Étude de la réponse au changement climatique de Bromus tectorum L., plante invasive de l'Ouest américain, au sein de la mixed-grass prairie

This master thesis focused on the effects of climate change on an invasive plant of the Western United States, the cheatgrass (Bromus tectorum L.), in a particular invaded ecosystem: the mixed-grass prairie. This annual grass invaded the United States, more than one century ago, and leads to various damages, from a biodiversity loss to huge wildfires with abnormal intensity and range.
I had the opportunity to join a Colorado scientific team, working for the United States Department of Agriculture (U.S.D.A.). On the field, I could get data from a large scale experiment: The Prairie heating and CO₂ enrichment experiment (P.H.A.C.E.).
One of the aims of this experiment was to study the development of cheatgrass plants, in different treatments: irrigation, native species influence, elevated ambient temperature, and CO₂ enrichment.
I measured several growth traits, and could also use last year similar measurements. The analysis of these datasets leads to interesting observations: B. tectorum doesn’t act like most invasive plants, with a bad response to CO₂ enrichment. In contrast, I observed a strong positive effect of the temperature.
Considering the current situation, and the results of the experiment, cheatgrass invasion will probably increase with climate change.