Paper No. 38
Presentation Time: 9:00 AM-6:00 PM


COX, Terry, Geology, St. Lawrence University, 23 Romoda Dr, Canton, NY 13617 and STEWART, Alexander K., Department of Geology, St. Lawrence University, Canton, NY 13617,

Dendrochronology can help determine the environmental effects of geology and weather on white pines (Pinus strobus L.) in the Adirondack Mountains. Lampson Falls is an approximately 10-meter waterfall over coherent, Precambrian-aged leucogranites with the surrounding, sloping terrain (approximately 16% grade to the southeast) covered with 0-50cms of soil. 12 living trees (mean height=28.8m) and seven uprooted trees (mean height=24.0m) were sampled twice from opposing sides of the tree bole with an increment borer. These cores were mounted and polished, so their ring-width variation could be analyzed by microscopy and then skeleton plotted. A master chronology of the sample trees covers 1920-2012 with 1956-57, 1961 and 1996-99 identified as marker years. Uprooted trees had ovate root plates without taproots (mean volume=3.54m3) and uprooting events were crossdated to 2006, 2007(2x), 2008, 2009 and 2010(2x). Within-tree growth variation noted by reaction wood differences between cores confirms a mean slope direction of 102o. Uprooted trees had a mean fall direction of 039o and likely succumbed to wind gusts coming from 220o. The combination of slope-induced, reinforcing growth to the southeast, perpendicular gusts to the northeast and a weakly fixed, over-fitted root plate leads to a ~8% chance/annum that white pines (>25m) may be windthrown due to wind gusts >12ms-1 (27mph). These factors can limit tree growth and increase windthrow, which may detract from the anticipated beauty of a touristy area.