Keywords :
Annual ring,
Cambial marking,
Dendrochronology,
Leaf phenology,
Wood anatomy
บทคัดย่อ :
The growth response to climatic variability was studied of Afzelia xylocarpa and Lagerstroemia
duperreana growing naturally at the Sakaerat Environmental Research Station, Thailand.
The monthly wood increments and leaf phenology of these two species were investigated for 1 yr.
The occurrence of axial parenchyma was considered as a marker for the annual ring boundary in
A. xylocarpa, while the variations in vessel size and fiber cell wall thickness and shape were used
to identify the annual ring boundary in L. duperreana. The monthly wood increments and leaf flush
in these trees were initiated at the onset of the rainy season or a month later. The cessation of wood
increment occurred in association with leaf abscission during the dry season, from December to
February. The two climatic components indicated by principal component analysis were Moisture
(rainfall, relative humidity and soil moisture content) and Temperature (maximum, minimum and
mean temperature); they illustrated the coupling effect of direct and indirect stimulation on tree
growth. By using path analysis, the Moisture and Temperature components could be used to explain
the occurrence of mature dark green leaves (MDL) 64% of the time in A. xylocarpa, while the
moisture component alone could be used to identify 41% of the MDL occurrence in L. duperreana.
Climatic components association with MDL could explain 45% and 67% of the formation of woody
cells in these two tree species, respectively. The association of climatic components, MDL and
wood increments induced 46% and 91% variation in the diameter over bark of A. xylocarpa and
L. duperreana, respectively.
เอกสารอ้างอิง :
Palakit, K., Lumyai, P., & Duangsathaporn, K. (2021). Periodic growth of Afzelia xylocarpa (Kurz) Craib and Lagerstroemia duperreana Pierre ex Gagnep. and their responses to climatic variability. Agriculture and Natural Resources, 55(2), 282-291.
