Ray Traits of Juvenile Wood and Mature Wood: Pinus massonia and Cunninghamia lanceolata

Ray traits affect secondary xylem development and wood properties. Pinus massonia and Cunninghamia lanceolata, commercially important timber species, were chosen to study the differences in wood ray traits of juvenile versus mature wood. Seven ray traits, i.e., percentage of rays, ray spacing, ray number, uniseriate ray height, fusiform ray height, ray parenchyma cell length and ray tracheid length, as well as eight wood axial tissue traits, were investigated quantitatively. Intraspecific variations in ray traits and axial tissue traits between juvenile wood and mature wood were displayed in violin plots. The results showed that anatomical differences between juvenile wood and mature wood were significant for both ray traits and axial tissue traits. Juvenile wood generally possessed the larger percentage of rays, higher ray spacing and ray number, smaller ray height and shorter ray cells than mature wood. A positive correlation was present between the ray parenchyma cell length and ray tracheid length. Negative correlations of the ray number and ray spacing with uniseriate ray height were found. Additionally, the axial tracheid cell wall thickness all had Pearson’s correlations with ray spacing, ray number and ray parenchyma cell length.

Chemotaxonomical identification of Holocenic bogwood recovered after 2007 Niigataken Chuestsu-oki Earthquake

A Holocenic coniferous bogwood salvaged from the 70 to 100 m-deep seabed after the 2007 Niigataken Chuetsu-oki Earthquake was analyzed anatomically and chemically. The main anatomical features of the wood were the presence of (i) large window-like pits in cross field and (ii) smooth-walled cells of ray tracheid. Feature (i) allowed identification of the wood as genus Pinus. Feature (ii) is characteristic of section Quinquefoliae, but possible decay by the long burial (3400–3210 cal BP) left the identification inconclusive. Chemical analysis showed that the major volatile components of the bogwood were cadinane-type sesquiterpenes. In contrast, those of modern pine samples were longifolene and monoterpenes from Pinus densiflora and Pinus thunbergii, nerolidol from Pinus parviflora and P. parviflora var. pentaphylla, and monoterpenes from Pinus koraiensis. Thus, none of the modern pines contained cadinane-type sesquiterpenes as major components. As organic components of wood are known to undergo diagenetic transformation under geological conditions, recent samples were subjected to heat treatment at 180°C for 24 h to simulate the long burial time. As a result, nerolidol, the main component of P. parviflora and P. parviflora var. pentaphylla was converted to cadinane-type sesquiterpenes. Therefore, it is highly likely that the bogwood sample was P. parviflora or P. parviflora var. pentaphylla, section Quinquefoliae subsection Strobus, agreeing with the anatomical feature of section Quinquefoliae.

DEFINITIVE IDENTIFICATION OF LARIX (PINACEAE) WOOD BASED ON ANATOMY FROM THE MIDDLE EOCENE, AXEL HEIBERG ISLAND, CANADIAN HIGH ARCTIC

This paper provides the first definitive identification of fossil Larix Miller wood using the characteristic features of ray-tracheid bordered pits. The wood was recovered from the middle Eocene (Lutetian/Uintan; 41.3– 47.5 Ma) Buchanan Lake Formation on eastern Axel Heiberg Island in the Canadian High Arctic and extends the fossil record of Larix wood further back in geologic time. A new and rapid embedding method is described which provides a firm and non-destructive matrix for thinsectioning and examining the well-preserved details of the wood. The wood is associated with Larix altoborealis LePage & Basinger, a shortbracted species, which was previously described from this locality as the earliest known species of Larix.

Confirmation and Significance of Bartholin's Method for the Identification of the Wood of Picea and Larix

Eighty-seven Picea and Larix samples from thirty-nine species were examined microscopically to confirm an accurate method of genus separation. The proportions and type of ray tracheid bordered pits as described by Bartholin (1979) were the only wood anatomical feature to correctly identify all specimens.