The October meeting of the SaddleBrooke Nature Club featured Dr. Randall S. Smith of the University of Arizona’s Tree Ring Lab. Dendrochronology, the study and dating of tree rings, is the newest of the sciences and the University of Arizona’s lab is the only one like it in the world. Imagine a complete archive of every piece of wood since Andrew Elliot Douglas established the lab in 1937 under the football stadium.
Not only can tree rings tell the age of a tree, but they can supply fire and temperature histories that include temperature range and length of cold and hot spells in the particular area in which the tree grew. Archeologists can use this data to date wood from buildings and even charcoal from fire pits. The Chaco Canyon ruins were some of the first sites to have benefited from this science.
By cross matching the data from core samples the lab can use the information obtained to identify and compare climate by patterns of ring growth. Each ring has both a light and dark part. The light part is one year’s sapwood growth and the dark is the heartwood growth from that year. In some cases the researcher may even be able to determine the rabbit population of a year as more acorns eaten mean less growth of the tree.
The lab at the University of Arizona is now in brand new quarters with room for storage and research. Tours of the Lab are offered and can be scheduled by calling 520-621-0984.
The Nature Club provides programs, field trips and activities throughout the fall, winter and spring. Meetings are the second Monday of each month at 4:00 p.m. in the Coyote Room at HOA 1. Dues are $15 per year; $20 for couples.