High-resolution densitometry and elemental analysis of tropical wood

Abstract

Key messageUnderstanding the mobility and distribution of chemical elements in wood is necessary to apply dendrochemistry. Crystals are likely stable and could be used to analyze changes in nutrient supply.AbstractDendrochemistry uses the variation in wood chemical composition to infer about past environmental conditions and possible effects on tree growth. Elemental or isotopic variation might also help to identify annual growth where tree rings are anatomically not distinct. However, most elements are—to a certain degree—mobile within wood and may be related to anatomical structures. Therefore, understanding what affects elemental distribution is important to make use of and critically assess the potential of dendrochemistry. We studied the variation of wood density and elements at high spatial resolution in wood of six species with anatomically distinct to rather indistinct tree rings from a Thai monsoon forest. Many elements had a higher concentration in parenchyma than in fiber cells, and the co-variation of elements differed strongly between elements and also between species. Strong wood density changes along the ring boundary were found only in Melia azedarach. In all species, the X-ray images showed crystals. EDX spectra showed that these consist of calcium or silicon (in Chukrasia tabularis) as major elemental components. A high concentration of heavy metals (Fe, Cu and Zn) was found in Vitex peduncularis. We conclude that at least for the species studied the radial variation of elemental concentration is unlikely to reveal annual rings that anatomy could not. However, if elements in crystals are more stable than in cell walls or living protoplasts, analyzing the distribution of elements present in crystals may show environmental conditions that, in turn, influence crystal formation and are little known.

Edaphic, structural and physiological contrasts across Amazon Basin forest–savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

“…(Mengel and Arneke, 1982;Egilla et al, 2001Egilla et al, , 2005Umar, 2006;Lebaudy et al, 2008;El-Mesbahi et al, 2012;Wang et al, 2013;Shabala and Pottosin, 2014). Further, an important role of potassium as a prime signaller of plant responses to abiotic stresses has also recently been postulated by several groups (Osakabe et al, 2013;Ahmad and Maathuis, 2014;Anschütz et al, 2014;Hafsi et al, 2014;Shabala and Pottosin, 2014), which -along with a previously unrecognised likely role for potassium as an osmoticum in woody stem tissues capable of high water storage (Braun et al, 1968;Hart, 1984;Borchert and Pockman, 2005;Pineda-Garcia et al, 2013;Hietz et al, 2014;Spicer, 2014) -all point to this element as a key chemical in soil water deficit signalling and response.…”

Edaphic, structural and physiological contrasts across Amazon Basin forest-savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

“…(Mengel and Arneke, 1982;Egilla et al, 2001Egilla et al, , 2005Umar, 2006;Lebaudy et al, 2008;El-Mesbahi et al, 2012;Wang et al, 2013;Shabala and Pottosin, 2014). Further, an important role of potassium as a prime signaller of plant responses to abiotic stresses has also recently been postulated by several groups (Osakabe et al, 2013;Ahmad and Maathuis, 2014;Anschütz et al, 2014;Hafsi et al, 2014;Shabala and Pottosin, 2014), which -along with a previously unrecognised likely role for potassium as an osmoticum in woody stem tissues capable of high water storage (Braun et al, 1968;Hart, 1984;Borchert and Pockman, 2005;Pineda-Garcia et al, 2013;Hietz et al, 2014;Spicer, 2014) -all point to this element as a key chemical in soil water deficit signalling and response.…”

Dendrochemical Challenge in Climate Science: Whether Chemical Elements in Wood Reflect the Fluctuations in Weather Parameters

“…Because of this, they may distort possible relationships between climatic parameters at the time of the ring growth and the elements’ deposition in the xylem. It is noteworthy to mention that no crystal-like structures similar to those reported by Hietz et al [ 14 ] were registered on X-ray images in the trees sampled.…”

“…Practically, precious little research has used treatment to obtain additional information from the scanned cores. Hietz et al [ 14 ] studied the distribution of elements in the wood of six monsoon forest species. The X-ray images revealed some entities of high density that were more or less concentrated near tree ring boundaries.…”