Keywords :
Annual ring,
dendrochronology,
earlywood,
intra-annual density fluctuations (IADFs),
latewood,
quantitative wood anatomy,
tree-ring
บทคัดย่อ :
The objectives of this research were to
identify and locate the position of false ring occurrences in natural teak (Tectona grandis) and to relate their
formation to local climate variability. Vessel diameters were measured and standardised from pith towards
the bark in order to identify false rings and define annual ring boundaries. Two types of false rings were
classified as false ring type I and II in earlywood and latewood respectively. False ring type I had one or more
rows of axial parenchyma associated with large vessels at the beginning of the annual ring. False ring type II
was divided into two groups based on their characteristics. The first group had an aggregation of large vessels
associated with paratracheal parenchyma while the second group did not have any paratracheal parenchyma.
The occurrences of false rings could be explained by the fluctuations of rainfall and temperature during the
growing season. False ring type I occurred during drought following heavy rainfall at the beginning of the
monsoon period. After dense fibre occurrences in latewood, heavy rainfall and warm temperature at the end
of the monsoon period re-stimulated large vessels and/or parenchymatous cells to form false ring type II.
เอกสารอ้างอิง :
Palakit, K., Siripattanadilok, S., & Duangsathaporn, K. (2012). False ring occurrences and their identification in teak (Tectona grandis) in north-eastern Thailand. Journal of Tropical Forest Science, 387-398.
