Table 2 The wood species and class value of each group for species identification using partial least squares discriminant analysis (PLS-DA)

A

P. densiflora for. erecta [+1]—P. sylvestris grown in Russia [−1]

B

P. densiflora for. erecta [+1]—P. sylvestris grown in Germany [−1]

C

P. densiflora [+1]—P. sylvestris grown in Russia [−1]

D

P. densiflora [+1]—P. sylvestris grown in Germany [−1]

E

All P. densiflora [+1]—all P. sylvestris [−1]