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Dendochronlogy


Facilities available:
  • LINTABTM 6 Tree-ring station (Tree-ring width measurement station).
Type of analysis
  • Tree-ring width measurement,
  • dating of annual growth rings to the level of calendar year of their formation.
Details of Sample preparation for the analysis.

PRE-PROCESSING OF TREE CORE

Air dry samples at room temperature for few days within the newspaper wrapping.
When dried, select cores (one by one) and write its identification number on the core mount (i.e. wooden core mount).
For mounting samples on wooden mounts, remove samples carefully from the newspaper by unwrapping the newspaper.
Place glue in the groove of the mount in the length of the core.
Mount cores carefully.
Following precautions are required to take during mounting.

  • The core mounted with its cells vertically aligned, i.e. straight up and down, similar to how they were positioned originally in the trees.
  • For this, use mark formed during coring on either side of the core by the borer.
  • If the core is in pieces, ensure that all pieces are in their correct order and in their correct alignment.
  • If required, apply steam to the cores to avoid twisting of samples.
Press core into the groove
Finally, tie with thread onto the mount firmly at both ends and in the middle of the core.
Keep for some hours until the glue dries completely.

 

SAMPLE POLISHING

Polish tree cores to make the cells and rings visible under the microscope. For the purpose, slice top surface of the core with a blade keeping at an acute angle to the direction of slicing with precaution not to give deep cut.

PPolish top surface of core with sand paper of different grades (400, 600 and 800) till all the cells and boundaries are clearly visible and ring details are quite prominent.

CROSSDATING OF GROWTH RINGS

Assign date to growth rings of each tree core to the level of calendar year of their formation using skeleton plotting method.

MEASUREMENT OF TREE RINGS

Measure each dated growth ring width using LINTAB TREE RING STATION.

A short guide regarding how to prepare and send samples

Samples would be prepared in the lab, however, following precautions must be taken while sending the samples for analysis:

  • Increment core:     Since the increment cores are fragile, it must be transported in safe box.
  • Disk:     sample would be prepared in the lab.

 

 
 
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