Celebrating Harry Vereecken: a rich scientific career, ongoing support of eLTER, and countless friendships

On 5th September 2025 about 150 colleagues and friends of Harry Vereecken gathered in Jülich, Germany, for his farewell colloquium as he is set to retire as Director of the Agrosphere Institute of Bio- and Geosciences of the Research Center Jülich. 

Picture 1: Friends and colleagues celebrating the rich scientific career of Harry Vereecken. Photo credit © Sascha Kreklau

Picture 2: Harry Vereecken (middle) with Michael Mirtl (left) and Steffen Zacharias (right) at the Farewell Colloquium in Jülich, Germany, in September 2025. Copyright: Michael Mirtl

Luckily,  this is only a ‘good-bye’ for some of the eLTER community and the eLTER ESFRI process, as Harry will continue to be involved in the establishment of the eLTER Topic Centre on Analyses and Modelling. Therefore, rather than saying ‘Farewell, Harry!’, Michael Mirtl and Steffen Zacharias used their talk to inspire the next phase of his life by sharing feedback from long-time colleagues, who also created a WordCloud capturing the qualities they associate with him.

Picture 3: Word cloud generated by long-time colleagues to describe Harry Vereecken

The dominant terms of this word cloud reflect Harry Vereecken’s professional and personal contributions to TERENO and eLTER. From the very beginning, he belonged to the core group of experts engaged in building the eLTER RI in the ESFRI context. The conceptual similarity of eLTER’s Whole System approach with TERENO, the network of German environmental observatories, which Harry headed as scientific coordinator for over 15 years, and its intensive research sites, have served as a major blueprint for eLTER and its in-situ facilities. Harry helped build the bridge between eLTER and the research communities working on the Critical Zone and hydrology. He supported integration instead of striving for ever more stand-alone and competing Research Infrastructures. This was an important trigger for integrating special cases like ‘system-focused hydrological observatories’ and transferring them into the system of eLTER Site Categories. From 2014 onwards Harry actively engaged, mentored and inspired eLTER RI to advance as a RI of true European and global significance. Despite all his other obligations he took the time to participate as a visionary pioneer and unifier in key eLTER meetings (Pic. 4)

Picture 4: Visionaries are not deterred by bad weather: participants of the eLTER ESFRI application conceptual workshop 2017 in Crete, Greece. Harry Vereecken is second on the left. Photo credit: Steffen Zacharias 

Harry’s commitment and scientific insights provided as eLTER’s Theme Lead for the climate-food-water nexus, as well as to eLTER PLUS and eLTER in general, are unique and invaluable for the emerging eLTER RI. His scientific vision, leadership, and unwavering commitment to holistic, integrated ecosystem research have left an indelible mark on eLTER and on the broader European environmental research landscape. 

The eLTER community thanks Harry Vereecken for the many years of inspiring collaboration, upholding scientific excellence, and for being just a great person. We look forward to our continued collaboration over the coming years!