Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Grassland (4)
- South Dakota (4)
- Bighorn sheep (3)
- Northern Great Plains (3)
- Survival (3)
-
- Arctic (2)
- Biodiversity (2)
- Biological control (2)
- Chronic carrier (2)
- Conservation (2)
- Cover crops (2)
- Mixed-grass prairie (2)
- Mycoplasma ovipneumoniae (2)
- Nest survival (2)
- Nest-site selection (2)
- Nesting ecology (2)
- Pneumonia (2)
- Prairie dogs (2)
- Resource selection (2)
- Tundra (2)
- Waterfowl management (2)
- Agriculture (1)
- Alfalfa (1)
- American mink (1)
- Aquaculture (1)
- Baci (1)
- Badlands National Park Bighorn Sheep Disease Population Genetics Survival (1)
- Behavior (1)
- Benthic macroinvertebrates (1)
- Bird (1)
Articles 1 - 30 of 46
Full-Text Articles in Physical Sciences and Mathematics
Effects Of Low-Cost, Low-Tech Tools For Riparian Restoration On Prairie Streams In Western South Dakota, James Andrew Joseph Bolyard
Effects Of Low-Cost, Low-Tech Tools For Riparian Restoration On Prairie Streams In Western South Dakota, James Andrew Joseph Bolyard
Electronic Theses and Dissertations
Despite making up less than two percent of the overall landscape in the arid and semi-arid western US, riparian areas are a crucial resource for agriculture, livestock, and wildlife. However, many have impaired function and reduced riparian cover. Low-Cost, Low-Tech Tools (LCLTT) are a subset of Process-Based Restoration (PBR) used for riparian restoration that were chosen for their cost-effectiveness and minimal technical requirements. LCLTT has been tested in mountainous areas of the western US but only recently implemented in the Northern Great Plains (NGP). Given their novelty as an approach toward restoration for the region, professional restoration and landowner communities …
Species Distribution Modeling Of Aquilegia Brevistyla (Ranunculaceae): A Critically Imperiled Black Hills Disjunct Species, Eric Daniel Puetz
Species Distribution Modeling Of Aquilegia Brevistyla (Ranunculaceae): A Critically Imperiled Black Hills Disjunct Species, Eric Daniel Puetz
Electronic Theses and Dissertations
Unchecked human activity is contributing to rising levels of greenhouse gas emissions, changes in land use, altered disturbance/fire regimes, spread of invasive species, and loss of biological diversity and related breakdown of ecosystem services. Additionally, climatic shifts may lead to phenological mismatches between species and their environments if these changes outpace a species’ ability to adapt or migrate to a more suitable habitat. Isolated mountain populations are particularly threatened by unpredictable climatic conditions, as they may have limited migration corridors and often lower levels of genetic diversity to move or adapt, respectively. As these negative feedbacks compound on the landscape, …
Effects Of Agricultural Chemicals On Native Plants Of The Northern Great Plains, Gabrielle Bolwerk
Effects Of Agricultural Chemicals On Native Plants Of The Northern Great Plains, Gabrielle Bolwerk
Electronic Theses and Dissertations
Agricultural chemicals are ubiquitous on the Northern Great Plains landscape and have negative impacts on non-target plant communities, even at small doses. Northern Great Plains grassland plant communities may experience herbicide drift from agricultural fields or be subject to livestock pharmaceuticals in grazing lands. My research objective was to evaluate if and how native plants are affected by agricultural chemical presence at different concentrations. In Chapter 2, I studied the effect of different concentrations of three common agricultural herbicides (2,4-D, atrazine, and trifluralin) on the germination, emergence, and growth of native plant species of the Northern Great Plains. I performed …
Factors Influencing Mortality Of Bighorn Sheep (Ovis Canadensis), Emily Moberg
Factors Influencing Mortality Of Bighorn Sheep (Ovis Canadensis), Emily Moberg
Electronic Theses and Dissertations
Reintroduced bighorn sheep (Ovis canadensis) in Nebraska faced a devastating pneumonia epizootic resulting in variable ewe reproductive success and poor lamb recruitment in many of the herds. From 2015-2017, no lamb recruitment was observed in the northern Pine Ridge subpopulation and as many as 60% of adults died. This was in stark contrast to the healthier Wildcat Hills herds to the south, where lamb recruitment was estimated to be between 50-70% during the same years. From 2018-2020, we radio-collared and recaptured 76 adult female bighorn sheep from 2 of 3 Pine Ridge herds and 1 of 2 Wildcat Hills herds. …
Relating Predator Community Ecology And Duck Nest Survival In Eastern South Dakota, Samantha R. Fino
Relating Predator Community Ecology And Duck Nest Survival In Eastern South Dakota, Samantha R. Fino
Electronic Theses and Dissertations
As conversion of native grasslands and wetlands to croplands continues in the Prairie Pothole Region (PPR), managers are tasked with maintaining sustainable waterfowl populations. Mesopredator community dynamics is a hypothesized mechanism driving spatiotemporal variation of waterfowl nest survival in the PPR, yet studies often lack detailed information on mesopredator species occurrence and abundance. Therefore, understanding spatial and temporal variation in behaviors of mesopredators provides valuable insights for understanding predator-prey interactions between mesopredators and upland duck nests. Further, differences in a predator community resulting from lethal removal of dominant species may influence composition and space use patterns of subordinate and non-target …
Eastern Redcedar (Juniperus Virginiana L.) Encroachment On South-Central South Dakota Rangelands: Impact On Plant Communities, Austin K. Domeier
Eastern Redcedar (Juniperus Virginiana L.) Encroachment On South-Central South Dakota Rangelands: Impact On Plant Communities, Austin K. Domeier
Electronic Theses and Dissertations
Grasslands historically covered 46 million km2 of Earth’s surface representing nearly 42% of the living vegetation. Encroachment of woody species onto grasslands and savannas is a widely researched global phenomenon, with eastern redcedar (ERC) (Juniperus virginiana L.) trees being the most prominent woody encroacher in the Northern Great Plains (NGP) due to the lack of prescribed fire and planted ERC escaping from shelterbelts. This encroachment poses a threat to native plant communities in terms of their reproduction, regeneration, and diversity. ERC are fierce competitors and can establish in most soil types, are drought tolerant, and prolific seed reproducers. These qualities …
Evaluating Avian Use Of Cover Crops In The Corn Belt, Megan Figura
Evaluating Avian Use Of Cover Crops In The Corn Belt, Megan Figura
Electronic Theses and Dissertations
The tallgrass prairie of North America has changed drastically since colonial settlement, with up to 99% of this region converted for agriculture and other land-uses. Concurrent with grassland conversion, grassland birds have experienced the most extreme, consistent, and widespread population declines of any avian guild. Agricultural lands in the U.S. Midwest were able to provide adequate habitat for several bird species until the 1950’s; however, altered and intensified management practices have degraded much of remaining suitable habitat and undermined ecosystem functions. Consequently, many grassland birds have been identified as Species of Greatest Conservation Need (SGCN) in many State Wildlife Action …
Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor
Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor
Electronic Theses and Dissertations
The Prairie Pothole Region (PPR) of North America provides critical habitat for waterfowl across life stages, but anthropogenic changes to the landscape have negatively impacted habitat quality for waterfowl. The mallard (Anas platyrhynchos) is abundant and socioeconomically valuable in the PPR, as it is a preferred target species of waterfowl hunters. Extensive research has evaluated breeding ecology of mallards in the PPR, but the period between juvenile mallards fledging and migrating has rarely been studied. The post-fledging ecology of juvenile mallards is a vital consideration for comprehensive waterfowl management. Further, juvenile mallards are a significant portion of hunter harvest at …
Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels
Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels
Electronic Theses and Dissertations
Conventional agricultural practices can have unintended consequences on the environment and wildlife. Insects and birds are declining at rapid rates around the world, and the current conventional agricultural paradigm is a major driver through habitat loss and the intensification of production. Invertebrates in agroecosystems provide services to both farmers and the rest of society. Regenerative systems may promote the functioning of an agroecosystem by influencing invertebrate abundance, diversity, and ecosystem services and mitigate bird and insect declines through conservation practices that increase soil health, reduce disturbances, and increase biological diversity. Here I address knowledge gaps of the effects of regenerative …
A Post-Pneumonia Epizootic Evaluation Of The Rapid City, South Dakota Bighorn Sheep Herd, Amanda N. Ensrud
A Post-Pneumonia Epizootic Evaluation Of The Rapid City, South Dakota Bighorn Sheep Herd, Amanda N. Ensrud
Electronic Theses and Dissertations
Pneumonia is a major factor affecting populations of free-ranging bighorn sheep (Ovis canadensis) across western North America. Pneumonia can occur in large-scale epizootics, during which greater than half of the population typically dies. After these epizootics, surviving ewes continue to conceive and bear lambs. However, lamb recruitment may remain low due to periodic or annual pneumonia outbreaks causing high lamb mortality rates, sometimes greater than 90%. Our study focused on the Rapid City, South Dakota bighorn sheep (BHS) herd that has recorded pneumonia-induced population decline since 2009. The first objective was to improve lamb health and survival by identifying and …
Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield
Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield
Electronic Theses and Dissertations
As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …
Spatial And Temporal Patterns Of Sympatric Bobcats (Lynx Rufus) And Coyotes (Canis Latrans) In An Agricultural Landscape, Marlin M. Dart
Spatial And Temporal Patterns Of Sympatric Bobcats (Lynx Rufus) And Coyotes (Canis Latrans) In An Agricultural Landscape, Marlin M. Dart
Electronic Theses and Dissertations
Bobcat (Lynx rufus) populations experienced declines in the Midwest during the 20th century due to land conversion for agriculture and over exploitation and were practically nonexistent in areas by the 1970-80s. Populations have been recovering following changes in land-use practices and habitat improvement. Eastern South Dakota was closed to bobcat harvest in 1977 but reopened in 2012 to select counties. Bobcats are elusive, have large home ranges, and occur at low densities, making monitoring their populations difficult. Camera trapping is an effective tool for monitoring elusive carnivores but can be burdened by low detection rates. Researchers often employ …
Pheasant Ecology In An Agricultural Landscape Of South Dakota, Sprih Harsh
Pheasant Ecology In An Agricultural Landscape Of South Dakota, Sprih Harsh
Electronic Theses and Dissertations
Habitat loss and fragmentation are the greatest threats to wildlife conservation. Grasslands are among the most threatened ecosystems worldwide. The large-scale conversion of North American grasslands to cultivation has been strongly associated with declines of grassland bird populations. The ring-necked pheasant (Phasianus colchicus) is a common grassland bird which is negatively impacted by the conversion of grassland to cropland. Though pheasants are non-native to South Dakota, they have become naturalized in most of the state. However, with increases in agricultural intensification in South Dakota, indices of pheasant abundance from brood route surveys suggest that pheasant populations have declined to historically …
An Evaluation Of The Bighorn Sheep Population In Badlands National Park, Austin J. Wieseler
An Evaluation Of The Bighorn Sheep Population In Badlands National Park, Austin J. Wieseler
Electronic Theses and Dissertations
Within the last century, bighorn sheep (Ovis canadensis) in the badlands ecosystem of western South Dakota have been subjected to complete extirpation, reintroduction, disease die-offs, genetic bottlenecking, and population augmentation. Subsequently, the population in Badlands National Park (BNP) appears to have recovered, but it was unknown to what degree past events had influenced the population. From 2017-2019, we conducted research on 5 subherds within 2 management units in BNP to 1) survey for the presence of respiratory pathogens and estimate the prevalence of other potentially infectious diseases; 2) assess adult and lamb survival and cause-specific mortality; 3) estimate population size …
Effects Of Harvest Regulations And Post-Release Hooking Mortality On Walleye Populations In South Dakota, Cade Lyon
Electronic Theses and Dissertations
Harvest regulations are commonly implemented to manipulate fisheries stocks. By regulating the size and number of fish that are harvested by anglers, managers are able to meet the goals and needs of regions. However, these management actions come with the potential for negative consequences. Overexploitation due to less restrictive harvest regulations can cause collapses in fisheries populations. In addition, indirect consequences such as hooking mortality brought on by length-based regulations can also be detrimental to populations. In this study, I investigated the effects of various harvest regulations on Walleye populations in three western South Dakota irrigation reservoirs: Angostura, Belle Fourche, …
Revegetating Salt-Impacted Soils In The Northern Great Plains, Abigail P. Blanchard
Revegetating Salt-Impacted Soils In The Northern Great Plains, Abigail P. Blanchard
Electronic Theses and Dissertations
In the northern Great Plains (NGP), an estimated 10.6 million hectares of land are affected by naturally occurring salt-impacted soil. Naturally occurring salt impaction results when rainfall causes salts in parent material to move upward through the soil profile and remain in the root zone causing osmotic and ionic stress, negatively affecting seed imbibition, germination, and plant growth. Common methods to remediate saltimpacted soils were developed in the irrigated soils of the Southwestern U.S., are ineffective in the non-irrigated soils of the NGP, and can exacerbate the problem. Therefore, new methods to remediate salt-impacted soil in the NGP are needed. …
Effects Of Predator Management And Parasitism On Over-Water Nesting Diving Duck Production In Southwestern Manitoba, Trenton E. Rohrer
Effects Of Predator Management And Parasitism On Over-Water Nesting Diving Duck Production In Southwestern Manitoba, Trenton E. Rohrer
Electronic Theses and Dissertations
Nest survival of upland nesting waterfowl (e.g., mallard [Anas platyrhynchos], blue-winged teal [Anas discors]) has been studied extensively in the Prairie Pothole Region (PPR) of North America. Conversely, over-water nesting diving ducks’ nest survival is poorly understood, likely because over-water nests are more challenging to find, may be less concentrated, and searching for these nests is physically demanding. Nest depredation is considered a leading cause of duck nest failure and is considered a limiting factor on upland nesting waterfowl production in the PPR. Similar factors limiting upland nesting duck production may limit over-water nesting duck productivity, but studies of this …
Evaluation Of Fall-Seeded Cover Crops For Grassland Nesting Waterfowl In Eastern South Dakota, Charles W. Gallman Iii
Evaluation Of Fall-Seeded Cover Crops For Grassland Nesting Waterfowl In Eastern South Dakota, Charles W. Gallman Iii
Electronic Theses and Dissertations
The Prairie Pothole Region is the primary breeding ground for many species of North American waterfowl. This landscape was historically dominated by mixed and tallgrass prairies interspersed with wetlands, but >70% of native grassland area has been lost due to widespread conversion to croplands, which may threaten waterfowl production. Cover cropping is a re-emerging farming technique that may provide suitable nesting cover for grassland nesting waterfowl on active farmlands. My research objectives were to evaluate the utility of fall-seeded cover crops to breeding waterfowl compared to perennial cover, determine if cover crops in rotation with row crops can successfully support …
Influence Of Mink Predation On Brown Trout Survival And Size-Structure In Rapid Creek, South Dakota, Austin Galinat
Influence Of Mink Predation On Brown Trout Survival And Size-Structure In Rapid Creek, South Dakota, Austin Galinat
Electronic Theses and Dissertations
I compared movement, home range, habitat selection, and mortality among radio-tagged Brown Trout (Salmo trutta) at an American Mink (Neovison vison)-removal site, improved habitat site, and an undisturbed stream site in Rapid Creek, South Dakota. I observed high, post-surgery (> 26 days) survival rate (90%) of radio tagged Brown Trout. Average gross movement of Brown Trout was greater at the improved habitat site (127 m) compared to the mink removal (31 m) site, while average home range size (i.e., stream distance) among all three sites was not significantly different indicating strong site fidelity (125 to 200 m). Brown Trout movements …
Epidemiological Investigations Of Bighorn Sheep Respiratory Disease And Implications For Management, Brandi L. Felts
Epidemiological Investigations Of Bighorn Sheep Respiratory Disease And Implications For Management, Brandi L. Felts
Electronic Theses and Dissertations
Infectious respiratory disease has long been identified as the cause of bighorn sheep (Ovis canadensis) historical declines and extirpations, and Mycoplasma ovipneumoniae (Movi) is the primary pathogen inducing disease and mortality. Population-level effects of pneumonia events range from mild to extirpation. Variable individual response to pathogen exposure emerges from dynamic interactions between competing evolutionary processes within the host and pathogen. Understanding impacts of this evolutionary warfare is essential to assessing long-term impacts of pathogen invasion and developing appropriate countermeasures to protect population health. Freeranging populations are faced with spillover infections from domestic sheep and goats as well as …
The Effect Of Neonicotinoid Clothianidin On Ring-Necked Pheasant Survival And Reproduction, Michael Sundall
The Effect Of Neonicotinoid Clothianidin On Ring-Necked Pheasant Survival And Reproduction, Michael Sundall
Electronic Theses and Dissertations
Ring-necked pheasants (Phasianus colchicus) are economically important to the state of South Dakota bringing in over one hundred million dollars in revenue each season. The population is known to fluctuate temporally for many reasons, often weather related. Unfortunately, no research has been conducted involving ring-necked pheasants that evaluated the impact or interaction of neonicotinoids on the species. The objective of our study was to gain an understanding of how the neonicotinoid, Clothianidin, affects survival and breeding in pheasants. Our first experiment was to determine if there was a selection bias for seeds treated with neonicotinoids. In this experiment, eight ring-necked …
Distribution, Density, Movement, And Support For Management Of Mountain Sucker, Pantosteus Jordani, In The Black Hills Of South Dakota, Seth J. Fopma
Distribution, Density, Movement, And Support For Management Of Mountain Sucker, Pantosteus Jordani, In The Black Hills Of South Dakota, Seth J. Fopma
Electronic Theses and Dissertations
Mountain Sucker, Pantosteus jordani, is a cold-water species native to the Intermountain West. Fringe populations of Mountain Sucker have experienced declines in recent decades. The population of Mountain Sucker found in the Black Hills of South Dakota represents the eastern fringe of the species’ native range. Recognized as both an indicator of biologic health and as a species of greatest conservation need in South Dakota, recent studies have suggested significant declines in both distribution and abundance. Despite the recent study of Mountain Sucker in the region, increased understanding of Mountain Sucker ecology is needed to effectively manage for the conservation …
Examining Biodiversity Metrics And The Utility Of Dna Barcoding In The Northern Great Plains, Sarah Herzog
Examining Biodiversity Metrics And The Utility Of Dna Barcoding In The Northern Great Plains, Sarah Herzog
Electronic Theses and Dissertations
Due to heavy threats to remaining global floral and faunal diversity, it is imperative we can identify species and quantify ecosystem health to find best practices for land management and conservation. The tallgrass prairies of the Northern Great Plains are one example of a heavily imperiled ecosystem. The tallgrass prairies have been reduced to less one percent of their historical extent and are facing continued loss. Genetic approaches and evolutionary theory offer insights for identifying species and assessing how biodiversity metrics may correlate with ecosystem processes. My two projects aim to address two facets imperative to conservation in the tallgrass …
Understanding How Agricultural Intensification Impacts Ring-Necked Pheasant Distribution And Survival In Eastern South Dakota, Hilary R. Kauth
Understanding How Agricultural Intensification Impacts Ring-Necked Pheasant Distribution And Survival In Eastern South Dakota, Hilary R. Kauth
Electronic Theses and Dissertations
Historically, pheasants (Phasianus colchicus) have thrived in South Dakota in conjunction with successful land retirement programs or early farming practices through the 1950s, which created interspersions of agriculture and native landscapes that were ideal for pheasants. Recently, the Prairie Pothole ecosystem has undergone rapid agroeconomic expansion, effectively reducing ideal interspersions of native prairie and cropland into agriculturally homogeneous landscapes. Indices of pheasant abundance have suggested persistent population declines since 2008, raising concerns regarding landscape suitability. Our goal was to understand how agriculture intensification impacts pheasant ecology. The objectives were to: 1) estimate overwinter hen probability of survival, resource …
Winter Patch Grazing, Patch Burn Grazing, And Bird Communities In Western South Dakota, Jennifer Lutze
Winter Patch Grazing, Patch Burn Grazing, And Bird Communities In Western South Dakota, Jennifer Lutze
Electronic Theses and Dissertations
Ground nesting bird species are on a considerable decline and research efforts are being made to increase these populations throughout the Great Plains. Ground nesting bird communities found in the Northern Great Plains are driven greatly by varying amounts of cover and area size. Past research implemented patch-burn grazing to increase structural heterogeneity and to increase grassland bird habitat in the tallgrass prairie. While bird populations were very responsive to this management in the Northern Great Plains fire management is viewed negatively, especially for Midwest cattle ranchers. We implemented research to determine if winter-patch grazing on mixed grass prairie could …
Higher Temperatures Have Contrasting Effects On Different Components Of Forage Quality For Caribou In Northern Alaska, Heidi Becker
Higher Temperatures Have Contrasting Effects On Different Components Of Forage Quality For Caribou In Northern Alaska, Heidi Becker
Electronic Theses and Dissertations
Rising temperatures in the Arctic may affect vegetation, which in turn can affect herbivores, such as caribou, that rely on these plants for forage. Several plant traits contribute to forage quality, including digestibility, nitrogen content, and antiherbivory secondary compounds, but the effect of temperature on these traits individually and combined is unclear. I conducted a three-component study on the effect of higher temperatures on the forage quality of graminoids, deciduous shrubs, and evergreen dwarf shrubs on the North Slope of Alaska. The components included: 1) short and long-term experimental warming, 2) natural temperature variation between south and north-facing slopes, and …
The Tortoise (Wildfire) And The Hare (Heavy Winter Grazing) For Promoting Heterogeneity And Improving Ecosystem Services, Lucas W. Zilverberg
The Tortoise (Wildfire) And The Hare (Heavy Winter Grazing) For Promoting Heterogeneity And Improving Ecosystem Services, Lucas W. Zilverberg
Electronic Theses and Dissertations
The Northern Great Plains (NGP) mixed-grass prairie developed under fire, grazing, and periodic droughts, which created a heterogeneous landscape. Since European settlement, heterogeneous landscapes have declined due to fire suppression and the maximization of livestock production, leading to the need for an alternative management practice. Our overall project objective was to determine if heavy winter grazing could be used as an alternative to patch-burn grazing for promoting heterogeneity and improving ecosystem services in the NGP. Fire has been used very effectively in patch-burn grazing management to create heterogeneity in pastures in some areas, however burning is not readily adopted in …
Winter Snow Depth In Arctic Alaska Results In Complex Changes In Caribou Forage Quality, Jessica C. Richert
Winter Snow Depth In Arctic Alaska Results In Complex Changes In Caribou Forage Quality, Jessica C. Richert
Electronic Theses and Dissertations
Caribou (Rangifer tarandus) rely on the short growing season for much of their annual nutrition, making them susceptible to even small changes in forage quantity and quality. Body condition in the summer and fall is linked to winter survival rates and fecundity in cows, critical factors in the robustness of caribou populations. Due to a warmer, wetter climate, snowfall is predicted to increase over Alaska’s North Slope in the next several decades. Deeper snow results in higher soil temperatures, allowing microbial mineralization of nitrogen to continue throughout the winter and increasing the availability of nitrogen for plants in spring and …
Effect Of Water Velocity And Temperature On Energy Use, Behavior, And Mortality Of Pallid Sturgeon Scaphirhynchus Albus Larvae, Joseph Thomas Mrnak
Effect Of Water Velocity And Temperature On Energy Use, Behavior, And Mortality Of Pallid Sturgeon Scaphirhynchus Albus Larvae, Joseph Thomas Mrnak
Electronic Theses and Dissertations
Pallid Sturgeon Scaphirhynchus albus are a federally endangered species endemic to the Missouri River basin. Natural reproduction has been limited for decades and a recruitment bottleneck is hypothesized to occur during the larval stage of development. Understanding factors that affect survival of Pallid Sturgeon larvae is key given their critical status and ongoing recovery efforts. In this study, I evaluated the effects of water velocity and temperature on energy use, behavior, and mortality of endogenously feeding Pallid Sturgeon larvae (< 25 mm TL). In the first experiment, I examined the effect of water velocity (0 – 8.3 cm s−1) on larval growth, energy density, swimming activity, and mortality. Larval growth rate at 16.3 °C was similar across …
Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson
Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson
Electronic Theses and Dissertations
The lack of suitable habitat conditions for beneficial organisms in simplified agroecosystems leads to unstable invertebrate communities and overreliance on chemical control of herbivores. It is possible to manage pest populations without agrichemicals by manipulating farmland so that herbivores are impaired by plant-driven bottom-up and enemy-driven top-down antagonisms. Interseeding cover crops between established crop rows is a method used by farmers to improve habitat suitability for natural enemies and hinder host-finding, feeding and movement by herbivores. Here I address three important research gaps related to interseeding cover crops. A calcium carbonate seed coating, used to improve seed-broadcasting efficiency, was tested …