Resolution of Respect: Juan José Armesto, 1953–2024

Abstract

Professor Juan José Armesto (Photo 1) passed away on 14 January 2024 in Santiago, Chile, from complications related to COVID-19. He is survived by his partner Marcela Bustamante, daughter Martina, and son Sebastian. Juan was born on 2 March 1953. His early years were spent in Santiago, Chile with his parents, Juan and Luisa Ecar, and two sisters, Bernardita and María Aurora, before the family moved to Iquique, Chile, just a few blocks from the sea. His early interests included creating newspapers and cartoons based on current events, as well as filmmaking. However, his love for nature prevailed. Juan obtained his Bachelor's Degree in Biology in 1977 from the Facultad de Ciencias of the Universidad de Chile where he was inspired by professors Eduardo Fuentes, Claudio Donoso, and especially Humberto Maturana. Shortly thereafter, he was hired as a Lecturer and together with Drs. Mary Kalin and Carolina Villagrán, he helped to establish the Laboratory of Plant Systematics and Ecology at the University of Chile.

In 1980, Juan entered the graduate program in Botany and Plant Physiology at Rutgers University (New Jersey, USA) where he worked under the mentorship of Steward T. A. Pickett studying the mechanisms of oldfield succession. Indeed, he was one of the early leaders in the experimental study of oldfield succession. His dissertation was titled, “Experimental studies of disturbance in oldfield plant communities: implications for species coexistence and succession” (1984). Using a field experiment in two different age oldfields, Juan demonstrated that the effects of disturbance were contingent on the degree of dominance in plant communities, an outcome that is still being observed and debated today. This research occurred right as the disturbance paradigm was transforming notions of stability in community ecology. Juan already had around 30 publications when he started his PhD program. One of us (SLC) recalls one time after Friday afternoon discussions that Juan showed up on Monday morning with the draft of a manuscript that he wrote over the weekend. Not only was Juan a quick writer, STAP considers him to be the best writer among the students he had the pleasure to advise. Not surprisingly, Juan was a highly prolific ecologist eventually authoring/coauthoring more than 200 articles and 12 books, one of which, “Ecología del Agua” in collaboration with Alicia Hoffman, was selected by the Ministry of Education for national distribution in schools and high schools in Chile. This reflects another fundamental aspect of Juan Armesto's career. He worked to bring knowledge from academic research into public education and local communities.

Juan noted that one of the hallmarks of Professor Maturana's mentoring style was to talk about and argue over concepts and processes in science. Juan's approach to graduate school certainly embodied that mentoring style. Juan, SLC, and STAP spent many afternoons and some evenings in a New Brunswick restaurant that had a model railroad circling around the ceiling talking about the need for more modern approaches to succession as an alternative to the Connell-Slatyer model. These discussions eventually resulted in Juan's second most cited article published in Botanical Review in 1987 (after being rejected by the American Naturalist).

Upon his return to Chile, after his doctoral studies at Rutgers, he initiated his own line of work to understand successional changes in forest and shrubland ecosystems of the Mediterranean climate zone in central Chile, work that emphasized the mechanisms of change, linked to human activities and interactions between plants and seed-dispersing animals. This work added a process-based approach to the emerging landscape ecology of the era which had been largely descriptive. These factors were summarized in a model with both conceptual and applied value for the recovery of impacted or degraded areas, which later provided valuable stimulus for local landscape restoration programs in central Chile maintained by private and public organizations. By that time Juan had become a major figure among Chilean scientists and a major inspiration for younger generations because of his wide knowledge of ecology but also because of his philosophy of science and ethics. He always wanted his research to not only advance ecological knowledge, but he also wanted that knowledge to be directly applied to solving environmental problems and making a better life for rural Chileans, an ethic that he instilled through his teaching, research, and outreach efforts.

Sometime after his return to Chile, he visited the forests of Chiloé, which led to one of the most important themes for his research career. Among his research results in Chiloé, he demonstrated that, contrary to the accepted paradigm of succession theory, old-growth forests are not in balance with respect to the internal cycling of nutrients. Along with his co-authors, Lars Hedin and Art Johnson, this work demonstrated that stream water export of nitrogen differed from Hubbard Brook in New Hampshire, USA, arguably the most famous study of nutrient cycling in a deciduous forest ecosystem globally. In Chiloé, losses were mostly as dissolved organic forms of nitrogen, rather than inorganic nitrogen like at Hubbard Brook. This work demonstrated that unpolluted old-growth forests could be described as “leaky” or not depending on whether researchers measured organic as well as inorganic forms of nitrogen, and that elevated levels of inorganic nitrogen in stream water at Hubbard Brook reflected high levels of atmospheric pollution.

Through this work Juan helped to establish biogeochemistry as a significant research subject in Chile. He organized (with Gene Likens) an international workshop on “A comparison of patterns and processes between cool temperate forest ecosystems of North and South America” in 1990, with support of the Andrew W. Mellon Foundation. This workshop brought the attention of the world to the moist, temperate forests of southern Chile, and opened a horizon of biogeochemical investigations into nutrient cycling in these forests. In addition, although the similarities of the ecologies of Mediterranean-climate zones of Chile and North America had been long known, Juan's work alerted the larger ecological world to the significance, research potential, and conservation value of the southern Andean temperate forests. This attention included using these remote forests as a global baseline for comparison of atmospheric deposition with temperate systems in the Northern Hemisphere. His biogeochemical interests also enriched research in the arid landscapes and remnant moist forests of northern Chile, contributing to the establishment of another LTER site within Parque Nacional Fray Jorge with colleagues such as Dr. Julio Gutierrez.

Through numerous field studies, Juan documented the importance of complex biotic interactions between animals and plants in temperate forests of southern South America. These interactions of plants with diverse species of insects and birds make possible their successful reproduction through pollination and seed dispersal, processes that are essential for the regeneration of plants across a gradient of forest ecosystems in Chile. Juan brought environmental research and education wherever his research led him, working for more than 20 years with local schools and providing training to landowners, government officials, park rangers, rural community dwellers, and others interested in conservation.

Over his academic career, Juan held positions in the Facultad de Ciencias, Universidad de Chile, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Visiting Professor, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, and Research Associate at Cary Institute of Ecosystem Studies, Millbrook, New York, USA. The researchers and administrative staff of Cary Institute looked forward to Juan's visits, not only because of his sparkling intellect, but because of his warmth and good cheer. Juan would always bring another person with him to Cary Institute, and he especially introduced members of the next generation of Chilean ecologists to the institute. OB notes that she herself, and several others who became important ecosystem researchers benefitted from the interactions at Cary that Juan created for them. Over his career, he mentored more than 10 postdocs, 30 graduate, and 40 undergraduate students. Many of his former graduate students and postdoctoral fellows are now professors at the Universities of Chile, Católica, Santiago de Chile, Concepción, Austral de Valdivia, and Magallanes carrying on his legacy, while others work in important governmental institutions.

Not only was Juan a prolific researcher, but he was also very active in creating opportunities for others. He helped, along with Dr. Mary F. Willson (University of Illinois), to establish the Fundación Senda Darwin (FSD) in 1996, which initially supported the establishment and maintenance of an unprecedented field research center, the Estación Biológica Senda Darwin, near the city of Ancud, on the Isla Grande de Chiloé, land that was once explored by Charles Darwin between 1834 and 1835. Through this effort, he brought research and science to this remote region of the country which had been largely neglected by educational and cultural institutions in the past. As President of the FSD in Chiloé, he promoted a new program that connected academics and regional interest groups in order to improve the management and protection of ecosystems that are needed to solve the acute problem of water supply faced by rural communities. At Estación Biológica Senda Darwin, each year he taught the Forest Ecology Summer School, a vivid example of his commitment to training new generations of ecologists.

Juan was one of the founders of the scientific organization known as “Southern Connection,” created in 1993, which brings together researchers from the southern hemisphere to explore the historical consequences of Gondwanic links in evolution and biogeography. He was the driving force behind the Chilean network of long-term social–ecological research sites (LTSER Network), a network that links long-term research in semi-arid ecosystems of the Fray Jorge National Park with studies in temperate evergreen forest ecosystems in Chiloé and sub-Antarctic ecosystems up to Cape Horn. This line of work placed Chile for the first time as a member of the International Long-term Ecological Research (ILTER) Network, which brings together research programs from more than 40 countries. ILTER held its 2014 annual meeting in Chile at the Universidad Austral de Chile, in Valdivia, and at the Estación Biológica Senda Darwin, Chiloé.

Juan Armesto received many honors and awards over his prolific career. He was a co-recipient of the Mercer Award from the Ecological Society of America in 1996. He was an elected member of the ESA governing Board from 2008 to 2009. He helped to create a South American Chapter of ESA, which integrated ecologists across South America. This chapter then expanded to become the Latin American Chapter, composed of ecologists from Mexico, Central, and South America. He won the Robert H. Whittaker Distinguished Ecologist Award from Ecological Society of America in 2021. He received a Presidential Chair in Sciences from the Government of Chile (1999) and Premio Patricio Sanchez from the Sociedad de Ecología de Chile (2023). He was a Corresponding Member of the Academia de Ciencias de Chile (2021) and elected as a foreign member of the US National Academy of Sciences in 2021. As a reflection of his life-long contributions to the citizens of Chile, his passing was noted by a minute of silence by the Chilean Senate.

It is hard to imagine a more productive, energetic, and inspiring career for an ecologist. And yet, despite his many accomplishments and accolades, Juan remained a modest, soft-spoken, kind, and gentle person with a great sense of humor. The global ecology community has lost an inspiring leader, and he is sorely missed by all of us.

Armesto, J. J., and S. T. A. Pickett. 1985. Experiments on disturbance in old-field plant communities: impact on species richness and abundance. Ecology 66:230–240.

Pickett, S. T. A., S. L. Collins, and J. J. Armesto. 1987. Models, mechanisms and pathways of succession. Botanical Reviews 53:335–371.

Pickett, S. T. A., J. Kolasa, J. J. Armesto, and S. L. Collins. 1989. The ecological concept of disturbance and its expression at various hierarchical levels. Oikos 54:131–139.

Hedin, L. O., J. J. Armesto, and A. H. Johnson. 1995. Patterns of nutrient loss from unpolluted, old-growth temperate forests: Evaluation of biogeochemical theory. Ecology 76:493–509.

Armesto, J. J., R. Rozzi, C. Smith-Ramírez, and M. T. K. Arroyo. 1998. Conservation targets in South American temperate forests. Science 282:1271–1272.

del-Val, E., J. J. Armesto, O. Barbosa, and P. A. Marquet. 2007. Effects of herbivory and patch size on tree seedling survivorship in a fog-dependent coastal rainforest in semiarid Chile. Oecologia 153:625–632.

Armesto, J. J., D. Manuschevich, A. Mora, C. Smith-Ramirez, R. Rozzi, A. M. Abarzúa, and P. A. Marquet. 2010. From the Holocene to the Anthropocene: A historical framework for land cover change in southwestern South America in the past 15,000 years. Land Use Policy 27:148–160.

Rozzi, R., J. J. Armesto, J. R. Gutiérrez, F. Massardo, G. E. Likens, C. B. Anderson, A. Poole, K. P. Moses, E. Hargrove, A. O. Mansilla, J. H. Kennedy, M. Wilson, K. Jax, C. G. Jones, J. B. Callicott, and M. T. K. Arroyo. 2012. Integrating ecology and environmental ethics: Earth stewardship in the southern end of the Americas. BioScience 62:226–236.

Hoffman, A., and J. J. Armesto. 2014. Ecología del Agua. Corporación Instituto de Ecología y Biodiversidad. Santiago, Chile.

Mujica, M. I., N. Saez, M. Cisternas, M. Manzano, J. J. Armesto, and F. Pérez. 2016. Relationship between soil nutrients and mycorrhizal associations of two Bipinnula species (Orchidaceae) from central Chile. Annals of Botany 118:149–158.

Moreira, F., D. Ascoli, H. Safford, M. A. Adams, J. M. Moreno, J. M. C. Pereira, F. X. Catry, J. J. Armesto, W. Bond, M. E. González, T. Curt, N. Koutsias, L. McCaw, O. Price, J. G. Pausas, E. Rigolot, S. Stephens, C. Tavsanoglu, V. R. Vallejo, B. W. van Wilgen, G. Xanthopoulos, and P. M. Fernardes. 2020. Wildfire management in Mediterranean-type regions: paradigm change needed. Environmental Research Letters 15:011001.

Castillam J. C., J. J.Armesto, M. J. Martínez-Harms, and D. Tecklin, editors. 2024. Conservation in Chilean Patagonia. Springer, New York.