Global Change is complex and its effects on ecology and plant-insect interactions are specific. Thus, it is vital to examine the nuances in plant behavior to better understand how to mitigate anthropogenic change. The more data points we can accumulate on the line of plant communication, the better we are able to assess the effects of change in natural systems. The invasion of Centaurea solstitialis (Yellow starthistle) is both a local and national crisis. Current and future increases in CO₂ will lead to further aggressive expansion of this weed. In my work I have found that Yellow starthistle may be dependent on indirect defense prior to flower-head formation, within a tri-trophic system that may have co-evolved prior to introduction of Yellow starthistle to North America, and identified the volatiles likely acting as indirect defense cues. In this first known report on the influence of climate change on volatile emission of Yellow starthistle in the field, global changes such as elevated temperature and CO₂ were not found to influence the volatile profile of the invasive. However, its induced emission as an anti-herbivory strategy may be more effective under elevated CO₂, hence explaining its increased growth under such conditions. Thus, for natural control purposes, attention should be given to monitoring both herbivore and predator populations during early growth of this weed. This work offers insight into the evolutionary purpose of volatile emission and will help document the ways in which ecosystem responses to global change may be facilitated by networks of chemical communication.  link to publication