Controlling Phalaris arundinacea through the use of shade while promoting native species recruitment in a wet meadow

Abstract

Phalaris arundinacea (reed canarygrass) is a grass species native to Eurasia and the Pacific Northwest of the U.S. By nature it is an aggressive species and particularly invasive in areas with abundant light and nutrient resources. Repeated introduction of cultivars to the U.S. for purposes of feedstock and soil stabilization particularly around farmlands from the 1850s onward allowed cross-pollination with native cultivars to occur. This resulted in more aggressive phenotypes capable of forming monotypic stands. The susceptibility of wetland areas to invasion has become particularly problematic in the Pacific Northwest and the Midwest. One widely recognized method of control for reed canarygrass growth and establishment is the use of shade. This study proposed the use of artificial shade in combination with the planting of native grass species in an attempt to diversify a wet meadow dominated by reed canarygrass. Three-way ANOVAs were utilized to analyze shade, disturbance patch size, and mowing as treatment levels. Results showed reed canarygrass to be noticeably impacted by shading while one native grass species successfully established itself under the same conditions. Given a sufficient length of time, diversity of this area could potentially be increased both aboveground and in the seed bank.