This study evaluated the effectiveness of chiselling and elemental sulfur fertilization in improving an upland and a swale range site with fine loamy, carbonatic, typic calcixeroll soils in the Ait Rbaa Perimeter of central Morocco. Ponding infiltration, soil water content on a mass basis of the 0- to 10-cm and 10- to 20-cm soil layers, peak season biomass production, and botanical composition were monitored during the two growing seasons following the treatments (1984/85 and 1985/86). Chiselling significantly improved infiltration on both sites, although the improvement was greater on the finer and less stony swale site, where chiselling resulted in more stable ridges. The land treatment also increased the average water content by weight of the 0- to 20-cm soil layer. The increase was more frequent on the upland site and most pronounced on its o- to 10-cm surface soil layer. In the chiselled treatments, average soil water content decreased with soil depth on the upland site while it increased on the swale site because of differential furrow stability and soil texture. Both the average infiltration rates of 5 cm of water and the average water content varied with sampling time, although generally in opposite directions. The application of elemental sulfur at the rates of 0, 30, and 60 kg ha-1 did not significantly affect any of the measured variables. Average peak season biomass production was 11% greater with chiselling. Chiselling also positively affected botanical composition on the upland site by depressing average forb proportion and increasing legume ratio in the first growing season. The gain in biomass does not seem to be high enough to strongly recommend chiselling in the Ait Rbaa Perimeter before performing an economic analysis of the operation.

While gamification has been extensively studied in specific fields, such as education and health, its application in other domains remains understudied. This thesis explores how battle passes, a common gamification system found in video games, are implemented and examines their potential challenges and limitations within and beyond video games. The study adopted a mixed-methods research approach, gathering qualitative and quantitative data through a survey designed to inquire battle pass users about how they use and are affected by the battle pass systems in Apex Legends, Destiny 2, Fortnite, Overwatch 2 and Valorant. The results indicate that gamers generally prefer completing the battle pass through passive generation of XP by playing the game. Challenges are still considered a fun addition to the battle pass system, although with varying levels of enjoyment. Gamers are motivated to complete even unenjoyable challenges to earn higher rewards, both highlighting the power of extrinsic motivators and the risks of implementing battle passes. It is important that companies implement battle passes responsibly, as these systems can be manipulative and exploitative. For example, entities implementing battle passes should consider that battle passes can cause exhaustion in users, and participation should as a consequence be optional. While the intentions of companies cannot be controlled, informing battle pass users about the potential negative impacts of battle passes can help them to protect themselves from exploitation. Overall, this study offers a foundation for future investigation into the effectiveness of gamification and battle passes.

Organism succession during ecosystem development has been well studied for aboveground plant communities while the associated pattern of change in microbial communities remains largely unknown. A study was conducted along developmental sand-dune chronosequences bordering Lake Michigan at Wilderness State Park and Altamaha river valley of southeast Georgia with the hypothesis that soil bacterial communities will follow a pattern of change that is associated with soil, plant, and ecosystem development. This study site included 5 replicate sites along 14 dunes ranging in age from 105 to 500,000 years since deposition. The microbial composition and diversity in the soil was studied using bacterial tag-encoded FLX amplicon pyrosequencing of the 16S rRNA gene. As hypothesized, Bray-Curtis ordination indicated that bacterial community assembly changed along the developmental gradient at both sites. However, there was no seasonal effect at Michigan sites despite likely differences in plant carbon inputs. At the Michigan site, soil Ca, Mg levels and pH showed a significant log-linear correlation with soil development (r = 0.83, 0.84 and 0.81, respectively). Bacterial diversity represented by Simpson’s reciprocal index (Simpson’s 1/D) showed a steady decline from the youngest to the oldest dunes with the largest decline (212 to 58) during the initial stages of soil development (105 to 450 years). The change in plant species abundance was higher in the youngest sites than the older sites. This change was significantly correlated with the change in microbial community distribution (p < 0.0001; r = 0.56). Similarly, at Georgia sites, soil development showed significant log-linear correlation with soil base cations (Ca and Mg) (r = 0.93and 0.95). However, diversity indices and PLFA failed to show any particular change in trend across the developing chronosequences. When the results from both sites were used to study bacterial spatial patterns, local geochemical features were found to be a dominant factor in driving bacterial community structure, while geographic distance as a single factor could contribute to some community variation at a scale (50 – 1700 km). The results suggest that soil nutrients and plant community could be a strong driving force in shaping microbial community assembly across a developing soil ecosystem.

Earlier planting to escape summer drought and high temperature has increased the importance of cold tolerance in corn. The objectives of this study were to assess cold tolerance among the corn hybrids using morpho-physiological traits and to classify hybrids into different groups of tolerance. Corn hybrids were subjected to optimum, low, and very low temperatures during seed emergence and seedling growth and morphological and physiological traits were assessed. Variability existed among the corn hybrids for the measured traits. Total, leaf and root weights and cumulative length and length per unit volume were the most important morphological traits in describing hybrid variability. Principle component analysis and total low temperature response index methods were used to categorize hybrid tolerance to low temperature. Based on relative scores assigned in this study and their yield potential in the niche environment, producer could select hybrids to maximize corn production in an early planting production system.

Bats are important components of biodiversity within forested ecosystems. This research addressed habitat characteristics that influence species occupancy and stable isotopes and wing morphology to assess community structure within the Sam D. Hamilton Noxubee National Wildlife Refuge. To meet these objectives, I deployed echolocation recorders, mist-nets and conducted roost checks to capture bat acoustics; fur samples were also collected to measure ratios of carbon (C13/12) and nitrogen (N15/14). Relationships between occupancy, habitat class and features were not apparent for most species. However, Lasiurus and Mytois spp. showed positive relationships with proximity to roads, Lasiurus, positive with stem density and Perimyotis subflavus, negative with basal area. Stable isotope analysis revealed some distinction of trophic niches while wing morphometrics indicated bats of similar wing shape and size show greater trophic overlap. Collectively, these results suggest that habitat management, as current within the study area, will have limited influence on local bat distributions.

White Crappie (Pomoxis annularis) and Black Crappie (P. nigromaculatus) are popular North American gamefish; however, frequent fluctuations in year class strength present a management challenge for recreational fisheries. Intensive aquaculture production has the potential to address this challenge through controlled hatchery reproduction for supplemental stocking, but further study is needed to refine and optimize techniques. Therefore, this study evaluated the effects of hormone injection timing on latency period and spawning success, examined effective cryopreservation techniques for black-stripe Black Crappie sperm (a preferred hatchery phenotype), and compared simulated spring duration on out-of-season spawning success. Latency period for White Crappie did not depend on the diel time of gonadotrophin-releasing hormone injection. Cryopreservation of black-stripe Black Crappie sperm and subsequent fertilization of White Crappie eggs was more effective using 5% dimethyl-sulfoxide than 10% methanol. A longer duration at final spring spawning conditions (3 vs. 2 weeks) increased egg fertilization in out-of-season spawning experiments.

The Mississippi River Valley Alluvial Aquifer (MRVAA) aquifer is the principal water source for Mid-South irrigators, but the current rate of withdrawal from the aquifer is not sustainable. Means to increase the sustainability of the MRVAA is to improve corn’s water use efficiency (WUE) while, concurrently, maintaining or improving profitability. The objectives of this experiment were to determine the effects of sensor-based irrigation threshold, planting date, and hybrid on corn grain yield, WUE, and net returns above seed and irrigation cost. Season long irrigation thresholds of -50 kPa full irrigation (FI) and -125 kPa limited irrigation (LI) were used, utilizing furrow irrigation. In conclusion, utilizing a delayed irrigation trigger of -125 kPa decreases grain yield and, ultimately, net returns in years with less naturally occurring rainfall, but increases WUE. Shifting the planting date earlier and using full-season (FS) hybrids, increases grain yield, WUE, and net returns.

Study was conducted to evaluate in vitro digestibility of native warm-season grasses. Three grasses were used: big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium Nash), and indiangrass (Sorghastrum nutans Nash). There were no differences in NDF, ADF, FAT and OM of the three grass species. However, DM, hemicellulose and CP were slightly different in the three grass species. Also, the frequency nested in cutting effects was determined. In vitro dry matter disappearance of big bluestem, little bluestem and indiangrass was evaluated to determine rate of disappearance. The 100 % indiangrass revealed the greatest rate of disappearance for IVDMD and 100 % little bluestem grass the least, respectively. However, that of other proportion mixtures of treatments and 100 % big bluestem grass were in between. There were no differences in in vitro neutral detergent fiber disappearances among treatments.

Factors affecting juvenile survival are poorly known in the world’s most northern antelope, the endangered saiga (Saiga tatarica), yet they are fundamental for understanding what drives population change. For saiga neonates monitored in Sharga Nature Reserve, western Mongolia, during 2008–2010, male and single calves were heavier than those of female and twins, respectively. However, there was no significant difference in seasonal and annual survival rate between male and female or singletons and twins. Litter size and birth mass varied among years, and there was a negative relationship between these variables. Multiple regression models suggest that summer precipitation in previous years and spring mean temperature explained inter-annual variations in twinning rate, and mortality was highest during summer. Covariates providing the best model fit included year, litter size, and body weight, suggesting that environmental conditions influence twinning rates and body mass may play a key role in neonate survival rate in the first year. We identified 3 sources of mortality – predation by raptors, foxes (red and corsac, Vulpes vulpes and V. corsac), and lynx (Lynx lynx). Most predation was by raptors, such as golden eagles (Aquila chrysaetos) and cinereous vulture (Aegypius monachus). Our results point to both environmental and biotic factors affecting juvenile survival.

Prescribed fire is a common land management tool in the southeastern United States. Historical fires occurred primarily in the growing season, but modern day prescribed fire is commonly restricted to the dormant season. Plant community responses to various fire regimes are relatively unknown, and managers require information on how fire regimes impact plant communities. To address these limitations, I studied the impacts of March and June fire on plant communities. Results indicated various woody midstory species respond differently to fire season and community response is driven by species composition. In another study, I examined impacts of February, May-June, and September-October backing and heading fires on midstory and understory vegetation. Results indicated May-June fires maximized midstory mortality and growing-season fires maximized herbaceous understory coverage while dormant-season fire promoted resprouting woody species. Managers can use this information to tailor fire prescriptions to specific properties to better meet management objectives.