Paleoenvironments
A central component of our studies is the reconstruction of past climate and vegetation from indirect or “proxy” evidence. For the recent past, the annual growth rings of living and dead trees provide information about the age of the trees and about growing-conditions (dendrochronology). Sampling is done on selected trees in the region by taking small cores. Tree ring widths are partially dependent on climate: in the highlands of Labrador , wider rings are formed during warmer periods. Further, tree ring width patterns from live (i.e., dated) trees can be matched to dead (i.e., undated) trees whose life span overlaps and precedes that of live trees, allowing the chronology to be extended back further in time.
Longer proxy records of past environmental conditions are available from undisturbed lake sediments in the region. Submerged logs and plant fragments as well as pollen and diatoms provide a picture of the sequence of past vegetation that can be dated using radiocarbon methods. This proxy history can reach back to the time when local glaciers melted, about 7000 years ago. Our research design envisions sampling a number of small lakes at different elevations in the Mealy Mountains and Red Wine Mountains. Lake sediment cores have already been obtained in Gros Morne National Park and those are being analyzed.
