会议名称：2023世界木材日研讨会暨第五届国际林联（IUFRO）林产品文化研究组讨论会
会议时间：2023年3月22日

报告嘉宾：Rowland Burdon
嘉宾简介：新西兰皇家研究院林业研究所 (SCION) 名誉科学家

摘要：
Within-tree variation in wood properties is often large, posing major problems for wood processing and utilisation. Understanding and characterising such variation are thus very important, scientifically and practically. Such variation can be addressed practically by both log segregation and processing practice for individual logs.
Widely studied are the radial variations in wood properties, physical, chemical and anatomical. Such variations are especially prominent and intensively studied in two highly domesticated pine species, Pinus radiata and P. taeda.  Importantly, such variation also means that average wood properties can vary strongly, up the tree and with tree age.
The variations are typically curvilinear, approaching asymptotic values well away from the pith. However, the curves differ among properties, and somewhat variably among trees or among environments.
Such variation from the pith outwards has been widely addressed, terminologically and conceptually, as a progression form juvenile to mature wood (alternatively, corewood to outerwood).  However, this conflicts sharply with the well-established botanical concept of maturation, whereby maturation level typically increases along stem axis from the root collar, with a roughly asymptotic approach to final maturation state.  Moreover, pith-to-bark trajectories, according to ring number or distance from pith, can vary markedly with height above ground up for some important wood properties.
An appropriate framework, conceptually and terminologically, is for different progressions in the radial and vertical axes: from corewood to outerwood radially, and from juvenile to mature wood up the vertical axis.  However, details of progressions and wood properties involved vary considerably among tree taxa.  While this framework may not be readily applicable for wood properties of some taxa, it is extremely helpful for a number of particularly important species.

责任编辑：iwcs2366H