Different microstructure of softwood and hardwood

Trees are classified into two main groups, softwoods (narrow leaf trees) and hardwoods (broad leaf trees). The major difference between the anatomy of hardwoods and softwoods is the lack of vessels in softwood. Vessels are created to conduct the fluid in the tree trunk. In softwood, the longitudinal tracheids perform the role of conducting the fluid (Wangaard 1979). These microstructural differences are the origin of different mechanical properties in softwood and hardwood.

Cross sectional views of two hardwood and softwood specimens, photo by Marjan 2006