Browsing by Subject "Ordination"
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Item Open Access Animal Movement in Pelagic Ecosystems: from Communities to Individuals(2009) Schick, Robert SchillingInfusing models for animal movement with more behavioral realism has been a goal of movement ecologists for several years. As ecologists have begun to collect more and more data on animal distribution and abundance, a clear need has arisen for more sophisticated analysis. Such analysis could include more realistic movement behavior, more information on the organism-environment interaction, and more ways to separate observation error from process error. Because landscape ecologists and behavioral ecologists typically study these same themes at very different scales, it has been proposed that their union could be productive for all (Lima and Zollner, 1996).
By understanding how animals interact with their land- and seascapes, we can better understand how species partition up resources are large spatial scales. Accordingly I begin this dissertation with a large spatial scale analysis of distribution data for marine mammals from Nova Scotia through the Gulf of Mexico. I analyzed these data in three separate regions, and in the two data-rich regions, find compelling separation between the different communities. In the northernmost region, this separation is broadly along diet based partitions. This research provides a baseline for future study of marine mammal systems, and more importantly highlights several gaps in current data collections.
In the last 6 years several movement ecologists have begun to imbue sophisticated statistical analyses with increasing amounts of movement behavior. This has changed the way movement ecologists think about movement data and movement processes. In this dissertation I focus my research on continuing this trend. I reviewed the state of movement modeling and then proposed a new Bayesian movement model that builds on three questions of: behavior; organism-environment interaction; and process-based inference with noisy data.
Application of this model to two different datasets, migrating right whales in the NW Atlantic, and foraging monk seals in the Northwest Hawaiian Islands, provides for the first time estimates of how moving animals make choices about the suitability of patches within their perceptual range. By estimating parameters governing this suitability I provide right whale managers a clear depiction of the gaps in their protection in this vulnerable and understudied migratory corridor. For monk seals I provide a behaviorally based view into how animals in different colonies and age and sex groups move throughout their range. This information is crucial for managers who translocate individuals to new habitat as it provides them a quantitative glimpse of how members of certain groups perceive their landscape.
This model provides critical information about the behaviorally based movement choices animals make. Results can be used to understand the ecology of these patterns, and can be used to help inform conservation actions. Finally this modeling framework provides a way to unite fields of movement ecology and graph theory.
Item Open Access Molecular Approaches to Estimating Soil Fungal Diversity and Community Shifts in Response to Land-Use Change(2010) Jackson, Jason AlexanderThe Piedmont region of the southeastern United States has undergone considerable land-use change since settlement by Europeans and Africans. Forests were cleared for agriculture, followed centuries later by land abandonment. Following abandonment, natural recruitment, plantings for erosion control, and plantation forestry have resulted in a large area of the region covered by loblolly pine, Pinus taeda. Today, the Piedmont is a mosaic of farm fields, pastures, pine forests, and relic woodlots. The Calhoun Experimental Forest, located in Union County, SC, has provided a unique history of land use change's alteration of soil properties and processes, the ability of reforestation to restore or deplete soil fertility, and provided insights into the effects this change has on biological diversity.
In this work, the diversity of fungi living in soil is examined in the context of land-use change and soil biogeochemical change in and around the Calhoun Forest. This study uses molecular tools to identify fungal species from soil and to identify mycorrhizal associates of loblolly pine in a bioassay of propagule diversity, and proposes a novel use of quantitative PCR to quantify the relative abundance of major fungal families affected by land-use change.
Fungal diversity in soils is high in all land uses, but fungal communities shift from agricultural field communities largely comprised of unicellular ascomycetes and basal lineages to forest communities dominated by saprophytic and symbiotic basidiomycetes. In addition to this shift across a land use gradient, fungal communities are also responding to changes in carbon quantity and quality, biologically available nitrogen and phosphorus, pH, acidity and texture.
ECM propagule communities also differ across a land use gradient of cultivated fields, grasslands, pine forests, and mixed hardwood stands. There are few ECM propagules able to associate with loblolly pine in cultivated and grassland soils. There is a trend towards higher ECM diversity in the hardwood and pine soils, and both of those soil communities are distinct from each other as well as from soils from field treatments.
Quantitative PCR, coupled with a nested set of taxon-specific, fungal primers, is a potential way to estimate the abundance of the given taxon relative to all fungi in an environmental DNA. Primers specific to several taxonomic level of fungi were tested to confirm amplification in PCR, then were tested for taxonomic specificity by generating clone libraries with environmental DNA. Several of the successful primers were tested with soil DNA extracts in QPCR and the calculated ratios of fungal abundance varied widely by method of analysis. The results suggest that many repeated measurements and many replicates are required for a robust estimate of the relative abundance of a specific taxon.
Item Open Access The Ordered Way of Ordination: United Methodist Ordination as a Way of Life(2024) Corpening, Daniel MThe aim of this project is to provide a compelling and theologically sound understanding of the ordination of Elders in the United Methodist Church. Unfortunately within 21st century United Methodism, the telos of the ordination process is often portrayed as a credentialing or licensure that most poignantly speaks to what someone has done to receive such a certification, but says little to nothing about what lies beyond it. This unintended and inadequate portrayal of the telos of the ordination process bears significant consequences for the depth of ordained leadership and the vitality of the church. In this thesis, I will argue that the ordination of Christian leaders is primarily a covenant made between God, the church, and the ordained regarding a particular ordered way of living that provides leadership to the church for the flourishing of communities and in service and witness to the Triune God. Ordination is not a possession. It is a confession and patterning of lives around the life of Jesus. In particular, I will demonstrate how this understanding of ordination is deeply “at-home” within the Methodist tradition, and how this understanding and praxis of ordination can cultivate a vibrancy in both ordained and lay leadership for the flourishing of our communities.
In order to make this argument, I will draw from the resources of scripture, tradition, reason, and experience which offer a fourfold lens of theological engagement that is central to the Methodist tradition. This project will begin by exploring a theology of ordination more broadly, followed by a more specific exploration of ordination in the Methodist movement. From here, this project will draw on the ecumenical witness of Saint Óscar Romero who offers a critical example for what ordination as an ordered way of living looks like. Finally, this thesis will work to establish the fourfold ministry of Elders – Word, Sacrament, Service, and Order – not simply as duties or tasks to complete, but rhythms by which Elders and congregations can pattern their lives in witness to the Reign of God being revealed in our midst.
Item Open Access Vegetation community change over decadal and century scales in the North Carolina piedmont(2007-05-07T19:07:38Z) Schwartz, Miguel JamesThis thesis examines vegetation community change at two temporal scales in the Piedmont of North Carolina. Using long-term plots in the Duke Forest, I examine decadal-scale changes in community composition of the forest understory and shed light on the potential drivers of that change. Using historical data from colonial survey records, I study presettlement forest communities of the Piedmont and attempt to reconstruct Piedmont forests as they may have been in the time before European arrival. The pattern of successional change in southeastern United States Piedmont forests has been assumed from chronosequence studies over the last half century. However, these assumptions for forest understory herb-layer populations and communities have not been tested using long term data sets. Using permanently marked plots in the Duke Forest (Durham, NC, USA) re-censused after a 23 year time step, species richness and community changes at 25m2 and 1000m2 scales are examined. I look at changes across life forms and examine these changes in relation to measured stand and environmental factors. Although total species richness stayed relatively constant through the 23 year step, herb richness declined with a concomitant increase in woody richness. Plot composition change was remarkably consistent and this change was not correlated to any measured stand or environmental factors. These community-level changes are consistent with previously reported changes in the understories of hardwood dominated stands in the Duke Forest, suggesting that landscape scale drivers may be more important than within-stand successional processes in patterning herbaceous communities at this time. Combined with growing evidence from other studies, this work indicates that forests in the temperate region may be experiencing changes different from those predicted by successional chronosequence studies. It indicates that one of the primary drivers of this change is the explosive growth of deer populations in the last two decades. Witness trees recorded in historical surveys have been used to reconstruct presettlement vegetation in many parts of North America, leading to a better understanding of vegetation patterns before the effects of Europeans. For some parts of North America, Government Land Office records make the process of reconstructing vegetation patterns easier - thus more is known about these areas. Because of the unique and unplanned nature of settlement in the southeastern U.S., less is known about the presettlement vegetation in this area of the country. Using a reconstructed cadastral map of a section of the North Carolina Piedmont, I was able to plot the positions of trees on the historical landscape. These data were then used to understand and reconstruct the composition of presettlement forests. Although the vegetation of some areas of the Piedmont is similar to what was expected, I find significant differences with the expected presettlement composition. In particular, pine species were common in some areas and rare in others, indicating that different disturbance regimes were active on the landscape.