Dynamics of Abies nephrolepis Seedlings in Relation to Environmental Factors in Seorak Mountain, South Korea

Abstract

We present novel evidence of environmental drivers of seedling density in Abies nephrolepis, an alpine and subalpine tree species. Continuous monitoring of natural conditions is required to understand forest ecosystem dynamics. We investigated Abies nephrolepis seedling dynamics in relation to biotic and abiotic factors. The survey, which included the measurement of trees and seedlings, was carried out from March to October in 2016 and 2018. Monitoring sites in the coniferous forests of Seorak Mountain were divided into 27 quadrats. We analyzed relationships using simple and multiple linear regression. The majority of Abies nephrolepis individuals had a diameter at breast height less than l0 cm, and the number of seedlings increased over the study period. This reflects survival and growth due to successive annual mast seeding events. Aspect direction (R2 = 0.201, p < 0.05), rock exposure (R2 = 0.364, p < 0.001), canopy openness (R2 = 0.322, p < 0.05), herbaceous cover (R2 = 0.268, p < 0.01), and basal area (R2 = 0.199, p < 0.05) show significant linear relationships with seedling density. Seedling density was positively related to rock exposure, canopy openness, and species richness, and there was a negative relationship between herbaceous cover and basal area (p < 0.0001). The relative importance of predictor variables was as follows: Rock exposure (40.3%), canopy openness (30.2%), basal area (13.9%), herbaceous cover (11.5%), and species richness (4.1%). Seedling density was most strongly influenced by the presence of large rocks, which provide shelter from harsh winds and a substrate for moss. We conclude that appropriate canopy openness creates a synergistic relationship. We found a positive association between the Abies nephrolepis seedling density in subalpine forests and certain physical environmental factors. Therefore, environmental gradients about the roles of rocks and canopies apply, even in this habitat.

Empirical Evaluation of the Elevational Rapoport’s Rule: The Species Richness Patterns for Vascular Plants on Seorak Mountain, Korea

“…The results of the empirical data collected were similar to those found in previous studies for various taxa (e.g., birds, land snails, and fish), as they were observed to decrease in abundance along the elevation slopes (Carvajal-Quintero et al, 2015;Liew, Schilthuizen & Lakim, 2010;Pan et al, 2016). Although Seorak Mountain is a low mountain with an altitude of 1708 m, its treeline begins at 1500 m, above which characteristic dwarf and arctic-alpine plants appear (Kim, Lim & Yun, 2019).…”

“…This is likely because of the shorter growing seasons, lower temperatures, lower mass circulation, and treeline-like environments (i.e., physical environments such as hard rock formations and physiological constraints due to extreme climatic conditions). The region around the Daecheongbong Peak of Mount Seorak has a strong wind and rocky terrain; this will benefit species with a small distribution range such as rare or endemic species (Kim et al, 2017;Kim, Lim & Yun, 2019).…”

“…The main peak of Seorak Mountain is Daecheongbong (1708 m), and it is the second highest mountain in Korea. The climate of the region is temperate, with a mean annual temperature of 3.05degC and mean annual precipitation of 1537.39 mm (Kim, Lim & Yun, 2019). Its temperate forests comprisePinus densiflora or Abies holophylla in the lowlands andBetula ermanii , Pinus koraiensis , Quercus mongolica , and Abies nephrolepis in the highlands.…”

The species range‐size patterns for vascular plants of Seorak Mountain (Korea): Relationship between group of life forms and phytogeography affinity along the elevational gradient

“…The main peak of Seorak Mountain is Daecheongbong (1,708 m), and it is the second highest peak in Korea. The climate of the region is temperate, with a mean annual temperature of 3.05°C and mean annual precipitation of 1,537.39 mm (Kim, Lim, et al., 2019 ). Its temperate forests comprise of Pinus densiflora or Abies holophylla in the lowlands and Betula ermanii , Pinus koraiensis , Quercus mongolica , and Abies nephrolepis in the highlands.…”

“…The rare and red list species found in Mountain Seorak have phytogeographic affinities (e.g., P. pumila , Leontopodium leiolepis , A. ruber , and Thalictrum coreanum ). In Korea's Seorak Mountain, native species or rare species appear in isolation after the Pleistocene Epoch (Chung et al., 2017 ; Kim, Lim, et al., 2019 ; Kong, 2002 , 2004 ). Rare or endemic plant species appearing in Seorak Mountain are considered tentatively as having a phytogeographical affinity, and most of the polar‐alpine plants appearing in Korea are isolated and distributed at elevations of 1,500–1,800 m or higher.…”