Hydrology and ecology meet—and the meeting is good

As a ‘hybrid’ scientist (I call myself an ‘ecophysiologist’) as well as an ‘eco’ partner in collaborative research with hydrologists, I’ve watched the growth and development of the new hybrid field, ecohydrology, with great interest. I’ve asked colleagues if they’ve heard of this new paradigm. Hydrologists typically respond enthusiastically by naming people who are helping to define the field, and they identify high-profile, international programs and recent conferences and special issues of journals devoted to ecohydrology. Ecologists, at least in my informal sample, are less likely to be aware of ecohydrology as an emerging discipline, but many will add something like, ‘but I suppose you could say that’s what I’ve been doing for most of my career’. Of course, this isn’t surprising, because the ecohydrology paradigm is emerging from the discipline of hydrology. But if ecohydrology is the science that studies the mutual interaction between the hydrological cycle and ecosystems (Porporato and Rodriguez-Iturbe, 2002), perhaps it is time for ecologists to participate more actively in discussions that seek to define opportunities for this emerging field. To that end, a group of ecologists, hydrologists and atmospheric scientists at Oregon State University organized a 10 week seminar series, ‘Perspectives on Ecohydrology’, during the fall of 2002. One goal of this seminar series was to promote cross-disciplinary communication. A hydrologist discussed her analyses of long-term streamflow measurements, inferring change in transpiration by vegetation in different places or at different times from the streamflow patterns; another shared studies of flowpaths and residence times of water in catchments, leading to discussions of how vegetation influences, and is influenced by, those flowpaths. An ecologist shared studies demonstrating a profound influence of small variations in elevation on species composition of plant communities due to differences in depth of the water table. She and another ecologist shared their recent data demonstrating significant vertical and lateral ‘hydraulic redistribution’: mass flow of water from moist to dry soil regions through living roots. Other participants talked about studies relating soil water content and nutrient cycles, about the potential influence of water tables on growth decline and mortality of Alaska yellow cedar, and about the strong influence of airflow patterns in and above the canopy atmosphere on transpiration and transport of water, and hence on soil water availability and plant growth. Along the way we taught one another some of our vocabularies. We learned, for example, that the hydrologists in the Copyright 2003 John Wiley & Sons, Ltd.