The quality and extent of coastal sedge/grass meadow habitat within Lake Ontario wetlands have been in a state of progressive decline for decades, principally as the result of stabilized hydroperiod and invasive cattail encroachment (Typha x glauca). Monotypic cattail stands competitively displace less aggressive native vegetation and significantly reduce habitability for local fish and wildlife. With the understanding that natural lake level fluctuations will not soon or readily be restored, we wondered if it was feasible to recreate some degree of former wetland character and function by performing a large-scale cattail control experiment and a smaller scale revegetation study. In early 2015, we created a series of channels and potholes through the sizable cattail stands at two coastal wetland sites, Buck Pond and Buttonwood Creek, and strategically placed excavated spoil material alongside in attempts to mimic the elevation and soil moisture at which sedge/grass meadow communities persist. A 2 x 2 full block factorial revegetation was conducted on the mounds, incorporating both seed applications and planted plugs of native species. A cattail control experiment, incorporating biologically-synched mowing and herbicide application, occurred concomitantly.
Floristic and hydrologic data collected at sites restored in Year 1 (2015) were used to clarify understanding of plant assemblages and invasion processes following restoration when compared to pre-restoration data from Year 0 (2014). Treatments at both sites were effective at reducing cattail growth; however, deposition mounds created at a lower elevation (Buttonwood Creek) were more likely to exhibit cattail re-sprouting as the result of subsidence, indicating the significance of initial berm design. Not all planted plugs had consistent survivorship. Planted Carex stricta plugs at both sites demonstrated a 65 percent survivorship and were twice as likely to survive under all treatments and most conditions (competition, substrate bulk density, elevation, and submergence) when compared to planted C. lacustris plugs. Initial data suggest that cattail control efforts have been effective, with site factors such as elevation playing a significant role in outcome. Discrete biotic and abiotic differences at the two sites support the inclusion of multiple field sites in order for relevant factors to become highlighted.