In May 2019, I took the great opportunity to participate in the 8th edition of the graduate thematic course, sponsored by CNRS, France and the Centre for Forest Research, Quebec Centre for Biodiversity Science. It was one of the best ecological experiences of my scientific life so far and I would definitely recommend to anyone interested in plant ecology (see website for applications and some impressions of this edition below).
Also check out some of the islands incredible trail running routes and annual trail running events (https://www.hyeres-tourisme.com/agenda-fetes-manifestations/trail-de-porquerolles/).