CLIMACTIC VARIABILITY IN THE MIDCONTINENT OF NORTH AMERICA: LESSONS FROM THE PAST

Professor Hu is a broadly trained ecologist working at the interfaces of biological, geological, and climatological sciences. The overall objective of his research is to understand patterns and mechanisms of long-term ecosystem dynamics under changing climatic conditions. To achieve this objective, he uses the “natural experiments of the past” that are archived in geological deposits. These deposits offer a long-term holistic perspective on past environmental conditions, some of which do not exist today, and may be analogs of different climatic conditions in the future. In pursuing his research interests, Professor Hu integrates traditional paleoecological techniques (e.g., pollen analysis) and state-of-the-art analytical tools (e.g., biomarker, stable-isotope, and chloroplast-DNA techniques). He has applied this integrative approach to the study of environmental dynamics at various spatial and temporal scales.

During his Center appointment, Professor Hu will conduct a research project that aims to test the hypothesis that the earth’s climate during the present interglacial period was punctuated by abrupt events in a rhythmic manner. He will use physical, chemical, and biological records preserved in lake sediment to address a number of specific questions:

• Did temperature and precipitation vary in a predictable manner at sub-decadal to millennial scales in the midcontinent of North America?
• How were these variations related to global climatic controls (e.g., solar cycles, ice-sheet dynamics)?
• Has the climate become unprecedentedly warm as a result of human activity?
• How have past climatic events shaped the grassland and peatland ecosystems of the midwestern United States?

Understanding past climatic rhythms and their biotic effects is of profound significance, as it directly pertains to our ability to predict future environmental change.