The early stages of secondary succession after clear-cutting in a deciduous broad-leaved forest

Abstract

Community structures and dynamics of dominant species in the early stages of secondary succession were observed from spring in 7-year-old to autumn in 10-year-old using a permanent plot after clear-cut of a deciduous broad-leaved forest. Community structures were rapidly developed during the study period; 3.8 to 5.4 m for community height, 814 to 966 stems per 200 m^2 for stem density and 3.5 to 10.2 m^2 ha^<-1> for basal area (BA). Twenty-seven species appeared in the permanent plot. Main species of each life form, tree species (Betula ermanii), sub-tree (Prunus grayana) and shrub (Hydrangea paniculata), simultaneously emerged just after clear-cutting. The size (diameter at breast height and tree height) differences among the three species were small in 7-year-old. Stem density of P. grayana and H. paniculata was more than two times of B. ermanii, and thus the both species dominated in 7-year-old. On the other hand, relative growth rates of B. ermanii was significantly higher than those of P. grayana and H. paniculata (P<0.05), and thus, BA and tree height of B. ermanii increased greatly during the study period. Moreover, the stem mortality of H. paniculata was rather high during the study period, and BA of B. ermanii surpassed that of H. paniculata in 10-year-old. Thus the pioneer sub-tree or shrub species, which invaded through buried seeds or stump sprouts, predominated with high stem density soon after clear-cutting. After canopy closing, the dominant species was succeeded to tree species depending on the difference of growth rate.