Sung-Won Son

Patterns of Genetic Diversity in Rare and Common Orchids Focusing on the Korean Peninsula: Implications for Conservation

To provide basic information for orchid conservation, we surveyed the plant allozyme literature to summarize genetic diversity and structure data for (i) rare orchids native to the Korean Peninsula, and (ii) their congeners irrespective of being common and rare or Korean or not. A total of 68 taxa (32 taxa in Korea and 37 outside Korea; Goodyera repens being included in both datasets) were considered in this study. Overall, rare Korean orchid species had significantly lower levels of genetic diversity than their common congeners and common orchids in general at both population and species levels. However, mean values of GST (or FST) for rare and common orchids (Korean or not) did not differ significantly from each other. We found patterns of both low and high genetic diversity in rare Korean orchids. Many rare orchids harbored a complete lack of allozyme variation or extremely low within-population variation, perhaps due to rarity associated with random genetic drift and/or, for the case of warm-temperate orchids, to founder effects during post-glacial re-colonization. In contrast, high levels of genetic variation were found for a few orchids that have become recently rare (due to over-collection during the past several decades), probably because there have not been sufficient generations for the initial diversity to be substantially eroded. In addition, several orchids occurring in the main mountain system of the Korean Peninsula (the Baekdudaegan), that served as a glacial refugium, maintained moderate to high levels of within-population genetic diversity. Based on our genetic data, conservation priority should be given to rare orchid species. Particularly, urgent measures should be implemented on Jeju Island, a popular vacation spot, because it also a hotspot for threatened orchids with low levels of genetic diversity.

Comparison of genetic variation between northern and southern populations of Lilium cernuum (Liliaceae): Implications for Pleistocene refugia

The so-called “Baekdudaegan” (BDDG), a mountain range that stretches along the Korean Peninsula, has been recently proposed as a major “southern” glacial refugium for boreal or temperate plant species based on palaeoecological and, especially, genetic data. Genetic studies comparing genetic variation between population occurring on the BDDG and more northern ones (i.e. in NE China and/or in Russian Far East) are, however, still too few to draw firm conclusions on the role of the BDDG as a refugium and a source for possible northward post-glacial recolonizations. In order to fill this gap, we selected a boreal/temperate herb, Lilium cernuum, and compared levels of allozyme-based genetic diversity of five populations from NE China with five populations from South Korea (home of its hypothesized refuge areas). As a complementary tool, we used the maximum entropy algorithm implemented in MaxEnt to infer the species’ potential distribution for the present time, which was projected to different past climate scenarios for the Last Glacial Maximum (LGM). Permutation tests revealed that Korean populations harbored significantly higher levels of within-population genetic variation than those from NE China (expected heterozygosity = 0.173 vs. 0.095, respectively). Our results suggest that the lowered levels of genetic diversity in NE Chinese populations might be due to founder effects associated with post-glacial migration from southern regions. Congruent with genetic data, past distribution models showed higher probability of occurrence in southern ranges than in northern ones during the LGM. In addition, a positive correlation was detected between the expected heterozygosity and environmental LGM suitability. From a conservation perspective, our results further suggest that the southern populations in South Korea may be particularly worthy of protection.

Environment and Vegetation Characteristics of Aconitum austrokoreense Koidz. habitats

본 연구는 희귀 및 특산식물과 멸종위기야생식물 II급으로 지정되어 있는 세뿔투구꽃의 자생지 환경을 조사하여 보전 및 복원 시 기초자료를 제공하고자 한다. 조사결과 세뿔투구꽃의 자생지는 해발고도 260-728m범위와 경사 4-39 ̊ 의 계곡부에 주로 생육하는 것으로 조사되었다. 식생 및 관속식물 조사결과 7개 지역의 20개 방형구내에서 조사된 관속식물은 총 147분류군이 출현하였으며, 각 조사구내 초본층 피도와 빈도를 기초로 한 세뿔투구꽃의 중요치를 산출한 결과 평균 24.3%로 나타났다. 종다양도는 1.23로 산출되었으며, 우점도와 균등도는 각각 0.22와 0.77로 확인되었다. 토양분석 결과 토성은 미사질양토(4site)와 사질양토(2site), 양토(1site) 순으로 나타났으며, 유기물함량은 7.83%, 전질 소함량은 0.35%, pH는 5.69으로 측정되었다. 환경요인과 개체군특성에 기초한 상관분석에서는 세뿔투구꽃의 자생지에 서 엽록소와 경사도간의 강한 부의상관이 인정되었고, 개화율과 토양습도는 부의상관이 인정되었다. 자생지의 안정적 인 유지를 위해서는 서식지 보전이 중요하며 서식지 주변에 보호구역을 설정이 필요하다고 판단된다.

The Korean Baekdudaegan Mountains: A Glacial Refugium and a Biodiversity Hotspot That Needs to Be Conserved

This research was supported by Korea Research Foundation grants; KRF-2013R1A1A2063524 to MYC and NRF-2011-0017236, NRF-2013R1A1A3010892, and NRF-2017R1A2B4012215 to MGC and was carried out as part of the Infrastructure for the Conservation and Restoration of Rare and Endemic Plants in Korea National Arboretum that supported to MGC from 2015 to 2018.