Profile of Sandra M. Diaz. Interview by Bijal P. Trivedi.

F luctuations in biodiversity are not just collateral damages in the face of global environmental change, according to Sandra Díaz, a professor of community and ecosystems ecology at Córdoba National University in Argentina and a senior principal researcher of the Argentine National Research Council. Díaz explores how the chemical and physical traits of plants— such as size, texture, and nutrient content of leaves, wood density, palatability to herbivores, and canopy architecture—influence a plant’s response to the environment and play an active role in the planet’s constant evolution in response to environmental change. Díaz has uncovered the important variables driving ecosystem functions and services, such as fodder and timber production, habitat for wildlife, and aesthetic enjoyment. Although biodiversity is often estimated by the number of species present, Díaz revealed that the function and benefits of an ecosystem are more accurately predicted by the combination of organisms and the specific traits they bring to the table. Her recent studies bridge the gap between ecology and social sciences. In her Inaugural Article (1), Díaz and colleagues from the ecological and social sciences offer a conceptual framework for linking different aspects of functional trait diversity with the needs of different social groups. “Almost everyone now agrees that biodiversity is important to people and that different people want different things; the challenge is therefore how to go about this in practice. We wanted to combine methodological guidelines, on-the-ground field experience, as well as new concepts,” she says. The guidelines and concepts Díaz introduced have earned her a seat among the world’s top environmental researchers as a member of the National Academy of Sciences of Argentina, the Academy of Sciences of the Developing World, and a foreign associate of the National Academy of Sciences. Her 2007 article in PNAS won the 2008 Cozzarelli Prize and the Sustainability Science Award from the Ecological Society of America (2009).