Research Seminar - Hawkesbury Institute for the Environment

Seminar abstract: The response of productivity, carbon storage, and diversity of terrestrial ecosystems to global change is critically important for our future. Predictions of these responses will aid in planning and adapting, and form a critical portion of the IPCC climate change predictions and assessments. All current models follow the same basic scheme that I call a Opush¹ model of photosynthesis. Models estimate photosynthesis as a function of leaf area, photosynthetic capacity and environment, and that carbohydrate is Opushed¹ out to respiration, growth and reproductive sinks with a fixed or variable partitioning scheme. Such models are simple to implement and can used satellite-derived leaf area and environment so they can be widely applied. Many studies show that the sinks may be more environmentally responsive than is photosynthesis, and that the sinks and their feedback to photosynthesis often control plant growth. This Opull¹ model (sink demand Opulls¹ photosynthesis) may be especially important in response to CO2, drought and nutrition, and how these responses change with ontogeny for forests.

About the speaker: Mike Ryan is a Senior Research Scientist at the Natural Resource Ecology Lab and the Graduate Degree Program in Ecology at Colorado State University, an Emeritus Research Ecologist for the USDA Forest Service, Rocky Mountain Research Station in Fort Collins, Colorado, and on sabbatical in Australia as a CSIRO McMaster Fellow. His research focuses on whole tree physiology, including the role of respiration in regulating productivity, tree carbon balance, mechanism of size-related productivity decline, mechanisms of drought tolerance and mortality, carbon allocation, and the role of source versus sink control of plant carbon balance. He has studied other aspects of the forest carbon cycle including changes in forest carbon with disturbance and recovery, the effects of global change, ecosystem respiration, soil carbon and nitrogen interactions, decomposition of soil carbon, and coordination of carbon, water, and nutrient cycles. Mike serves as an editor for Tree Physiology, and is on the editorial review boards of Plant, Cell and Environment and New Phytologist. He received his B.S. from the University of Pittsburgh, M.S. from Northern Arizona University, Ph.D. from Oregon State University and was a post-doctoral fellow at the Ecosystems Center at the Marine Biological Laboratory.

For more information on Dr Ryan, please visit http://lamar.colostate.edu/~mryan/ or http://www.fs.fed.us/rmrs/profiles/?last=Ryan&first=Michael+G No RSVP is required, we hope to see you all there.