Life Sciences Commons^™

Management Of Channel Catfish Ictalurus Punctatus In The Missouri River, Nebraska, Brandon L. Eder

School of Natural Resources: Dissertations, Theses, and Student Research

The popularity of catfish Ictaluridae nationally as a sport fish is well documented and angling for catfish on the Missouri River in Nebraska (NMR) is especially popular. Catfish monitoring program by the Nebraska Game and Parks Commission (NGPC) began in 1974 and several short-term evaluations of Channel Catfish population dynamics have been performed. However, no long term analyses of population characteristics have been conducted since the early 1990s. The focus of this research was to summarize the status of Channel Catfish populations in the NMR and give recommendations for future management. I summarized population characteristics, modeled length limit regulations, and …

Decision Support Tools To Address Climate Change: Climate Model - Land Surface Models, Zea Mays L. (Corn) Phenology And Evapotranspiration-Yield Sensitivity Models For Nebraska, Usa., Jane A. Okalebo

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska's climate is highly variable and is expected to change in the future with anthropogenic global warming (AGW), resulting in warmer spring and summer temperatures coupled with more erratic rainfall events. This has strong implications for agriculture in the region, yet it is not clear that current modeling and decision-support tools are adequate to address these looming changes and provide planning, mitigation and adaptation strategies. To address climate change and its implications to agriculture in Nebraska, a set of robust decision support tools are very crucial. This study herein are divided into three chapters, with each chapter addressing a specific …

A Case Study Of Changing Cropping Diversity And Agricultural Risk In The Doulthabad Mandal Of Telangana State In India, Srikanth Kondabolu

School of Natural Resources: Dissertations, Theses, and Student Research

The Doulthabad^[1] Mandal is a hot semi-arid agro-ecological sub-region (Rao et al. 2006) located in Mahbubnagar District on the North Telangana Plateau in the state of Telangana. Agriculture is the main occupation in this region, which is populated mostly with small and marginal farmers. This study uses the time period from 1971 to 2004 to study the variation in cropping pattern diversity and distribution of rainfall during the monsoons and understand the implications on production risk in agriculture. Quantitative methods were used in determining the changes in rainfall while qualitative methods were used to study cropping system changes. The …

Informing Flood Plain Wetland Restoration Using Amphibian Monitoring, Ashley Vanderham

School of Natural Resources: Dissertations, Theses, and Student Research

Wetlands are among the most important and complex ecosystems in the world. They contribute to nutrient cycling, the hydrologic cycle, and provide critical habitat for many plants, fish, and wildlife. Channelization of Missouri River resulted in the loss of many floodplain wetlands. Despite ongoing restoration efforts, there are few ecologically-based performance guidelines, and managers need methods to quantify and assess the success of restored riverine wetland systems.

In 2008 a multi-institutional herpetofauna monitoring project, funded by the U.S. Army Corps of Engineers, was initiated in four states (Kansas, Missouri, Iowa, and Nebraska). The main goal of the project is to …

Influence Of Non-Native Trout On Native Non-Game Fish In Nebraska Headwater Streams, Kelly C. Turek

School of Natural Resources: Dissertations, Theses, and Student Research

Introduced, non-native trout may have detrimental competitive or predatory interactions with native fishes. However, few studies have experimentally examined interactions between introduced trout and native non-game species. Therefore, the objectives of this study were to determine 1) if non-native rainbow trout Oncorhynchus mykiss influence survival, behavior, movement, or distribution of native longnose dace Rhinichthys cataractae under laboratory conditions, 2) if non-native rainbow trout influence survival of native longnose dace under in-situ conditions using in-stream enclosures, and 3) if native fish populations or communities differ in the presence and absence of non-native trout under natural conditions.

Rainbow trout preyed on longnose …

Response Of Large River Fishes To A Prolonged High Water Event In The Missouri River, Nebraska, Nicholas Paul Hogberg

School of Natural Resources: Dissertations, Theses, and Student Research

Regulation and modification of large rivers to accommodate human uses have been a root cause of freshwater biodiversity declines. The Missouri River is among the most drastically-altered large river systems in North America, with a series of mainstem impoundments in the upper watershed altering flow characteristics downstream, and channelization throughout the lower river homogenizing instream habitat and reducing off-channel habitat. Precipitation events during the winter and spring 2010-2011 caused flooding of the greatest magnitude and duration since reservoir completion. The large magnitude and long duration of this flood made it unlike any flood in recent history and provided a unique …

Accuracy Or Precision: Implications Of Sample Design And Methodology On Abundance Estimation, Lucas K. Kowalewski

School of Natural Resources: Dissertations, Theses, and Student Research

Estimation of population size by spatially replicated counts (point-count method) has been used for many large-scale animal-monitoring programs, yet its application in aquatic environments has been limited. Multiple site-specific estimates of abundance can be averaged and combined with covariate data to predict total abundance across an area of interest. Covariate data also provide an understanding of the relationship between abundance and habitat use, which is a fundamental interest of many animal-population investigations. Design of sampling scenarios for point-count population-estimate surveys can influence the accuracy and precision of the population estimate. The first objective of this study was to examine how …

Development Modeling Of Lucilia Sericata And Phormia Regina (Diptera: Calliphoridae), Amanda L. Roe

School of Natural Resources: Dissertations, Theses, and Student Research

The relationship between insect development and temperature has been well established and has a wide range of uses, including using blow flies for postmortem (PMI) interval estimations in death investigations. To use insects in estimating PMI, we must be able to determine the insect age at the time of discovery and backtrack to time of oviposition. Unfortunately, existing development models of forensically important insects are only linear approximations and do not take into account the curvilinear properties experienced at extreme temperatures. A series of experiments were conducted with two species of forensically important blow flies (Lucilia sericata and Phormia …

Fear Effects On Pheasant Reproductive Ecology And A Curriculum To Teach Wildlife Habitat Selection, Jessica Laskowski

School of Natural Resources: Dissertations, Theses, and Student Research

Predation risk is an important source of selection that shapes prey density, distribution and abundance. The immediate impacts of predator consumption on prey populations are widespread and well-studied, and a growing body of research demonstrates immediate impacts of predator-induced fear (independent of prey mortality) on prey behavior, physiology and life-history expression. However, predation risk is often seasonally variable and while it is clear that consumption effects often carry over to influence prey population demography for years after predators have disappeared, the temporal carry-over effects of fear on prey populations remain largely unexplored. We assessed effects of fall hunting activity by …