Shrinkage of tracheid cells with desorption visualized by confocal laser scanning microscopy

Confocal laser scanning microscopy (CLSM) was applied as a new method of visualizing the shrinkage of wood and its anisotropy. Control of relative humidity and temperature in a specialized environment chamber made it possible to acquire transverse images of tracheids of Akamatsu (Pinus densiflora) from the saturated condition to the dried condition. The shrinkage of tracheid cells was also determined by measuring the tangential diameter of tracheid and lumen, the radial diameter of tracheid and lumen, and the thickness of tangential and radial walls. Moreover, this technique makes it possible to discuss the relationship between moisture content and tracheid cell shape. We found the CLSM technique to be an effective method for visualizing shrinkage of tracheid cells with desorption.