Hydro-geomorphological influences on plant patch density and distribution in bedrock shoal habitats of the Cahaba River, AL

dc.contributorEdmonds, Jennifer
dc.contributorHart, Justin
dc.contributor.advisorDavis, Lisa
dc.contributor.authorVaughn, Ryan Scott
dc.contributor.otherUniversity of Alabama Tuscaloosa
dc.date.accessioned2017-03-01T17:37:00Z
dc.date.available2017-03-01T17:37:00Z
dc.date.issued2014
dc.descriptionElectronic Thesis or Dissertationen_US
dc.description.abstractAbstract There is a growing body of research that examines bedrock channels. Despite this, biotic-abiotic interactions remain a topic mostly addressed in alluvial systems. This research seeks to identify patch-scale hydro-geomorphic factors operating at the patch-scale in bedrock shoals of the Cahaba River (AL) that help determine the distribution of the emergent aquatic macrophyte, Justicia americana. Macrophyte patch density (number of stems/m2) and percent bedrock void surface area (rock surface area/m2 occupied by joints, fractures, and potholes) were measured (n = 24) using stem counts and underwater photography, respectively. One-dimensional hydrologic modeling (HEC-RAS 4.1.0) was completed for one cross-section within a shoal to examine whether velocity and channel depth are controlling variables for macrophyte patch density. A Pearson's Correlation test between bedrock surface void area and stem density demonstrated a statistically significant positive correlation (r=.665, p=0.01). Results of an independent t-test between the velocity and depth model outputs for within and outside plant patches showed a significant difference in average velocity (p =0.011) and depth (p = 0.001) between the two types of locations across discharges, ranging from 7 m3/sec to 226 m3/sec. These results suggest that the amount of void space present in bedrock surfaces and localized depth and velocity help control the macrophyte patch density, and by extension, the distribution of macrophytes in bedrock shoal complexes. The utility of geomorphology in explaining patch-scale habitat heterogeneity in this study demonstrates potential to use geomorphology to explain macrophyte habitat heterogeneity at reach and system-scales and highlights the need for more research that helps understand biotic-abiotic interactions in bedrock fluvial systems.en_US
dc.format.extent63 p.
dc.format.mediumelectronic
dc.format.mimetypeapplication/pdf
dc.identifier.otheru0015_0000001_0002090
dc.identifier.otherVaughn_alatus_0004M_11894
dc.identifier.urihttps://ir.ua.edu/handle/123456789/2476
dc.languageEnglish
dc.language.isoen_US
dc.publisherUniversity of Alabama Libraries
dc.relation.hasversionborn digital
dc.relation.ispartofThe University of Alabama Electronic Theses and Dissertations
dc.relation.ispartofThe University of Alabama Libraries Digital Collections
dc.rightsAll rights reserved by the author unless otherwise indicated.en_US
dc.subjectGeomorphology
dc.subjectEcology
dc.titleHydro-geomorphological influences on plant patch density and distribution in bedrock shoal habitats of the Cahaba River, ALen_US
dc.typethesis
dc.typetext
etdms.degree.departmentUniversity of Alabama. Department of Geography
etdms.degree.disciplineGeography
etdms.degree.grantorThe University of Alabama
etdms.degree.levelmaster's
etdms.degree.nameM.S.
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