Quantifying the relative value of Phragmites australis and Spartina alterniflora habitat is important to evaluate the benefits and risks of different attempts to address Phragmites expansion on the U.S. eastern seaboard. Two contrasting approaches commonly used to restore tidal marsh habitats invaded by Phragmites communities involve spraying Phragmites with herbicide only when its coverage of a particular marsh area is near or close to 100%. Alternatively, after the first application, herbicide is annually applied on any surviving patches of Phragmites present in a mosaic of other marsh vegetation. A model is introduced to evaluate the relative habitat value of these control regimes, here termed the Intermittent and Continuous. Compared to the Intermittent approach, the area of herbicide application in the Continuous approach is higher in the first 6 yr, but lower the reafter. The cumulative gain in habitat quality after 20 yr in either approach is sensitive to the presumed relative values of Phragmites versus Spartina habitat, and may even be negative if they are nearly equal. Annual applications of herbicide to patches of Phragmites appears to generate more habitat value and with less herbicide than occasional applications when Phragmites cover is at is maximum.
Turner, R., & Warren, R. S. (2003). Valuation of Continuous and Intermittent Phragmites Control., 618-623. Retrieved from https://repository.lsu.edu/oceanography_coastal_pubs/135