Frontiers of Ecology

integration and collaboration as we meet the challenge of understanding the great complexity of biological systems. Ecological subdisciplines are rapidly combining and incorporating other biological, physical, mathematical, and sociological disciplines. The burgeoning base of theoretical and empirical work, made possible by new methods, technologies, and funding opportunities, is providing the opportunity to reach robust answers to major ecological questions. In December 1999 the National Science Foundation convened a white paper committee to evaluate what we know and do not know about important ecological processes, what hurdles currently hamper our progress, and what intellectual and conceptual interfaces need to be encouraged. The committee distilled the discussion into four frontiers in research on the ecological structure of the earth’s biological diversity and the ways in which ecological processes continuously shape that structure (i.e., ecological dynamics). This article summarizes the discussions of those frontiers and explains why they are crucial to our understanding of how ecological processes shape patterns and dynamics of global biocomplexity. The frontiers are 1. Dynamics of coalescence in complex communities 2. Evolutionary and historical determinants of ecological processes: The role of ecological memory 3. Emergent properties of complex systems: Biophysical constraints and evolutionary attractors 4. Ecological topology: Defining the spatiotemporal domains of causality for ecological structure and processes Each of the four research frontiers takes a different approach to the overall ecological dynamics of biocomplexity, and all require integration and collaboration among those approaches. These overlapping frontiers themselves are not necessarily new. Within each frontier, however, are emerging questions and approaches that will help us understand how ecological processes are interconnected over multiple spatial and temporal scales, from local community structure to global patterns.