Allotment And Vocalization Habits Of A Small Population Of Poeppig’S Woolly Monkey (Lagothrix Lagotricha Poeppigii) In The Ecuadorian Amazon, Marina Smith-Hanke

Independent Study Project (ISP) Collection

Poeppig’s woolly monkey (Lagothrix lagotricha poeppigii), a species of primate native to the Amazonian regions of western Brazil, eastern Ecuador, and northeastern Peru, is classified as endangered by the IUCN. These large, frugivorous primates are threatened by habitat loss and climate change as a result of human interference. Deforestation, hunting, petroleum mining, and illegal trafficking are all huge threats to this species. As a result of these pressures, their populations have decreased by at least 30% over the past three generations. However, as keystone seed dispersers, they are essential for Amazonian ecosystem health; without their seed dispersal services, a loss …

Afforestation And Biodiversity: Bryophyte Richness Changes Between Icelandic Forest Types, Kian Mcdonough

Independent Study Project (ISP) Collection

Forest-dwelling bryophytes (mosses, liverworts, hornworts) greatly contribute to biodiversity and ecosystem function but are largely under-studied in comparison to vascular plants. With Iceland’s large-scale afforestation efforts there is a need to understand how different afforestation species are affecting biodiversity, including bryophyte diversity. This study looked at differences in ground-floor bryophyte richness across Sitka spruce, lodgepole pine, and downy birch forests and found that bryophyte richness was highest in the Sitka spruce forests and lowest in downy birch forests. While this suggests a negative correlation between bryophyte richness and light availability, since the conifer species have the densest copy cover, other …

The Role Of Frugivorous Birds As Seed Dispersers: Feeding Selection And Preference Of Madagascar’S Avian Frugivores In Analamazaotra Forest, Thaddeus Bashaw

Independent Study Project (ISP) Collection

Madagascar is a country rich in floral and faunal diversity. However, anthropogenic habitat destruction and climate change increasingly threaten its biodiversity. Endozoochorous plants that dependent on frugivory for seed dispersal are under threat due to increasing rates of localized extinctions of frugivorous lemurs, the primary seed dispersers of the island. While lemurs are the islands most abundant frugivores, other frugivorous vertebrates like birds and bats likely play a significant role in seed dispersal, although this role is still poorly understood. This study, conducted in Analamazaotra forest, compares the rates of visitation and consumption of six endemic fruiting tree species by …

The Specific Richness Of Forest Cockroach Communities In The Region Of Aflou (Laghouat; Algeria), Fatiha Masna, Siham Bounadji, Saliha Benhissen, Zakaria Hedjouli, Abdelmadjid Yagoub Asloum, Sarra Habbachi, Waffa Habbachi

Journal of Bioresource Management

Forest cockroaches are among the insects that play an important and effective role in forest formations, they are insects with incomplete metamorphosis belonging to the order of Blattodea. This work is a contribution to the knowledge of Blattoptera species existing in the forest environments of Aflou’s region (Laghouat; Algeria).The inventory was carried out monthly in the El-Khnegue Forest (Aflou) from February 2019 to May 2019. It revealed the presence of six species of forest Cockroaches, which belongs to 4 genera of the Blattelidae family. After identification, it was demonstrated that, these species were: Dziriblatta nigriventris (Chopard, 1936), Dziriblatta stenoptera (Chopard, …

The Effects Of Drought And Shade On Bottomland Hardwood Regeneration, Charles Joseph Pell

LSU Doctoral Dissertations

Floodplain forests support a high diversity of tree species adapted to regenerate under fluctuating water and light availability. Regeneration regulates species composition, and shade and flood tolerance influence the likelihood of regeneration. Regeneration failure of shade-intolerant and flood-tolerant tree species commonly occurs in southcentral and southeastern floodplain forests of the United States, also known as bottomland hardwoods (BLHs). In many BLHs reduced flooding has resulted in a dryer floodplain. These changes in flooding are linked to recent shifts in species composition. The mechanisms controlling regeneration in BLHs and these composition shifts are poorly understood. In a controlled germination experiment, I …

Flora Of Doe Mountain Recreation Area, Johnson County, Tennessee, Benjamin Mccullough

Electronic Theses and Dissertations

A botanical inventory of Doe Mountain Recreation Area (DMRA) in northeastern Tennessee was conducted to help guide conservation-based management. A total of 484 species were found in DMRA, comprising 94 families, and 285 genera, 10 species listed in the state rare plant list, and 76 exotic species. Two species, Liatris virgata and Lycopodiella inundata, were new state records. Water in the Lycopodiella seep was an order of magnitude more acid than at other sites. An analysis of the wildland-urban interface showed that only 13% of the area was classified as uninhabited. The inventory-invasion index, introduced to quantify the relative …

Evaluating The Functional Traits Of The Pioneering Species: Insights To Forest Restoration, Rovana Mansul Jawani, Nomar Ali Ramoncito, Gretchen Quimson

Journal of Environmental Science and Sustainable Development

The influence of plant traits on interspecific demographic rates to growth and mortality has recently received an increasing attention because it allows understanding of the underlying determinants of species success especially in open degraded areas. This study examined the trait-based approach in selecting potential species for forest restoration. Five (5) native/indigenous pioneer species were evaluated for functional traits such as plant height, branching architecture, leaf dry matter content, specific leaf area, stem density, and bark thickness. All samples were collected from healthy and well grown mature trees growing in secondary forest of Central Mindanao University. The range of values for …

Soil Quality Indicators And Vegetation Responses Following Ecological Restoration Thinning Of Ponderosa Pine On Three Soil Parent Material Types Under Grazing And Non-Grazing In Northern Arizona, Christopher Macdonald

Electronic Theses and Dissertations

This research was performed in a northern Arizona ponderosa pine (Pinus ponderosa P. & C., Lawson) forest. The objectives were to a) increase understanding of long-term vegetation responses to ecological restoration treatments on three soils types, with and without grazing, b) evaluate the responses soil physical, chemical, and biological properties to restoration treatments, with and without grazing, c) determine the utility of measured soil quality indicators to informing risks to sustainable soils management in southwestern ponderosa pine forests.

There were no significant differences in soil bulk density by soil type, treatment type, or grazing treatment. No significant differences …

Contribución A La Conservación De La Orquídea Rodriguezia Granadensis (Lindl.) Rchb.F. En La Hacienda Betania (Fusagasugá, Colombia), Arlette Ivonne Gil Clavijo, Jenny Paola Moreno Lopez, Laguandio Del Cristo Banda Sánchez

Ciencias Agropecuarias

Esta cartilla, creada por el Grupo de Investigación PROSAFIS de la Universidad de Cundinamarca, presenta los resultados del proyecto Aproximación a la ecología de orquídeas nativas en el ecosistema hacienda Betania con proyección a su conservación, manejo y producción. Se destaca la orquídea Rodriguezia granadensis, adaptada a forofitos (phorophytes) de cítricos y guayabos, representando el 83,3 % de los individuos observados. Predominó la fase vegetativa (fenología) durante todo el período, con más floración y cápsulas en épocas lluviosas, sincronizando su fase reproductiva con el régimen de lluvias. En las raíces se encontró el hongo endófito (endophyte) Rhizoctonia en …

Responses Of Nutrient Resorption To Human Disturbances In Phoebe Bournei Forests, Dehuang Zhu, Suhong Peng, Jinyan Wang, Dafeng Hui

Biology Faculty Research

Nutrient resorption plays an important role in the nutrient conservation of plants and ecosystem nutrient cycling. Although community succession and nutrient addition could regulate plant nutrient resorption, how resorptions of foliar nutrients vary with human disturbances remains unclear. With the economic development, Phoebe bournei forests (PF) have suffered varying degrees of human disturbances in China. In this study, the leaf nutrient resorption efficiency (RE) of the PF under two disturbances (i.e., severe and mild disturbances) were investigated. Results showed that the phosphorus (P) contents of green leaf, senesced leaf, and soil were low under both disturbances, reflecting that the PF …

Diversity-Productivity Relationships In Forests Of The Southeastern United States: Leveraging National Inventory Data And Tree Functional Traits, Elizabeth Baach

Theses and Dissertations

Numerous studies have evaluated the relationship between biodiversity and productivity, with general trends suggesting a positive relationship. While most studies only use species richness, this study also analyzed how productivity changes with functional diversity and Shannon’s diversity index. Functional diversity gives important context to the examination of biodiversity-productivity relationships due to the direct link between organisms’ functional traits and their role in a given ecosystem. This study used data from the USDA Forest Service Forest Inventory and Analysis (FIA) database collected in Alabama, Louisiana, and Mississippi to estimate plot-level productivity and diversity. Structural equation modeling was used to determine the …

Climate Sensitive Diameter Growth Models For Major Tree Species In Mississippi, Sujan Subedi

Theses and Dissertations

Anticipated climate change and increasing wood demand require dependable diameter growth models for adaptive forest management. We used a mixed-effects modeling approach with Forest Inventory and Analysis (FIA) data to fit diameter growth models for loblolly pine, other softwood species (slash pine, shortleaf pine, and longleaf pine), sweetgum, and other hardwood (southern red oak, red maple, and water oak) species. Climatic variables coupled with individual tree attributes and competition factors improved climate insensitive models. Growth of loblolly pine and sweetgum was positively correlated with mean temperature of the coldest month. Mean temperature of the warmest month negatively influenced diameter growth …

Just Cut It Out, Jack Barbosa, Ashley Curcio, Emiliana Martinez-Nobrega, Matthew Robledo

Student Work

Why should we care about trees? Social, Economic, and Environmental benefits.

Restoration Through Reassembly: Evaluating The Role Of Native Plants In Combatting Chinese Tallow, Olaniyi Ajala

Electronic Theses and Dissertations

Non-native, invasive species disrupt ecological processes and functions, posing a serious threat to natural ecosystems. By examining the growth metrics of the non-native, invasive tree, Chinese tallow (Triadica sebifera [L.] Roxb.), hereafter tallow, across different flooding and light regimes, I investigated how restructuring native communities with valuable native species will prevent the reestablishment of tallow. I studied the changes in morphological and physiological traits of tallow when growing with water tupelo (Nyssa aquatica L.), sugarberry (Celtis occidentalis L.), and green ash (Fraxinus pennsylvanica Marshall). I found that in the non-flooded and high irradiance treatments, tallow's growth …

Climatic Influences On Summer Use Of Winter Precipitation By Trees, Gregory R. Goldsmith, Scott T. Allen, Sabine Braun, Rolf T. W. Siegwolf, James W. Kirchner

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Trees in seasonal climates may use water originating from both winter and summer precipitation. However, the seasonal origins of water used by trees have not been systematically studied. We used stable isotopes of water to compare the seasonal origins of water found in three common tree species across 24 Swiss forest sites sampled in two different years. Water from winter precipitation was observed in trees at most sites, even at the peak of summer, although the relative representation of seasonal sources differed by species. However, the representation of winter precipitation in trees decreased with site mean annual precipitation in both …

Species Diversity And Growth Rates Of Overstory Vegetation Over 25 Years In Response To Physical And Chemical Properties In Long-Term Monitoring Plots At The University Of Mississippi Field Station, Mitchell Tharp

Honors Theses

Overstory vegetation for twenty-two long-term monitoring plots (LTMPs) was sampled from 1996 to 2021 to study the changes in vegetation due to natural and human disturbance. From the fall of 2020 through the fall of 2021, the overstory of the 22 LTMPs was resampled and soil samples were collected from each plot. The circumference at breast height (CBH) and species diversity were recorded and compared to previous years’ data. The objectives of this study were to: (1) document changes in the overstory species of the LTMPs, (2) measure growth rates of surviving trees, (3) survey how elevation and slope impact …

Plant Community Responses To Interactive Anthropogenic Disturbances Along A Natural-Wildland-Urban Gradient And Undergraduate Students’ Attitudes Toward Disturbances, Mali M. Hubert

Doctoral Dissertations

Anthropogenic disturbances are defined as any change caused by human activity that alters biodiversity. Wildfire and urbanization disturbances are among the most influential on the landscape because of their individual and interactive properties. Areas deemed wildland-urban interfaces (WUI; area where environment intermingles with human-built structures) are increasing near protected lands because of human population growth and movement, which often facilitates fire ignitions by humans. Houses that are adjacent to or overlap with wildland vegetation can complicate protection of urban development and wildlands from fires. The expansion of the WUI due to population growth will exacerbate fire risk, which can ultimately …

Assessing The Long-Term Effects Of Natural Disturbance-Based Silvicultural On The Avian Assemblage At The Acadian Forest Ecosystem Research Program, Carl Pohlman

Electronic Theses and Dissertations

Active forest management alters the resources available to forest-obligate species. Large-scale intensive management practices where timber production is the primary objective can lead to notable ecological changes in forest ecosystems. A key concept of ecological forestry is to design forest management activities to emulate natural disturbance regimes as a way to maintain the ecological integrity of forests. The Acadian Forest Ecosystem Research Program (AFERP) was undertaken as an experimental demonstration of management reflective of the region’s disturbance regime, which typically produces small canopy gaps. AFERP includes nine research areas assigned to three silvicultural treatments: unharvested control, small gap (expanding-group selection …

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 …

Effects Of Prescribed Fire Seasonality On Forest Structure And Bird Populations In The Southern Appalachians, Allison Melcher

All Theses

Decades of fire suppression have contributed to the loss of historical ecosystems and to the decline of wildlife populations throughout the Southern Appalachian region. Recognizing the importance of fire in enhancing habitat and wildlife diversity, forest managers in recent years have begun implementing fire as a management tool to recover traditional disturbance regimes. Most of these burns take place during the dormant season, but some research has indicated dormant season burns are not effective in restoring ecosystem heterogeneity, and there has been a push to expand the use of fire into the growing season. However, much is still unknown about …

Chronic Wasting Disease In Deer And Elk Herds In Arkansas, Baker Kendrick

Scholars Day Conference

This presentation gives a broad introduction to Chronic Wasting Disease. It goes over what the disease is and its history, symptoms, how it works on a molecular level, effects on the hunting industry, host range, management and regulation, transmission, treatment, and research.

Landscapes Are Cornerstones Of Sustainability Programs, Don Spence

Sustainability Conference

Typical American landscapes are not sustainable in an economic or biological framework. The essence of the idea of sustainable growth and development are centered on the idea that those activities are not degrading natural resources or that they are outstrip budgets. A significant piece of any sustainable management plan is tied to how we manage our landscapes, how we use plants; specifically, how much grass there is, and how many native plants there are. Sustainable landscapes should require less chemical and financial inputs, which in the end, saves money and increases the biological value of the land and creates a …

A Quantitative Study Of Orchids And Their Proximate Environments Over An Elevational Gradient On The Northern Slope Of Montagne D’Ambre, Hazel Schrader

Independent Study Project (ISP) Collection

This research investigated change in orchid populations and their proximate environments on the Northern slope of Montagne d’Ambre, a subhumid forest in Northern Madagascar. Orchid density, way of life (epiphyte or terrestrial), phenology, and associations were recorded over 100m elevation gradients and between forest types (primary, secondary, dry, and humid forests at the same altitude). Additionally, orchid preferences for certain heights in the forest and DBH of host trees were analyzed. The establishment of 50X20m plots in 100m elevation gradients combined with ground survey yielded significant results demonstrating change along with elevation as well as forest types. Orchid density increased …

Occurrence And Ecosystem Effects Of Hiking Off-Trail In Michaux State Forest, Diana Biesecker, Quinn Doherty, Kevin S. Ganjon

Student Publications

American public lands provide significant outdoor recreational opportunities that enhance an individual's physical and mental well-being. Hiking is an example of a highly accessible and affordable recreational activity that is popular and easy for people to engage in no matter how experienced they are. While hiking has improved the well-being of many individuals, its impacts on local ecosystems are often disregarded. For our research, we focused on the impacts that hikers deviating off-trail may have on a local ecosystem in Michaux State Forest in Southern Pennsylvania. Through partnering with the foresters at Michaux State Forest and using AllTrails data, we …

Comparing Amphibian Species Diversity And Abundance In Natural Forest And Cacao Agroforest At Finca La Magnita, Changuinola, Bocas Del Toro, Panamá Lake Barrett, Lake Barrett

Independent Study Project (ISP) Collection

Amphibians are currently undergoing rapid and drastic biodiversity loss worldwide, largely due to the disease Chytridiomycosis. Because of this, efforts to conserve amphibian biodiversity are urgent and have been given increasing importance. However, studies investigating the effectiveness of agroforestry systems, a commonly used agricultural method in which trees and other elements of forests are retained on land used for agriculture, for amphibian conservation are uncommon. As a result, the capacity of agroforests to serve as a tool for amphibian conservation is unclear. To determine if agroforests can serve as a habitat for amphibians and a tool for their conservation, this …

From River To Ridge: The Influence Of Elevation And Habitat On Herpetofauna Species Abundance And Diversity In The Llanganates-Sangay Ecological Corridor, Ecuador, Elle Hankin

Independent Study Project (ISP) Collection

Ecuador is one of the most reptile-diverse countries and is home to the highest abundance of amphibians per unit area, with new species being discovered frequently. The Río Pastaza basin is located to the east of the Andes and is characterized by a steep elevational gradient, converging tropical forest types, and high levels of biodiversity and endemicity. Visual surveying was conducted at night for a total of 48 hours in four different study sites to investigate the influence of elevation and habitat on herpetofauna diversity and abundance. Two comparisons were drawn between the four study sites, grouping SKIS and Waska …