Tree ring analysis

Each year, the tree forms new cells, arranged in concentric circles called annual rings or annual growth rings. These annual rings show the amount of wood produced during one growing season .

A cross section of a tree shows much more than its age!

Diameter growth is particularly sensitive to fluctuations in the environment:

1. moisture in the soil and air2. temperature3. sunlight

Very broad rings generally indicate a good growing year.

Similar patterns occur in the rings of different tree species over a large geographic area due to variations in the amount of annual perception .

Years in which adequate precipitation occurs produce wider rings of growth , but years of drought produce much narrower rings .

The inner portion of a growth ring is formed early in the growing season, when growth is comparatively rapid (hence the wood is less dense) and is known as “early wood”.

The outer portion is the “late wood” (and has sometimes been termed “summer wood”, often being produced in the summer, though sometimes in the autumn) and is denser .

It is possible to study ring sequences that go back to several thousands years

1.master chronology:

An average tree-ring chronology for a particular region, or one derived locally from a number of closely matching individual tree-ring chronologies. The master chronology forms the reference against which new ring series may be compared and dated.

2.Dendrochronology : (dendron= tree, chronos = time) is a scientific

method that uses tree-ring sequences to date annual growth rings of plant to their exact year of formation. It is applied in several scientific fields, namely archaeology, climatology, geomorphology, glaciology, hydrology, fire history, entomology.

Dendrochronology it is the study of bot visible and microscopic details of tree rings.

Uses :1 tree ring analysis has been extremly useful in

investigation of prehistoric sites of native Americans in the southeast

2.tree ring data are also useful in other disciptions including ecology to study changes in forest community over time

3. Environmental science to study the effects of air pollution on tree growth

4. ecology to date the earthquakes and volcanic eruptions