images showing the presence of pores in hardwoods (
oak, top) and absence in softwoods (
pine, bottom) Softwood is
wood from
gymnosperm trees such as
pines and
spruces. Softwoods are not necessarily softer than hardwoods. The hardest hardwoods are much harder than any softwood, but in both groups there is enormous variation with the range of wood hardness of the two groups overlapping. For example,
balsa wood, which is a hardwood, is softer than most softwoods, whereas the
longleaf pine,
Douglas fir, and
yew softwoods are much harder than several hardwoods. Several specific natural, macroscopic and microscopic features of wood are used in the identification process of a softwood species. Softwoods are generally most used by the construction industry and are also used to produce
paper pulp, and card products. In many of these applications, there is a constant need for density and thickness monitoring and gamma-ray sensors have shown good performance in this case. Certain species of softwood are more resistant to insect attack from
woodworm, as certain insects prefer damp hardwood. ==Examples of softwood trees and uses==