Forest Sciences Commons^™

A Historical Floristic Inventory Of Pine Rockland Fabaceae (Leguminosae), Adel L. Pena

FIU Electronic Theses and Dissertations

The objectives of this study were to investigate temporal changes in the diversity of pine rockland Fabaceae, induced by anthropogenic factors. Herbarium collections spanning 170 years were used to analyze species frequency and richness. The results indicated temporal fluctuations in diversity with frequency of native species highest previous to the year 1920, and exotic-invasive species richness peaking after the 1960s. The accompanying species list resulting from the inventory included 122 Fabaceae species, in 56 genera, with an additional 19 species not previously listed for pine rocklands. The results emphasize the damage caused by early and deliberate introductions of exotic species, …

It’S Not About Wolves: Interdisciplinary Knowledge For A Sustainable, Just And Prosperous World, John A. Vucetich

Distinguished Lecture Series

Dr. John Vucetich presented the Fall 2017 Distinguished Lecture at the Michigan Tech Research Forum. His lecture, It’s Not About Wolves: Interdisciplinary Knowledge for a Sustainable, Just and Prosperous World, took place November 7, 2017. Vucetich discussed environmental ethics and how it bridges the world of environmental sciences and natural resource management.

"Much of my work is aimed at developing insights that emerge from the synthesis of science and ethics,” says Vucetich, a professor in the School of Forest Resources and Environmental Science (SFRES) at Michigan Technological University. "Environmental ethicists and environmental scientists have a common goal, which is to …

Prevalence Of Moniliophthora Roreri In Theobroma Cacao In Relation To Clone Variety, Community Composition, Environmental Factors In An Organic Cacao Farm In Charagre, Bocas Del Toro, Panamá: A Case Study, Kara Eckberg

Independent Study Project (ISP) Collection

Moniliophthora roreri, or Frosty Pod Rot (FPR) is a widespread pathogen that affects the fruit of Theobroma cacao, a tree commonly known as the cacao tree. Often, cultivators seek to control spread of M. roreri through fungicidal compounds. However, these fungicides place selective pressure for resistance on M. roreri. Additionally, they can have adverse environmental and human health effects and are difficult to integrate into practice for smallholders. Therefore organic farms in Bocas del Toro in western Panama, have turned to biocontrol agents to reduce the spread of M. roreri. These strategies include increasing hybrid variety, modifying community composition, altering …

Hummingbird Foraging Preference: The Hierarchical Impacts Of Color, Position, And Concentration On Visitation Frequency, Erin O'Connor

Independent Study Project (ISP) Collection

Hummingbirds are well adapted to efficiently locate high quality nectar sources, but relatively few studies have examined the mechanisms of that process under natural conditions in the field. This study investigates the visual signals that allow hummingbirds to do just that, as well as the external factors that limit their choices in foraging. More specifically, feeder color and nectar concentration were manipulated to determine the effect of those independent variables on visitation frequency. An initial experiment was conducted in order to explore color preference among the visiting species. Red, orange, and blue feeders were filled with nectar of equal concentrations …

Carbon Sequestration In The Cloud Forest: A Comparative Evaluation Of Aboveground Biomass Carbon Stock Potential In The Río Guajalito Reserve, Elli Mapstone

Independent Study Project (ISP) Collection

As carbon dioxide levels in the atmosphere continue to rise at a rapid rate, it is necessary to understand how forests can both contribute to CO₂ levels but also stop them from rising. Carbon sequestration levels in tropical montane cloud forests are a relatively understudied topic. Gathering carbon stock levels is the first step necessary to start a REDD+ project. Carbon stock levels can be studied on a global, regional or local level. This study used the University of Oxford/ Global Ecosystems Monitoring Network (GEM) methodology to examine carbon sequestration levels of aboveground biomass, specifically ground litter, large branches …

Elevated Temperature And Co2 Concentrations Affect Carbon Flux In Two Boreal Conifers, Sasha Madhavji

Electronic Thesis and Dissertation Repository

Elevated temperatures and CO₂ will alter carbon flux in two dominant boreal tree species Picea mariana (black spruce) and Larix laricina (tamarack). Trees were grown in three temperature treatments (ambient, ambient +4 °C, and ambient +8 °C) at either 400 ppm or 750 ppm CO₂, to simulate climate conditions between now and the year 2100. Spruce acclimated to increasing temperature detractively; warming scenarios reduced spruce net carbon gain. Tamarack maintained comparable levels of net photosynthesis (A_net) across warming treatments and both species acclimated respiration (R_dark) with increasing growth temperature. Elevated CO₂-grown …

Walking As Ontological Shifter: Thoughts In The Key Of Life, Bibi (Silvina) Calderaro

Dissertations, Theses, and Capstone Projects

With walking as ontological shifter I pursue an alternative to the dominant modernist episteme that offers either/or onto-epistemologies of opposition and their reifying engagements. I propose this type of walking is an intentional turning towards a set of radical positions that, as integrative aesthetic and therapeutic practice, brings multiplicity and synchronicity to experience and being in an expanded sociality. This practice facilitates the conditions of possibility for recurring points of contact between the interiority perceived as ‘body’ and the exteriority perceived as ‘world.’ While making evident the self’s at once incoherence with it-self, it opens to a space beyond the …

Tropical Cyclones Disrupt The Relationship Between Tree Height And Species Diversity: Comment, Teng-Chiu Lin, Lixin Wang, Chengyang Zheng, Ryan W. Mcewan, Chung-Te Chang, Jyh-Min Chiang, Chung-Hao Chi

Biology Faculty Publications

In a recent report on the patterns of tree species richness in eastern and western North America, Marks et al. (2016) claimed to have identified an operational indicator of environmental harshness (maximum tree height) and concluded that environmental stressors that limit tree height also act as ecological filters on species richness. Marks et al. (2017) attributed the positive association between species richness and maximum tree height to both the direct effects of environmental harshness on species richness and the indirect effects of environmental harshness on species richness as mediated by maximum tree height.

This finding overlooked the fact that many …

Examination Of Human Impacts On The Biodiversity And Ecology Of Lichen And Moss Communities, Hannah Marie Prather

Dissertations and Theses

Globally, more than half of the world's population is living in urban areas and it is well accepted that human activities (e.g. climate warming, pollution, landscape homogenization) pose a multitude of threats to ecosystems. Largely, human-related impacts on biodiversity will hold consequences for larger ecological processes and research looking into human impacts on sensitive epiphytic lichen and moss communities is an emerging area of research. While seemingly small, lichen and moss communities exist on nearly every terrestrial ecosystem on Earth and contribute to whole-system processes (e.g. hydrology, mineral cycling, food web energetics) worldwide. To further examine human impacts on epiphytic …

Tree Damage From Hurricane Matthew Affecting Forest Dynamics In Congaree National Forest, Connor Lentz

Senior Theses

The Congaree National Forest serves as an ecological model for bottomland-hardwood forests. Hurricanes periodically strike the Southeast United States, with high-wind speeds causing damage affecting the Congaree National Forest and modifying forest dynamics. This has been well-studied from the effects of Hurricane Hugo in September 1989 (Sharitz et al. 1993). In October 2016, Hurricane Matthew, a category 5 storm, made landfall in the Southeastern United States, and eventually moved through the Congaree National Forest. The high winds and precipitation caused widespread tree damage throughout Congaree. This study used a belt-transect survey of 14.7km of trails throughout the park to record …

Variation In Density Dependent Seedling Survival Across Forests Of Different Successional Age And Hunting Protection Status, Nohemi Huanca-Nunez

School of Biological Sciences: Dissertations, Theses, and Student Research

Over 50% of the original extent of tropical forests has been cleared. Restoration of secondary forests is important for maintaining the ecosystem services that mature tropical forests provide. Density dependence (DD) is thought to be a major mechanism for shaping forest community structure and may cause reduced spatial aggregation among individuals of the same species, allowing for maintenance of diversity. While much research has focused on DD in mature tropical forests, few studies have examined how DD may influence community structure in secondary forests, many of which are also exposed to hunting. There are several important agents of negative and …

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …

Monitoring Anuran Populations In Bosque Protector Candelaria: A Multi-Year Comparison Of Frog Populations In An Ecuadorian Cloud Forest, Mindee Goodrum

Independent Study Project (ISP) Collection

For many years, amphibian populations around the world have been declining due to climate change, habitat loss or change, and diseases such as Ranavirus or the Chytrid fungus. However, there is still a great lack of information regarding the diversity of frogs, especially in the cloud forests of Ecuador where this study was conducted. This study was conducted in April and May of 2017 in the Ecominga Reserve of Cerro Candelaria in El Placer, Ecuador. The objective was to conduct visual-encounter surveys of several sites in the reserve and compare the results to studies that have been conducted in the …

Factors Influencing Impact Of Biological Control Agents Of The Emerald Ash Borer, Theresa Murphy

Masters Theses

Agrilus planipennis, the emerald ash borer (EAB), is a destructive invasive forest pest decimating North American ash trees. Population-wide management of EAB focuses on biological control, with the introduction of four parasitic wasps; one egg parasitoid, Oobius agrili and three larval parasitoids- Spathius galinae, Spathius agrili and Tetrastichus planipennisi. This thesis examines some of the factors influencing the establishment of these larval biocontrol agents. Chapter 1 examines the relationship between woodpeckers and the parasitoids S. agrili and T. planipennisi. Both woodpeckers and these parasitoids attack the larval stage of EAB, which means their impacts overlap and …

Occam's Razor Vol. 7 - Full (2017)

Occam's Razor

No abstract provided.

Effectiveness Of Chemical Defense In A Tropical Millipede Species On A Potential Predator, The Tarantula Megaphobema Mesomelas, Maya L. Klem

Occam's Razor

Millipedes are known to have a variety of physical and chemical defenses to deter predators. Some species of tropical millipedes have considerably reduced primary defenses when compared to other tropical millipedes, but do retain chemical defense mechanisms. This study uses the tarantula Megaphobema mesomelas to test the effectiveness of a secondary defense mechanism, cyanide and benzaldehyde, from a species lacking a robust primary defense. Five tarantulas were found and collected around Monteverde, Costa Rica and brought into the Monteverde Biological Station. They were housed in tanks to allow for controlled feeding trials. Two treatment groups were created: millipedes with cyanide …

The Influence Of Native Woody Species, Combretum Glutinosum And Piliostigma Reticulatum, On Soil Fertility In Dialacoto, Senegal, Gwen Jacobson

Dissertations, Master's Theses and Master's Reports

In the low-fertility soils of Senegal, West Africa, management of woody species in agricultural fields has the potential to improve soil fertility and crop production. However, optimal species for this purpose have not been clearly defined. Thus, the objective of this study was to evaluate the potential for two native woody species, Combretum glutinosum and Piliostigma reticulatum, to improve soil fertility. Soil samples were collected from beneath tree crowns of P. reticulatum and C. glutinosum and compared with fertilizer-amended and non-amended soil from adjacent open fields in a bioassay experiment. Two common crops, millet (Pennisetum glaucum) and maize (Zea mays), …

Toward An Improved Conceptual Understanding Of North American Tree Species Distributions, Paige E. Copenhaver-Parry

Faculty Publications - Department of Biological & Molecular Science

Species distributions have often been assumed to represent climatic limitations, yet recent evidence has challenged these assumptions and emphasized the potential importance of biotic interactions, dispersal limitation, and disturbance. Despite significant investigation into these factors, an integrated understanding of where and when they may be important is lacking. Here, we review evidence for the factors underlying the historical and contemporary distributions of North American tree species and argue that a cohesive conceptual framework must be informed by an understanding of species ecological and evolutionary history. We further demonstrate that available evidence offers little indication of a significant, independent influence of …

An Analysis Of White-Tailed Deer, Odocoileus Virginianus, Killed In Deer Vehicle Accidents On Bulloch County, Ga Roadways, Mackenzie P. Payne 4003933

Honors College Theses

White-tailed deer, Odocoileus virginianus, are native to Georgia. With over 1.2 million individuals in the state, White-tailed deer have been implicated in a large number of motor vehicle collisions (ca. 1 million) each year. It is unknown, however, if deer are more likely to be killed: 1) if they are of particular ages (or classes), and 2) in areas with specific road characteristics. We addressed these two questions by collecting the remains of 20 White-tailed deer killed in deer vehicle collisions (“deer vehicle accidents” - DVAs) in Bulloch County, GA. When a deer was located, the road characteristics were …

Modeling The Spread Of Sudden Oak Death Across A Heterogeneous Landscape In Redwood National Park Using A Spatially-Explicit Epidemiological Model, Laura A. Morgan

Cal Poly Humboldt theses and projects

The pathogen Phytophthora ramorum, the causal agent of Sudden Oak Death (SOD), is responsible for the deaths of millions of oak (Quercus spp.) and tanoak (Notholithocarpus densiflorus) trees in California and Oregon (USA). A recent infection in Redwood National Park (RNP) in California (USA) provided an opportunity to adapt an existing SOD model to assess the efficacy of current and proposed management strategies. A common method of SOD treatment includes killing both infected and uninfected hosts in the area of infection, as well as the area surrounding the infection to create buffers to account for undetected …

In The Face Of Drought: Do Fuel Treatments Promote Resistance To Multi-Year Drought In A Mixed-Conifer Forest Of Northern California?, Michael Vernon

Cal Poly Humboldt theses and projects

Climate change is predicted to increase the frequency, duration, and severity of drought events across many bioregions. Forest managers have two active management techniques to promote resistance and resilience to drought: prescribed fire and mechanical thinning. Generally applied to reduce fuels and fire hazard, treated areas may also reduce competition for resources that may improve tree-growth during drought and reduce mortality. The recent severe and prolonged drought in California allowed me to investigate the effects of climate stress and fuel treatments on tree growth responses in a dry mixed-conifer forest ecosystem.

To assess tree-growth responses to fuel treatments during severe …

Molecular Diversity Of Foliar Fungal Endophytes In Relation To Defense Strategies And Disease In Whitebark Pine, Lorinda Bullington

Graduate Student Theses, Dissertations, & Professional Papers

An invasive fungal pathogen, Cronartium ribicola (the causative agent of white pine blister rust) infects and kills whitebark pine (Pinus albicaulis) throughout the western US. Blister rust has decreased whitebark pine populations by over 90% in some areas. Whitebark pine, a keystone species, has been proposed for listing under the Endangered Species Act in the U.S., and the loss of this conifer is predicted to have severe impacts on forest composition and function in high elevations. Hundreds of asymptomatic fungal species live inside whitebark pine tissue, and recent studies suggest that these fungi can influence the frequency and …