Looking up

This blog has been very quiet in 2025, and you readers are entitled to the question : is this thing still running ? How is the whole project going ? What are you up to ? I am here today to provide some good, important (at least for me) news : pending internal mobility procedures at CNRS, I will normally soon join the Experimental and Theoretical Ecology Station in Moulis, Ariège (SETE) as full-time ecology researcher and in the capacity of adjoint director of the station.

But first, some scientific updates. I have initiated two research projects in ecology over the last two years, one mixing aquatic ecosystems modelling and fluid dynamics, and one on the multiscale spatio-temporal dynamics of food webs, involving a PhD student and a colleague at SETE. These two projects rely on a new numerical modelling tool for community ecology, PATOU, which I developed over the last two years from a fork of the very powerful and versatile computational fluid dynamics code IDEFIX developed by my astro colleague Geoffroy Lesur in Grenoble. One of my goals is to make this code a useful community tool in due course, but with the two first projects we are currently still busy developing and crash-testing a bunch of ecological modelling capabilities involving complex networks, competition models, and interfacing ecological dynamics with models of physical (abiotic) dynamical processes occurring on similar timescales as biological and ecological processes.

Signs that things are making good progress on this front, I gave two talks in 2025, one on transferring my experience in numerical and theoretical astrophysical fluid modelling to a theoretical ecology research context, in a multiscale physics Simons conference in June in Germany, and one in December at the theoretical ecology GDR in Bordeaux in December, where I introduced PATOU and showed some first applications. No papers so far, but it’s now a matter of time, as we have some results emerging and are working on two drafts (+ polishing the code). Besides these first ongoing projects, the possibilities opened by the development of this numerical tool look very broad and exciting. I already have many ideas from the most fundamental to the more applied with several colleagues working with with field data and with experiments too. So, some research proposals, and a broader research program are now also in the making.

But, on top of these ecology research projects, a lot more has been brewing behind the scenes. 2025 was my last year as head of group in astro in Toulouse at IRAP, and I have also been very busy with the supervision of my last PhD student in astro, who defended (brilliantly) his PhD last November. Finally, I just published my last piece of work in astrophysical fluid dynamics, what I think is a significant contribution to the understanding of the dynamical mechanism underlying the solar activity cycle. Throughout 2025, my mind has been busy trying to cross t’s and dot i’s with my astro projects and commitments, and thinking about what to do next after all of this was finished. Should I leave astro for good or not ? Should I move to SETE, the ecology lab I have been visiting weekly for the last three years ? What could be my longer-term ecology research vision and programme beyond the first short-term “bridge” modelling projects outlined above ?

Last May, something unexpected happened that suddenly altered the fundamental nature of my reflexions. INEE (the French CNRS national institute for ecology & environmental research) published an open call for the position of director of the SETE. Cue three months of discussions with colleagues, and meetings with many people there, and I ended up in September applying for the job. Why ? I will likely write a whole post on that in the near future, but I can provide the two most important ideas here: one was my long-time desire to get into a more operational position in research or elsewhere, at least part time, to get closer to the real world. The second is that I have fallen in love with the place, with the lab, and with the area, and I thought this was probably a once-in-a-lifetime opportunity to serve in an operational role in such an environment, serving research and ecological themes that I deeply value. Finally, despite my lack of track record in ecology, I thought I was qualified and ready for this kind of job after being head of group for 5 years in a big lab in Toulouse, and with 20 years of career at CNRS.

The selection process for the job has been long, stressful and full of emotions. This is not the place to describe what happened in the last six months in detail, but the main outcome is that things are on their way to happen. The plan for the time-being, agreed with INEE and SETE, is for me is to have a comfortable transition period over the next 18 months, as an adjoint director, during which I will hone my direction project and learn the specifics of the SETE management, while also developing my scientific integration and research projects there.

This is a major change and a professional challenge that is inevitably going to lead to important changes in my life, starting with my personal and family life organization. I have been thinking for months about the pros and cons of this move, and didn’t make the decision lightheartedly. In the end, I came to the conclusion that it was the right time and opportunity to make a move like this, because it made sense to me, in the times we are living in, in terms of personal values, meaning and for the small service I am able to provide to the broader world. Over the last five years, I had been thinking very, very hard about how to best align my work and professional commitments with my moral values and scientific training, also keeping my family’s interest in mind. And I think this checks most of the boxes.

This move also seems entirely natural scientifically to me at this stage. I have almost no regrets, and actually feel relieved to leave aside astrophysics after working part-time in the field of ecology for 2-3 years now. Throughout my career in astro, I have been honest and supportive of all the people who put some trust in me. I have been transparent with everyone at all echelons throughout this transition process. In the end I think I have given everything I could to the field, sacrificing some good bits of my mental health in the process. In the end I think I have produced a solid corpus of fundamental science results that start to withstand the test of time, and have written and transmitted essentially everything I have learned, developed and researched, passing the baton to the younger generation through my last PhD student in the process. I have sincerely reached the end of my personal journey in theoretical astrophysics, and can’t wait to start this next science and human adventure in ecology.