Abstract
We surveyed the germination and survival rates, morphological characteristics, spatial pattern of root extension, and the mass distribution into each organ of current and 1-year-old Picea jezoensis seedlings growing on fallen logs with no moss (FLB), short moss (FLS), and tall moss (FLT) in a natural coniferous forest in central Hokkaido, northern Japan, in order to estimate the in FLUence of moss height on the establishment of P. jezoensis seedlings on fallen logs. The germination rate was significantly lower on FLT than on the others. The survival rate of seedlings did not differ among the logs. Almost all parts of the tap roots of living and dead seedlings were distributed in the humus and wood layers of the logs, irrespective of moss height. Seedlings on FLT had longer stems and greater stem masses than seedlings on the other logs, which indicated their morphologic and allometric acclimation to shading from the tall moss. The masses of individual current-year seedlings were lower on FLT than on the others. The masses of individual 1-year-old seedlings were lower on FLB than on FLS. The root extension of 1-year-old seedlings on FLB was inhibited and resulted in shorter roots and a higher T/R ratio. Consequently, the growth of 1-year-old seedlings on FLB was inhibited. Therefore, FLS is the most suitable for the establishment of P. jezoensis seedlings.
