Evaluation and utilization of Japanese cedar and Taiwan cypress trees quality grown with different stand ages and plantation spacings using nondestructive techniques

The purpose of this study was to explore the evaluation and utilization of Japanese cedar and Taiwan cypress plantation trees quality grown with different stands ages and densities using nondestructive techniques. The nondestructive techniques include ultrasonic wave, X-ray densitometer, Pilodyn and Fractometer methods for dynamic modulus of elasticity, rinmg characteristics, penetration depth, and crushing strength. moreover, these results maybe to decide evaluation wood parameters by nondestructive methods and to raise accuracy and practicability by further analysis under forest ecological management for tree health.