The WBFC Invasive Biota Committee was formed in 2012 to study the extent of invasive plant species on Plummers Island. From 2013 to 2015 we ran 20 (spring and fall), 10 m diameter plots with internal line transects to score cover and frequency of all species, duplicating 13 plots run by Beth Wells in 1997 to evaluate the impact of flood plain levels on invasive species, and adding 9 more plots above the flood prone zone. The top 10 invasive species were determined to be: Lonicera japonica, Lonicera maackii, Celastrus orbiculatus, Alliaria petiolata, Glechoma hederacea, Persicaria longiseta, Polygonum cespitosum, Ailanthus latissimus, Microstegium vimineum, Ampelopsis brevipedunculata. Since then, Ficaria verna (Ranunculus ficaria) has rapidly expanded, and Corydalis incisa has established on the Island. Rod Simmons added 2 NPS type plots in the Potomac River Bedrock Terrace Hardpan Forest community, which he described as new for the National Vegetation Classification database. The data from these plots and Simmons’ broad experience with vegetation types in our region lead to the production of the Natural Communities of Plummers Island Montgomery County, Maryland, map with descriptions of 12 plant communities (Simmons et al. 2016).
R. J. Soreng, 13 March 2021.