Monster Seminar JAM - Towards Understanding and Forecasting Food Web Responses to Environmental Changes in Salmon-bearing Rivers
Dr. Mary E. Power, Department of Integrative Biology, University of California, Berkeley
Scientists interested in understanding, and eventually forecasting ecological change must step up to the challenge of linking local food webs to regional regimes and fluxes. Marine biologists and oceanographers have overcome formidable logistical challenges of field work on the high seas to make some remarkable progress towards this goal. In river drainage networks, we are interested in similar questions, and can address them at smaller scales in ecosystems with clear physical structure and organization. Despite these advantages, we still have much to learn about linkages between landscape fluxes and local food webs in river networks. Longitudinal (downstream) gradients in habitat structure, sediment supply, energy sources, productivity and disturbance regimes exert strong effects on river organisms, but their effects on species interactions are just beginning to be explored. Even less is known about the influence of network structure per se (e.g. hierarchical branching, confluence nodes). New sensing, tracing, and mapping technologies are revealing landscape (or seascape) features (e.g. watershed divides, ocean fronts or circulation cells) that channel or contain ecosystem fluxes and species interactions. Field experiments and direct in situ observations of basic natural history, however, remain as vital as ever in interpreting the response of biota to potential limiting factors. Both approaches in combination should greatly assist our efforts to manage watersheds and coastlines in ways that sustain river and anadromous populations in the face of intensifying human pressure.
Date and Time:
May 12, 2005,
11:00 am - 12:30 pm