Invader complexes or generalist interactions? Seasonal effects of a disturbance gradient on plants and floral visitors

Disturbances can facilitate the spread of exotic plants, which establish mutualisms with bees, constituting invader complexes. However, a disturbance-mediated increase in flower resources also promote native floral visitors due to fact that plant-pollinator interactions are generalist. We experimentally tested these ideas northern Patagonian woodlands. In three sites, we examined effect harvesting intensity (HI) (0%, 30%, 50%, 70% biomass removal) on density (exotic: herbs; native: herbs, shrubs, trees) and visitor honey bumblebees; bees wasps, hoverflies, other flies, beetles, ants). For four years, made observations throughout flowering period test seasonality. HI had most substantial positive followed by it was null trees. The effects herbs depended site. enhanced bumblebees, hoverflies; but no showed variable floral-visitor groups. Although seasonality relevant, there strong interaction HI. general, visitors, is better explained generalist rather than