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Increasing Liana Abundance And Basal Area In A Tropical Forest: The Contribution Of Long‐Distance Clonal Colonization, Suzanne R. Yorke, Stefan A. Schnitzer, Joseph Mascaro, Susan G. Letcher, Walter P. Carson

Biological Sciences Faculty Research and Publications

Recent evidence suggests that liana abundance and biomass are increasing in Neotropical forests, representing a major structural change to tropical ecosystems. Explanations for these increases, however, remain largely untested. Over an 8‐yr period (1999–2007), we censused lianas in nine, 24 × 36 m permanent plots in old‐growth and selectively logged forest at La Selva Biological Station, Costa Rica to test whether: (1) liana abundance and basal area are increasing in this forest; (2) the increase is being driven by increased recruitment, decreased mortality, or both; and (3) long‐distance clonal colonization explains the increase in liana abundance and basal area. We …

Ecology And Flock-Following Behavior Of The Wedge-Billed Woodcreeper In Eastern Ecuador, Abigail Darrah

Graduate Theses and Dissertations

The wedge-billed woodcreeper (Glyphorynchus spirurus) is a common understory suboscine passerine of lowland Neotropical rainforests. It frequently joins mixed-species understory flocks but also regularly forages alone, and thus is an excellent model species on which to conduct comparative behavioral observations to examine the hypothesized costs and benefits of flock-following. Individuals exhibit variable flocking propensities (proportion of time spent with flocks), and thus observing the correlations between flocking propensity and physical and environmental factors can provide further insight into the importance of flock-following to the ecology of this species. Despite its abundance at many sites and its wide geographic range, surprisingly …

The Effectiveness Of Internet And Instant Messaging Approaches In Promoting Intention To Breastfeed, Brigett Landry Scott

Dissertations

Breastfeeding rates for the southern portion of the United States are low compared to the rest of the country. This study sought to determine the effectiveness of electronic delivery of breastfeeding education compared to written education in regards to intention to breastfeed in a convenience sample of pregnant women in coastal Louisiana and Mississippi. The final sample included 147 women randomized into one of three groups to complete the six week education intervention study. Questionnaires measuring demographics, Need for Cognition Scale (NFC), the Iowa Infant Feeding Attitude Scale (IIFAS), and the IFI Feeding Intentions Assessment were utilized. MANCOVA was used …

Warm Springs, Early Lay Dates, And Double Brooding In A North American Migratory Songbird, The Black-Throated Blue Warbler, Andrea K. Townsend, T. Scott Sillett, Nina K. Lany, Sara A. Kaiser, Nicholas L. Rodenhouse, Michael S. Webster, Richard T. Holmes

Dartmouth Scholarship

Numerous studies have correlated the advancement of lay date in birds with warming climate trends, yet the fitness effects associated with this phenological response have been examined in only a small number of species. Most of these species–primarily insectivorous cavity nesters in Europe–exhibit fitness declines associated with increasing asynchrony with prey. Here, we use 25 years of demographic data, collected from 1986 to 2010, to examine the effects of spring temperature on breeding initiation date, double brooding, and annual fecundity in a Nearctic - Neotropical migratory songbird, the black-throated blue warbler (Setophaga caerulescens). Data were collected from birds breeding at …

Friends Or Foes: Interpreting The Relationship Between Two Synoptic Small Mammals In Southeastern Virginia, The Hispid Cotton Rat (Sigmodon Hispidus) And Eastern Harvest Mouse (Reithrodontomys Humulis), Sarah A. Crawford

Biological Sciences Theses & Dissertations

Relatively little is known about the relationship between the hispid cotton rat (Sigmodon hispidus) and the eastern harvest mouse (Reithrodontomys humulis). Literature on these two syntopic genera in other areas of the United States suggests that competition may exist; however, both species seem to be greatly affected by environmental changes, making it difficult to draw any definite conclusions. Live trapping and microhabitat data collected from 2 old fields in Chesapeake, Virginia over a 9-year period were used to assess the biotic and abiotic influences on space use by these two species. Each I-ha plot consisted of 2 live traps placed …

An Experimental Investigation Of Nest Reuse And Nest Site Selection In An Open-Cup Nesting Passerine, Sarah A. Cancellieri

Dissertations and Theses

Eastern Kingbirds (Tyrannus tyrannus) breed from coast to coast in North America and build open-cup nests in trees. They have been extensively studied across most of their range and have only on occasion been documented to reuse a nest from a previous season. However, at Malheur National Wildlife Refuge (MNWR), located in southeastern Oregon, ~10 % of female Eastern Kingbirds reuse old nests of mainly American Robins (Turdus migratorius). In an attempt to address why nest reuse is so common at MNWR, I used artificial nests to evaluate two hypotheses as to why nest reuse is common in this breeding …

Prolonged Dormancy Interacts With Senescence For Two Perennial Herbs, Juha Tuomi, Elizabeth E. Crone, Jennifer R. Gremer, Anne Jakalaniemi, Peter Lesica, Bard Pedersen, Satu Ramula

Biological Sciences Faculty Publications

1. Senescence is characterized by a decline in survival, fecundity and reproductive value with age among adult individuals. Simple age-dependent life cycles progress forward through developmental stages, with each successive stage being characterized by age-specific vital rates. In contrast, size- or stage-based life cycles for perennial plants are more complex and often include stasis and retrogression to previous vegetative or reproductive life stages, indicating possible slowing or even reversing the developmental progress.

2. Many plants remain in nonemergent, below-ground stages during the growing season (prolonged dormancy), which may affect the process of senescence. Stasis in the dormant stage implies that …

The Value And Propriety Of Reintroduction As A Conservation Tool For Rare Plants, Edward O. Guerrant Jr.

Environmental Science and Management Faculty Publications and Presentations

Three recent reviews of reintroduction for conservation purposes, which draw on substantial and largely non-overlapping data sets, have come to strikingly different conclusions about its value. One concludes that “reintroduction is generally unlikely to be a successful conservation strategy as currently conducted.” Another that “…this review cannot conclusively comment on the effectiveness of re-introductions…” The third concludes there is “strong evidence in support of the notion that reintroduction, especially in combination with ex situ conservation, is a tool that can go a long way toward meeting the needs it was intended to address.” The argument over the conservation value of …

Greater Sexual Reproduction Contributes To Differences In Demography Of Invasive Plants And Their Noninvasive Relatives, Jean H. Burns, Eleanor A. Pardini, Michele R. Schutzenhofer, Y Anny Chung, Katie J. Seidler, Tiffany M. Knight

Biology Faculty Research

An understanding of the demographic processes contributing to invasions would improve our mechanistic understanding of the invasion process and improve the efficiency of prevention and control efforts. However, field comparisons of the demography of invasive and noninvasive species have not previously been conducted. We compared the in situ demography of 17 introduced plant species in St. Louis, Missouri, USA, to contrast the demographic patterns of invasive species with their less invasive relatives across a broad sample of angiosperms. Using herbarium records to estimate spread rates, we found higher maximum spread rates in the landscape for species classified a priori as …

Juvenile Ornamentation: Its Evolution, Genetic Basis, And Variation Across Habitats, Angela Tringali

Electronic Theses and Dissertations

Ornamental traits are considered honest advertisements of fitness, and their evolution is usually explained in terms of sexual selection. This explanation remains unsatisfactory in some instances, for example, juvenile birds whose plumage is molted prior to adulthood and breeding. I first evaluate whether juvenile plumage reflectance signals dominance status in the Federally Threatened Florida scrub-jay (Aphelocoma coerulescens) using a combination of observational and experimental methods. Then I estimate the heritability, non-genetic maternal and environmental effects, and strength of selection on juvenile plumage reflectance using archived feather samples and a pedigree constructed from historical nest records. Finally, I compare plumage reflectance …

Diurnal Vertical Distribution Of Zooplankton In A Newly Formed Reservoir (Tahtalı Reservoir, Kocaeli): The Role Of Abiotic Factors And Chlorophyll A, Zeynep Dorak, Özcan Gaygusuz, Ali̇ Serhan Tarkan, Hamdi̇ Aydin

Turkish Journal of Zoology

Although water level fluctuations and related environmental variations occurring within reservoirs have a considerable effect on the zooplankton community, studies on zooplankton dynamics of reservoirs are very limited. In the present study, we aimed to elucidate the diurnal vertical migration of zooplankton in relation to the concentration of physicochemical factors and chlorophyll a content in a recently formed water reservoir (Tahtalı Reservoir, Kocaeli, northwestern Turkey). During the sampling period 20 zooplankton taxa were identified, which were mostly indicative of eutrophic waters, as confirmed by the physicochemical factors of the water in the reservoir. Rotifera was the most abundant group, followed …

Relative Tolerance Of Some Tropical Freshwater Microcrustaceans To Acidification, Priyanka Mallick Halder, Pathik Kumar Jana, Susanta Kumar Chakraborty, Samir Banerjee

Turkish Journal of Zoology

The present work reports on the effects of low pH values on the mortality of 3 freshwater zooplankton available in the freshwater ponds of Midnapore district. Acute bioassay tests on Daphnia lumholtzi, Moina brachiata, and Heliodiaptomus viduus to varying acidic pH levels of water were performed in the laboratory using serial grades of hydrochloric acid solution. Among the 3 genera, M. brachiata was found to respond sharply to acid stress in a 1-h assay, since 100% mortality was achieved at pH 5.79 (2.347 mM HCl), as compared to H. viduus, which showed 100% death in 1 h only below pH …

Age Structure And Body Size Of The Strauch's Racerunner, Eremias Strauchi Strauchi Kessler, 1878, Abdullah Altunişik, Çi̇ğdem Gül, Nurhayat Özdemi̇r, Murat Tosunoğlu, Tuğba Ergül

Turkish Journal of Zoology

We studied, for the first time, the age structure of Eremias strauchi strauchi (Kessler, 1878) from a sample (18 adults) of a population living in the vicinity of Iğdır (eastern Turkey) using the skeletochronological method. The maximum observed longevity was 7 years for males and 5 years for females. The age of males ranged from 4 to 7 years (mean 4.91, n = 12), while that of females ranged from 4 to 5 years (mean 4.66, n = 6). The average snout–vent length (SVL) was 61.10 mm in males and 60.82 mm in females. The differences in mean age and …

Impacts Of Climate Variability And Human Colonization On The Vegetation Of The Gala´Pagos Islands, Alejandra Restrepo, Paul A. Colinvaux, Mark B. Bush, Alexander Correa-Metrio, Jessica L. Conroy, Mark R. Gardener, Patricia Jaramillo, Miriam Steinitz-Kannan, Jonathan T. Overpeck

Biomedical Engineering and Sciences Faculty Publications

A high-resolution (2-9 year sampling interval) fossil pollen record from the Galapagos Islands, which spans the last 2690 years, reveals considerable ecosystem stability. Vegetation changes associated with independently derived histories of El Niño Southern Oscillation variability provided evidence of shifts in the relative abundance of individual species rather than immigration or extinction. Droughts associated with the Medieval Climate Anomaly induced rapid ecological change that was followed by a reversion to the previous state. The paleoecological data suggested nonneutral responses to climatic forcing in this ecosystem prior to the period of human influence. Human impacts on the islands are evident in …

Aerobic Exercise As A Means Of Reducing Low Back Pain A Systematic Review, Theresa Privett

HIM 1990-2015

Background: Low back pain (LBP) is considered the leading cause of inactivity and lost employment time. It can be extremely difficult to treat as most conventional therapies have poor success rates. People with LBP need to be made more aware of the diverse and economical treatments available in order to save on expenses and diminish stress. Patients and healthcare professionals have many choices when deciding on the best plan of care; however, it is often difficult to determine which option is best. Objectives: The purpose of this systematic review was to determine if aerobic exercises play a role in reducing …

Demography And Reproductive Biology Of The Gopher Tortoise (Gopherus Polyphemus) Population At White Oak Plantation, Nassau County, Florida, Julia Rachel Smith

UNF Graduate Theses and Dissertations

The demography and reproductive biology of the gopher tortoise (Gopherus polyphemus) was studied for two years at White Oak Plantation (WOP), located in northeast Florida along the St. Mary’s river. Two sub‐populations were studied in regions I referred to as Site A and Site B. I located 312 burrows and captured 109 different tortoises, either by hand or using bucket traps. Tortoise density was 4.48/ha at Site A and only 1.15/ha at Site B. Juveniles were the most abundant age class overall, while hatchlings were numerous at Site A but virtually absent at Site B. The combined sex ratio for …

Reproductive Success Of The Rare Endemic Orchis Galilaea (Orchidaceae) In Lebanon, Nisrine Machaka Houri, Mohammad Souheil Al-Zein, Duncan Brian Westbury, Salma Nashabe Talhouk

Turkish Journal of Botany

The biology and ecology of Orchis galilaea Schltr., a species endemic to Lebanon, Palestine, and Jordan, is poorly studied, a fact that hinders present and future management and conservation efforts concerning this species. In this paper, we report findings of a field investigation that assessed the impact of altitude, population density, and plant size on the reproductive success of O. galilaea. The results revealed that plant size and population density were significantly correlated with reproductive success while altitude was not. This study is part of ongoing research on the ecological responses of O. galilaea and provides a baseline for understanding …

Seed Production With Insect Herbivory And Fungal Occurrence For The Rare Penstemon Haydenii, Kay L Kottas, James Stubbendieck, Erin E. Blankenship, Jay B. Fitzgerald

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

We quantified seed production and viability, floral herbivory and fungal infection on blowout penstemon (Penstemon haydenii S. Watson), an endangered species of the Nebraska Sandhills, USA, in order to determine the potential for perpetuation of this, and possibly other short-lived, rare perennials of fragmented habitats. Over three years, the number of seeds per infructescence averaged 518 (SE 29.01). Plants produced an average of 1398 seeds. Seed viability of 38% reduced reproductive potential to 531 viable seeds per plant. Plants in multiple blowout sites in two counties were assigned to one of four treatments: insecticide, fungicide, both, or neither (control). …

Human Alu Insertion Polymorphisms In North African Populations, Lotfi Cherni, Sabeh Frigi, Hajer Ennafaa, Nabil Mtiraoui, Touhami Mahjoub, Amel Benammar-Elgaaied

Human Biology Open Access Pre-Prints

Several features make Alu insertions a powerful tool used in population genetic studies: the polymorphic nature of many Alu insertions, the stability of an Alu insertion event and, furthermore, the ancestral state of an Alu insertion is known to be the absence of the Alu element at a particular locus and the presence of an Alu insertion at the site that forward mutational change. This study analyses seven Alu insertion polymorphisms in a sample of 297 individuals from the autochthonous population of Tunisia (Thala, Smar, Zarzis and Bou Salem) and Libya with the aim of studying their genetic structure with …

Anthropogenic And Natural Causes Influencing Population Genetic Structure Of Juniperus Procera Hochst. Ex Endl. In The Ethiopian Highlands, Demissew Sertse, Oliver Gailing, Nicolas George Eliades, Reiner Finkeldey

Michigan Tech Publications, Part 1

Juniperus procera is economically highly important but threatened tree species. It is the only species among 67 taxa in the genus Juniperus that naturally grows in Africa and south of the equator extending up to 18°S in Zimbabwe. Ethiopia is assumed to host the largest J. procera populations, which are also believed to have high genetic variation owing to their wide ecological amplitude. This study assessed genetic variation at AFLPs of J. procera populations in the Ethiopian highlands. In the study six populations, namely Chilimo, Goba, Menagesha-Suba, Wef-Washa, Yabelo and Ziquala were included. A total of 20-24 trees from each …

Survival, Breeding Frequency, And Migratory Orientation In The Jefferson Salamander, Ambystoma Jeffersonianum, Stephen P. De Lisle, Kristine L. Grayson

Biology Faculty Publications

Accurate estimates of demographic parameters, such as survival and breeding frequency, are necessary for the conservation and management of animal populations. Additionally, life-history data are required for gaining an empirical understanding of the ecology of natural populations. We monitored a population of Jefferson Salamanders (Ambystoma jeffersonianum) breeding in a permanent mountain-top pond at the southern limit of this species’ geographic range in Virginia over four years. We used closed multistate mark-recapture models with Pollock's robust design to estimate the demographic parameters of this population. Additionally, we used point-of-capture data to compare the orientation of migrations into and out …

Reproductive Success And Soil Seed Bank Characteristics Of Astragalus Ampullarioides And A. Holmgreniorum (Fabaceae): Two Rare Endemics Of Southwestern Utah, Allyson B. Searle

Theses and Dissertations

Astragalus ampullarioides and A. holmgreniorum are two rare endemics of southwestern Utah. Over two consecutive field seasons (2009-2010) we examined pre-emergent reproductive success, based on F/F and S/O ratios, from populations of both Astragalus ampullarioides and A. holmgreniorum, estimated the density of the soil seed bank of A. holmgreniorum as a measure of potential post-emergent reproductive success, and estimated seed persistence within the soil seed bank. Fruit/flower (F/F) ratios and seed/ovule (S/O) ratios varied significantly between populations and among years in both species, and showed low reproductive output in both taxa. In Astragalus ampullarioides F/F and S/O were 0.06±0.01 …

Patterns Of Transience, Sex Bias, And Body Mass In Open-Habitat Rodent Populations, Stephen Edward Rice

Biological Sciences Theses & Dissertations

Rodents are assumed to live their lives in circumscribed (natal) areas with males being more prone to disperse than females and juveniles more prone to disperse than adults. To test these assumptions we examined the initial captures of geographic populations of hispid cotton rat, meadow vole, prairie vole, and marsh rice rat obtained through capture-mark-recapture methods. Capture records were obtained from Kansas and Illinois from long-term studies, and through live-trapping in Chesapeake, Virginia. I evaluated proportions of residents and transients, adults and juveniles, and males and females for significant differences among seasons, years, and geographic locations. The overall body masses …

Population Dynamics Of The Western Prickly Pear, Opuntia Macrorhiza (Cactaceae), Kathleen H. Keeler, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Although most cacti that have been studied are long lived, following individually marked plants in Boulder County, Colorado, for >7 years, we determined that average life span of Opuntia macrorhiza, the western prickly pear, is 3 years. A few individuals probably live >10 years. Vegetative reproduction, produced by rooting of cladodes, exceeded reproduction by germination and establishment from seeds. Both types of new recruits, from vegetative reproduction and seeds, had higher death rates than established plants. Size and frequency of flowering increased with age, although size both increased and decreased, sometimes dramatically, between years. Flowering correlated more strongly with …

Individualistic Response Of Piñon And Juniper Tree Species Distributions To Climate Change In North America's Arid Interior West, Jacob R. Gibson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Piñon and juniper tree species have species-specific climatic requirements, resulting in unique distributions and differential responses to climate change. Piñons and junipers co-dominate the arid woodlands of North America as groups with widespread hybridization. Two piñons, Pinus edulis; P. monophylla, and four junipers, Juniperus deppeana var. deppeana; J. monosperma; J. occidentalis; J. osteosperma, are endemic to the midlatitude interior west and form three groups of hybridizing sister species, P. edulis-P. monophylla; J. deppeana var. deppeana-J. monosperma; J. occidentalis-J. osteosperma. Recent droughts have caused widespread mortality among piñons, but have had less impact on …

The Role Of Historical And Contemporary Processes On Phylogeographic Structure And Genetic Diversity In The Northern Cardinal, Cardinalis Cardinalis, Brian T. Smith, Patricia Escalante, Blanca E. Hernandez-Banos, Adolfo G. Navarro-Siguenza, Sievert Rohwer, John Klicka

Ornithology Program (HRC)

Background

Earth history events such as climate change are believed to have played a major role in shaping patterns of genetic structure and diversity in species. However, there is a lag between the time of historical events and the collection of present-day samples that are used to infer contemporary population structure. During this lag phase contemporary processes such as dispersal or non-random mating can erase or reinforce population differences generated by historical events. In this study we evaluate the role of both historical and contemporary processes on the phylogeography of a widespread North American songbird, the Northern Cardinal, Cardinalis cardinalis …

Molecular Evolution And Historical Biogeography Of New World Birds, Brian T. Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Deciphering the patterns of how biodiversity has evolved across time and space has remained a fundamental objective for biologists for the last 200 years. Researchers are faced with the challenge of interpreting the complexity of evolutionary patterns that have been generated over the deep history of the Earth. The advancement of DNA sequencing technology has yielded a new and powerful genetic toolkit that has allowed biologists to address novel evolutionary questions. For my dissertation research, I used molecular genetics and a statistical framework to study the evolution and historical biogeography of birds distributed in North and South America. My dissertation …

Species Trees And Species Delimitation With Multilocus Data And Coalescent-Based Methods: Resolving The Speciation History Of The Liolaemus Darwinii Group (Squamata, Tropiduridae), Arley Camargo Bentaberry

Theses and Dissertations

The inference of species boundaries and phylogenetic relationships are fundamental for evolutionary, ecological, and conservation studies. The resolution of species boundaries and the inference of phylogenetic relationships among species are required to define the units of analysis and to find the most closely related units for evaluating alternative models of speciation. I highlight lizards as model organisms for ecological and evolutionary studies, emphasizing their contributions to advances in understanding linkages between phylogeography and speciation. In this dissertation, I focus on the phylogenetic relationships of the lizards in the Liolaemus darwinii group, and the species boundaries of a nested clade within …

Compiling, Synthesizing And Analyzing Existing Boreal Forest Fire History Data In Alaska, Diana L. Olson, James B. Cronan, Donald Mckenzie, Jennifer L. Barnes, Anne E. Camp, Mike Tjoelker, Jennifer Northway, Paige Eagle

Joint Fire Science Program Research Project Reports

Wildland fires play a critical role in maintaining the ecological integrity of boreal forests in Alaska. Identifying and maintaining natural fire regimes is an important component of fire management. There are numerous research projects that directly or indirectly address historical fire regimes in the Alaskan boreal forest, but many are unpublished, have many unprocessed dendrochronological (tree age and fire scar) samples, or their data were used for other purposes. Furthermore, no assessment of these data exists to understand how fire has historically affected the boreal forest ecosystems of Alaska. The goal of this project was to compile and synthesize existing …

Fire Regimes Of Montane Grasslands Of The Valles Caldera National Preserve, New Mexico, Donald A. Falk, Craig D. Allen, Robert Parmenter, Thomas Swetnam, Clifford Dils

Joint Fire Science Program Research Project Reports

Montane grasslands are an important ecosystem type in Southwestern landscapes, occurring from the forest borders of piñon-juniper woodland to high elevation subalpine and alpine ecosystems. Thus, they often represent a mosaic element embedded in the forest landscape matrix, playing key roles in processing water and nutrients, and providing habitat for unique suites of species, often at higher levels of diversity than those found in surrounding uplands. Soils, local temperature and moisture gradients, and disturbance all play roles in determining the distribution and extent of montane grasslands. Of these factors, fire plays the most dynamic role in regulating the location and …