U.S.-Romania Environmental Biology Research on Community Resistance and Susceptibility to Invasion Effects of Soil Microbes and Native Plant Communities on Centaurea Maculosa.

University Of Montana, Missoula MT

Investigators

Abstract

The goal of this U.S.-Romanian research project between Ragan Callaway of the University of Montana and Alecu Diaconu of the Biological Research Institute, in Iasi, is to determine how some invasive weeds change from minor components of their natural communities to overwhelming dominants in invaded communities. This will be accomplished by studying biogeographical variations in the output and the effects of allelopathic and antimicrobial root exudants from Centaurea maculosa (spotted knapweed). The selected study sites in Romania have populations that are closest in genotype to those in North America. The researchers hope to learn why this ecologically successful North American invader is not as successful in European native communities. The US-Romanian team will pursue answers to questions related to the ecological effect of the allelochemicals secreted by C. maculosa on plant and microbe interactions in the rhizoshpere. Their research plan includes sampling seeds and soils in both countries, experiments with catechin additions to plant rhizoshperes in the field, and quantitative comparisons. Results are expected to explain how C. maculosa changes from a subordinate species in Europe to an overwhelming competitive dominant in North America. Broadly, success may lead to the formulation of a new theory on the organization of natural ecological communities and how they are invaded by exotic species. Practically speaking, this new knowledge may facilitate development of novel and practical weed management practices for controlling knapweed invasions. This plant ecology project fulfills the program objective of advancing scientific knowledge by enabling experts in the United States and Central Europe to combine complementary talents and share research resources in areas of strong mutual interest and competence. Broader impacts include the introduction of U.S. students to the international plant ecology community through work at the Romanian partner institution and direct involvement in the project's field sampling and modeling techniques for invasive plants.