Dr. Hugh Henry will talk on
Production and nutrient cycling in temperate ecosystems: how winter climate matters
at 12:30 in the EEB lounge (BioSciences 4338)
Climate exerts strong controls over plant growth and nutrient cycling, but the mechanisms underlying climate responses have mainly been studied over the growing season. However, winter processes can also play an important role in driving ecosystem responses, and northern temperate regions in particular are sensitive to variability in winter climate. I examined projections of soil freezing responses to climate change using a variety of modeling, observational and hindcasting approaches. Overall, despite a general pattern of a decreased numbers of days of frozen soil and decreased numbers of days with snow on the ground, projected responses of soil freezing dynamics to climate change have been regional in nature, and many northern temperate regions are expected experience an increased number of soil freeze thaw cycles as a result of reduced snow cover. The responses of plants and nitrogen dynamics to changes in soil freezing are sensitive to the timing, frequency, length and severity of soil freezing. I have conducted a range of laboratory, mesocosm and field experiments to examine the important thresholds inherent in these responses, and to assess how freezing damage may interact with increases in atmospheric N deposition over the next century.
Dr. Hugh Henry is an associate professor at Western University. He completed his Master’s at Queen’s (with Lonnie Aarssen) and his PhD at the University of Toronto (with Robert Jefferies). Hugh is broadly interested in nutrient cycling, plant physiology, and global climate change, and how these factors affect plants and micro organisms at the individual, community and ecosystem level. Current research in the Henry lab examines nitrogen (N) uptake during winter (when N uptake is assumed to be unimportant) and during late fall and early spring when freeze-thaw cycles and water runoff create dynamic transitions in the nitrogen cycle. To explore these ideas, Hugh uses large-scale experiments that simulate climate warming, laboratory techniques, and theoretical modeling. His work has taken place in sunny California, snowy Ontario, and salt marshes in the Arctic.
Everyone is welcome to attend
Coffee and treats available at the seminar