Author
Evans, Jeffrey | |
LANKAU, R - University Of Georgia | |
Davis, Adam | |
RAGHU, S - Commonwealth Scientific And Industrial Research Organisation (CSIRO) | |
LANDIS, D - Michigan State University |
Submitted to: Functional Ecology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/1/2016 Publication Date: 7/15/2016 Citation: Evans, J.A., Lankau, R.A., Davis, A.S., Raghu, S., Landis, D. 2016. Evolutionary feedbacks on the ecology of the invasive plant Alliaria petiolata. Functional Ecology. 30:1053-1061. Interpretive Summary: Better understanding of the mechanisms by which invasive plant populations spread and compete with native plant communities can help land managers combat these pests more effectively. Our aim was to quantify the evolutionary feedbacks underlying changes over time in the population dynamics and allelopathic potential of garlic mustard (Alliaria petiolata), an aggressive invader of temperate forests of North America. As garlic mustard populations age, natural selection drives down production of its important secondary allelochemical, sinigrin, making it less competitive with native plant communities. We show that population growth rates and plant density are positively related to sinigrin concentration measured in seedling roots. Together, these illustrate how the evolution of a trait shaped by natural selection can influence the ecology of a species over a period of just years to decades, potentially altering the trajectory of population growth and the species’ interactions with the communities it invades. These results may help managers to prioritize particular garlic mustard populations for control; those populations at the leading edge of a garlic mustard invasion in a particular location are likely to be the fastest growing, and also the most competitive with other plants. Technical Abstract: Ecological and evolutionary processes historically have been assumed to operate on significantly different time scales. We know now from theory and work on short-lived organisms that these processes can feed back on each other on mutually relevant time scales. Here, we present evidence of an evolutionary feedback on the population dynamics of an invasive biennial plant, Alliaria petiolata. As populations age, natural selection drives down production of A. petiolata’s important secondary allelochemical, sinigrin. We show that population growth rates and plant density are positively related to sinigrin concentration measured in seedling roots. Together, these illustrate how the evolution of a trait shaped by natural selection can influence the ecology of a species over a period of just years to decades, potentially altering the trajectory of population growth and the species’ interactions with the communities it invades. |