Sponsor
Portland State University. Department of Environmental Science Management
First Advisor
Mark Sytsma
Term of Graduation
Fall 2009
Date of Publication
11-4-2009
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Environmental Science and Resources
Department
Environmental Science and Management
Language
English
Subjects
Purple loosestrife -- Biological control -- Columbia River Estuary (Or. and Wash.), Galerucella -- Columbia River Estuary (Or. and Wash.)
DOI
10.15760/etd.5464
Physical Description
1 online resource (2, vii, 61 pages)
Abstract
Galerucella pusilla and G. calmariensis have provided successful biological control of purple loosestrife (Lythrum salicaria L.) in non-tidal areas but only marginal control in areas of tidal influence. While a previous study identified mechanical scour by tidal waters as the main cause of establishment failure, purple loosestrife stem density explained more than 80% of the variability in presence and absence of Galerucella at my study sites in the Columbia River Estuary. A logistic regression model using purple loosestrife stem density, elevation, and their interaction as predictors accurately predicted 92.5% of Galerucella presence or absence observations of a test data set (n= 201). Field data also identified a critical threshold of approximately 32 purple loosestrife stems/m2, above which Galerucella were present 100% of the time at the release sites.
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).
Persistent Identifier
http://archives.pdx.edu/ds/psu/20309
Recommended Citation
Moore, Lynda Kathryn, "Biological Control of Purple Loosestrife (Lythrum salicaria): Factors Affecting Galerucella pusilla and Galerucella calmariensis Establishment in Tidal Areas" (2009). Dissertations and Theses. Paper 3580.
https://doi.org/10.15760/etd.5464
Comments
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