All ETDs from UAB

Advisory Committee Chair

Jere Boudell

Advisory Committee Members

Ken R Marion

Robert Fischer

Vanessa Beauchamp

Document Type

Thesis

Date of Award

2014

Degree Name by School

Master of Science (MS) College of Arts and Sciences

Abstract

As awareness of the deleterious effects of urbanization on urban watersheds increases, restoration of degraded streams has increased. Ecologists understand the vital role healthy soil plays in nutrient cycling and the revegetation of degraded riparian ecosystems. However, restoration projects in the southeast typically focus on stabilizing streambanks and improving water quality, not recovering soil health. Manipulating riparian soils to facilitate restoration success is common, yet these methods do not influence soil health. This case study sought to discover if the recovery of critical soil properties is possible when the stressor of urbanization has not been removed. Additionally, this case study used critical soil properties to predict the recovery trajectory of a restored urban riparian ecosystem based on its similarity to a gradient of restored and urbanized sites. An unrestored degraded urban stream reach, a restored urban stream reach 8+ years post-restoration, and a rural stream reach 80+ years post-restoration were selected for study. The restored reach, East Jesters Creek (EJC), was divided into urban and forested sides based on bordering land use. Soil nutrient concentrations (NPK), soil organic matter (SOM), soil compaction, and mycorrhizal fungi were assessed within six 10-m2 sites in active channel bars, stream banks, and riparian forests at each reach. Data were analyzed using Generalized Linear Models (α = 0.05). A holistic interpretation of the critical soil properties at EJC indicates that it is recovering along a reclamation trajectory. Soil nutrients and soil compaction on the forested side of EJC were most similar to the rural-matured reach. However, the urban side of EJC was most similar to the degraded reach. Variability in the range of soil nutrients at the urban reaches indicates that nutrient cycling in the riparian soils is impaired. Together these findings indicate that persistent urbanization stress is hindering the traditional recovery trajectory of EJC. Urban riparian ecosystems are novel ecosystems that provide some ecosystem function in a continually stressed environment and may be more resilient to the range of conditions predicted for many regions.

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