E&E Seminar: Soil biota as drivers of exotic plant invasions by Ray Callaway, University of Montana (John Lussenhop Memorial Talk)
September 24, 2019
12:00 PM - 1:00 PM
John Lussenhop Memorial Talk
Abstract: The leading explanation for successful biological invasions by exotic plant species is the Enemy Release Hypothesis – the idea that translocation to a distant non-native range allows some exotic plant species to escape top-down controls imposed by consumers in the native range. Specialist herbivores are the most reasonable suspects to escape because translocated plant species are unlikely to encounter their co-evolved specialists in non-native, evolutionarily naïve communities. But recently, studies have shown that exotic invaders can also escape from the less discriminatory effects of generalist consumers. Soil biota comprise a broad group of generalist consumers and mutualists that have complex, but strong negative and beneficial effects on plants. Many experiments with soil biota from the non-native ranges of plant species more strongly suppress exotic plant species than native species. But the most powerful evidence for enemy release from soil biota comes from biogeographic experiments which show that soil biota from the native ranges of plant species often have much stronger negative effects on those same species than soil from their non-native ranges. Just as biogeographic escape from antagonistic soil biota in the native range can promote the success of invasive plants, so too can novel associations with beneficial soil biota in the non-native range. But because soil mutualists can often also have parasitic effects they can have either disproportionately improve or inhibit the performance of exotic invasive plants. Invaders can also disrupt native mutualisms. For example, the non-mycorrhizal European invader of North American forests, Alliaria petiolata, suppresses the growth of North American species by disrupting their relationships with mycorrhizae. In summary, a rich literature indicates that the trajectory of plant invasions – for better or for worse – can be tied to interactions between plants and the soil microbial community
Faculty Host: Hormoz BassiriRad
Date posted
Jul 9, 2019
Date updated
Sep 16, 2019