Browsing by Subject "prairie"

Now showing 1 - 6 of 6
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    Dry Prairie Restoration Using Mycorrhizal Inoculants
    (2021) Migdal, Nathan
    Converting high-input agricultural land from conventional crop production to prairie vegetation requires careful planning and timely execution. This ongoing research is examining commercial mycorrhizal inoculants used for soil regeneration within a suboptimal restoration area. The primary goal of this study is to quantify plant biological responses to various blends of mycorrhizal fungi applied at specific quantities while seeding plots.
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    Evaluating Landscape and Local Drivers of Pollination in Melittophilous Tallgrass Prairie Forbs: Effects of Surrounding Land-use on Pollen Limitation of Chamaecrista fasciculata & Prescribed Burning on Flowering and Pollination of Dalea purpurea
    (2020-01) Ritchie, Alan
    Tallgrass prairies are one of the most endangered ecosystems in North America. Habitat loss and degradation of remaining prairies threaten both the biodiversity and functioning of these ecosystems. At the landscape scale, loss and fragmentation of existing prairie may limit regional pools of species and abundance of individuals, hampering movement of plants and animals between suitable habitats. At the local scale, degradation of prairies has been exacerbated by loss of native grazers and suppression of fire, the major ecological forces that historically shaped prairie species and communities. While the impacts of these factors on biodiversity in prairies is well-established, little is known about the role of these factors on plant-pollinator interactions, an important ecological process for many prairie forbs. As restoration of prairie habitats is one of the chief means of protecting prairie habitats and biodiversity, evaluating the roles of these factors in mediating ecological processes such as pollination will be critical to their reconstruction. Within this thesis, I explore how two important aspects of habitat restoration management, landscape context and prescribed burning, influence pollination in two common, widespread prairie forbs reliant on insects, namely bees, for pollination. The findings of these studies serve as initial assessments of two under-explored topics with relevance to tallgrass prairie conservation: how placement of a restoration effects recruitment of pollinators and the pollination they provision a habitat, and how animal-mediated pollination influences prescribed burning’s effects on plant reproduction.
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    Fitness and Adaptive Capacity in a Minnesota Prairie
    (2016-12) Eule-Nashoba, Amber
    Wild populations are subject to environments that are changing at unprecedented rates. Assessing natural selection and the capacity to adapt in wild populations is crucial to planning for and understanding how species will fare under climate change. The goal of this research was to empirically examine selection and adaptive capacity in a natural population of Chamaecrista fasciculata. In Chapter 1, I present an empirical quantitative genetic study of C. fasciculata to predict the rate of change in mean fitness using Fisher’s Fundamental Theorem of Natural Selection (FTNS). The additive genetic variance for fitness was found to be substantial and statistically significant in both 2013 and 2014. Application of FTNS predicts increases in mean fitness of 1.68 (2013) seeds and 8.08 (2014) seeds in the next generation. These findings demonstrate that this population has the genetic capacity to respond to natural selection and is predicted to increase in fitness and thus, become better adapted to their environment. The objective of Chapter 2 is to compare predicted and observed mean fitness of C. fasciculata in a natural selective environment. Observed mean fitness of both second-generation cohorts was, however, lower than predicted by the FTNS and lower than their respective first-generation cohorts. However, comparison of first and second-generation cohorts growing in the same year and, hence, common conditions, demonstrated an increase in mean fitness. Thus, environmental differences between years, as well as genotype-by-environment interaction, contribute to the deviation of observed from predicted mean fitness. In Chapter 3, I performed a quantitative genetic study of phenotypic selection on C. fasciculata to examine the effect of selection and environment on the phenology of germination and reproductive initiation. In this population, selection for advancement in reproductive stage was detected, as well as a response of 2.2 days earlier flowering in the second generation. Overall, findings of these chapters present a population that has demonstrated a response to selection in flowering phenology and significant genetic variation for evolutionary fitness. This evidence of adaptation and substantial adaptive capacity conveys crucial information regarding the likelihood of population persistence, information that could be utilized for other species towards conservation goals.
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    Leaf carbon fraction data from tree and grassland species collected at the Cedar Creek Ecosystem Science Reserve in 2015 and 2016
    (2020-08-12) Schweiger, Anna K; Lapadat, Cathleen; Kothari, Shan; Cavender-Bares, Jeannine; cavender@umn.edu; Cavender-Bares, Jeannine
    This data set contains results from carbon fraction analysis (Fiber Analyzer 200, ANKOM Technology), including non-structural carbohydrates, hemicellulose, cellulose, lignin, neutral detergent fiber, and acid detergent fiber contents in percent (%) from tree and grassland species sampled at the Cedar Creek Ecosystem Science Reserve in East Bethel, MN. The data was collected as part of the Dimensions of Biodiversity project “Linking remotely sensed optical diversity to genetic, phylogenetic and functional diversity to predict ecosystem processes”. Samples were collected in or near the old fields chronosequence, the oak savanna, and the Forest and Biodiversity Experiment (FAB 1) plots. We used this data together with leaf-level spectral measurements to build partial least squares regression (PLSR) models for predicting leaf traits from spectra.
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    R Code and Data for: Prescribed fire increases the number of ground-nesting bee nests in tallgrass prairie remnants
    (2023-02-15) Brokaw, Julia, N; Cariveau, Daniel; Portman, Zachary, M; Bruninga-Socolar, Bethanne; broka028@umn.edu; Brokaw, Julia, N
    Bees were collected using emergence traps from June 13, 2019 to August 22, 2019 from four remnant prairie sites in western Minnesota that were patch burned in spring of 2019 to determine whether ground-nesting bees prefer to nest in burned or unburned areas of prairies. Bees were identified to species and the number of nests was used to determine community similarity using Bray-Curtis index and to determine the Effective Number of Species of bees. For each site and sample round, we also measured various characteristics of the floral community and microhabitat that may relate to bee nesting preferences. We measured floral abundance by counting flowers and determining average flowers per site and round. We also measured flower diversity by identifying flowering species every site and round. We determined floral community similarity using the Bray-Curtis index and determined the Effective Number of Species using the species and abundance data for the floral community. We also measured mean percent bare ground, mean vegetative cover, and mean thatch depth per site and same round.
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    The Revery Alone Won't Do: Fire, Grazing, and Other Drivers of Bee Communities in Remnant Tallgrass Prairie
    (2019-04) Pennarola, Nora
    The bee community in Minnesota’s tallgrass prairie is doubly threatened. The conversion of prairie to agriculture and development has fragmented the landscape nearly beyond recognition. Over vast swathes of the state, single species exist in monocultures where once highly diverse grasslands grew. On top of this, bees across the continent face pressures from parasites, pathogens, and pesticides. The pockets of remnant prairie that persist are dependent on human-mediated disturbance. Grazing and burning, which can be seen as analogues to historic disturbance patterns, are effective and important tools in maintaining prairie health. Through this thesis, I seek to parse out the differing impacts of these two management techniques on bee communities and to explore how environmental characteristics impact the suite of traits bees display in remnant prairies.