Dr. Erik t nilsen Professor of Biology Virginia Tech Special Seminar 4: 10 pm, Monday, April 3

Dr. Erik T Nilsen
Professor of Biology
Virginia Tech

Special Seminar
4:10 PM, Monday, April 3^{rd
118 Horticulture Hall}

Title: Thermonastic leaf movement in Rhododendron: probing physiological mechanism and functional significance

Abstract: The diverse and abundant leaf movements in plants have major impacts on photosynthesis, water relations and thermal dynamics. By changing leaf azimuth, angle, curling, and rolling leaves can severely modify the temporal dynamics of radiation impinging on the leaf lamina. Within this context, themonastic leaf movements have been a focus of my research. Rhododendron leaves curl and roll in response to freezing temperature in the winter. The patterns of leaf curl and roll on plants in situ will be shown. In addition, the variation in thermonastic leaf movements between sister species pairs and its relationship to cold tolerance will be discussed. The results of several lab and field manipulation experiments will be considered and the functional significance of thermonastic leaf movements will be demonstrated. Lastly, new research on the putative mechanism for thermonastic leaf curling and leaf rolling will be highlighted. I will consider what is known and what is yet to be known about this important leaf movement pattern for evergreen shrubs.

Bio of Professor Nilsen

Erik Nilsen received his B.S. at the U. of Miami in Florida where he did undergraduate research on invasive trees with Taylor Alexander and Ron Hofstetter. Following a master’s degree at the U. of California-Santa Barbara, on the comparative invasion pressure by two Schinus species, he completed his Ph.D. with Walter Muller at UCSB on the developmental regulation of summer deciduousness in Lotus scoparius including studies on water relations, photosynthesis and nitrogen cycling in response to early succession nitrogen fluxes in post fire chaparral. Erik moved to a post-doctoral fellowship at the U. of California-Irvine with Phillip Rundel and studied the water relations, productivity, and nitrogen cycling of Prosopis glandulosa woodlands in the Sonoran desert. Erik then moved east to Virginia Tech where he is currently professor of Biology and focuses on understanding the mechanisms of tolerance and avoidance of environmental stresses by plants. While at Virginia Tech., Erik’s professional activities have been research associate at UCLA, sabbatical at Stanford, two terms as EEP program officer at the NSF and Wilder Chair for distinguished botanist at the University of Hawaii. Erik’s current research is focused on the functional significances of leaf structures, interactions between cold tolerance and drought tolerance at the scale of the vascular system, mechanisms by which understory evergreen shrubs inhibit canopy tree recruitment, and functional traits of invasive species. His work has resulted in 2 books on plant stress physiology and over 100 articles in journals and book chapters.