PAUL L. KOCH Professor of Earth & Planetary Sciences Department Chair Isotope Biogeochemistry and Vertebrate Paleontology
		Office: EMS A250 Phone: 831-459-5861 Fax: 831-459-3074 E-mail: pkoch@es.ucsc.edu Lab: D206, x9-5088		For more information: • Publications • Lab Website

Education and Training

B.A., University of Rochester
M.S., Ph.D., University of Michigan

Research Interests

Climate exerts a powerful influence on the diversity and organization of continental ecosystems. Paul Koch's research explores this connection in three ways. First, he develops new geochemical techniques to reconstruct paleoclimate on land in the distant past.

Recently, Koch and his students have used the oxygen isotope chemistry of soil minerals (calcite and hematite) and mammal teeth to reconstruct the oxygen isotope composition of rainfall, which is closely tied to mean annual temperature. In their studies of climate change in the Rocky Mountains across the Paleocene/Eocene boundary, they have shown that the first appearance of several major groups of plants and animals is closely linked to local climatic warming.

Working with Jim Zachos, Koch has demonstrated that these episodes of warming in the Rocky Mountains correspond to relatively brief intervals of high-marine temperatures, and consequently that mammalian migration and evolution may be directly modulated by rapid changes in global climate.

To evaluate the links between climate change and faunal evolution, Koch studies the ecology of extinct animals and plants using biogeochemical, microstructural, and morphometric techniques. For example, he has used carbon isotopes to examine how the diets of mastadons, mammoths, and other species changed during the rapid deglaciation at the end of the last ice age. He is testing the idea that sudden changes in floral composition, driven by climate change, may have driven these animals to extinction. Similarly, he and his students are developing methods to examine the nutritional status of extinct mammals through analysis of nitrogen isotopes in preserved bone proteins. Also, he has explored the migration patterns of extinct salmon and mammals using the strontium isotope composition of teeth and bones. Finally, these same biogeochemical approaches can be used to study modern organisms to address questions in ecology and conservation biology.

In recent work, Koch has been using isotope variations to assay current and historical patterns of resource and habitat use by modern African elephants. The isotopic study of modern elephants also has ramifications for a proposed method of monitoring ivory trade.

Teaching Interests

History of Life, The Fossil Record, Paleontology Seminar