Heartwood and sapwood development within maritime pine ( Pinus pinaster Ait.) stems

Abstract

Heartwood and sapwood development in maritime pine (Pinus pinaster Ait.) is reported based on 35 trees randomly sampled in four sites in Portugal. It was possible to model the number of heartwood rings with cambial age. The heartwood initiation age was estimated to be 13 years and the rate of sapwood transformation into heartwood was 0.5 and 0.7 rings year 1 for ages below and above 55 years, respectively. Reconstruction of heartwood volume inside the tree stem was made by visual identification by image analysis in longitudinal boards along the sawn surfaces. This volume was integrated into the 3D models of logs and stems developed for this species representing the external shape and internal knots. Heartwood either follows the stem profile or shows a maximum value at 3.8 m in height, on average, while sapwood width is greater at the stem base and after 3 m remains almost constant up the stem. Up to 50% of tree height heartwood represents 17% of stem volume, in 83-year-old trees and 12-13% in 42 to 55-year-old trees. Tree variables such as stem diameter, DBH and tree total height were found to correlate significantly with the heartwood content.

Heartwood and sapwood variation in Eucalyptus globulus Labill. trees at the end of rotation for pulp wood production

“…54% of the cross-section at the 5% height level, values somewhat higher than the 42% found by Gominho and Pereira [8] for 9-year-old E. globulus trees, but lower than the 73% found by Miranda et al [18] for 18-year-old E. globulus trees. This indicates the role of tree age in increasing the heartwood proportion as has been referred, too for E. grandis [2], Populus tremuloides [29], Pseudotsuga menziesii [13], Abies balsamea [11] and Pinus pinaster [21].…”

Allométrie du bois de cœur et de l’aubier pour sept espèces d’arbres tempérées chinoises

“…Heartwood volume (HV, cm 3 ) and sapwood volume (SV, cm 3 ): the HV and xylem volume (XV, cm 3 ) for each stem segment were calculated as a truncated cone by the Simpson formula (Pinto et al, 2004):…”

“…Heartwood formation rate (HFR, rings y −1 ), heartwood initiation age (HIA, y) and heartwood initiation xylem radius (HIXR, cm): the slope of the function of HRN against CA represented the HFR (the rings transformed from sapwood to heartwood per year). The HIA was estimated by extrapolating the regressive curve of HRN against CA to zero HRN (Pinto et al, 2004). Similarly, the slope of the function of HR against XR represented the radial heartwood formation rate, and the extrapolation was HIXR.…”

“…Developing allometry of sapwood/heartwood and exploring wood development are essential for understanding tree growth, water transport and carbon allocation, timber production and use (Mäkelä, 2002;Ogle and Pacala, 2009;Pinto et al, 2004), because (1) sapwood contains water conducting pipes (i.e., tracheids and vessels); (2) sapwood stores most carbohydrates for tree survival and growth (Hoch et al, 2003); (3) the living parenchyma cells in sapwood and sapwood growth contribute to most respiration cost of the whole tree (Pruyn et al, 2003); and (4) heartwood contains abundant extractives that improve heartwood natural durability and enhance the crown support (Taylor et al, 2002), although it is physiologically inactive in terms of water conduction and energy reserve materials.…”

Mineral content in relation to radial position, altitude, chemical properties and density of Persian ironwood

“…Some researchers have reported that wood density decreases with age or distance from the pith (Pinto et al 2004). This is supported by the fact that heartwood is usually known to be of a lower density than sapwood.…”