Theses and Dissertations at Montana State University (MSU)

Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733

Browse

Search Results

Now showing 1 - 10 of 15

Sierran mixed conifer forest wildfires: a biodiversity comparison between active and passive timber land management
(Montana State University - Bozeman, College of Agriculture, 2019) Dalby, Caitlin M.; Chairperson, Graduate Committee: William Kleindl
The mixed conifer forests of the Northern Sierras have great value in their biodiversity. Timber land management in this region varies by land owner and their objectives, including timber harvest and conservation. An increase in annual wildfires each year indicates a need to understand how different silvicultural strategies before and after fires affect the overall ecosystem biodiversity. Ecosystem functions and services can be affected by many factors involving anthropogenic activities in combination with fires. The aim of this study was to determine to what degree active (private timber company) and passive (United States Forest Service) management after a wildfire may affect plant biodiversity, and to compare those silvicultural approaches to active and passive pre-fire management. The study takes place within the vicinity of the 2012 Chips fire burn scar in Plumas County, California. Using tree canopy and plant species percent cover, in addition to presence and absence data, within frames and nested frames along 50 meter transects, statistical analyses revealed little significant difference between active and passive management. Analysis from data collected in this study concluded that tree canopy cover is significantly different under active post-fire management than under passive post-fire management and pre-fire conditions. There was not a significant difference in understory biodiversity (richness and evenness) among the four treatments. Dissimilarity in plant species composition was significant among the burned and unburned treatments, as well as between the two differently managed burned treatments. While the treatments were significantly dissimilar, there was not enough data collected to account for the high degree of variability seen in the data and so further data collection and analyses across multiple spatial and temporal scales would give better insight into the differences in biodiversity between treatments.
Geomorphology, biodiversity and ecosystem function, and food web dynamics in large riverscapes
(Montana State University - Bozeman, College of Letters & Science, 2021) Scholl, Eric Arthur; Chairperson, Graduate Committee: Wyatt F. Cross; This is a manuscript style paper that includes co-authored chapters.
Humans have transformed the Earth's surface so extensively that we now play a dominant role in regulating geomorphological processes around the world. These effects are particularly prevalent in large rivers, which despite their high biophysical complexity, face widespread habitat alteration and simplification. The way species respond to such changes will unquestionably impact the structure and function of ecosystems, with cascading effects on numerous goods and services they provide. Consequently, efforts to understand how the physical habitat template shapes the structure and function of larger river ecosystems are critically needed to predict how future perturbations will impact these imperiled and iconic environments. My dissertation blends approaches from the physical and ecological sciences to uncover connections between the geophysical habitat template, biodiversity and ecosystem function, and the dynamics of food webs in large riverscapes. My questions were: 1) what are the spatial patterns and potential drivers of riverbed habitat, and how do they relate to process domain structures in large rivers? 2) how does the geophysical habitat template influence connections between invertebrate diversity and secondary production? and 3) how are trophic interactions supporting the federally endangered Pallid Sturgeon (Scaphirhynchus albus) shaped by the geophysical habitat template? I found consistent patterns of nested patchiness in riverbed substrate, indicating that multiple factors operating at different scales influence spatial patterns of substrate in the Missouri and Yellowstone Rivers. Invertebrate assemblages were tied to attributes of the geophysical habitat template, with strong relationships between large sediments and diversity. Invertebrate diversity, in turn, was positively related to secondary production, with the most diverse assemblages found in secondary production 'hotspots'. Finally, I found a general relationship between habitat diversity and trophic interaction strengths supporting Pallid Sturgeon, with geophysically diverse areas containing much weaker, and thus potentially stabilizing, interactions than homogenous areas. Additionally, habitat characteristics, such as sediment size, intensified these effects. Together, the chapters of my dissertation broadly highlight the role of nature's stage in governing patterns in biodiversity, secondary production, and trophic interactions across large and dynamic riverscapes, and provide empirical insights for guiding future management and conservation of large rivers in an increasingly simplified world.
Wetland biodiversity in Grand Teton National Park
(Montana State University - Bozeman, College of Letters & Science, 2022) Levandowski, Mary Lynn; Chairperson, Graduate Committee: Andrea Litt; Andrea R. Litt was a co-author of the article, 'Spatial and temporal isolation and size of wetlands influence richness and functional composition of aquatic macroinvertebrates' which is contained within this thesis.; Andrea R. Litt, Megan F. McKenna, Shan Burson and Kristin L. Legg were co-authors of the article, 'Multi-method biodiversity assessments from wetlands in Grand Teton National Park' in the journal 'Ecological indicators' which is contained within this thesis.
Freshwater wetlands support high biodiversity, yet many wetlands are subject to shifts in precipitation and temperature under projected climate patterns. These changes can alter wetland hydrological regimes, potentially leading to longer or more frequent dry periods, with effects that differ among taxa. In this thesis we aim to build on the understanding about biodiversity in wetlands and how these species may be affected by climate change, in hopes of providing information for land management. To accomplish these goals, we first focused on macroinvertebrates, a group that employs diverse strategies for surviving wetland drying. We explored the roles of wetland size, spatial isolation, and temporal isolation on macroinvertebrate richness and community composition. In summer 2018, we collected macroinvertebrates from 18 wetlands in Grand Teton National Park. We found macroinvertebrate family richness increased with wetland depth and slower rates of drying. We also found the interaction between spatial and temporal isolation explained the most variation in community composition for all the life history strategies we examined. Second, we explored the utility of different automated tools to monitor biodiversity in wetlands. In 2017, we placed wildlife cameras, as well as acoustic (audible and ultrasonic) recorders at 4 permanent wetlands in Grand Teton National Park for a week in June and August; we also completed a visual survey during each of these time intervals. We compared the number and type of species detected by each method over the summer to evaluate the effectiveness of each method for monitoring. Using wildlife cameras, in addition to visual surveys, increased the observation time at surveyed wetlands, captured complementary species, and recorded dynamics in the water level during the summer. These two chapters provide insights about how changes resulting from increased drying may affect one of the most biodiverse taxa and offer methods that allow monitoring of many taxa simultaneously.
Population structure, gene flow, and genetic diversity of Rocky Mountain bighorn sheep informed by genomic analysis
(Montana State University - Bozeman, College of Agriculture, 2020) Flesch, Elizabeth Pearl; Chairperson, Graduate Committee: Jennifer Thomson; Jay J. Rotella, Jennifer M. Thomson, Tabitha A. Graves and Robert A. Garrott were co-authors of the article, 'Evaluating sample size to estimate genetic management metrics in the genomics era' in the journal 'Molecular ecology resources ' which is contained within this dissertation.; Tabitha A. Graves, Jennifer M. Thomson, Kelly M. Proffitt, P.J. White, Thomas R. Stephenson and Robert A. Garrott were co-authors of the article, 'Evaluating wildlife translocations using genomics: a bighorn sheep case study' in the journal 'Ecology and evolution' which is contained within this dissertation.; Tabitha A. Graves, Jennifer M. Thomson, Kelly M. Proffitt and Robert A. Garrott were co-authors of the article, 'Genetic diversity of bighorn sheep population is associated with dispersal, augmentation, and bottlenecks' submitted to the journal 'Biological conservation' which is contained within this dissertation.
This dissertation evaluated the genomics of bighorn sheep (Ovis canadensis) herds across the Rocky Mountain West to determine optimal sample size for estimating kinship within and between populations (Chapter Two), to detect gene flow due to natural dispersal and translocations (Chapter Three), and to evaluate the correlation between genetic diversity and influences on population size (Chapter Four). To date, wildlife managers have moved many bighorn sheep across the Rocky Mountain West in an effort to provide new genetic diversity to isolated herds. However, little is known about the genetics of these herds and the real impacts of translocations. To learn how populations have been impacted by these management actions, we genotyped 511 bighorn sheep from multiple populations using a new cutting-edge genomic research technique, the Illumina Ovine High Density array, which contained about 24,000 to 30,000 single nucleotide polymorphisms informative for Rocky Mountain bighorn sheep. First, we determined that a sample size of 20 to 25 bighorn sheep was adequate for assessment of intra- and interpopulation kinship. In addition, we concluded that a universal sample size rule for all wild populations or genetic marker types may not be able to sufficiently address the complexities that impact genomic kinship estimates. Secondly, we synthesized genomic evidence across multiple analyses to evaluate 24 different translocation events; we detected eight successful reintroductions and five successful augmentations. One native population founded most of the examined reintroduced herds, suggesting that environmental conditions did not need to match for populations to persist following reintroduction. Finally, we determined that influences on population size over time were correlated with genetic diversity. Gene flow variables, including unassisted connectivity and animals contributed in augmentations, were more important predictors than historic minimum population size and origin (i.e. native vs. reintroduced). This hypothesis-based research approach will give wildlife managers additional biological insight to help inform various management options for bighorn sheep restoration and conservation.
Integrating cover crop mixtures in the northern Great Plains: an ecological assessment on crop productivity, biodiversity, and temperature and moisture conditions
(Montana State University - Bozeman, College of Agriculture, 2020) DuPre, Mary Ellyn; Chairperson, Graduate Committee: Fabian D. Menalled and Tim F. Seipel
Cropping systems can impact crop productivity and functioning of biodiversity in the Northern Great Plains, a region heavily reliant on low diversity crop rotations and off-farm inputs, and a region predicted to experience warmer and drier climate scenarios by mid-century. In three complementary studies, I compared the impacts of cover crop mixtures and termination methods on crop productivity and three forms of the associated biodiversity (weeds, soil fungi, and ground beetles), under varying temperature and soil moisture conditions. First, I assessed the impacts of the presence (cover crops and fallow) and composition (cover crop mixtures) of cover crops, termination methods (herbicide, cattle-grazing, and haying), as a function of temperature and soil moisture conditions on crop yields, and weed communities. A 5-species, early-spring mixture generated cooler temperatures, produced more biomass, and suppressed weed biomass under warmer and drier conditions, compared to summer fallow and the 7-species, mid-spring mixture. However, lower soil moisture and subsequent reduced grain yields following the mixtures, especially under warmer and drier conditions, suggests that continuously rotating wheat with mixtures may not be the optimal method to diversify small-grain cropping systems. Second, I assessed the impacts of the presence and composition of cover crops, termination methods and temperature and soil moisture conditions on fungal communities. The early-season cover crop mixture reduced plant pathogen abundance and enhanced AM fungal richness in both the soil and subsequent wheat root crop. The enhancement of beneficial fungi and fewer plant pathogens may be a proxy to better support ecosystem services through the use of cover crop mixtures. Third, I compared ground beetle communities among cover crops treatments and termination methods. Ground beetle activity density was not impacted by termination methods and was greatest in the early-season mixture at the beginning of the growing season and in summer fallow at the end of the growing season, while the mid-season mixture peaked in the middle. Ground beetle diversity peaked in the middle and differed in community composition earlier in the growing season. These results indicate that cover crop mixtures can act as an ecological filter to ground beetle communities to better support pest regulation. Overall, these studies indicate that cover crop mixtures can support crop productivity and the associated biodiversity with changes to temperature and soil moisture, although, with agronomic and ecological trade-offs.
Implementing a citizen science project in a 9-12 high school science classroom
(Montana State University - Bozeman, College of Letters & Science, 2019) Langager, Paula Marie; Chairperson, Graduate Committee: Walter Woolbaugh
This classroom action research (AR) project explored the impacts of project-based learning on high school students critical thinking, decision-making, data collection and data analysis skills through the implementation of a citizen science project. AP® Environmental Science (APES) students co-developed a citizen science project that explored their local schoolyard biodiversity by designing and researching their own scientific investigative question. An evaluation of students changes in science self-efficacy, and attitudes toward science research and specific science tasks was tracked throughout the project. Pre- and post-Likert surveys, open-ended questions, field journals, focus group interviews, and a biological solutions science poster were employed as data collection tools. A mixed methodology (qualitative and quantitative) was used to analyze the data. These results showed that students made reasonable gains in data collection and analysis skills, critical thinking and decision-making abilities. Noticeable improvements were detected in student attitudes toward science and science self-efficacy. A discernable change was observed in the student's overall data and data analysis skills related to a field study.
Distributions, abundances, and movements of small, nongame fishes in a large Great Plains river network
(Montana State University - Bozeman, College of Letters & Science, 2019) Duncan, Michael Bennett; Chairperson, Graduate Committee: Alexander V. Zale
The Yellowstone River is the longest unimpounded river in the conterminous United States and was thought to support a diverse fish assemblage; however, comprehensive data on the small nongame fish assemblage was lacking. I evaluated the sampling methods often used to capture small-bodied fishes in the channel margins of large Great Plains rivers, determined the distributions and abundances of these fishes in the Yellowstone River, characterized the movements of selected native cyprinids between the Yellowstone River and its tributaries, and assessed assemblage differences between the Yellowstone and Missouri rivers. Catch-per-unit-effort, species richness, and ranges of total lengths were greater in fyke net catches than in seine catches. Forty-two species (24 native and 18 nonnative) were captured in fyke nets in the lower Yellowstone River. Emerald Shiners Notropis atherinoides, Western Silvery Minnows Hybognathus argyritis, Flathead Chubs Platygobio gracilis, Sand Shiners Notropis stramineus, and Longnose Dace Rhinichthys cataractae composed nearly 94% of fyke net catch. Sturgeon Chubs Macrhybopsis gelida, Channel Catfish Ictalurus punctatus, Flathead Chubs, Stonecats Noturus flavus, and Sicklefin Chubs Macrhybopsis meeki composed 89% of the otter trawl catch. Sicklefin Chubs were captured as far as 18 river kilometers upstream of Glendive, Montana; Sturgeon Chubs were captured as far upstream as the Tongue River confluence. Otolith microchemistry analysis revealed that 69% of Western Silvery Minnows, 65% of Flathead Chubs, and 42% of Sand Shiners moved between main-stem and tributary habitats. The timing, frequencies, and patterns of movements varied among species. In my comparison of the Yellowstone and Missouri river fish assemblages, native and nonnative species richness were highest in Yellowstone River fyke net catches but proliferation of nonnative species was low. Total CPUE was highest in the Yellowstone River (median = 152 fish/net night), intermediate in the Missouri River below the Yellowstone River confluence (44 fish/net night), and lowest in the Missouri River above the confluence (21 fish/net night). Collectively, these studies provide a better understanding of the biotic and abiotic factors that help influence the distributions, abundances, and diversity of life-history strategies of small, nongame fish in Great Plains rivers.
Paleofire patterns in Tasmania: postglacial and Holocene record of fire and vegetation from Cradle Mountain-Lake St. Clair National Park, Tasmania, Australia
(Montana State University - Bozeman, College of Letters & Science, 2017) Stahle, Laura Nicole; Chairperson, Graduate Committee: Cathy Whitlock; Cathy Whitlock was a co-author of the book chapter, 'Getting information from the past: paleoecological studies of terrestrial ecosystems' in the book 'Key methods in geography' which is contained within this thesis.; Cathy Whitlock and Simon G. Haberle were co-authors of the article, 'A 17,000-year-long record of vegetation and fire from Cradle Mountain National Park, Tasmania' submitted to the journal 'Frontiers in ecology and evolution' which is contained within this thesis.; Cathy Whitlock and Simon G. Haberle were co-authors of the article, 'The postglacial and holocene record of fire and vegetation from Cradle Mountain National Park, Tasmania, Australia' which is contained within this thesis.
On centennial to millennial timescales fire regimes are driven by climate changes, vegetation composition, and human activities. In this study, I reconstructed the vegetation and fire history of Cradle Mountain-Lake St Clair National Park in northwestern Tasmania, and linked vegetation changes to variations in the fire regime, large-scale climate patterns, and anthropogenic activity. Postglacial vegetation and fire dynamics were inferred from five high-resolution pollen and charcoal records from lakes in the montane and subalpine zones of the National Park. Watershed-scale reconstructions of fire and regional trends in vegetation composition were compared to independent records of past climate and the regional archeological record to assess long-term climate-vegetation-fire-human linkages. Pollen and charcoal data indicate that during late-glacial period, the vegetation was largely open and fires were rare. During the Pleistocene-Holocene transition, rainforest taxa and subalpine woody shrubs began to increase in abundance. In the early Holocene, a fire activity maximum occurred at the three lower elevation sites while biomass burning remained low at the higher sites. The elevational differences and basin characteristics likely resulted in climate-controlled differences in vegetation and fuel flammability. The high biomass burning in the early Holocene occurred during the warmest interval of the Holocene as recorded by regional paleoclimate proxy records. The mid-Holocene period featured a multi-millennial phase of cool, temperate rainforest dominance at all sites. The relatively wet conditions of the mid-Holocene likely allowed the rainforest to reach its maximum extent. The late Holocene marks a regional shift toward open sclerophyll woodland associated with increased climate variability and decreased precipitation. A large fire episode occurred at all five sites during this period and hastened the shift in compositional balance from rainforest to a mosaic of sclerophyll woodlands and shrublands, rainforests, buttongrass moorlands, and alpine vegetation. Overall, the vegetation became substantially more open in the late Holocene. The human-fire linkages in Cradle Mountain are tenuous. There is no clear evidence that fire regimes or vegetation were extensively modified by humans prior to European settlement. Climate was the primary driver of fire activity over millennial timescales as explained by the close relationship between charcoal and climate proxy data.
Multi-species cover crops in the northern Great Plains : an ecological persepctive on biodiversity and soil health
(Montana State University - Bozeman, College of Agriculture, 2016) Housman, Megan Leigh; Chairperson, Graduate Committee: Catherine A. Zabinski; Susan M. Tallman, Clain A. Jones, Perry R. Miller and Catherine Zabinski were co-authors of the article, 'Soil water, soil nitrate, and residue quanity associated with cover crop mixtures in the northern Great Plains' submitted to the journal 'Agriculture, ecosystems, and environment' which is contained within this thesis.; Susan M. Tallman, Clain A. Jones, Perry R. Miller and Catherine Zabinski were co-authors of the article, 'Multi-species cover crops: effects on soil biology after one and two rotations in the semi-arid northern Great Plains' submitted to the journal 'Soil biology and biochemistry' which is contained within this thesis.
As summer fallow is replaced by cover crops, we aim to address how cover crops influence soil properties. Past studies conducted across the Northern Great Plains have investigated the short- and long- term effects of LGMs on water, nitrate, and carbon storage, soil parameters including potentially mineralizable nitrogen (PMN) and enzymatic activity, and wheat yield. Less knowledge exists regarding similar short- and especially long-term effects of CCMs in the NGP. This four-year study replicated at four sites in Montana allows us to investigate how site characteristics and annual weather patterns can influence the performance of cover crop growth and the subsequent effect on soil quality. Our research approach to building cover crop mixtures using functional group composition rather than species composition aims to make the work more broadly applicable to other regions. Other regions may utilize more adapted legume or brassica species and could still use our results to estimate their effects on soil and nitrate use throughout the soil profile or their effects on soil biological parameters.
Influences of ungulate carcasses on Coleopteran communities in Yellowstone National Park, USA
(Montana State University - Bozeman, College of Agriculture, 1994) Sikes, Derek Scott

Theses and Dissertations at Montana State University (MSU)

Browse

Filters

Settings

Sort By

Results per page

Search Results