This session honors and reflects on the legacies of one of ESA’s preeminent scientists, Harold A. "Hal" Mooney, in building the science, practice and policy of ecology. Over the past six decades, Mooney has made diverse and influential contributions to many key areas of ecology, including physiological plant ecology, ecosystem ecology, biodiversity and ecosystem functioning, invasive species, and international science and policy initiatives. At the same time, he has inspired, mentored and engaged a wide range of people. As such, Hal Mooney’s legacies include not only advancing our scientific understanding, but also providing a leading example of how science can be communicated and applied at all scales from local to global. Here we bring together an array of scientists who have worked closely with Mooney to reflect on his contributions in growing our understanding of ecology. Rather than simply a celebration of Mooney’s accomplishments, these talks aim to examine how various aspects of his work have developed over time and what the current state of the science is. This session contributes directly to the conference theme of linking biodiversity, material cycling and ecosystem services in a changing world, with talks covering many aspects of this theme. The talks will collectively provide both inspiration and vision for a new generation of ecologists to follow in Hal Mooney’s footsteps in developing both the scientific and policy underpinnings that work towards a better understanding of the world’s ecosystems and their management into the future.