Throwing shade: performance of native Pacific Northwest shrubs in shading out invasive reed canarygrass (Phalaris arundinacea)
Aroeste, Shaan (author)
Marcoux, Hélène (chair)
Owens, Susan (committee member)
Cohen-Fernandez, Anayansi (committee member)
British Columbia Institute of Technology School of Construction and the Environment (Degree granting institution)
Simon Fraser University Faculty of Environment (Degree granting institution)
(Degree granting institution)
© Shaan Aroeste, 2021. All rights reserved. No part of this work covered by the copyright heron may be reproduced or used in any form or by any means – graphics, electronic, or mechanical including photocopying, taping, or information storage and retrieval systems – without written permission of the author.
British Columbia Institute of Technology
Reed canarygrass (Phalaris arundinacea) is an invasive grass common in wetlands and riparian areas throughout the Pacific Northwest. It is highly adaptable and resistant to many control methods, but is vulnerable to shading. We sought to control reed canarygrass by establishing desirable native shrubs to overtop and shade it. Plots were rototilled, mulched, live-staked, and monitored for 2-6 growing seasons. We tested 1) effective planting densities by live-staking hardhack (Spiraea douglasii) at 50, 30, and 15 cm spacing, 2) relative species performance by planting hardhack, red-osier dogwood (Cornus sericea), and thimbleberry (Rubus parviflorus), all at 30 cm densities, and 3) alternative site preparation methods by using cardboard mulch or excavating the top 20 cm of topsoil. Higher planting density significantly reduced reed canarygrass cover and biomass. Both hardhack and red-osier dogwood successfully suppressed reed canarygrass, though thimbleberry did not. No significant differences between site preparation methods were observed.
invasive species management
Reed canary grass
Ecological Restoration Program
Master of Science