Tree rings from a giant sequoia
Friday, March 20, 2015
Drought History in Tree Rings
Tree rings can be used to study drought history of particular regions. The lighter parts of a tree's rings correspond to its growing seasons each year, and multiple close-together dark lines signify a drought period. Giant sequoias can live to be over 3,000 years old, so cross sections of their trunks can show centuries of drought history. Hughes, 1992 shows the findings of a research team that studied giant sequoias in the Sierra Nevada mountain range and produced a climate history of the years 101 BC to 1988 AD. The past century has had a low drought frequency so far. It would be interesting to see how the current drought in California would look compared to other droughts recorded by these trees.