Increasing the Effectiveness of Reed canary grass (Phalaris arundinacea L.) Control in Wet Meadow Restorations

Abstract

Restoration practices are often based on trial and error or anecdotal information because data from controlled experiments are not available. In wet meadow restorations of the upper Midwest United States, Reed canary grass (Phalaris arundinacea L.) is controlled with spring burning and spring glyphosate herbicide applications, but the relative effectiveness of either treatment with respect to P. arundinacea growth and life history has not been assessed. We designed a multiyear field experiment to evaluate effects of burning and herbicide application timings on P. arundinacea populations. Burning did not reduce P. arundinacea biomass but reduced the P. arundinacea seed bank, potentially limiting recolonization of P. arundinacea. Glyphosate applications in late August and late September were more effective than in mid-May (due to enhanced glyphosate translocation to rhizomes), such that two mid-May applications reduced P. arundinacea biomass to a level equivalent to that achieved by one late-season application. Phalaris. arundinacea recolonized rapidly from the seed bank and, in plots that received suboptimally timed (mid-May) herbicide, from rhizomes. Establishment of native species was very low, likely due to competition with recolonizing P. arundinacea. Unplanted species (from the seed bank and refugial populations) accounted for the majority of non-P. arundinacea biomass. Recolonization of other species was strongly limited by a threshold level of P. arundinacea biomass. Adequate site preparation (over multiple growing seasons) and aftercare (selective removal of P. arundinacea) will be the key to facilitating subsequent wet meadow vegetation establishment. This research provides an example of the importance of experimental evidence as the basis to improve the efficiency of restoration practices.

Factors controlling the distribution of aquatic macrophyte communities with special reference to the rapid expansion of a semi-emergent Phalaris arundinacea L. in Bibi River, Hokkaido, northern Japan

“…Recently, Phalaris arundinacea L. (''reed canary grass'') has invaded wetlands in temperate zones such as in North America, dominating landscapes with monospecies-dominant communities, and excluding many hydrophytes (Green and Galatowitsch 2002;Herr-Turoff and Zedler 2005;Lavoie et al 2005;Adams and Galatowitsch 2006). Many studies have demonstrated the importance of nutrient input in the growth of P. arundinacea in wetlands; increased nutrient input stimulates increases in P. arundinacea biomass (Dubois 1994;Kercher and Zedler 2004;Herr-Turoff and Zedler 2007), shoot growth (Green and Galatowitsch 2002), the expansion of distribution (Herr-Turoff and Zedler 2007), and occurrence mainly at productive, P-rich sites (low mean N:P ratio) (Gusewell 2005).…”

Effects of the herbicide imazapyr on juvenile Oregon spotted frogs

“…For reed canarygrass, herbicide application in September may achieve the greatest control with the least amount of herbicide [12]. Postmetamorphic juveniles are the youngest OSF life stage (i.e., potentially the most vulnerable to herbicide toxic effects) present in September (A. Yahnke, unpublished data).…”

Ecological Restoration and Physiology: An Overdue Integration

“…For example, Adams and Galatowitsch (2006) used studies of carbohydrate metabolism in the invasive reed canary grass (Phalaris arundinacea) in wet-meadow environments to reveal late-season storage of carbohydrates in rhizomes. Given that systemic herbicides are typically trans located to rhizomes through carbohydrates, this information provided a means to enhance the effectiveness of herbicide use through late-season applications.…”