Ecology and Evolutionary Biology Commons^™

The Influence Of Conservation Tillage And Conventional Tillage On Soil Bacterial Diversity In Southern Illinois, Nasser Syed

Dissertations

Agriculture in the Midwest United States (Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin) is a critically important component of the United States economy and also for world exports of food grain. This is well reflected in the 2012 Census of Agriculture which showed that these states had a market value of crop and livestock products sold in excess of $80,000,000,000 (USDA, 2012). Within the U.S. the three Midwest states, Illinois, Iowa, and Minnesota are ranked 2nd, 3rd, and 4th for the economic value of crops sold. This economic value of agriculture in the Midwest encompasses not only corn, soybeans, …

Root Dynamics Of Crop Plants In A High Carbon Dioxide World: Effects Of Elevated Versus Ambient Carbon Dioxide Levels And No-Till Versus Conventional Agricultural Management, Charlotte Barker

Dissertations

Due to the continuing increases is atmospheric carbon dioxide levels and its potential effect on food sources, there is an interest in evaluating the effect of elevated CO₂ concentration versus ambient CO₂ concentration in agricultural crop plants although more studies have focused on the aboveground portions of plants rather than the roots. Additionally, the conservation agricultural method, no-till, has been widely suggested as a possible method of increasing soil organic carbon and increasing soil moisture in a hotter world.

This research involves two major agricultural plants, Sorghum bicolor (sorghum), and Glycine max (soybean) grown under four conditions including …

Personality In California Sea Lions (Zalophus Californianus) And Harbor Seals (Phoca Vitulina): Methodological Convergence And Species-Specific Emotional Repertoires, Amber De Vere

Dissertations

Despite the wide acceptance of animal personality as a valid area of study, research on marine mammal personality remains remarkably scarce. What literature does exist predominantly focuses on bottlenose dolphins (Frick, 2016; Highfill & Kuczaj, 2007; Kuczaj, Highfill & Byerly, 2012; Lilley, de Vere, Yeatre & Kuczaj, 2018; Moreno, Highfill & Kuczaj, 2017). There is also strong evidence for individual differences in grey seals (Robinson et al., 2015; Twiss & Franklin, 2010; Twiss, Culloch & Pomeroy, 2011; Twiss, Cairns, Culloch, Richards & Pomeroy, 2012), and preliminary research has provided evidence of broad personality factors in pinniped species using behavioral coding …

The Ecology Of Nest Cavity Use By Arboreal Ants In The Brazilian Cerrado: Resource Availability, Nest Modification, And Trophic Interactions, Galen Priest

Dissertations

Arboreal ants in the Brazilian Cerrado rely on cavities in living trees as nest sites. These cavities are created by a community of, wood-boring beetles, which act as ecosystem engineers. Despite the importance of these cavities as a resource, little is known about their natural abundance and heterogeneity, how ants use and modify them as nest sites, and how this interaction between cavities and their ant occupants influences trophic interactions on cerrado trees. Here I use natural history observations and manipulative experiments to address these questions. In the first chapter I quantified the occurrence, heterogeneity, and use of beetle-created cavities …

The Ecology And Feeding Behavior Of Mosquitoes In The Galapagos Islands, Samoa S. Asigau

Dissertations

Mosquitoes remain important vectors in transmitting wildlife diseases. This dissertation aims to understand the role that mosquitoes play in transmitting wildlife diseases such as avian malaria, a protozoan parasite belonging to the genus Plasmodium. Using data from wild-caught mosquitoes captured in multiple years and across multiple islands on the Galapagos Archipelago, we describe distributional patterns of mosquitoes, their range limits and assess whether there exists a disease-free refuge as occurs in Hawaii. We show that altitudinal ranges for disease transmission of avian malaria may not be bounded by a stable disease-free refuge, since mosquitoes are found at all elevations, …

Haemosporidian Parasites And Host Immune Function Of Galapagos Avifauna, Maricruz Jaramillo

Dissertations

The large number of emergent infectious diseases witnessed in the past few decades has increased interest in the ecology and distribution of potentially threatening pathogens worldwide. Island species are often considered more vulnerable to parasites due to their impoverished parasite communities, long isolation from disease and low genetic diversity. Avian surveys done by our group on the Galapagos Islands have found various pathogens infecting their endemic avifauna, including haemosporidian parasites of the genera Plasmodium and Haemoproteus. My research seeks to understand the relationships between two haemosporidian parasites (blood parasites) and their multiple bird hosts in Galapagos and to explore …