Characteristics of Seedlings in Logging Gaps of Forests at Different Succession Stages in Changbai Mountain

The seedlings in logging gaps were studied at following different forest succession stages in Changbai Mountain: Populus davidiana-Betula platyphylla secondary forest at the early succession stage,secondary broad-leaved forest at the transitional stage and broad-leaved korean pine mixed forest at the late succession stage.The result showed that the mean height,mean basilar diameter,diversity and uniformity of seedlings in the logging gaps were bigger than those in the non-logging gaps in all the three types of forests,while the dominance of seedlings in the logging gaps was lower.The composition of seedlings in the non-logging gaps in the secondary broad-leaved forest was similar to that in the Populus davidiana-Betula platyphylla secondary forest,but the composition of seedlings in the logging gaps in the secondary broad-leaved forest was similar to that in the broad-leaved korean pine mixed forest.This result suggests that logging gaps accelerated the succession of secondary broad-leaved forest to broad-leaved korean pine mixed forest.The korean pine seedlings were the dominate species in the non-logging gaps of broad-leaved korean pine mixed forest.