Laboratory investigations of the Botanical Kind: Dendroclimatology

There are four major disciplines related to tree rings:

1. Dendrochronology (dendron = tree, chronos = time, logos = word = the science of): The science that uses tree rings dated to their exact year of formation to analyze temporal and spatial patterns of processes in the physical and cultural sciences.

2. Dendroclimatology: The science that uses tree rings to study and reconstruct the past and present climate of an area. Example: analyzing ring widths of trees to determine how much rainfall fell per year long before weather records were kept.

3. Dendroecology: The science that uses tree rings to study factors that affect the earth's ecosystems. Example: analyzing the effects of air pollution on tree growth by studying changes in ring widths over time.

4. Dendropyrochronology: The science that uses tree rings to date and study past and present changes in wildfires. Example: dating the fire scars left in tree rings to determine how often fires occurred in the past.

Download the Rainfall Data in Excel format

Use Google Docs version of the Rainfall Data

Need the procedure? Download it in MS Word Format 

Information on the White Ash from  Dendrology at Virgina Tech

A nice explanation of Dendrochronology

The homepage for the Laboratory of Tree-Ring Research at the University of Arizona

What makes Tree Rings Special?.... The Principle of Limiting Factors

As used in dendrochronology, this principle states that rates of plant processes are constrained by the primary environmental variable that is most limiting. For example, precipitation is often the most limiting factor to plant growth in arid and semiarid areas. In these regions, tree growth cannot proceed faster than that allowed by the amount of precipitation, causing the width of the rings (i.e., the volume of wood produced) to be a function of precipitation. In some locations, rainfall is not the most limiting factor. For example, in the higher latitudes, temperature is often the most limiting factor that affects tree growth rates. In addition, the factor that is most limiting is often acted upon by other non-climatic factors. While precipitation may be limiting in semiarid regions, the effects of the low precipitation amounts may be compounded by well-drained (e.g. sandy) soils.