Invertebrate community composition is similar to non-invaded sites after Phragmites australis treatment in a Great Lakes coastal wetland

Invasive Phragmites australis subsp. australis is a dominant wetland plant that has spread extensively across Great Lakes coastal wetlands in Canada and the USA, displacing native species and altering ecosystem structure and function. At Point Pelee National Park, where P. australis has homogenized large areas of marsh, small-scale manual treatments using cutting and burning were initiated in 2020. We assessed the effects of this management on emerging aquatic invertebrate communities by comparing a P. australis-invaded site, a treated site, and a non-invaded reference site. Within each site, we deployed four emergence traps across stratified water levels from July to September, collecting and identifying all captured invertebrates. Two years post-treatment, invertebrate abundance and family-level richness were highest at the non-invaded (826 individuals/m 2 ; 17.00 taxa/m 2 ) and treated (503 individuals/m 2 ; 18.80 taxa/m 2 ) sites, and lowest at the invaded site (291 individuals/m 2 ; 13.10 taxa/m 2 ). Community composition differed among all three wetland types. Our findings suggest that invertebrate abundance and richness can recover relatively quickly following P. australis removal, but community composition remains distinct from reference conditions after 2 years.