I am a PhD student, having started my thesis in October 2021 at the SETE-CNRS laboratory in Moulis. My thesis focuses on the theoretical notion of stability of communities subjected to environmental perturbations. So far, I have been studying the notion of 'fragility (or robustness) of coexistence' of a community and I am moving towards an exploration of the notion of 'resistance', i.e. the capacity of a community to buffer a disturbance. The idea is to explore the transmission of the disturbance from the ecosystemic and abiotic level to the community's response. Generally speaking, the approach adopted during my PhD is theoretical and mixes notions of ecology with mathematics (linear algebra, matrix calculations, probabilities) and programming (numerical simulations).