introduction - Pennsylvania Natural Heritage Program

lutetiana), cutgrass (Leersia virginica), bedstraw (Galium sp), a rye-grass species (Elymus sp.), wildgermander (Teucrium canadense var. virginicum), and sedges (Carex pensylvanica, Carex swanii).Threats and StressesThe greatest threat to this area is the prevalence of invasive exotic species. Japanese knotweed(Polygonum sachalinense, Polygonum cuspidatum) and reed canarygrass (Phalaris arundinacea)have displaced native vegetation along much of the herbaceous zone immediately adjacent to theriver, while Japanese stiltgrass (Microstegium vimineum) threatens to displace native herbaceousspecies in the floodplain forest areas.RecommendationsThe communities of this BDA are adapted to natural disturbance, and can likely tolerate foot trafficwithout lasting damage. However, motorized vehicle traffic should be avoided, as it generates moreintensive disturbance than is natural. Monitoring the distribution and abundance of invasive speciesat this site, to determine if they are spreading further, would provide a basis for evaluating whetherremoval strategies are warranted.93