Soil microbial communities in Typha x glauca invaded wetlands. soil metagenome

Invasive plants can overwhelm wetlands, reduce biodiversity, and alter the ability of wetlands to provide critical ecosystem services, including nutrient cycling. One prominent example is the hybrid cattail Typha × glauca, which has invaded and reduced biodiversity in wetlands throughout the Laurentian Great Lakes region. Several approaches have been used for the restoration of Typha-invaded wetlands, but long-term studies assessing the benefits of these restoration efforts are limited. A previous study demonstrated positive effects of aboveground harvesting of Typha × glauca stems and litter on plant species diversity in a Great Lakes coastal wetland. In the current study, we extended the analysis of the effects of this treatment to four years post-treatment and have quantified biomass harvest effects on soil nutrients, ecosystem processes, and the composition of soil microbial communities. The aboveground harvest treatment resulted in a dramatic reduction in Typha litter cover that persisted for four years, and an increased abundance of the native plant genus, Carex. However, the treatment did not significantly reduce Typha density, nor did it have significant effects on soil physical/chemical properties, carbon fluxes, or the taxonomic composition of soil microbial communities. At the scale this experiment was implemented at (4 x 4-m plots), our results indicate that a single aboveground removal of Typha × glauca is not a sufficient long-term method to restore freshwater wetland communities. Comparison of plots that varied in time since Typha invasion revealed correlations between duration of Typha invasion, soil properties and bacterial community composition that warrant further study.