Rose M. Martin
Northeastern Naturalist 24(3)
DOI: | Published online: Sept 2017


The introduced Eurasian subspecies of Phragmites australis (Common Reed) is a common invader of North American coastal wetlands where it outcompetes native high-marsh species such as Spartina patens (Saltmeadow Cordgrass). Although Common Reed is known to colonize coastal marshes via clonal replication, recent research has indicated that germination from seed may also be an important mechanism by which this species spreads in saltmarsh systems. Sexual reproduction via outcrossing introduces genetic diversity into populations; thus, an increase in seed germination may have implications for the plant’s invasiveness. I tested the effect of temperatures projected to occur by the year 2100 on germination rates of 2 species: invasive Common Reed, and Saltmeadow Cordgrass. Projected end-of-century temperatures doubled Common Reed germination, but inhibited Saltmarsh Cordgrass germination. The potential for variability in responses to warming among Common Reed and Saltmeadow Cordgrass populations at larger geographic scales precludes generalization of results of this study without further investigation. However, my results suggest that warming may differentially affect germination of Common Reed and a native species it commonly displaces. This finding may have ecological implications depending on how these and other invasive and native species respond to continued climate change.