Research projects

Individual Research Projects



Effects of Invasive Trees on Native Floodplain Forest Vegetation & Breeding Birds

Research mentors: Drs. Mark Dixon and David Swanson, Department of Biology

(2 students/summer)

Project Background: Floodplain forests, particularly those dominated by plains cottonwood (Populus deltoides), support among the highest levels of bird diversity of any habitat type in the Great Plains region, but native floodplain forests have been greatly reduced and degraded since the time of Euro-American settlement.  These changes have promoted the invasion of floodplain forests by native upland and non-native tree species.  These changes are likely to substantially impact breeding bird populations and nesting success, so we propose to investigate (1) the factors influencing the abundance and distribution of invasive woody plant species along the Missouri River and (2) the relative habitat quality of habitats dominated by native vs. invasive woody species.  

REU Research Project: For question #1, we will evaluate relationships between landscape factors (e.g., fragmentation), site factors (e.g., soils, management history), historical land cover change and the distribution, abundance, and age structure of invasive woody plants along the Missouri River.  For question #2, we will compare nest site selection and nesting success for bird species occupying habitats dominated by native and invasive trees and shrubs within floodplain forests along the Missouri River. We will compare nesting success using statistical models, with variables including the preponderance of invasive tree species, to determine factors influencing nesting success for floodplain forest birds. REU students will work with Drs. Dixon and Swanson to conduct vegetation surveys, find and monitor bird nests, and conduct statistical analyses of both vegetation and nest data. Students will learn identification skills and survey methods for birds, bird nests and floodplain forest plants, as well as methods of data analyses for bird nesting and community ecology data.

Student Qualifications:  No prior experience is necessary for this research project, but coursework in ecology and ornithology and skills in bird identification would be beneficial.  This project involves field work, so the student must be willing and able to work outside in summer conditions.

Effects of Modified Sediment Loads on Missouri River and Tributary Hydrology

Research mentor: Dr. Mark Sweeney, Department of Sustainability & Environment

Project Background: Suspended load is an important component of the total sediment load carried by a river, and it is an important nutrient source for numerous aquatic organisms. The installation of Gavins Point Dam resulted in a drastic reduction in suspended sediment load along the 59-mile stretch of the Missouri National Recreational River (MNRR), while also increasing sedimentation in Lewis and Clark Lake upstream of the dam. A recent two-year assessment of the suspended sediment contribution of tributaries to the Missouri River within the MNRR indicated that the tributaries had minimal impact on the river’s overall sediment load, however, a longer study is needed to evaluate seasonal impacts and long-term trends. A study upstream of the dam sought to determine sources of sediment depositing in Lewis and Clark Lake, predicted to fill in about 160 years. This REU project seeks to accurately determine seasonal changes in suspended load of Missouri River tributaries, and to help identify potential sources of that sediment by evaluating land use. 

REU Research Project: This research will measure the suspended load concentrations of the major tributaries (from bridges) at multiple times throughout the summer which will help to determine the role of the tributaries in sedimentation on the Missouri River. The REU student will use a depth-integrated sampler to collect samples and will process samples in the lab. The REU student will compare suspended load data to previous work and analyze the data for trends. S/he will investigate how differing land uses surrounding the Missouri River and its tributaries (e.g. grazing land, row-crop agriculture, riparian forest) affect local sediment contributions and the overall sediment load of the Missouri River. The student selected for this project will work in a geoscience-focused group of 2-3 students and compare data with GIS land-use mapping of the watershed.

Student Qualifications: Introductory coursework in environmental sciences or geosciences is required. The REU student must be able to work outdoors and repeatedly (several times over the course of 30 minutes) lower and lift a heavy, ~30-lb sampling device by rope >20 feet from a bridge. Student may also need to wade shallow streams for sampling purposes. The student must also have a valid driver’s license and may be expected to drive to and from field sites.


Effects of Invasive Fish on Missouri River Food Webs

Research mentor: Dr. Jeff Wesner, Department of Biology

Project Background:  Invasive fishes, including the bigheaded carp, are present in the Missouri River. While the effects of fishes in aquatic food webs are relatively well-studied, their effects on terrestrial food webs are not. The goal of this research is to understand how invasive fish affect linked aquatic-terrestrial food webs in the Missouri River. In particular, Dr. Wesner’s research group measures how fish affect emerging aquatic insects and the terrestrial predators they feed. They use manipulative experiments and field surveys to determine whether carp ingest insects during feeding, and if their presence alters the emergence of aquatic insects to terrestrial ecosystems. The effect of invasive fish on emerging aquatic insects will be measured using field surveys in the Missouri River and in artificial streams at USD’s Experimental Aquatic Research Site (ExARS). Fish effects on terrestrial food webs will be measured by quantifying fish diets and the density of terrestrial long-jawed spiders, which track aquatic insect emergence.

REU Research Project:  The REU student will assist with manipulative experiments, and will lead the diet survey with the assistance of Dr. Wesner. Specifically, the REU student will collect fish, extract gut contents, and identify prey items to determine what life-stage of insects fish eat. The REU student will learn concepts in life-history, entomology, food webs, experimental design and ecosystem ecology.

Student Qualifications:  Required qualifications are an ability to work independently and in relatively strenuous outdoor conditions. Preferred qualifications include coursework in ecology, ichthyology, experimental design, or other related subjects.


Geological Heritage Sites Along the Missouri River Corridor

Research mentor: Dr. Brennan Jordan, Department of Sustainability & Environment

Project Background: Geological heritage, commonly called geoheritage, is concerned with cataloging, conserving, and utilizing sites of geological interest. DeWever et al. (2015) provide a useful introduction to the concept of geoheritage, geoheritage comprises "...geological features and sites with global, national or local importance and that represent processes or a testimony of the Earth's history. Geoheritage- related objects at any scale are intrinsically or culturally important. They offer information or insights into the formation or evolution of the Earth, into the history of science or can be used for research, reference, educational purposes or other societal purposes, such as artistic inspiration." Geoheritage also serves a role in developing and supporting geotourism.

REU Research Project: The objective of this project is to undertake a geoheritage survey of the Missouri River corridor upstream from Sioux City, Iowa (extending some distance from the river in to South Dakota and Nebraska). Students will work with Dr. Jordan to develop an assessment method for geoheritage sites suitable for the scope of this project. We will then assess the catalog known geoheritage sites, and seek out less well known sites to include in the survey. Sites will be cataloged in a GIS database.

Student Qualifications:  Students should only apply for this course if they have has at least three geology courses, preferably including a course in stratigraphy or sedimentalogy. Some experience with GIF software (ArcGIS in particular) is desirable. The student must also have a valid driver's license and may be expected to drive to and from field sites.

Examining the Effects of Pesticides on Amphibian Disease

Research mentor: Dr. Jacob Kerby, Department of Biology

Project Background:  Corn and soybean production, which routinely includes the use of multiple agrochemicals, is the dominant land use in the MNRR watershed and is the leading cause of water pollution within the Corn Belt. Additionally, new strains of deadly pathogens are continually being introduced into altered aquatic systems like the Missouri River Basin. The interactive effects of agrochemical pollution and increased pathogen load has been purposed to be a potential cause of amphibian declines across the US, and is likely contributing to the declines of amphibian abundance in the Missouri River Basin. Due to the large number of potentially problematic contaminants in the Missouri River system, Dr. Kerby’s research group conducts both field and laboratory studies examining the impacts of agrochemicals and disease dynamics in several amphibian and turtle species. Dr. Kerby’s group has extensively researched the potential interactions between contaminants and pathogens along the Missouri River using amphibians as the focal taxon. His research group runs thousands of samples annually to diagnose the presence of amphibian pathogens via quantitative PCR methods.

REU Research Project:  The REU student will gather water quality data on contaminant concentrations via field surveys along established Missouri River study sites. The student will also examine the interactive effects on amphibian and turtle disease via experimental manipulations. This work will provide important information on water quality and its potential effects on aquatic organisms. Additionally, it will provide a wide range of training opportunities for the REU student including field-survey methods, toxicological experiments, and molecular laboratory skills.

Student Qualifications:  Students must be committed to conducting field work.  Dr. Kerby's group spends several weeks camping outdoors in tents and doing physical work on wetland and river systems.

A Changed River's Effects on Native Turtle Distribution

Research mentor: Dr. Jacob Kerby, Department of Biology

Project Background:  Dams installed on the Missouri River in the 1950's have dramatically changed the river landscape. For many of the aquatic species, these alterations have resulted in dramatic population declines. This project is focused on informing state biologists on how to best manage the imperiled False Map Turtle to encourage its persistence in areas where it formally flourished. Our laboratory has spent the past two years gathering data in Lake Oahe to determine what predicts the presence of differing native species of turtles along the Missouri River. This REU project will follow up on these data to add data to this effort and to improve modeling efforts to inform the state of practical solutions to improve habitat for turtle species.

REU Research Project:  The REU student will gather  data on habitat variables and turtle populations via field surveys along established Missouri River study sites. The student will also examine GIS layers to model these factors at a landscape level. This work will provide important information on habitat quality and its potential effects on native turtle distributions. Additionally, it will provide a wide range of training opportunities for the REU student including field-survey methods, toxicological experiments, and molecular laboratory skills.

Student Qualifications:  Students must be committed to conducting field work.  Dr. Kerby's group spends several weeks camping outdoors in tents and doing physical work on wetland and river systems.


Ethnohistorical Relationships among American Indian Tribes & the Missouri River

Research mentor: Dr. David Posthumus, Department of Anthropology

Project Background: In order to understand the Missouri River basin as a dynamic ecosystem, and in particular, the impacts of invasive elements on the sustainability of the river and those who depend upon it, an ethnohistorical baseline explicating the relationships between the Indigenous inhabitants of the region, the Missouri River, and its resources must be established. Numerous American Indian tribes are connected to the Missouri River basin, including the Sioux (Lakota, Yankton, and Yanktonai), Omaha, Arikara, Mandan, and Hidatsa, yet an ethnographic synthesis of these relationships has not been completed.

REU Research Project (2018): The objective of this research is to establish a baseline of cultural and historical data documenting traditional Indigenous relationships with the Missouri River in the Plains region. Utilizing ethnohistorical sources—both published and unpublished archival materials—this research explores and documents the historical values of Native communities who have lived in close proximity to the Missouri River and their evolving patterns of interaction with it. In particular, this research seeks to identify traditional cultural properties: “significant remnants of the past, present, and future of Native American and other traditional societies” (Kenmotsu et al. 1995:237) or places “associated with cultural practices or beliefs of a living community that (a) are rooted in that community’s history, and (b) are important in maintaining the continuing cultural identity of the community” (Parker and King 1990:1). Dr. Posthumus’s research expertise and the resources contained in USD’s South Dakota Oral History Center, which remain largely untapped by scholars, are strong assets to the project.

Student Qualifications: No prior experience is necessary for this research project, but coursework in anthropology, history, and Native American studies are preferred. The REU student will combine methods and theory from both anthropology and history. The REU student will address pre- and early-contact period ecological relational patterns of Indigenous peoples in the region with the Missouri, focusing on subsistence and sustainability. Using data from both primary and secondary sources the student will construct a baseline of ethnohistorical data in the form of a 25-page research paper that will be used in the next two phases of this project.


The Importance of Aquatic Insect-derived Fatty Acids to Riparian Birds Along the Missouri River

Research mentors: Dr. Jeff Wesner and Dave Swanson, Department of Biology

Project Background:  Adult aquatic insects represent an important dietary subsidy for riparian birds. However, the importance of aquatic insects to bird diets depends not only on the quantity of insects available, but also on the quality of insects. For example, aquatic insects can obtain highly unsaturated omega-3 fatty acids (HUFA's) from their algal-based diet, thereby making these essential HUFA's available to riparian birds. Diets based on terrestrial plant food webs do not contain HUFA's. As a result, terrestrial insects may have lower food quality than aquatic insects. This project will compare HUFA's between aquatic insects emerging from the Missouri River, terrestrial insects in the adjacent riparian habitat, and membranes of bird red blood cells. We will also use stable isotopes in bird feathers, blood and breath to use isotope signatures to the relative contribution of aquatic and terrestrial insects to diets of select riparian forest bird species. The results will determine the importance of aquatic insects in bird diets and their contribution as sources of dietary HUFA's to terrestrial riparian insectivores.
 
REU Research Project
:  The REU student will collect data with the assistance of graduate students and Drs. Wesner and Swanson, and will learn concepts in physiology, life-history, entomology, ornithology, food webs, and ecosystem ecology.
 
Student Qualifications
: Required qualifications are an ability to work independently and in relatively strenuous outdoor conditions. Preferred qualifications include coursework in ecology, entomology, physiology, ornithology, or other related subjects.

Perceptions of Multifunctional Landscapes Along the Missouri National Recreational River

Research mentor: Dr. Meghann Jarchow, Department of Sustainability & Environment

(2 students/summer)

Project Background:  The dominant land-use surrounding the Missouri National Recreational River (MNRR) is agriculture especially annual row-crop production. These row-cropped landscapes have been designed to maximize the production of commodity crops (e.g. corn, soybean) rather than optimizing the landscape for a wider range of ecosystem services, but increasing interest and need for more multifunctional landscapes may drive diversification in these simplified landscapes. The purpose of this research is to evaluate how landscapes could be designed to increase their multifunctionality and to evaluate residents' perceptions of these landscapes. 
 
REU Research Project
:  The REU students working on this project will use information from existing studies to develop scenarios of alternative landscapes that have greater multifunctionality for the region surrounding the MNRR.  The Sustainable RIVER students will conduct semi-structured interviews with urban and rural residents who live around the MNRR about their perceptions of these alternative landscapes. These alternative landscapes will include existing and new landscape features such as wind turbines, perennial bioenergy crops, food crops, and managed prairie. Interviewees will be asked to evaluate opportunities/advantages and concerns/disadvantages of the alternative landscapes. The REU student will assess the acceptability of these alternative landscapes by residents using qualitative data analysis methods.
 
Student Qualifications
:  No prior experience is necessary for this research project, but coursework in sustainability, sociology, qualitative data analysis, or GIS would be beneficial.