Climatic influences on intra-annual stem radial variations and xylem formation of Toona ciliata at two Asian tropical forest sites with contrasting soil water availability
Issued Date
2022-05-01
Resource Type
ISSN
01681923
Scopus ID
2-s2.0-85126573521
Journal Title
Agricultural and Forest Meteorology
Volume
318
Rights Holder(s)
SCOPUS
Bibliographic Citation
Agricultural and Forest Meteorology Vol.318 (2022)
Suggested Citation
Kaewmano A., Fu P.L., Fan Z.X., Pumijumnong N., Zuidema P.A., Bräuning A. Climatic influences on intra-annual stem radial variations and xylem formation of Toona ciliata at two Asian tropical forest sites with contrasting soil water availability. Agricultural and Forest Meteorology Vol.318 (2022). doi:10.1016/j.agrformet.2022.108906 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/83255
Title
Climatic influences on intra-annual stem radial variations and xylem formation of Toona ciliata at two Asian tropical forest sites with contrasting soil water availability
Other Contributor(s)
Abstract
Climate extremes will increasingly influence ecosystem productivity of tropical forests, but little is known about their effects on tree stem radial growth, a major component of forest productivity. To analyze the role of climatic drivers and local site differences on tree growth at sub-annual timescales, we studied the timing, magnitude and climatic drivers of stem growth and xylem formation at two tropical forest sites with contrasting soil water availability in southwestern China. We combined high-resolution point dendrometer recordings and microcoring to investigate intra-annual stem radius variation and xylem formation of Toona ciliata over three consecutive years (2018–2020). Stem radial increment of T. ciliata derived from dendrometer data showed distinct seasonal patterns, with growth mainly occurring during March to October. The start day of stem radial growth coincided with the occurrence of the cell enlarging phase, and its end day occurred concomitantly with the cessation of cell enlarging as identified from microcores. Toona ciliata trees at the tropical ravine rainforest site with higher soil water availability showed higher mean annual stem radial increment, higher daily growth rates, and longer duration of xylem productivity than that at the tropical karst forest site. Weekly stem radial growth rates increased with precipitation and air temperature at the wetter ravine rainforest site, while relative humidity had a positive effect at the drier karst forest site. Our findings indicate that drought stress advances and shortens the growing season for T. ciliata. Our study highlights the strong influence of soil water capacity mediating the impact of climate, so response to drought is site-specific, which should be considered in growth models.