For 70 million years, volcanoes have spewed magma into the Pacific Ocean, lava that hardens to form an island. As the Earth's shifting plates carry the baby island northwest, more magma creates new masses, and thus was born the chain of Hawaiian Islands.
Peter Vitousek, professor of population and resource studies at Stanford University, spent his childhood in Hawaii. Now he examines Hawaiian soil to understand how global ecosystems grew. Discussing \Sources of Nutrients During Four Million Years of Soil and Ecosystem Development"" at UW-Madison's 10th Annual Fall Ecology Symposium last week, Vitousek outlined his research of how nutrients cycle throughout worldwide forest ecosystems.
For instance, phosphorus concentrations vary predictably as the soil ages. Phosphorus is released into the soil as rock erodes, influencing the ecosystem's diversity and composition, he said.
Nutrients that cycle globally also affect soil development: Winds carry desert dust from across the Atlantic, and the ocean nourishes the soil and forests. Humans also affect soil-irrigation, fertilizers and fossil fuel exhaust have more than doubled the nitrogen content in the last century.
Together these factors shape the fingerprint of an ecosystem and the ways a forest adjusts to survive. Vitousek hopes to expand this localized understanding to the global environment.
""Islands in general, and Hawaii in particular, are excellent model systems"" to study the many processes in ecosystems, Vitousek said. The outcomes might vary among ecosystems, he said, ""but a model system is a really useful way to identify the processes.""
Hawaii is Vitousek's ecological lab rat, because its topology and volcanic rock foundation are similar on all islands. Hawaii's isolation also makes it a difficult place for organisms to reach, and the few that do radiate to all the other islands.
""Peter's not afraid to think big,"" said Don Wailer, UW-Madison botany professor. ""He finds the simple process that reveals the key variables.""
The UW-Madison Ecology Group, an organization of faculty and students dedicated to ecological research, sponsored Vitousek's talk.
""It's really an interdisciplinary approach,"" said UW-Madison zoology student Dan Skelly, citing the zoologists, soil scientists, entomologists and ecologists who participated.
Vitousek said he hopes Stanford will steal the idea of an ecology symposium, so its scientists too can experience ""how much fun it really is.\
