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Life Sciences Commons

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Ecology and Evolutionary Biology

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Purdue University

Theses/Dissertations

2015

Articles 1 - 7 of 7

Full-Text Articles in Life Sciences

Effects Of Temperature And Pollinator Availability On Plant Reproductive Success In The Indiana Spring Ephemeral Community, Asya Robertshaw Apr 2015

Effects Of Temperature And Pollinator Availability On Plant Reproductive Success In The Indiana Spring Ephemeral Community, Asya Robertshaw

Open Access Dissertations

Temperature is a key driver of phenology in both plants and insects, and even small changes in temperature can impact the reproductive success of insect-pollinated plants by influencing access to pollinator services. While it is well-established that temperature variation directly impacts the flowering phenology of many plant species, the mechanisms by which it ultimately influences seed production via the pollinator community are not well understood. Climate change has the potential to disrupt the temporal synchrony between plants and their primary pollinators, especially if the two rely on different seasonal cues for the timing of their life history events. If the …


Undercover Predators: Vegetation Mediates Foraging, Trophic Cascades, And Biological Control By Omnivorous Weed Seed Predators, Carmen K Blubaugh Apr 2015

Undercover Predators: Vegetation Mediates Foraging, Trophic Cascades, And Biological Control By Omnivorous Weed Seed Predators, Carmen K Blubaugh

Open Access Dissertations

Weed pressure is the most costly challenge that vegetable growers face, requiring more labor investment than other production inputs. Vertebrate and invertebrate seed predators destroy a large percentage of weed propagules on the soil surface, and their ecosystem services may ease labor requirements for farmers in herbicide-free systems. Cover provided by living vegetation is an important predictor of seed predator activity, and my dissertation takes a comprehensive approach to understanding the behavior, predator, and environment-mediated mechanisms by which cover impacts weed seed predation in crop environments. ^ First, I performed a meta-analysis of 27 studies to quantitatively evaluate what is …


Consequences Of Short-Term Water Temperature Variability To Fish: Current And Future Climate Change Impacts, David P. Coulter Apr 2015

Consequences Of Short-Term Water Temperature Variability To Fish: Current And Future Climate Change Impacts, David P. Coulter

Open Access Dissertations

Water temperature has a profound influence on aquatic ectotherms by affecting all aspects of biological organization; from chemical and molecular functioning to whole-organism and population-level impacts. Natural processes and anthropogenic activities can create conditions where temperatures vary greatly through space and time. While exposure to temperature changes lasting ≥ 24 hours have been examined in some species, it is unclear how more rapid (< 24 hours; sub-daily) thermal fluctuations affect aquatic ectotherms. I used a combination of field observations, laboratory experiments, and modeling simulations to understand: 1) how habitat quality of aquatic ectotherms is affected in thermally dynamic environments; 2) the role of sub-daily temperature fluctuations on growth, survival, and stress responses in juvenile and adult fish; 3) how fish early life stages are affected by sub-daily temperature fluctuations; and 4) what impact thermally dynamic environments have on a model species at a population-level. A model quantifying habitat quality around power plant thermal discharges indicated that elevated and variable discharge temperatures affected habitat quality over a relatively small spatial area for aquatic ectotherms. Models examining elevated temperatures representing climate warming showed that the effects of industrial discharges and climate warming could have an interactive effect on habitat quality by increasing the spatial area and duration over which industrial thermal effluents impact aquatic ectotherms. Laboratory experiments indicated that closely related fishes can respond differently to the same sub-daily temperature fluctuations. Yellow perch (Perca flavescens) had higher consumption and growth under sub-daily temperature fluctuations but developed skin lesions; an indication of thermal stress. In contrast, these same fluctuations reduced growth in physiologically similar walleye (Sander vitreus) …


Carrion-Associated Arthropods In Rural And Urban Environments, Serena Daye Gross Apr 2015

Carrion-Associated Arthropods In Rural And Urban Environments, Serena Daye Gross

Open Access Dissertations

Preferences of arthropods are important in forensic entomology, as the species collected can help determine the postmortem interval or if remains have been moved. This study looked at arthropods that are attracted to pig carcasses in rural and urban habitats in Northwest Indiana. The species and number of carrion-associated arthropods that are found at a carcass vary with habitat type, month, and stage of decomposition. Lucilia sericata (Diptera: Calliphoridae) is a synanthropic species that was found in higher numbers in urban locations for both adults and larvae. Though L. sericata had higher numbers in urban habitats, caution must be exercised …


Use Of Plastic Bottles As An Alternative Container Type For Propagation Of Forest Tree Seedlings In Restoration Programs, Safiullah Khurram Apr 2015

Use Of Plastic Bottles As An Alternative Container Type For Propagation Of Forest Tree Seedlings In Restoration Programs, Safiullah Khurram

Open Access Theses

Deforestation and forest degradation is a global issue, especially in poor and developing regions of the world. In order to combat deforestation it is critical to enhance the productivity of forest restoration operations, which often involve planting of nursery-grown forest tree seedlings. Production of low quality stock types with deformed and spiraled root systems is a significant issue hindering successful restoration programs. Polybags (i.e., small plastic bags) are a common container type for seedling propagation in developing countries. However, polybags produce seedlings with spiraled and deformed root systems that reduce outplanting survival and performance. Use of discarded plastic water bottles …


Extended Scaffolding: A More General Theory Of Scaffolded Cognition, Zachary R. Murphy Apr 2015

Extended Scaffolding: A More General Theory Of Scaffolded Cognition, Zachary R. Murphy

Open Access Theses

New and emerging technologies called neuroprostheses are challenging our ideas about where one's mind ends and the environment begins. Cochlear implants, which completely replace the functioning of the inner ear, are now a common treatment for deafness. Berger et al. developed a device that replaces long-term memory in rats (2012), while Hampson et al. created a brain-machine interface that converts a desire to move one's arm into the motor neuron impulses required to achieve that movement (2013)--both offering promising treatments for dementia, Alzheimer's disease, and paralysis. Deep brain stimulation is now a common way of regulating neural activity to manage …


Biology And Ecology Of Bigheaded Carp In An Invaded Ecosystem, Alison Adele Coulter Apr 2015

Biology And Ecology Of Bigheaded Carp In An Invaded Ecosystem, Alison Adele Coulter

Open Access Dissertations

Globally, the homogenization of species has become a threat to biodiversity. As species are transported around the world, a portion of these species, released intentionally or accidentally, may become invasive and can produce negative impacts. Great effort has been invested into early identification and prevention of invasions as these are considered less expensive than managing an invasion. Unfortunately, species may exhibit varying characteristics across ecosystems, and so their behavior and potential survival in a new environment may be difficult to predict. Therefore, I examined trends in the biology and behavior of invasive fishes, including the plasticity surrounding these and how …