Biologie der invasiven Beifuß-Ambrosie

01/09/2016 to 30/09/2017

The project explores how a herbivore antagonist drives the ecology and evolution of an invasive plant species under present and expected future climatic conditions. To address this question, we established replicated Ambrosia artemisiifolia L. (common ragweed) populations in an invaded field site in Northern Italy, with two experimental treatments: (1) with/without inclosure of the accidentally introduced and now locally common leaf beetle Ophraella communa into the experimental cages around the populations, and (2) with/without temperature warming created through open top chambers (OTCs). We study the effect of the leaf beetle on the population dynamics and defence chemical changes of ragweed, and we test in particular for rapid evolution of the ragweed populations in response to beetles and climate warming, through molecular genetic analysis of the populations over time, and through common garden experiments where we test for heritable phenotypic changes in the populations.