Distribution and synchronized massive flowering of Sasa borealis in the forests of Korean National Parks

Abstract

Background: Genus Sasa, dwarf bamboos, are considered to be species that lower biodiversity in the temperate forests of East Asia. Although they have a long interval, they, the monocarpic species, have a unique characteristic of large-scale synchronized flowering. Therefore, once they have flowered and then declined, it may be an opportunity for suppressed surrounding species. A previous study reported that Sasa borealis showed specialized flowering nationwide with a peak in 2015. However, this was based on data from a social network service and field survey at Mt. Jeombong. Therefore, we investigated S. borealis in the forests of five national parks in order to determine whether this rare synchronized flowering occurred nationwide, as well as its spatial distribution. Results: We found a total of 436 patches under the closed canopy of Quercus mongolica-dominated deciduous forests in the surveyed transects from the five national parks. Of these patches, 75% occupied a whole slope area, resulting in an enormous area. The patch area tended to be larger in the southern parks. Half (219 patches) of the patches flowered massively. Among them, 76% bloomed in 2015, which was consistent with the results of the previous report. The flowering rate varied from park to park with that of Mt. Seorak being the highest. The culms of the flowering patches were significantly taller (F = 93.640, p < 0.000) and thicker (F = 61.172, p < 0.000). Following the event, the culms of the flowering patches declined, providing a good opportunity for the suppressed plant species. The concurrent massive flowering of the mature patches was believed to be triggered by some stress such as a spring drought. Conclusion: We confirmed that the rare synchronized flowering of S. borealis occurred with a peak in 2015 nationwide. In addition, we explored that S. borealis not only monopolized an enormous area, but also dominated the floors of the late-successional Q. mongolica-dominated deciduous forests. This presents a major problem for Korean forests. As it declined simultaneously after flowering, there are both possibilities of forest regeneration or resettlement of S. borealis by massively produced seeds.

Synergistic Effect of Dwarf Bamboo Flowering and Wild Boar Rooting on Forest Regeneration

“…We focused our interest on the very rare phenomenon of large-scale nationwide flowering of S. borealis in Korea [31] and studied its effect on subsequent forest regeneration. Sasa spp.…”

“…Sasa spp. are a typical species constituting the recalcitrant understory, but they have the monocarpic trait of synchronized dieback after synchronized flowering [31,49]. Therefore,…”

“…Sasa spp. are a typical species constituting the recalcitrant understory, but they have the monocarpic trait of synchronized dieback after synchronized flowering [31,49]. Therefore, we proposed the first hypothesis that such phenomena would help release the forests that had been suppressed by S. borealis and promote forest regeneration.…”

Fine-Scale Species Distribution Modeling of Abies koreana across a Subalpine Zone in South Korea for In Situ Species Conservation

“…Jiri and Mt. Halla subalpine zones, interference with the growth of coniferous trees and the decrease in subsequent tree growth opportunities have become crucial considerations [38]. Accordingly, it was necessary to consider the impact of competition from other species on the potential habitat changes of A. koreana.…”

Habitat preference of wild boar (Sus scrofa) for feeding in cool-temperate forests

“…The bulb of E. japonicum is buried about 12 cm below the ground surface (Lyang and Lee 2010), and it could be the reason why the wild boar dug deeper in the Quercus forest type than other forest types. The wild boar digs even Sasa borealis stands in the Quercus forest, which is dominated by S. borealis and has very low species diversity (Cho et al 2018a(Cho et al , 2018b. The food sources such as acorns and insects for the wild boar are presumably between the packed roots or dense culms of S. borealis.…”