Esteban G. Jobbágy, Rosaly M. C. Lopes, and Christopher M. Reddy received the 2018 Ambassador Award at the AGU Fall Meeting Honors Ceremony, held 12 December 2018 in Washington, D. C. The award is in recognition of “outstanding contributions to one or more of the following area(s): societal impact, service to the Earth and space community, scientific leadership, and promotion of talent/career pool.”  

Dr. Esteban Jobbágy drives positive change in the world as an ambassador of science, bringing rigor to environmental decision-making and fostering the growth of the next generation of environmental leaders.

Esteban has uncovered important ecohydrologic mechanisms by which land use change and human activities alter ecosystems. His seminal work on eucalyptus plantations in Argentina demonstrated a disruption of the natural water balance through an increase in evapotranspiration and an induced hydrologic transfer from surrounding grasslands to plantations. Hydrologic alteration between patches laterally redistributes nutrients and salts, initiating vegetation feedbacks and in some cases, adverse impacts on soil fertility. He advocates systems that integrate trees into grassland as more sustainable alternatives to single-species plantations.

However, Esteban is not content merely to publish peer-reviewed articles; he works with farmers and foresters to improve best practices and spreads his message to those who can effect change. In the documentary film Gran Chaco, Esteban highlighted the deforestation of the second-largest forest in South America. The changes to the dry forest ecosystem, biodiversity, hydrology, economy, and culture of the region that have occurred in the past 15 years cannot be overstated. Similarly, in Rio Nuevo, Esteban’s narration provides a riveting story of the ecohydrologic feedbacks by which land use change on the Argentinian plains has led to water excess and the surprising formation of new rivers. The documentaries featuring Esteban are raising awareness of socioenvironmental cascades that previously received little global attention.

Esteban has worked tirelessly with Argentinian government agencies, local growers associations, and agricultural corporations. He organizes workshops and two-way interactions to combine the collective wisdom of hundreds of farmers and the scientific community to develop decision support tools. Cultivating and maintaining these personal relationships has been key to translating Dr. Jobbágy’s research into measurable impacts across South America, leading to a more sustainable balance between food production, flooding, the economy, and the environment. For his efforts, Dr. Jobbágy was honored with the Bernardo Houssay Award by Argentinian president Cristina Fernández de Kirchner for contributions by a scientist under 45 years of age.

Dr. Jobbágy’s tremendously creative and pragmatic research style has led to major discoveries on the imprint of vegetation on hydrologic and biogeochemical processes. His work has had, and will continue to have, a sustained impact on environmental decision-making in South America. Through his passionate advocacy, communication, and stakeholder outreach, his legacy will be preserved in the work he has done and the students he has trained.

—Steven P. Loheide III, University of Wisconsin–Madison

It is a warm and encouraging surprise to receive the AGU Ambassador Award for my work connecting science with real-life problems in the plains of southern South America. I especially thank AGU and my nominators and supporters, Steve Loheide, Ying Fan, and Rob Jackson. Their enthusiasm in nominating me is the best gift I am receiving. This award invites me to reflect upon the beginning of my career at the Agronomy School of the University of Buenos Aires 30 years ago. There, lively discussions with fellow students about the imprint of farming on nature pushed me to learn more about the vagaries of nutrient and water cycles. After a decadelong immersion into pure biogeochemical and ecohydrological quests at labs in the United States and Argentina (and at many mind-blowing AGU events), I started to contact an amazing community of sharp and curious farmers. These people, like me, were full of questions about nature. We all wanted to know the causes of the widespread hydrological transformations of the Argentine Pampas, to understand the mysterious “dialogue” between shallow groundwater and crops that we were cluelessly observing, to make sense of the confusing effects that cutting or planting forests had on soil and water salinity. Slowly, this vibrant community brought me back to my agronomic start, engaging me in an amazing collaborative exchange of observations, hard fieldwork, and, once again, lively discussions about the imprint of farming on nature. Argentina hosts one of the last agricultural frontiers of our modern world. Its brutal expansion over natural grasslands and forests has offered a unique experimental setting to study how ecosystems shape water cycling, nutrient distributions, and soil carbon stocks. With unexpected success, I attracted colleagues from all over the world to embark on that adventure, together with some of the best students I could possibly have dreamed to advise. I am deeply indebted to all these good friends, and they own a substantial part of this award. The same land use changes that opened unique scientific opportunities are posing urgent environmental and social challenges to my country. Staying away from the controversies that arise from them has been impossible for me, and thanks to that, I discovered a whole new world in the exchange with county- to national-level policy makers. I have witnessed science and farming shape each other. So far, being part of this reciprocal transformation has been the biggest joy. —Esteban G. Jobbágy, Universidad Nacional de San Luis, San Luis, Argentina; and Conseja Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina