I successfully defended my PhD and received an exceptional mention! It took a whole village to carry out this thesis, which is above all a team effort. I would therefore like to sincerely thank all the people who participated in this adventure from near and far.I have been blessed to be able to count on passionate and dedicated people who have allowed me to present this work today, in particular interns for field and laboratory assistance, but also scientific and administrative support people at the Centre sur la biodiversité, the Institut de recherche en biologie végétale and the Département de Sciences biologiques of the Université de Montréal. My journey has been rich in passionate and exciting people, from the education I received in Guadeloupe to today in Quebec, who have grown the scientist in me. The latest to date are Etienne Laliberté and Mark Vellend, whom I thank warmly for leading this thesis with confidence, patience, excellence and much more. This thesis was made possible by their direct involvement in the design and realization of the various studies presented, but also as mentors and experts from whom I have been trying to draw inspiration and learn for more than four years now. I have also had the opportunity to benefit from the advice of other experienced researchers, including Pierre-Luc Chagnon, Simon Joly, Mélanie Roy and Ben Turner, whom I would like to sincerely thank. I would also like to thank Nicolas Fanin and David Rivest for being part of the jury for this thesis. Impossible to get through it without the continued support and countless discussions with wonderful colleagues including Marie Beigas, Vanessa Grenier, Vlad Parasquive, Nicolas Pinceloup, Julian Wittische, as well as Andrew Blackney, Alizée Girard and Simon Morvan whom I thank especially for their comments on this thesis. I would also like to warmly thank Mila Bathurt for the revision of this thesis. I sincerely thank all the people who have and continue to develop free platforms, and the community federated around the sharing of knowledge and data, allowing science to advance in a freer and more open way. This thesis would not have been possible without the funding that was awarded to me first by Etienne, then by the Fonds québécois de la recherche sur la nature et les technologies, and also by the Département de sciences biologiques, the graduate school of the Université de Montréal, as well as the Institut de recherche en biologie végétale. I also had the opportunity to participate and present the results of this thesis at conferences in Quebec and abroad thanks to generous funding from the Centre sur la science de la biodiversité au Québec, the Centre d'études sur la forêt and the Institut de recherche en biologie végétale. Finally, I would like to thank my family for their unconditional support. I was pampered by my village, thank you.