Review on the succession process of Pinus densiflora forests in South Korea: progressive and disturbance-driven succession

Abstract

Background: Most of the Pinus densiflora forests, occupying the largest area, have been restored in South Korea since the 1970s. As young pioneer forests, the succession process is under way. Since the forests are distributed nationwide and are vulnerable to disturbances, the process may differ depending on the geography and/or site conditions. Therefore, we reviewed the direction, the seral communities, and the late-successional species of progressive and disturbance-driven succession nationwide in the cool-temperate zone through meta-analysis and empirical observations. Main text: As a result of a meta-analysis of the direct succession and vertical structure, we found that the P. densiflora forest is in a directionally progressive succession, changing to the broadleaved forest after forming a mixed forest with its overwhelming successor, Quercus species (particularly Q. mongolica and Q. serrata). In dry stands in a relative sense, the Quercus species was favored occupying over 80% of the abundance of the succeeding species. Therefore, in dry stands, it is presumed that Quercus-dominated stage would last for a long time due to the current dominance and long life span, and eventually, it settles as Quercus-broadleaved forest with a site change. Contrary to this, it is presumed that in mesic stands where Quercus species do not occur or have low abundance, the late-successional broadleaved species settle early to form a co-dominant forest with multiple species. Due to geographical limits, the species composition of the two late-successional forests is different. Disturbances such as insect pests and fire retrogressed vulnerable P. densiflora forest for a while. However, it was mostly restored to the Quercus forest and is expected to be incorporated in the pathway of the dry stand. Conclusions: We revealed the succession process of P. densiflora forests according to geography and moisture and found that stand moisture had a decisive effect on the species and abundance of the successor. Although the P. densiflora forest is undergoing structural changes, the forest is still young; so within a few decades, physiognomy is not likely to change. Therefore, the decrease in the forest area may be due to other causes such as disturbances and forest conversion rather than due to succession.

Annual and spatial variabilities in the acorn production of Quercus mongolica

“…Our study only revealed the acorn production for Q. mongolica. Although this species dominates in South Korea including both the parks (Choung et al 2020), further studies on other oak species such as Q. serrata and Q. variabilis are also necessary. Different species will have different reproductive characteristics in terms of production and masting.…”

“…Most species in the Genus Quercus have high resistance and resilience to disturbances, thereby making them highly adaptable against such disturbances. Additionally, they have been considered as a member of the late successional forests due to their long life span although they are not late-successional species themselves (Abrams 1992;McShea and Healy 2002;Choung et al 2020). These characteristics contribute to the successful formation of large oak forests in the world.…”

“…Among the abovementioned 6 oak species, the first four are 1-year species, and the last two are 2-year species (Lee 2003). In particular, Q. mongolica, a 1-year species, is the most predominant across the country (NGII 2016;Choung et al 2020). Most forests in South Korea had been restored since 1970s after repeated and long disturbances, resulting in area of young forest that is overwhelmingly large.…”

“…The relatively mature oak forests could be found in well-preserved areas, such as the national parks. Since oak species are succeeding P. densiflora trees in the succession process, the area of oak forest can increase significantly in the near future (Choung et al 2020).…”

Determination of Diversity, Distribution and Host Specificity of Korean Laccaria Using Four Approaches

“…The main objectives of the current study were to investigate (1) the number of Laccaria species in Korea, (2) how these species are distributed, and (3) their host types. Oak and pine are the major tree species in Korea [ 34 ], and their ecosystems are affected by climate change. Therefore, we focused our research on Quercus mongolica and Pinus densiflora as hosts of Laccaria species.…”