Effect of morphological variability of incrusted pit membranes on efficiency of transverse compression to improve liquid uptake

Abstract

Abstract The present study examined the effect of morphological variability of incrusted pit membranes (PMs) on efficiency of transverse compression to improve liquid uptake. The heartwoods of four conifers were investigated, and the deformations and ruptures of incrusted PMs were evaluated after subjecting them to several treatments such as transverse compression, ethanol-benzene extraction, and combination of extraction and compression. (1) The PMs in Cunninghamia lanceolata Hook, formed a brittle surface that was easily broken by compression, and the wood showed improved liquid uptake; (2) In Cryptomeria japonica D. Don, additional margo gaps were exposed after extraction resulting in substantial liquid uptake; and (3) in Larix leptolepis Gordon and Pseudotsuga menziesii Franco, tori strongly stuck to the pit aperture, preventing any increase in liquid uptake despite all types of treatment. Moreover, the pit borders in C. lanceolata and C. japonica deformed like a viscoelastic body, whereas those in L. leptolepis and P. menziesii displayed irregular deformations during compression. These results demonstrate the influence of the unique morphology of the incrusted PM on the efficiency of liquid uptake enforced by transverse compression.