Print PageGarlic mustard (Alliaria petiolata) allelopathy is known to affect ectomycorrhizal (ECM) colonization on conifer and hardwood hosts, though effects on ECM community structure are under early study. To better clarify how ECM community properties may be influenced by garlic mustard allelopathy, studies were conducted to examine responses of ECM colonization, morphotype composition, and diversity from red oak (Quercus rubra) to garlic mustard densities in the field and to water soluble garlic mustard extracts. In one study, roots were extracted from beneath red oak canopy trees growing amid low and high garlic mustard densities and examined for ECM colonization and community structure. In another study, red oak seedlings were grown in ECM inoculated soils removed from control sites and exposed to extracts.
Results/Conclusions
Results from the first study found red oak roots to have lower ECM colonization and morphotype diversity from high compared to low density and control samples while results from the second study found lower ECM colonization and diversity on red oak seedlings exposed to a high extract treatment compared to a lower treatment and a control. These findings suggest that ECM colonization and morphotype diversity decrease on red oaks growing amid high garlic mustard densities in the field, and that such reductions may be due to garlic mustard allelopathy that directly reduces ECM colonization and diversity on this host.
