Variation of internal checks related to anatomical structure and density in Eucalyptus nitens wood

The occurrence of internal checks and their relationship with anatomical structure and basic density in three clones of Eucalyptus nitens plantation trees grown in the eighth region of Chile were studied. Two trees per clone were sampled. The number, radial location, and length of internal checks were determined in samples oven-dried at temperatures increasing from 50 to 100 C. Wood anatomical features including vessel frequency and diameter and annual growth ring width were measured by image analysis. Results show that internal checks were greater for clones with lower basic density. Internal check frequency decreased with height in the tree and increased from pith to bark. A low wood basic density was related to greater ring width and vessel frequency, which contributed to the development of internal checks.