Vessel feature changes as a tool for detecting annual rings in tropical trees

Seasonal variations in the stable oxygen isotope ratio of wood cellulose reveal annual rings of trees in a Central Amazon terra firme forest

“…such as stable carbon (δ 13 C) and oxygen isotope ratios (δ 18 O) of wood (e.g., Leavitt and Long 1991;Evans and Schrag 2004;Poussart et al 2004;Verheyden et al 2004a), vessel density and size (Verheyden et al 2004b(Verheyden et al , 2005aOhashi et al 2009Ohashi et al , 2014, and calcium in wood (Poussart et al 2006). These indicators show cyclic intra-annual variations, which are attributed to seasonal changes in environmental conditions and/or the physiological status of trees, allowing annual rings to be identified.…”

“…However, the underlying mechanisms of these cyclic features are not well understood, limiting the applicability of these alternative indicators. The number of the studies in the humid tropics, where monthly precipitation usually exceeds 60 mm throughout the year, remains limited (e.g., Pons and Helle 2011;Ohashi et al 2014).…”

“…The δ 13 C wc variation depends on stomatal conductance, photosynthesis rate (Farquhar et al 1989;McCarroll and Loader 2004), and post-photosynthetic processes, such as use of carbon reserves (Helle and Schleser 2004). The variation in vessel features relies on the biological response to water availability and unidentified internal factors that seem to be related to leaf phenology and phytohormones (Ohashi et al 2014). In addition, the radial growth of trees in the humid tropics tends to be asynchronous even within the stem circumference of an individual tree, and the growth cycle does not seem to be strictly annual (Ogata et al 2002;Ohashi et al 2014).…”

Occurrence and anatomical features of growth rings in tropical rainforest trees in Peninsular Malaysia: a preliminary study

“…The variation of vessel size and/or density is most likely caused by changes in water availability to trees (e.g., Baas 1976;Baas et al 1983; Alves and Angyalossy-Alfonsi 2000; Ohashi et al 2009). Ohashi et al (2013) reported that vessel features varied independent of water availability in all species studied grown in rainforest climate and most species grown in savanna and monsoon climate. Ohashi et al (2013) also stressed that even water availability influences variation in vessels for some trees in the tropics, it is also depend on the species characteristics such as vessel porosity, leaf phenology and drought adaptations, and internal factors such as phytohormones.…”

“…Ohashi et al (2013) reported that vessel features varied independent of water availability in all species studied grown in rainforest climate and most species grown in savanna and monsoon climate. Ohashi et al (2013) also stressed that even water availability influences variation in vessels for some trees in the tropics, it is also depend on the species characteristics such as vessel porosity, leaf phenology and drought adaptations, and internal factors such as phytohormones. However, the actual factor causing variation in vessel size and/or density in tropical trees are still in dispute.…”