Following up on research that demonstrated that garlic mustard’s (Alliaria petiolata) production of chemicals detrimental to other plants declined the longer a population had been established, Lankau now reports on the ability of a native plant to resist the phytotoxins.
Clearweed, Pilea pumila, commonly occurs in areas invaded by garlic mustard. In habitats where many native species are present, Alliaria petiolata produces more sinigrin, a compound that kills the mycorrhizal fungi that help plants obtain more nutrients. Clearweed growing with the more toxic garlic mustard has evolved some resistance to the chemical.
The author speculates based on his transplant studies that using more resistant plants in restoration projects could lead to greater establishment success of the natives. The two studies also show that over long periods of time some invasive plants may come to co-exist with native plants.
Lankau, R. A. 2012. Coevolution between invasive and native plants driven by chemical competition and soil biota. PNAS, published ahead of print June 25, 2012, doi:10.1073/pnas.1201343109
Lankau, R. A., V. Nuzzo, G. Spyreas and A. S. Davis. 2009. Evolutionary limits ameliorate the negative impact of an invasive plant. PNAS 106 (36) 15362-15367.
