The nanostructure of the cell wall of softwoods and its functions in a living tree

Trees are large engineering structures that have to withstand major wind and static forces and translocate considerable volumes of water. Natural selection has over millions of years optimised tree structure to maximise survival of the species. Naturally this process does not necessarily optimise the properties of the resultant lumber such as hardness, stiffness and strength. Such wood properties can now be improved by genetic engineering and tree breeding. If this is done without understanding the contribution of wood structure to tree survival, this can lead to increased susceptibility to windthrow, splitting and branch damage in the standing tree and internal checking and collapse during wood drying. As a first step to quantifying these potential problems this paper reviews latest findings on the nanostructure of the cell wall of softwoods and then discusses the probable relationships between microfibril directions in the secondary cell wall layers and potential threats to the survival of trees such as excessive vibration and crack propagation.