Forest litter and shrubs act as an understory filter for the survival of Quercus mongolica seedlings in Mt. Kwan-ak, South Korea

Abstract

Forest succession from Pinus to Quercus has often been observed in temperate forest, although the succession mechanism is not clearly understood. This study investigated factors that affect the succession of forests from pine to oak, using forest vegetation inventory data at plots at Kwan-ak mountain in Korea. Analyses of understory canopy coverage, light intensity, and tree numbers and ages in P. densiflora forests indicate that Q. mongolica can only invade these forests before understory shrub establishment. The results from analyses of all environmental factors indicate that similar adverse effects from environmental factors occur in established P. densiflora and Q. mongolica forests that inhibit Q. mongolica seedling survival. However, the observed survival rate of Q. mongolica seedlings under P. densiflora during winter were much higher than Q. mongolica seedlings under Q. mongolica trees, and it is due to accumulated snow over Q. mongolica forest litter which breaks or inhibits the emergence of Q. mongolica seedlings. Protecting seedlings with plastic cups significantly increased the survival rate which confirms that forest floor litter acts as a filter for the regeneration and succession of Q. mongolica forests. This paper thus concludes that understory shrubs and forest litter affect the succession dynamics of P. densiflora and Q. mongolica forests.