Obituary: Professor Jari Niemelä 1957–2022

We are deeply saddened to have learned that Professor Jari Niemelä, former Rector of the University of Helsinki, after a long-term disease, passed away at the age of 64. We have known Jari for many years and his death represents a deep loss for the global research community. Professor Niemelä was a key scholar in the development of urban science, and in particular the ecological dimension of this rapidly emerging field. Being among one of the very first and well-established researchers in the field of urban ecology, he published numerous highly influential articles and books and collaborated with other leading urban ecologists throughout the world. He was among the first to clarify the distinction between ecology in cities, ecology of cities (including the hinterlands for cities), and ecology for cities aiming at an interdisciplinary approach to urban areas and development and greatly influenced our own work and an entire generation of urban ecology scholars. Professor Jari Niemelä has in our view been at the absolute global frontier when it comes to deepening our understanding of socio-ecological systems and driving solutions-oriented sustainability science, particularly in the urban context. Niemelä made globally important scientific discoveries concerning how to spatially identify and integrate the multiple values of nature into biodiversity conservation and ecosystem service assessments.