Monster Seminar JAM - Sources of Nutrients During 4 Million Years of Soil and Ecosystem Development in the Hawaiian Islands
Dr. Peter M. Vitousek, Professor, Department of Biological Sciences, Stanford University
The Hawaiian Islands are a useful model system for understanding the nature and consequences of nutrient limitation in terrestrial ecosystem. With many colleagues, I developed an age sequence of montane rainforests across the Hawaiian archipelago; in these sites, we can determine the sources of nutrient elements (eg weathering, biological nitrogen fixation, atmospheric deposition of marine aerosol, long-distance transport of continental dust) with a precision that's difficult to duplicate elsewhere. We find that the weathering source of rock-derived elements other than phosphorus is depleted within a few thousand years of soil and ecosystem development - and even phosphorus is depleted in about a million years. Productivity in older sites is maintained by atmospheric deposition of marine aerosol - and in the case of phosphorus, by long-distance transport of dust from central Asia.
Date and Time:
December 2, 2004,
11:00 am - 12:30 pm