(Universidad Autónoma de México, Mexico & Stanford University, USA)
Rodolfo Dirzo studied Biology at the University of Morelos, México. He completed his Masters (M.Sc.) and Doctorate (Ph.D) in Ecology at the University of Wales, Great Britain. He has been a Professor at UNAM, where he was researcher, and Director of the Los Tuxtlas Research Station. Currently he is a Professor at Stanford University in the Biology Department, and the Director of Stanford’s Center for Latin American Studies. He is actively involved in teaching at undergraduate and postgraduate levels both in the USA and Latin America. In addition, he is committed to science education among children and the general public.
His scientific work centers on the study of the ecological and evolutionary relationships between plants and animals and on the impact of human activities on natural ecosystems. His recent work includes a documentation of the global magnitude of animal extinction (“defaunation”), and how this affects plant diversity, and how this may lead to increased risks of human disease. He is member of the Mexican Academy of Sciences, the US National Academy of Sciences and the American Academy of Arts and Sciences, and the California Academy of Sciences.
"Herbivory as a selective pressure and the diversity of tropical plant responses"
The impact of herbivores on tropical plants is frequently indirect and even cryptic, and varies with plant ontogeny. However herbivory is omnipresent and evidence shows that at least in some cases it operates as an important selective pressure for tropical plants. Such selective pressure leads to a plethora of anti-herbivory responses, beyond the diversity of defensive (secondary) compounds. In this talk I will review the diversity of plant responses, which ranges from phenological disruptions, to associations with conventional and non-conventional biotic mutualistic defenders. Yet, as I will illustrate, distinguishing between proximal and ultimate responses remains an aspect in need of additional research. Beyond this, anthropogenic impact has become a major force of disruption of species interactions, including herbivory. I will illustrate how human impact threatens biodiversity not only via the extinction of species and populations, but via the extinction of ecological processes, including those that led to the exuberance of adaptations of plants to animals –and vice versa– that we see, or used to see, in tropical forests.