Soft X-ray observation of water distribution in the stem of Cryptomeria japonica D-Don II: Types found in wet-area distribution patterns in transverse sections of the stem

Using soft X-ray photography, two-dimensional observations were made of the water distribution within the green stem of Cryptomeria japonica D. Don. V ariations in the distribution pattern of the "wet area" in the horizontal p lane of the lower stem were described. The distribution patterns showed ext reme variation among individual tries, with broad wet-area distribution typ es appearing, namely, the regularly distributed wet area and the irregularl y distributed wet area. We defined five basic types of wet-area distributio n patterns on the basis of their regularity or irregularity. It was conclud ed that the between-tree variation in the wet-area distribution causes the between-tree variation in the mean moisture content of the heartwood. The d istribution patterns of the wet area were similar for individual trees with in each plus-tree clone.