<p>This study was performed to better understand the physiological responses of the cricket <em>Acheta domesticus</em> to dietary restriction and nutritional geometry (relative nutritional balance). Dietary restriction in crickets decreases the growth rate, survivorship, maturation mass and delays maturation, but it has the benefit of increasing their maximum longevity. Measurements of maturation mass, maturation age and longevity were obtained and used to calculate adult duration, growth rate and survivorship. This experiment combined both dietary restriction and nutritional geometry. Treatments were dietary restricted and provided with one of three macronutrients: lipid, carbohydrate or protein. The macronutrients were predicted to modulate the effects of dietary restriction while still producing an increase in maximum longevity. The lifetime restricted males and females obtained the highest maximum longevity of all treatments. The females of the carbohydrate treatment experienced significant increases in survivorship when compared to the lifetime restricted treatment. The males of the carbohydrate treatment achieved the second highest maximum longevity as well as a significant increase in longevity when compared to the lipid and protein males. A significantly earlier maturation age was obtained by the carbohydrate males when compared to the lifetime restricted treatment. The protein females had a significantly higher maximum longevity than the control treatment. The lipid treatment had an extremely low survivorship, a decreased adult duration as well as a low maturation mass. In summary, carbohydrates decreased the maturation age and increased the survivorship of the female crickets and increased the longevity of the male crickets. The protein treatment did not obtain the expected increases in growth rates or maturation mass associated with high protein diets. Therefore, different high protein diets should be tested in conjunction with the carbohydrate diet, in order to offset the negative effects of dietary restriction.</p> / Master of Science (MSc)

<p>When environmental philosophy began as a political movement, one of its original goals was to transform people's lifestyles. This required appeals to everyday intuitions and emotional writing evoking the intrinsic value of nature. This style exists in institutional environmental philosophy today, but sits uneasy with academic pressure toward rigor and careful analysis. The first half of my thesis criticizes various problems in environmental philosophy regarding these issues and arguments for other moral principles that displace intrinsic value. I attempt to return the concept of intrinsic value to a prominent place in environmental philosophy, not as a popular intuition, but as an answer to one central philosophical question: the point of human existence. Engaging with particular topics in ecology, biology, phenomenology, ethology, complexity theory, and the assemblage theory of Deleuze and Guattari, the second half of my thesis builds a concept of selfhood that I hope is adequate to answer that question of why humanity should bother ensuring its survival.</p> / Doctor of Philosophy (PhD)

Fire suppression, combined with lack of forest thinning and short-rotation, monodominant management, has drastically altered the landscape in the southeastern U.S., leading to the loss of open pine ecosystems and associated avian species. Management of open pine ecosystems is a common practice; yet, there remains uncertainty regarding how vegetation structure impacts priority species. Using empirical data, I assessed changes in species abundance and associated vegetation characteristics before and after management. I also sought to identify vegetation characteristics that influence home range establishment and microhabitat selection of Bachman’s Sparrows. Priority species were negatively associated with hardwood midstory and abundance per site increased following management. Home range establishment of Bachman’s Sparrows was influenced by disturbance, canopy cover, and slope, while microhabitat selection was influenced by pine basal area, available perching options, vegetation density, and herbaceous groundcover. Understanding how vegetation structure impacts priority species may be helpful in guiding conservation and management efforts.

Responses of migratory birds to seasonal climate and long-term environmental changes have been a central theme of avian migration ecology. Atmospheric conditions (e.g., winds and thermals), climate, and land cover and land use (LCLU) are major factors influencing the flights of soaring birds. Soaring American White Pelicans (Pelecanus erythrorhynchos) (hereafter, AWPEs) migrate between the subtropical Gulf of Mexico (GOM) and the temperate Northern Great Plains. American White Pelicans are also economically important piscivorous birds, causing enormous damages to the commercial Channel Catfish (Ictalurus punctatus) aquaculture in the Southeastern US. My studies aimed to evaluate the effects of climate, wind, and LCLU on the geographic range distributions, seasonal movements, and annual survival of AWPEs. I used Bayesian integrated species distribution models to estimate the occupancy probability and space-use intensity of AWPEs at the breeding and non-breeding grounds in 2005, 2010, and 2015, respectively, with data from eBird, Breeding Bird Survey, and Christmas Bird Count. Decreases in wind speeds and surface net thermal radiation and increases in waterbodies, wetlands, and non-woody covers enhanced AWPE occupancy at both the breeding and non-breeding grounds. I used 72 GPS-tracked AWPE data to study circannual hourly movement speeds and seasonal home ranges of AWPEs from 2002 to 2012. American White Pelicans had shorter hourly movement distances and smaller seasonal home ranges in the Southern than Northern GOM during winters; however, the difference did not carry over to the shared breeding grounds during summers. Last, I built Bayesian integrated population models to estimate annual survival and population dynamics of AWPEs with mark-resight-recovery data and annual nest counts at Chase Lake, North Dakota, the US from 1960 to 2014. Increases in upward wind velocity during autumn migration enhanced hatch-year AWPE survival. Increased winter precipitation on the non-breeding grounds improved annual survival of yearling and adults. On the other hand, increased precipitation at the breeding grounds reduced annual survival of hatch-year AWPEs. My findings can help develop management plans for mitigating the economic damages of AWPEs by predicting what areas AWPEs may occupy with high abundances in the future changes in climate and LCLU.

Urban landscapes can support pollinator conservation, but traditional landscape designs lack the diverse mixtures of native plants needed to support native pollinators. Although native plants support pollinators and can survive with less water and fertilizer than non-native landscape plants, they do not always grow well under modified urban soil conditions and irrigation regimes. A better understanding of the factors influencing flower production and the quality of native plants is needed if we are to design landscapes that support pollinator conservation. This study focused on how flower production and quality in different native plants responded to compost and irrigation treatments. The experiment consisted of 27 native plant species grown in sixteen 6.1 x 9.1 m plots with or without compost and with regular or as-needed irrigation in a randomized complete block design. We quantified total flower production and examined nectar production and flower size in select plant species. Results showed that compost addition greatly increased flower production and that the floral traits of individual plant species varied in their response to compost additions and different irrigation regimes. Unraveling the complexities of these interactions is important for designing urban landscapes that support pollinator conservation.

As the earth’s landscape becomes increasingly urbanized, local wildlife must adapt to urban conditions or migrate to areas that are more rural. Urban wildlife face challenges such as direct loss of habitat, competition with non-native species, disturbance due to anthropogenic noise, and micro-climatic changes. Factors such as temperature, relative humidity, and noise affect the acoustical environment and may affect the ability of many animals, including birds, to communicate. Understanding how urbanization affects birds’ singing behavior is critical because singing often plays a vital role in attracting mates and defending territories. In addition, as global climate change occurs it will become increasingly important to understand the influence of abiotic factors such as temperature on the singing behavior of birds. Developing a deeper understanding of how those abiotic factors affect singing and other associated behaviors may help guide future conservation actions. Carolina Wrens are often used to study the role of singing in defending territories. They are also a common subject for ranging studies. However, surprisingly little research has been conducted on the factors influencing Carolina Wren song activity over the course of a day. No studies have compared the singing activity of Carolina Wrens in urban and rural environments. The purpose of this study was to compare the singing activity of Carolina Wrens in urban and rural areas. Specifically, this study looked for patterns in the timing of songs throughout the day and examined the effects of season, temperature, and anthropogenic noise on singing activity in urban and rural settings. I analyzed data from 4 SongMeter© SM2 data loggers (2 located at an urban park in Bowling Green, KY and 2 located at a rural preserve in Hart County, KY). The data loggers were programmed to record ambient sound for 3 minutes at the beginning of every hour. A Hobo® data logger was deployed with each SongMeter© SM2 data logger to record temperature and relative humidity at 15-minute intervals. One week of data in May and one week of data in July were analyzed. Both weeks had similar photoperiods, temperatures, and amounts of precipitation. For each recording, I documented the number of Carolina Wren songs I heard and a categorical assessment of the precipitation and anthropogenic noise due to traffic or machinery. I conducted Chi-square analyses to compare the seasonal or site-based observed frequencies of singing activity to the corresponding expected frequencies. In May, Carolina Wrens at the urban site sang more than their rural counterparts. Daily activity patterns were visually analyzed using the average number of songs detected for each hour’s sampling period. No Carolina Wrens were heard singing the hour before sunrise or the hour after sunset. In May, the dawn chorus lasted nearly twice as long as in July. Zero-inflated Poisson regressions were used to determine the correlations between Carolina Wren singing activity and temperature or anthropogenic noise. Carolina Wren singing activity had significant correlations with both variables.

Piratebush (Buckleya distichophylla (Nutt.) Torr.) is a rare, hemiparasitic shrub with the only extant populations in western North Carolina, northeastern Tennessee, and southwestern Virginia. The preferred natural hosts of piratebush, Carolina and eastern hemlocks, have seen sharp declines over the last decade due to the invasive hemlock woolly adelgid. Virginia pine, another important host of piratebush, is also susceptible to disease, specifically Cronartium appalachianum, a rust fungus for which piratebush is the secondary host. This study described and analyzed current demographic parameters of three Tennessee piratebush populations. Additionally, spatial patterns of disease and demographic characters were analyzed. These data were compared to data from previous censuses to infer the impacts of diseases on piratebush and its host. All three populations were relatively stable in numbers and age structure over the past thirty years. Plant height and stems per shrub were similar among populations and stable over time. Seedlings represented 14%-19% of populations and non-flowering plants 33%-41% of populations. Two populations had an equal sex ratio and one population was male-biased. Disease prevalence was similar among populations but disease was more severe at Temple Ridge. The effects of hemlock decline were most acute at the Temple Ridge population where areas of high hemlock decline were associated with lower vigor piratebush individuals. Piratebush individuals near Virginia pines were more likely to be infected by C. appalachianum, and individuals infected by the rust fungus were more likely to have lower vigor. If hemlock decline is causing a piratebush host shift toward Virginia pine, piratebush populations may also decline because of potential enhanced infection by C. appalachianum. Treatment to prevent HWA infestation may be needed because of its effectiveness in improving the health of both hemlock and piratebush populations.

Cyanobacteria are a group of photo-oxygenic bacteria found in nearly every ecosystem, but much cyanobacterial diversity, in various habitats, has yet to be explored. Cyanobacteria are often conspicuous components of photosynthetic flora, providing significant carbon and nitrogen inputs to surrounding systems. As possible primary colonizers of stone substrates not native to this region, cyanobacteria isolated from headstones may provide biogeographically informative data. An exploratory study of lichen-dominated microbial consortia, growing on headstones, was conducted to isolate and identify novel microaerophytic cyanobacteria, and resulted in the establishment of four novel cyanobacterial taxa. Phylogenetic analyses of photobionts in one tripartite lichen revealed two novel taxa: Brasilonema lichenoidesand Chroococcidiopsis lichenoides. Using a total evidence approach, analyzing ecology, morphology, ITS structure, and molecular data two additional taxa were described: Brasilonema geniculosusand Calothrix dumas. Analysis of secondary structures of the Internal Transcribed Spacer (ITS) regions of the 16S-23S operon in cyanobacteria are commonly used in cyanobacterial taxonomy studies and were applied to the identification of the new taxa in this study. However, the relationship between ITS structures, hairpin loops (helices) in a region of non-coding DNA, has not been thoroughly evaluated. The 16S-23S operon is one of many in prokaryotes with multiple copies and there is evidence that operons may vary due to differential selective pressures or drift. A study was undertaken analyzing ITS operons from 224 previously published cyanobacterial taxa for domain inclusion and exclusion, intragenomic heterogeneity of ITS operons, and the possible relevance of variable selective pressures affecting individual domains. Analysis revealed highly variable ITS domain inclusion even in complete sequences, as well as high variation between domains containing two or no tRNA sequences. Recommendations were made to standardize ITS analysis in the future to account for this possible variation. Further study is required to statistically demonstrate to what extent ITS secondary structures correlate with taxonomy.

Coral cover is in decline on a global scale, with increased mortality events being attributed to a number of global and regional stressors. While the impacts of global stressors (e.g. sea surface temperature rise, ocean acidification) are well documented, there is growing interest in identifying and understanding the impacts of regional stressors. The reason for this change in focus is that regional stressors can often work in combination, sometimes synergistically, with global stressors and that stressors on a regional scale tend to be more easily mitigated by management practices. One regional stressor that impacts a myriad of marine organisms in the southeastern United States is the annual red tide blooms produced by the dinoflagellate, Karenia brevis. Their impacts, along with the lipid soluble polyether neurotoxins they produce, termed brevetoxins, are well studied in economically important organisms, such as bivalves. However, little is known of their impacts on organisms that possess ecological importance, such as species of scleractinian coral. To address this gap in knowledge, a multifaceted study is discussed herein, which evaluated the effects of ecologically relevant concentrations of K. brevis and associated brevetoxins on different coral life history stages and coral species. The second chapter addresses the impacts of red tide on larval behavior, settlement and survival of the coral species Porites astreoides, as well as impacts of photochemical efficiency and oxidative stress within different coral species (P. astreoides larvae, P. astreoides adults, Acropora cervicornis, Cladocora arbuscula, and Phyllangia americana). The third chapter confers the use of broad-scale proteomic analysis to identify the cellular response of the non-model coral species, P. astreoides, following exposure to red tide. Coral larvae actively avoided both medium and high bloom conditions of K. brevis and brevetoxins, while percent larval settlement and survival were impacted following exposure to high bloom concentrations of K. brevis. Photochemical efficiency of in hospite Symbiodinium was reduced following exposure to both K. brevis and brevetoxin in P. astreoides larvae, as well as exposure to K. brevis in P. astreoides adults, while being unimpacted in A. cervicornis. Compared to controls, high bloom conditions resulted in an increase in biomarkers of lipid peroxidation in C. arbuscula. This was also seen in P. astreoides larvae at 24 hours; however, this difference was indistinguishable following 48 hours. Surprisingly, no other biomarker of oxidative stress analyzed were impacted. Broad-scale proteomic analysis of P. astreoides following exposure to red tide conditions revealed variable changes in proteome expression depending on if the corals were exposed to K. brevis or brevetoxins. Exposure to brevetoxins resulted in differential expression of proteins related to DNA organization, chromatin formation and transcription expression; while exposure to K. brevis resulted in differential expression of proteins related to redox homeostasis, protein folding, energy metabolism, and production of reactive oxygen species. The results of this study demonstrate the potential for annual red tide blooms to act as a regional stressor on coral species. They highlight the ability of red tide conditions to negatively impact coral at multiple life history stages and that the extent of these effects may be species specific. They also provide further incite of coral’s response to red tide exposure at the cellular level.

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence that treatment prescription differentially affects fine-scale genetic structure and effective gene flow in this species. In my third chapter, I describe the development of a dense linkage map for Pinus balfouriana which I use in chapter four to assess the quantitative trait locus (QTL) landscape of water-use efficiency across two isolated ranges of the species. I find evidence that precipitation-related variables structure the geographical range of P. balfouriana, that traits related to water-use efficiency are heritable and differentiated across populations, and associated QTLs underlying this phenotypic variation explain large proportions of total variation. In chapter five, I assess evidence for local adaptation to the eastern Sierra Nevada rain shadow within P. albicaulisacross fine spatial scales of the Lake Tahoe Basin, USA. Here, genetic variation of traits related to water availability were structured more so across populations than neutral variation, and loci identified by genome-wide association methods show elevated signals of local adaptation that track soil water availability. In chapter six, I review theory related to polygenic local adaptation and literature of genotype-phenotype associations in trees. I find that evidence suggests a polygenic basis for many traits important to conservation and industry, and I suggest paths forward to best describing such genetic bases in tree species. Overall, my results show that spatial and genetic structure of trees are often driven by their environment, and that ongoing selective pressures driven by environmental change will continue to be important in these systems.