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.

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Veikko Somerpuro

Prof J Niemelä, widely recognized to have developed the field of Urban Ecology, was among the first to clarify the distinction between ecology in cities, ecology of cities, and ecology for cities.

Professor Niemelä started his research career in the early 1980s. His PhD work focused on applying the theory of island biogeography and he developed an interest in how to use this and other ecological theories and approaches in nature conservation. After acquiring his PhD degree in 1988 he spent three years in Canada (University of Alberta, Edmonton). focusing on forest conservation. Upon returning to Finland in 1992, Prof. Niemelä deepened his research on forest ecology, biodiversity and conservation. Furthermore, he continued research on urban ecology which he had started in the 1980s. In the 1990s there was a clear need for both theoretical development of the ecology of urban areas and for applications of ecological understanding in urban planning. Towards the late 1990s urban ecology became the main research area of Prof. Niemelä. In 2000, he was appointed to the first professorship in urban ecology in Finland. Thereafter, his and his team’s research in the area has expanded to cover several aspects of urban ecology. For instance, he worked on human perception of urban green space, the use of ecological knowledge in urban planning and the overall integration of natural and social sciences in urban research.

Prof. Niemelä received numerous awards and distinctions including in in 2012 the State Award for Public Information, and also in the same year The University of Helsinki J.V. Snellman Prize for popularization of science. In 2017 he received the Silver Medal of the University of Helsinki for serving the University.

Prof. Niemelä’s impact on environmental policy is evident. He served in several. expert positions at universities and in the society at large in which he advanced the use of ecological information in decision-making. For instance, Professor Niemelä was very active in WWF international and WWF Finland for several years (e.g., chairperson of the Board of WWF Finland). He was also one of the most influential in terms of policy support through chairmanship of the national IPBES panel (Intergovernmental Platform on Biodiversity & Ecosystem Services) and thereby membership of the official Finnish delegation to IPBES annual plenaries. IPBES is an intergovernmental organization preparing assessments of the state of biodiversity across the world and supporting policy formulation to protect biodiversity.

Under Niemelä’s leadership, a new multidisciplinary Helsinki Institute of Sustainability Science (HELSUS) at the University of Helsinki was established. Through HELSUS he contributed to progress sustainability research, education and its impact on society. In his role as Rector of the University of Helsinki he strived for embedding sustainability science and practices in all university activities and his contributions to the University of Helsinki helped make it a widely recognized ‘lighthouse’ for inter-disciplinary research on solutions-oriented sustainability science and its use in the society. For example, he was instrumental in ensuring that environmental sustainability was embedded in all aspects of university endeavour (teaching, research, outreach and operations) when co-creating the University of Helsinki Strategic Plan (2021–2030).

Prof. Niemelä will be deeply missed not only in Finland, but also in Sweden, and among his many colleagues in Europe, North America and rest of the world. Stockholm, Helsinki and New York, August 17, 2020.