tree rings 6 th grade science aprende middle school
TRANSCRIPT
Tree Rings6th grade science
Aprende Middle School
Dendrochronology??
Dendrochronology – study of tree rings.Dendrochronologists – scientist that studies tree rings.Pronounced
den – dro - kron – o - la – gee
Word rootsdendro (from dendros, greek for tree)chrono (from chronos, greek for time or past events)logy (from logos, greek for reason or word. “ology” indicates a study or theory)
• Growth – varies throughout year in our climate
• Late Spring/Summer – wide light coloured ring (lots of growth)
• Late summer/autumn – narrow darker ring (little growth)
• Winter – dormant (no growth)
What are tree rings?
From LTTR, Arizona
• One year’s growth is a dark and light ring together = annual growth ring = X
X
From LTTR, Arizona
• Earlywood – appears light in colour – cells are thin walled and large in diameter
• Latewood – appears dark in colour – cells have thick walls and are small in diameter
• Total ring width = a light and dark band
Photos by Grassino-Mayer at UTK (see web address)
Year-to-year changes in the weather create the patterns.
Trees respond to temperature, rainfall and other environmental conditions by altering growth.
Wide rings of certain species of trees = wet years
Narrow rings of certain species of trees = dry seasons
Ring counting cannot be based fully on the amount of rainfall in that year.There are other factors (variables) that can affect the rings of a tree.
Slope Gradient Sun Wind Soil properties Temperature and snow accumulation.
The more factors a tree endures, the more variation in ring to ring growth will be present.
A complacent tree will have less variation between rings because it was not affected by those factors.It had constant climate conditions.
A sensitive tree will have more of a variation between rings because it was affected by those factors.
Marking of actual years and events on a tree
section
2002
The year England won the world cup?
The new millennium?
? When were you born?
You are now going to find out more about tree ring growth and label your own
tree ring!!!