Community Partner

Clean Water Services

First Advisor

Joseph Maser

Date of Award

Fall 2021

Document Type

Project

Degree Name

Master of Environmental Management (MEM)

Department

Environmental Science and Management

Language

English

Subjects

Wetland restoration -- Oregon -- Tualatin River Watershed, Wetland planting, Carex -- Growth -- Oregon -- Tualatin River Watershed, Carex -- Mortality -- Oregon -- Tualatin River Watershed, Wetland plants

DOI

10.15760/mem.76

Abstract

Clean Water Services (CWS) currently increases the diversity of their wetland restoration projects using a plug planting method utilizing juvenile herbaceous plants. They have planted most of their projects using this method and plan to continue until a better one is discovered. According to the literature reviewed in this paper, juvenile plants are smaller and weaker than more mature plants and therefore have higher mortality rates. This paper is the culmination of work completed of phase 1 of this two-phase project. The objective of this project (both phases) was to design and establish a study that would test, in the field, two common wetland planting methods: installation of plugs of juvenile plants at a relatively high density and installation of containerized, more mature plants at a lower density. This study will examine three species of Carex frequently used in wetland restoration (Carex stipata, C. obnupta, and C. unilateralis) and compare the growth and mortality of mature versus juveniles of these species within Thomas Dairy Site in the Tualatin River Watershed. For phase 2, at Thomas Dairy Site, 13 randomly selected plots will each contain six subplots including a subplot planted with monocultures of each of the three plants, and two sizes (i.e., mature C. stipata, juvenile C. stipata, mature C. obnupta, juvenile C. obnupta, mature C. unilateralis, and juvenile C. unilateralis). These will be monitored for five years, during which mortality rates will be recorded once a year and total percent cover recorded three times a year. I hypothesize that the mature plants will have a higher percent cover after five years because juvenile plants are more susceptible to die over that timeframe and may have slower growth rates overall. Answering these questions will allow CWS and other wetland restoration managers to achieve greater plant coverage, reduce waste, and reduce costs.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Comments

A project report submitted in partial fulfillment of the requirements for the degree of Master of Environmental Management.

Persistent Identifier

https://archives.pdx.edu/ds/psu/36797

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