This movement can be seen in this graph which depicts the abundance of trees above current treeline for five sites typical of the eastern crest of the Sierra Nevada in Sequoia National Park. In the cool, dry climate of the Sierra Nevada, dead foxtail pine trees at high elevations are preserved in situ for millennia.
Dead trees located above current treeline testify to the dynamic behavior of treeline in the past.
In order to date each tree, we extracted increment cores from each tree and used tree-ring dating techniques to identify the calendar year of each tree's inner and outer ring. In order to document general trends within Sequoia National Park, we sampled five sites on the eastern crest of the Sierra Nevada. Our ability to interpret treeline movements in terms of past climatic variation was made possible by the results of SNGC studies of past climatic variation. No aspect is indicated for the Meadow plot, because it is on a flat valley bottom. The distance from current to maximum paleo-treeline is the distance to the nearest living forests.