Dr. David Frank, Professor and Director, Laboratory of Tree-Ring Research, U. of A.
Thursday, June 6, 2019, 2:30-3:30 p.m., The Arizona Senior Academy Building
The growth of forest trees all over the world is becoming more water-limited as climate warms. This effect is most evident in northern climates and at high altitudes where primary limitation on tree growth had been cold temperatures, according to Dr. David Frank, Director of the Laboratory of Tree-Ring Research at the U. of A. Current studies at the laboratory are the first of tree growth at a near-global scale showing that trees are becoming more limited by water across the vast majority of the earth’s surface.
The researchers associated with Dr. Frank compared the annual growth rings of trees during time periods of 1930-1960 and 1960-1990. Tree rings width are wider when growing conditions are better, narrower when conditions are worse. Over these two periods, average temperatures, precipitation and measures of drought stress were mapped. In the earlier period, temperature limited growth, but now the researchers report shifts toward moisture-drought limitation. Dr. Frank will discuss how these findings have implications for future forest and tree growth and forest management. This most recent research has been reported in Science Advances as “Twentieth Century redistribution in climatic drivers of global tree growth,” http://advances.sciencemag.org/content/5/1/eaat4313.
The Laboratory of Tree-Ring Research (LTRR) at the University of Arizona was established in 1937 for the scientific study of tree-rings in America.. As part of Dr. Frank’s lecture, he will provide some additional recent advances in dendrochronology and a bit of history of the LTRR.
David Frank is co-author of many papers in dendrology and, with E.R. Wahl, of a book: Evidence of environmental change from annually resolved proxies with particular reference to dendrochronology and the last millennium (2012). He is a Professor of Dendrology and a member of the faculty of Global Change, and teaches introductory courses in both programs.
Written by Norm Scott, Academy Village Volunteer