Last week, we published our findings in the journal ISME. We show that invasions by knapweed and spurge, but not cheatgrass, increased arbuscular mycorrhizal fungal (AMF) abundance and diversity relative to native remnant communities. AMF can help plants acquire nutrients and protect against some plant pathogens, and are often considered beneficial. Our findings are unexpected, because the assumption has been that invasive plants seldom associate with AMF and therefore reduce AMF abundance and richness upon invasion. This, in turn, lowers the competitiveness of more AMF-dependent native plants and promotes further invasions. We argue that AMF richness and abundance are low in remnant native communities due to the dominance of grasses, because native grasses supported a lower abundance and fewer AMF species than native forbs.
The abundance of native forbs have declined in many intermountain grasslands due to the application of forb-specific herbicides used to combat exotic forb invasions. From the AMF’s perspective, exotic forb invasion is a welcome increase in good host abundance, and it does not matter if the plants are native or non-native. We will research the effects of these findings for native plant restoration. Is it possible that native forbs will thrive after knapweed?
We show that plant invasions can benefit selected soil microbial groups. What are the consequences of this for plant restoration?
Ylva graduated from the Swedish University of Agricultural Sciences with a M.Sc. in Biology and Horticulture in 1996 and a Ph.D. in Ecology from Penn State University in 2004. She received the Alumni Association Dissertation Award for her work in agroecology and subsistence farming in Sub-Saharan Africa. Post-doctoral positions at Montana State University and later at Copenhagen University as a Marie Curie Fellow have allowed her to explore the role of mycorrhiza, a root-fungus symbiosis, for geothermal plants in Yellowstone National Park and coastal grasslands in Denmark. Her research has been published in journals such as Ecology, Journal of Ecology and New Phytologist.
Ylva currently works at MPG Ranch as a soil ecologist. She explores the role of mycorrhiza in the success of exotic plants and examines the use of specific pathogens to combat invasions. In her spare time Ylva mountain-bikes, plays soccer, and maintains a large vegetable garden.