Paleo Slide Set: Tree Rings: Ancient Chronicles of Environmental Change
Foxtail pines (Pinus balfouriana) at upper treeline, Sierra Nevada Mountains, California.

A sub-field of dendrochronology, dendroclimatology, is the study of the relationships 
between climate and tree-ring characteristics, and the reconstruction of climate records 
from these relationships. The growth of trees, as well as other organisms, proceeds only 
as fast as allowed by the most limiting environmental factor. The year-to-year variations 
in this factor are reflected in the variations in annual ring characteristics. To obtain 
climate information, trees that are sensitive to climate must be located and sampled. 
Sites that are good candidates for dendroclimatic studies are those in which trees 
are strongly influenced and stressed by climate, while not greatly affected by 
non-climatic factors such as competition from other trees, fire, or human activities. 
Different species of trees have different ecological ranges in which they will grow. 
Frequently, trees that are the most sensitive to climate will be found at the margins 
of their ecological ranges or at environmentally stressed sites within their range. 
In this figure, foxtail pines near alpine treeline are at the upper elevational limits 
of their range, and their growth is strongly influenced by the harsh climate.

Photo Credits:
Anthony Caprio
Sequoia and Kings Canyon National Parks, CA