Date of Award
9-22-2016
Document Type
Dissertation
Degree Name
Environmental Sciences, Ph.D.
First Advisor
Jerry Farris
Committee Members
Carole Cramer; Justin Murdock; Matt Moore; Seo-Eun Choi; Steve Green
Call Number
LD 251 .A566t 2016 H83
Abstract
Until recently, agricultural drainage ditches and urban stream systems have been underrepresented within aquatic research studies. This underrepresentation has led to gaps in knowledge within the area of ecosystem structure and function, characteristics of agriculture and urban stream stressors, and management strategies for those streams. Many of the factors (increased nutrients, changes to the quantity and composition of organic carbon inputs, light alterations, and sedimentation) that impair water bodies associated with agricultural drainage and urbanization also influence stream processes. Stream organic matter production and consumption measured as ecosystem metabolism, is a fundamental process comprised of gross primary production (GPP) and ecosystem respiration (ER) used to characterize the ecological functioning of aquatic systems. The first study investigated the influence of structural changes (weir versus non- weir and cut vegetation versus uncut vegetation) on ecosystem metabolism in experimental agricultural drainage ditches that had been amended with nutrients. ER was significantly influenced by the cut vegetation and GPP was significantly influenced by the presence of weirs. Factors effected by the structural changes (temperature, pH, stream metabolism) could affect ecological and chemical processes. In the second study, rates of GPP and ER were examined in multiple sized ditches and wetland cells. Size and water quality were important factors that affected the rate of GPP within the drainage system, and size was the factor that most affected ER. The last study examined environmental and structural attributes that influence the rates of GPP and ER in an urban creek. GPP appeared to be significantly influenced by environmental attributes, such as temperature, conductivity, DO, and stream width. The ER rates were significantly influenced by both environmental and structural (pH, nitrite, turbidity and stream depth) attributes. Stream metabolism rates were also significantly influenced by the habitat along the continuum. While greater emphasis is being placed on ecosystem valuations and water mitigation measures, research into fundamental functional processes are needed to actualize critical component values. The information from these investigations in sites where metabolism is uncommonly used, can help build on the platform of using stream metabolism within an assessment or monitoring plan. This incorporation would allow for an integrated approach to investigate the effects of disturbance, best management practices, storm water management and restoration projects.
Rights Management
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Hudson, Traci Carmen, "Assessing Aquatic System Metabolism Response to Disturbance" (2016). Student Theses and Dissertations. 652.
https://arch.astate.edu/all-etd/652
