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The Nari Caldera on Ulleung Island, an oceanic intraplate volcano, is a significant repository of information on the latest volcanic activity. To interpret the characteristics of the latest volcanic activity, it is essential to understand the caldera structures formed by the most explosive eruption of the Ulleung volcanic edifice. This study presents a three-dimensional (3-D) resistivity model based on audio-magnetotelluric (AMT) data and interprets the caldera structure of Ulleung Island. New land and ocean terrain models were used for the 3-D inversion of the AMT data, and a finer, nonuniform grid was generated for the caldera area. Subsequently, 3-D inversion and imaging were conducted on the AMT data at 25 stations. In the caldera area of Ulleung Island, the 3-D resistivity model is divided into two bodies: a high resistivity body located in the south and a low resistivity body located in the north. This structure is consistent with the location of the two calderas, Seongin Caldera and Nari Caldera, as inferred from geological studies. Furthermore, the high resistivity body located in the south exhibited a bowl shape in the 3-D space. Therefore, we suggest that the high resistivity body located south of the caldera on Ulleung Island is a structure of the Seongin Caldera. The Seongin Caldera has a diameter of approximately 1.5 km and a caldera fill height of approximately 0.8 km, as measured from the resistivity model. Based on the stratigraphy of Ulleung Island and the physical properties of the rock types, the interior of the Seongin Caldera was considered to have been filled with trachytic lavas of the Seonginbong Group. From the high geothermal gradient of Ulleung Island and the stratigraphy of the GH-4 borehole, the low resistivity body extending from the shallow depths of the Nari Caldera to the lower part of the Seongin Caldera could be interpreted as trachytic rocks that underwent hydrothermal alteration. In addition, a low resistivity body contains highly porous and/or weathered rock. This study presents information on the calderas of Ulleung Island that can aid in interpreting the characteristics of the latest volcanic activity. We expect this information to contribute to the preparation for potential volcanic hazards. [ABSTRACT FROM AUTHOR]

Temporary seismic networks on Mt. Halla and Ulleung Island volcanoes were deployed, which employ broadband and geophone arrays to monitor potential volcanic activities and to estimate high-resolution magmatic structures beneath these volcanoes. The purpose of this paper is to introduce these networks and present early results through basic seismic analyses, suggesting the potential for future comprehensive seismological studies. The array in Mt. Halla volcano consists of five broadband sensors (JH array), and it has been operational around the Baengnokdam summit crater since October 2020. There was an additional linear geophone array (HL array) installed in September 2021 for detailed shallow subsurface imaging. Ulleung Island volcano had been under observation for two years since June 2021 with a network of nine broadband sensors (UL array) along its coast and in the Nari crater basin, complemented by a 52-geophone array (UG array) deployed in May 2022 for high-resolution subsurface studies. Despite the noisy environments typical of temporary setups, power spectral density analyses confirmed the quality of data as comparable to established reference noise models in permanent stations. Our study aimed to initiate studies uncovering seismic activities and structures beneath Mt. Halla and Ulleung Island volcanoes, specifically regarding volcanic activity. This approach detected no clear sign of volcanic seismicity on both islands, suggesting a period of magmatic dormancy. Seismic velocity variation (dv/v) analyses further indicated that environmental factors, rather than volcanic processes, influenced the changes in the physical properties of the underground structures. Conversely, the receiver function analysis and ambient noise data processing hinted at the presence of complex subsurface structures, potentially indicative of volcanic features, such as partial melting. Despite the lack of direct evidence for active magmatic processes, the collected seismic data provides a crucial baseline for future monitoring and a deeper understanding of the magmatic and tectonic dynamics beneath these volcanoes, offering valuable insights for ongoing volcanic research. [ABSTRACT FROM AUTHOR]

Abstract Background The intricate textural patterns commonly observed in metamorphosed and recrystallized zircon (ZrSiO4) underscore the crucial necessity of understanding the underlying mechanisms governing their formation to ensure accurate interpretation of the chemical and isotope data they contain. This study employed a combination of microanalytical techniques, including electron backscattered diffraction (EBSD) analysis, electron microprobe (EMP) mapping, and scanning electron microscope (SEM) imaging, to investigate the processes of formation and modification of zircon in a late Pleistocene (~ 35 ka) syenite enclosed within the Nari Tephra Formation on Ulleung Island in South Korea. Findings Under cathodoluminescence (CL), zircons within the syenite reveal dark, featureless, or oscillatory-zoned cores containing numerous inclusions of britholite. These cores are partially or entirely replaced by inward-penetrating bright-CL domains that exhibit minimal inclusion presence. Despite these changes, the external morphologies of the zircons remain largely unchanged, and the faded oscillatory zoning is preserved in the replaced regions. EMP mapping discloses amoebiform micro-domains with high Y, U, and Th concentrations within the dark-CL cores, while the bright-CL domains are relatively deficient in these trace elements. Microstructural analysis of the zircons using EBSD mapping indicates no significant misorientation between the dark-CL cores and the bright-CL rims. Deformation-related low-angle boundaries by lattice distortion are clearly observed in certain grains, cutting across the discrete SEM and EMP domains, and often aligned along submicron pore trails. Conclusions Microstructural and microchemical analyses carried out in this study establish that the zircons within the Ulleung syenite have undergone subsolidus recrystallization, a process likely influenced by the presence of fresh melts or fluids. This recrystallization process could be attributed to either coupled dissolution and reprecipitation or thermoactivated particle and defect volume diffusion due to inherent lattice strain. The subsequent deformation observed in the zircons might be a result of increased stress within the magma system after the recrystallization.

[Display omitted] • Microanalytical data from zircon on Ulleung Island are employed in this study. • Zircons reveal an extended crystallization in the Pleistocene. • SEM textures suggest subsolidus recrystallization of zircon. • Zircon oxygen isotopes indicate the persistent presence of shallow crustal reservoirs. • The explosive volcanism was likely triggered by the injection of new melt. The microanalytical data obtained from zircons collected on Ulleung Island, an emergent peak of a Quaternary alkaline magma system in the southwestern East Sea (Sea of Japan) back-arc basin, provide new insights into the origin of magma, magmatic processes, and the trigger of explosive eruptions. The U-Th ages of zircons extracted from a pumice layer formed during the intense Plinian eruption at ∼11 ka, known as the Ulleung-Oki tephra, show a wide range spanning the pre-eruption equilibrium state (>350 ka) up to the eruption event itself. Zircon grains derived from syenite and gabbro fragments entrained within the tephra yield weighted mean U-Th and U-Pb ages of 34.7 ± 2.3 ka and 1378 ± 22 ka, respectively. Under cathodoluminescence, zircons from the syenite reveal dark, featureless, or oscillatory-zoned cores, containing numerous inclusions of britholite-like Y-rich phases and pyrochlore. These cores are partially or entirely replaced by inclusion-free, brighter domains, suggesting that in situ dissolution and precipitation processes significantly influenced the transformation of zircon. The consistently low δ18O values (5.4–2.6‰) of zircons from Middle Pleistocene trachyte lavas, the Ulleung-Oki tephra, and lithic fragments indicate the persistent presence of shallow crustal magma reservoirs beneath Ulleung Island. These reservoirs have undergone substantial assimilation of hydrothermally altered rocks, with assimilation rates typically around 10–30% and reaching a maximum of approximately 50%. Zircon core-to-rim variations in oxygen isotopic composition, along with textural observations, suggest the rejuvenation of magma reservoirs through the injection of new melt, which likely served as a trigger for the explosive eruptions at Ulleung Island. The similarity in the range of ε Hf values between the core and rim (+7.4 to −4.3) implies the Hf isotopic consistency of the recharge melt. [ABSTRACT FROM AUTHOR]

Korean wasabi occurs naturally on the young oceanic, volcanic Ulleung Island off the east coast of the Korean Peninsula. Although the Ulleung Island wasabi is reported as Eutrema japonicum and has been suggested to be morphologically identical to cultivars in Korea, very little is known about its taxonomic identity and relationship with other cultivars. In this study, we sequenced the complete chloroplast DNA sequences of three naturally occurring Ulleung Island wasabi plants and six cultivars ('Daewang', 'Daruma', 'Micado', 'Orochi', 'Green Thumb', and 'Shogun') from continental Korea and determined the taxonomic identity of Korean wasabi on Ulleung Island. The size and organization of the complete chloroplast genomes of the nine accessions were nearly identical to those of previously reported wasabi cultivars. In addition, phylogenetic analysis based on the complete plastomes suggested that Ulleung Island wasabi most likely comprises various wasabi cultivars with three chlorotypes ('Shogun', 'Green Thumb', and a unique Chusan type). Based on the complete plastomes, we identified eight chlorotypes for the major wasabi cultivars and the Ulleung Island wasabi. Two major groups (1—'Mazuma' and 'Daruma', and 2—'Fujidaruma'/'Shimane No. 3'/Ulleung Island wasabi/five cultivars in Korea) were also identified based on mother line genealogical history. Furthermore, different types of variations (mutations, insertions/deletions (indels), mononucleotide repeats, and inversions) in plastomes were identified to distinguish different cultivar lines and five highly divergent hotspots. The nine newly obtained complete plastomes are valuable organelle genomic resources for species identification and infraspecific phylogeographic studies on wild and cultivated wasabi. [ABSTRACT FROM AUTHOR]

Background: The intricate textural patterns commonly observed in metamorphosed and recrystallized zircon (ZrSiO4) underscore the crucial necessity of understanding the underlying mechanisms governing their formation to ensure accurate interpretation of the chemical and isotope data they contain. This study employed a combination of microanalytical techniques, including electron backscattered diffraction (EBSD) analysis, electron microprobe (EMP) mapping, and scanning electron microscope (SEM) imaging, to investigate the processes of formation and modification of zircon in a late Pleistocene (~ 35 ka) syenite enclosed within the Nari Tephra Formation on Ulleung Island in South Korea. Findings: Under cathodoluminescence (CL), zircons within the syenite reveal dark, featureless, or oscillatory-zoned cores containing numerous inclusions of britholite. These cores are partially or entirely replaced by inward-penetrating bright-CL domains that exhibit minimal inclusion presence. Despite these changes, the external morphologies of the zircons remain largely unchanged, and the faded oscillatory zoning is preserved in the replaced regions. EMP mapping discloses amoebiform micro-domains with high Y, U, and Th concentrations within the dark-CL cores, while the bright-CL domains are relatively deficient in these trace elements. Microstructural analysis of the zircons using EBSD mapping indicates no significant misorientation between the dark-CL cores and the bright-CL rims. Deformation-related low-angle boundaries by lattice distortion are clearly observed in certain grains, cutting across the discrete SEM and EMP domains, and often aligned along submicron pore trails. Conclusions: Microstructural and microchemical analyses carried out in this study establish that the zircons within the Ulleung syenite have undergone subsolidus recrystallization, a process likely influenced by the presence of fresh melts or fluids. This recrystallization process could be attributed to either coupled dissolution and reprecipitation or thermoactivated particle and defect volume diffusion due to inherent lattice strain. The subsequent deformation observed in the zircons might be a result of increased stress within the magma system after the recrystallization. [ABSTRACT FROM AUTHOR]

Abstract As volcanoes are closely related to the living environment of humans, in particular via natural hazards and geothermal energy, scientific studies on volcanic edifice structures are required. Ulleung Island is a Quaternary volcanic island located in the mid-western East Sea (Sea of Japan). In this study, we conducted an audio-frequency magnetotelluric (AMT) survey to image the substructure of the Ulleung volcanic edifice. In addition, the electrical structure was interpreted from the geothermal system perspective, geochemical compositions of volcanic rocks, and the possibility of the presence of a magma reservoir. AMT data were obtained from 25 stations and processed using the remote reference technique. Then, the three-dimensional (3-D) approach was reasonably adopted according to dimensionality analysis. Before conducting the 3-D inversion, the effects on topography and ocean were analyzed using a simplified 3-D synthetic model, because Ulleung Island is surrounded by sea and the topography is undulating. Most AMT stations on Ulleung Island are distorted by topographical and oceanic effects; in particular, oceanic effects are significant at frequencies lower than 10 Hz. The 3-D inversion was conducted with full impedance components and vertical magnetic transfer functions in a frequency range of 10,000–1 Hz. The results show that the Ulleung volcanic edifice is characterized by two layers of electrical structures as follows: near-surface resistive anomalies and an underlying conductive layer. Considering the high geothermal gradient on Ulleung Island, we suggest that the conductive layer of the volcanic edifice is due to hydrothermal alteration of basaltic rocks, with a potential heat source underneath. Based on the geochemical characteristics of the Ulleung volcanic rocks, the possibility of heat transfer from a trachytic magma reservoir within the shallow crustal is suggested. In summary, this study presents a geological interpretation of shallow volcanic structures beneath Ulleung Island and the possibility of an active magma reservoir as a potential heat source for the volcanic edifice. Graphical Abstract

As volcanoes are closely related to the living environment of humans, in particular via natural hazards and geothermal energy, scientific studies on volcanic edifice structures are required. Ulleung Island is a Quaternary volcanic island located in the mid-western East Sea (Sea of Japan). In this study, we conducted an audio-frequency magnetotelluric (AMT) survey to image the substructure of the Ulleung volcanic edifice. In addition, the electrical structure was interpreted from the geothermal system perspective, geochemical compositions of volcanic rocks, and the possibility of the presence of a magma reservoir. AMT data were obtained from 25 stations and processed using the remote reference technique. Then, the three-dimensional (3-D) approach was reasonably adopted according to dimensionality analysis. Before conducting the 3-D inversion, the effects on topography and ocean were analyzed using a simplified 3-D synthetic model, because Ulleung Island is surrounded by sea and the topography is undulating. Most AMT stations on Ulleung Island are distorted by topographical and oceanic effects; in particular, oceanic effects are significant at frequencies lower than 10 Hz. The 3-D inversion was conducted with full impedance components and vertical magnetic transfer functions in a frequency range of 10,000–1 Hz. The results show that the Ulleung volcanic edifice is characterized by two layers of electrical structures as follows: near-surface resistive anomalies and an underlying conductive layer. Considering the high geothermal gradient on Ulleung Island, we suggest that the conductive layer of the volcanic edifice is due to hydrothermal alteration of basaltic rocks, with a potential heat source underneath. Based on the geochemical characteristics of the Ulleung volcanic rocks, the possibility of heat transfer from a trachytic magma reservoir within the shallow crustal is suggested. In summary, this study presents a geological interpretation of shallow volcanic structures beneath Ulleung Island and the possibility of an active magma reservoir as a potential heat source for the volcanic edifice. [ABSTRACT FROM AUTHOR]

The genus Allium, with over 900 species, is one of the largest monocotyledonous genera and is widely accepted with 15 recognized subgenera and 72 sections. The robust subgeneric and sectional relationships within Allium have long been not resolved. Based on 76 species of Allium (a total of 84 accessions), we developed a highly resolved plastome phylogenetic framework by integrating 18 newly sequenced species (20 accessions) in this study and assessed their subgeneric and sectional relationships, with special emphasis on the two subgenera Anguinum and Rhizirideum. We retrieved the three major evolutionary lines within Allium and found that the two subgenera Anguinum and Rhizirideum are monophyletic whereas others are highly polyphyletic (e.g., Allium, Cepa, Polyprason, and Melanocrommyum). Within the subgenus Anguinum, two strongly supported sublineages in East Asian and Eurasian-American were found. Allium tricoccum in North America belonged to the Eurasian clade. The distinct taxonomic status of A. ulleungense and its sister taxon were further determined. In subg. Rhizirideum, the Ulleung Island endemic A. dumebuchum shared its most recent common ancestor with the species from Mongolia and the narrow Korean endemic A. minus. Two Ulleung Island endemics were estimated to originate independently during the Pleistocene. In addition, a separate monotypic sectional treatment of the east Asian A. macrostemon (subg. Allium) and sister relationship between A. condensatum and A. chinense was suggested. [ABSTRACT FROM AUTHOR]

Carbon flux metasomatism in the subduction environment is an important process, but it remains poorly understood. The paucity of exposed lower crust and upper mantle rocks in continental arcs renders xenoliths a major target for studying the slab-derived carbon cycle. This study of the carbonate phases in volcanic rocks from three drill cores in Ulleung Island, South Korea, sheds light on the interaction of carbon flux in the upper mantle and lower crust in a back-arc setting. The volcanic rocks from Ulleung Island range in composition from trachybasalt to trachyte and contain abundant euhedral pseudomorphic carbonate grains, ulvöspinel-hosted and biotite-hosted carbonate-silicate melt inclusions, and irregular carbonate globules. Integrated petrographic and geochemical studies of a variety of phenocrysts, carbonate phases, and carbonate-silicate inclusions in biotite and ulvöspinel indicate that recharging of carbon flux affected magma evolution. Carbon and oxygen isotopes of the pseudomorphic carbonate grains overlap with mantle values, indicating a carbonatite-like origin of the carbonate phases. The (MgO,FeO,CaO)-rich silicates in ulvöspinel-hosted silicate inclusions and pseudomorphic carbonate grains likely represent a primary melt, which formed from the partial melting of carbonated eclogite of the subducted slab within the mantle wedge beneath Ulleung Island. A petrogenetic model is proposed to illustrate that the crystal mush in the magma chamber was intruded by carbonate-rich liquids and caused alteration of cumulate crystals to generate the euhedral pseudomorphic carbonate grains. The extrusive magma captured those pseudomorphic grains and erupted to form the trachybasalt-trachyte units. The observed carbonate phases and their geochemical characteristics indicate that carbon flux metasomatism played a fundamental role in this back-arc magmatism. [ABSTRACT FROM AUTHOR]

Of the two major speciation modes of endemic plants on oceanic islands, cladogenesis and anagenesis, the latter has been recently emphasized as an effective mechanism for increasing plant diversity in isolated, ecologically homogeneous insular settings. As the only flowering cherry occurring on Ulleung Island in the East Sea (concurrently known as Sea of Japan), Prunus takesimensis Nakai has been presumed to be derived through anagenetic speciation on the island. Based on morphological similarities, P. sargentii Rehder distributed in adjacent continental areas and islands has been suggested as a purported continental progenitor. However, the overall genetic complexity and resultant non-monophyly of closely related flowering cherries have hindered the determination of their phylogenetic relationships as well as the establishment of concrete continental progenitors and insular derivative relationships. Based on extensive sampling of wild flowering cherries, including P. takesimensis and P. sargentii from Ulleung Island and its adjacent areas, the current study revealed the origin and evolution of P. takesimensis using multiple molecular markers. The results of phylogenetic reconstruction and population genetic structure analyses based on single nucleotide polymorphisms detected by multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq) and complementary cpDNA haplotypes provided evidence for (1) the monophyly of P. takesimensis ; (2) clear genetic differentiation between P. takesimensis (insular derivative) and P. sargentii (continental progenitor); (3) uncertain geographic origin of P. takesimensis , but highly likely via single colonization from the source population of P. sargentii in the Korean Peninsula; (4) no significant reduction in genetic diversity in anagenetically derived insular species, i.e., P. takesimensis , compared to its continental progenitor P. sargentii ; (5) no strong population genetic structuring or geographical patterns in the insular derivative species; and (6) MIG-seq method as an effective tool to elucidate the complex evolutionary history of plant groups. [ABSTRACT FROM AUTHOR]

Of the two major speciation modes of endemic plants on oceanic islands, cladogenesis and anagenesis, the latter has been recently emphasized as an effective mechanism for increasing plant diversity in isolated, ecologically homogeneous insular settings. As the only flowering cherry occurring on Ulleung Island in the East Sea (concurrently known as Sea of Japan), Prunus takesimensis Nakai has been presumed to be derived through anagenetic speciation on the island. Based on morphological similarities, P. sargentii Rehder distributed in adjacent continental areas and islands has been suggested as a purported continental progenitor. However, the overall genetic complexity and resultant non-monophyly of closely related flowering cherries have hindered the determination of their phylogenetic relationships as well as the establishment of concrete continental progenitors and insular derivative relationships. Based on extensive sampling of wild flowering cherries, including P. takesimensis and P. sargentii from Ulleung Island and its adjacent areas, the current study revealed the origin and evolution of P. takesimensis using multiple molecular markers. The results of phylogenetic reconstruction and population genetic structure analyses based on single nucleotide polymorphisms detected by multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq) and complementary cpDNA haplotypes provided evidence for (1) the monophyly of P. takesimensis; (2) clear genetic differentiation between P. takesimensis (insular derivative) and P. sargentii (continental progenitor); (3) uncertain geographic origin of P. takesimensis, but highly likely via single colonization from the source population of P. sargentii in the Korean Peninsula; (4) no significant reduction in genetic diversity in anagenetically derived insular species, i.e., P. takesimensis, compared to its continental progenitor P. sargentii; (5) no strong population genetic structuring or geographical patterns in the insular derivative species; and (6) MIG-seq method as an effective tool to elucidate the complex evolutionary history of plant groups.

Of the nearly 40 endemics present on Ulleung Island, Campanula takesimana Nakai represents an anagenetically derived lineage of a continental progenitor, C. punctata Lam. Other than its low morphological divergence, little is known about the genetic diversity and population structure of the species pair or the geographical origin of C. takesimana. We sampled a total of 240 accessions in 22 populations, including one Dokdo Island population, of the two species, sequenced four noncoding chloroplast regions (rps16-trnK, trnQ-rps16, psbD-trnT, and psbM-trnD; 4482 bp), and assessed the genetic consequences of anagenetic speciation. Based on chloroplast DNA, we found substantially lower genetic diversity statistics for C. takesimana compared to its progenitor, significant population genetic structuring in insular derivative species, and significant molecular divergence between C. punctata and C. takesimana. Mutually exclusive haplotypes were found in the two species, and the haplotype network suggested that Ulleung Island haplotypes were derived from the Dokdo Island haplotype, which was originally derived from a C. punctata population in Bonghwa-gun, Gyeongsangbuk-do Province. This study pinpoints a very narrow geographical source area and suggests the potentially important role of Dokdo Island as an initial stepping stone for Ulleung Island endemics. [ABSTRACT FROM AUTHOR]

Abstract: Long-term changes in the Sea of Japan level are estimated based on the Ssalto/Duacs satellite altimetry data. Linear sea level trends for 1993-2005 are positive for the entire sea area and average 3.3 mm/yr, which is close to the mean value for the World Ocean. Trends are weakened by 2.5 times after elimination of annual variation and intra-annual variability (low-frequency data filtering). A quasi-decadal oscillation that accounts for the in-phase rise in 1995-2000 and 2008-2013 (positive phases) and fall in 2001-2007 (negative phase) of the Sea of Japan level for the entire sea area has been observed. The positive phase in 1995-2000 is consistent with an increase in the volume transport into the Sea of Japan through the Korea (Tsushima) Strait and the negative phase is consistent with the transport decrease. Positive sea level trends have dominated in the positive phases (an average of 12.9 and 7.1 mm/yr in 1995-2000 and 2008-2013, respectively) in the entire sea and negative trends with an average of -6.4 mm/yr have been observed during the negative phase in the subtropical sea area. The strongest trends, both positive (10-20 mm/yr and more) and negative (down to -20 mm/yr) have been detected over the western Yamato Basin and near Ulleung Island in the subtropical part of the sea. [ABSTRACT FROM AUTHOR]

The complete chloroplast genome of Lamium takesimense (Lamiaceae), an endemic species in South Korea, are presented in this article. The genome size is 150,626 bp in length, with 38.6% of GC content. It consists a large single-copy (LSC) region (82,527bp) and a small single-copy region (SSC) (17,185bp) which were separated by two inverted repeat (IRs) regions (25,457bp). The complete chloroplast genome contains 111 unique genes, including 77 protein-coding genes, 4 rRNA genes, and 30 tRNA genes.

Cotoneaster wilsonii Nakai is an endangered species endemic to Ulleung Island, Korea. Here we reported the first complete chloroplast gnome sequences of C. wilsonii, which is 159,999 bp in total length with the large single copy (LSC) region of 87,868 bp, the small single copy (SSC) region of 19,335 bp, and two inverted repeat (IR) regions of 26,399 bp. The plastome contains 131 genes, including 84 protein-coding, eight ribosomal RNA, and 37 transfer RNA genes. The overall GC content is 42.6% and those in the LSC, SSC, and IR regions are 34.2, 30.3, and 42.6%, respectively. Phylogenetic analysis of 21 representative plastomes within the family Rosaceae suggests strongly the monophyly of Cotoneaster and C. wilsonii being sister to the clade of Cotoneaster franchetii and Cotoneaster horizontalis.

We used next-generation sequencing to determine the complete chloroplast genome of Fagus multinervis (Fagaceae), a beech endemic to Ulleung Island in South Korea. This genome is 158,348 bp long, has a typical quadripartite structure, and contains a large single copy region (87,659 bp), small single copy region (18,903 bp), and two inverted repeats (25,893 bp). Overall GC content is 37.1%. The genome encodes 129 genes, including 83 for proteins, 38 for tRNA, and 8 for rRNA. Based on a comparison of 63 protein-coding genes from related species, we placed Fagus at a basal position on our phylogenetic tree.

The first complete chloroplast genome sequences of Korean endemic pokeweed in Ulleung Island, Phytolacca insularis, were reported in this study. The P. insularis plastome was 156,419 bp long, with the large single copy (LSC) region of 86,106 bp, the small single copy (SSC) region of 18,335 bp, and two inverted repeat (IR) regions of 25,989 bp. The plastome contained 132 genes, including 84 protein-coding, eight ribosomal RNA, and 39 transfer RNA genes. The overall GC content was 36.8%. Phylogenetic analysis of 13 representative plastomes within the order Caryophyllales suggests that P. insularis is closely related to the species in family Aizoaceae.

Previous phylogenetic studies have suggested that Rubus takesimensis (Rosaceae), which is endemic to Ulleung Island, Korea, is closely related to R. crataegifolius , which is broadly distributed across East Asia. A recent phylogeographic study also suggested the possible polyphyletic origins of R. takesimensis from multiple source populations of its continental progenitor R. crataegifolius in China, Japan, Korea, and the Russian Far East. However, even though the progenitor-derivative relationship between R. crataegifolius and R. takesimensis has been established, little is known about the chloroplast genome (i.e., plastome) evolution of anagenetically derived species on oceanic islands and their continental progenitor species. In the present study, we characterized the complete plastome of R. takesimensis and compared it to those of R. crataegifolius and four other Rubus species. The R. takesimensis plastome was 155,760 base pairs (bp) long, a total of 46 bp longer than the plastome of R. crataegifolius (28 from LSC and 18 from SSC). No structural or content rearrangements were found between the species pairs. Four highly variable intergenic regions ( rpl 32/ trn L, rps 4/ trn T, trn T/ trn L, and psb Z/ trn G) were identified between R. takesimensis and R. crataegifolius . Compared to the plastomes of other congeneric species ( R. corchorifolius , R. fockeanus , and R. niveus ), six highly variable intergenic regions ( ndh C/ psa C, rps 16/ trn Q, trn K/ rps 16, trn L/ trn F, trn M/ atp E, and trn Q/ psb K) were also identified. A total of 116 simple sequence repeats (SSRs), including 48 mononucleotide, 64 dinucleotide, and four trinucleotide repeat motifs were characterized in R. takesimensis . The plastome resources generated by the present study will help to elucidate plastome evolution within the genus and to resolve phylogenetic relationships within highly complex and reticulated lineages. Phylogenetic analysis supported both the monophyly of Rubus and the sister relationship between R. crataegifolius and R. takesimensis . [ABSTRACT FROM AUTHOR]

The multi-stage magmatic plumbing system beneath the Ulleung, Dokdo, and Oki-Dogo Island has attracted considerable attention but has seldom been investigated in detail. Herein, we present a comprehensive geochemical analysis of volcanic rocks sampled at the Ulleung Island, including whole–rock major and trace elements as well as Sr and Nd isotopic compositions. Late Cenozoic alkaline volcanic rocks from the Ulleung Island are commonly divided into basaltic rocks (tephrite basanite and basalt) and acidic rocks (trachyte and rhyolite) based on the large petrologic and geochemical variations. All rocks are significantly enriched in light rare-earth elements (REEs) and large-ion lithophile elements and relatively depleted in heavy REEs. The acidic rocks have slightly enriched 87 Sr/ 86 Sr and ε Nd ratios (0.704895–0.705173; −2.48 to −1.91) and distinctly negative Ba, Sr, P, Eu, and Ti anomalies relative to the basaltic rocks (0.704733–0.705006, -2.61– -1.17). A multi-stage magma evolution model was finally developed beneath the Ulleung, Dokdo, and Oki-Dogo Island, characterized by at least two magma reservoirs at different depths approximately ranging between 20 and 100 km. These ascending magmas were retained in a shallower reservoir for ~1.0, ~0.5, and ~4.5 Ma, respectively, prior to eruptions with significant crystal fractionation. Mantle-derived basaltic melts either directly travelled to the surface to erupt as tephrite-basanite and basalt, or were stagnated in shallower reservoirs where they differentiated into acidic magma to erupt as trachyte and rhyolite. The Late Cenozoic Korean Peninsula basalts are mainly divided into two groups, i.e., the depleted mantle (DM) and enriched mantle 1 (EM1) mixing trend beneath the Ulleung and Dokdo Island, and the DM-EM2 mixing connection beneath the Jeju Island, which likely indicates the traversed boundary beneath Korean Peninsula that represents a simple lateral continuation of the boundary between the southeast and northeast China Blocks. [ABSTRACT FROM AUTHOR]

We assessed the seroprevalence of Coxiella burnetii (C. burnetii) in cattle on Ulleung Island, Korea in a population-based follow up study for 4 years and determined the spatial distribution and risk factors associated with C. burnetii. The seroprevalence of C. burnetii was determined to be 1.4–2.0% during 2011–2014. Overall, nine cattle from three farms that tested seropositive showed C. burnetii antibody seroconversions between 2011 and 2014. The number of seropositive cattle was low, suggesting that movement of and contact between animals was possible risk factors for the transmission of C. burnetii. [ABSTRACT FROM AUTHOR]

Premise of the Study: To enhance our understanding of evolutionary consequences and to establish a suitable conservation strategy, we isolated microsatellite markers for the endangered Bupleurum latissimum (Apiaceae), which is endemic to the oceanic Ulleung Island. We also attempted cross‐amplification in B. euphorbioides and B. longeradiatum to investigate its continental progenitors. Methods and Results: Using high‐throughput sequencing data, we developed 26 polymorphic microsatellite loci in three multiplexes, of which 13 loci were polymorphic in the two related species. For B. latissimum, alleles numbered two to four and the observed and expected heterozygosity ranged from 0.000 to 0.500 and 0.061 to 0.529, respectively. Conclusions: These developed markers will be useful for understanding evolutionary patterns of B. latissimum in an oceanic island system and for establishing suitable conservation strategies at the genetic level. [ABSTRACT FROM AUTHOR]

Ulleung Island is a biodiversity hotspot in South Korea. During a survey of indigenous fungal species from Ulleung Island conducted from 2015 to 2016, we discovered 10 unrecorded macrofungi in Korea. These macrofungi were identified to the species level using morphological features and phylogenetic analysis based on the internal transcribed spacer region: Deconica phyllogena, Mycena zephirus, Phaeomarasmius proximans, Phlebia radiata, Pluteus semibulbosus, Postia alni, Resinicium pinicola, Scytinostroma portentosum, Tricholomopsis flammula, and Tyromyces kmetii. We also provide detailed morphological descriptions for these 10 species. [ABSTRACT FROM AUTHOR]

The first complete chloroplast genome sequences of Korean endemic basswood in Ulleung Island, Tilia insularis, were reported in this study. The T. insularis plastome was 162,565 bp long, with the large single-copy (LSC) region of 91,100 bp, the small single-copy (SSC) region of 20,381 bp, and two inverted repeat (IR) regions of 25,542 bp. The plastome contained 131 genes, including 86 protein-coding, eight ribosomal RNA, and 37 transfer RNA genes. The overall GC content was 36.5%. Phylogenetic analysis of 14 representative plastomes within the family Malvaceae suggests that T. insularis is closely related to other congeneric species in subfamily Tilioideae.

The first complete chloroplast genome sequences of Korean endemic Epilobium in Ulleung Island, Epilobium ulleungensis, were reported in this study. The E. ulleungensis plastome was 160,912 bp long, with the large single copy (LSC) region of 88,915 bp, the small single copy (SSC) region of 17,327 bp, and two inverted repeat (IR) regions of 27,335 bp. The plastome contained 131 genes, including 84 protein-coding, eight ribosomal RNA, and 37 transfer RNA genes. The overall GC content was 36.5%. Phylogenetic analysis of nine representative plastomes within the family Onagraceae suggests strongly that E. ulleungensis is sister to the clade containing species of Oenothera in tribe Onagreae.

Prunus takesimensis is an endemic flowering cherry on Ulleung Island, Korea. The complete chloroplast (cp) genome of P. takesimensis was generated by de novo assembly using whole-genome next-generation sequencing approach. The cp genome size was 157,948 bp in length consisting of four regions; large single copy region (85,959 bp), small single copy region (19,117 bp), and a pair of inverted repeat regions (26,436 bp). The genome contained a total of 128 genes, including 83 coding genes, 8 rRNA genes, and 37 tRNA genes. Phylogenetic analysis for 20 reported genomes within the family Rosaceae showed the monophyly of the genus Prunus including newly sequenced P. takesimensis.

The complete chloroplast genome sequence of Sorbus ulleungensis, a recently described endemic species to Ulleung Island of Korea, was determined. The genome size was 159,632 bp in length with 36.5% GC content. It included a pair of inverted repeats (IRa and IRb) of 26,402 bp, which were separated by small single copy (SSC: 18,824 bp) and large single copy (LSC: 88,003 bp) regions. The cp genome contained 111 genes, including 78 protein coding genes, 29 tRNA genes, and four rRNA genes. Phylogenetic analysis of the combined 78 protein coding genes and four rRNA genes showed that S. ulleungensis was most closely related to Pyrus pyrifolia.

We extensively reviewed the macrozoobenthos around Dokdo, Korea, by analyzing metadata collected over the past 50 years. The Dokdo macrozoobenthos was represented by 578 species belonging to 243 families from 12 phyla, where four major phyla (or classes) collectively accounted for 86% to total. Mollusks, arthropods, and cnidarians were semi-equally occurred in intertidal and subtidal areas, while polychetes dominated the subtidal zone. The northern most region of Dokdo had the greatest biodiversity (173 species). The taxonomic distinctness analysis (delta +) indicated a close association between species by region, although the number of species varied greatly. About half of the species did not occur cross the locations (n = 20), indicating strong habitat preferences of Dokdo macrofaunal assemblages. Overall, the diversity of Dokdo was greater than that of Ulleung Island (east coast), but comparable to that of the well-developed tidal flats in the western Korean waters, highlighting its status as a biodiversity hotspot. [ABSTRACT FROM AUTHOR]

Two major modes of speciation, i.e., cladogenesis and anagenesis, have often been used to explain the generation of distinct plant diversity on oceanic islands. Anagenetic speciation is of particular interest to plant endemics on Ulleung Island, Korea because, of nearly 40 endemics, approximately 88% or even all endemic species are thought to be anagenetically derived. Despite its important role in Ulleung Island, the full scope of the anagenetic speciation and the genetic consequences of this speciation mode have been limited to a very few families (i.e., Apiaceae, Sapindaceae, and Ranunculaceae). Based on extensive sampling (a total of 322 individuals) and trnL-F cpDNA noncoding sequences, we conducted phylogenetic and haplotype network analyses for the species pair of Rubus crataegifolius (continental progenitor)- R. takesimensis (insular derivative). Rubus takesimensis on Ulleung Island is not a monophyletic group, suggesting at least two independent introductions from geographically and genetically divergent source populations. No significant reduction in cpDNA haplotype diversity and genetic differentiation in R. takesimensis are consistent with expectations from the anagenetically derived species. A further study based on comprehensive sampling and more variable molecular markers will shed light into the genetic consequences of anagenetic speciation in Rubus on Ulleung Island. [ABSTRACT FROM AUTHOR]

Most known species in the Physalacriaceae are saprotrophs that grow on decaying leaves and wood, and approximately 21 genera in the Physalacriaceae have been reported worldwide. During an ongoing survey of indigenous fungi in Korea, four specimens belonging to the Physalacriaceae were collected on Ulleung Island. These specimens were identified as three species based on morphological characteristics and molecular analysis of rDNA-internal transcribed spacer sequences. Three species in three genera were shown to be new records in Korea: Hymenopellis orientalis, Paraxerula hongoi, and Ponticulomyces orientalis. The latter two are the first records of these genera in Korea. In this study, we provide detailed morphological descriptions of these species and describe their phylogenetic position with in the Physalacriaceae. [ABSTRACT FROM AUTHOR]

The unique material properties of volcanic soils may cause stability problems within the soil. However, few studies have examined the composition and engineering characteristics of volcanic soils below sea level. The objective of this study is to investigate the engineering properties of volcanic soils sampled from Ulleung Island. For the volcanic soils, the index properties, particle geometry, and mineralogy are analyzed in the laboratory. An oedometer cell incorporated with bender elements is used to measure the small-strain stiffness and compressibility of the volcanic soils. To obtain the large strain strength parameter and hydraulic conductivity of the volcanic soils, direct shear tests, and constant head permeability tests are performed. The experimental results show that the basic index properties of volcanic soils sampled from Ulleung Island are very similar to the values of previously published reference data: poorly graded with a median grain size, very low fine fraction, and slightly high specific gravity. In addition, the particle surface texture features and elementary analysis indicates a dark grain color, small pits or holes in the grain, and relatively low SiO2and high Fe2O3contents. The friction angle of the volcanic soils depends on the relative density, and the hydraulic conductivity varies according to e3/(1 + e) and D102. The characterization of the electrical properties in Ulleung Island needs to be conducted with caution due to the high Fe2O3content in the volcanic soils. [ABSTRACT FROM AUTHOR]

The genus Allium , with over 900 species, is one of the largest monocotyledonous genera and is widely accepted with 15 recognized subgenera and 72 sections. The robust subgeneric and sectional relationships within Allium have long been not resolved. Based on 76 species of Allium (a total of 84 accessions), we developed a highly resolved plastome phylogenetic framework by integrating 18 newly sequenced species (20 accessions) in this study and assessed their subgeneric and sectional relationships, with special emphasis on the two subgenera Anguinum and Rhizirideum . We retrieved the three major evolutionary lines within Allium and found that the two subgenera Anguinum and Rhizirideum are monophyletic whereas others are highly polyphyletic (e.g., Allium , Cepa , Polyprason , and Melanocrommyum ). Within the subgenus Anguinum , two strongly supported sublineages in East Asian and Eurasian-American were found. Allium tricoccum in North America belonged to the Eurasian clade. The distinct taxonomic status of A. ulleungense and its sister taxon were further determined. In subg. Rhizirideum , the Ulleung Island endemic A. dumebuchum shared its most recent common ancestor with the species from Mongolia and the narrow Korean endemic A. minus . Two Ulleung Island endemics were estimated to originate independently during the Pleistocene. In addition, a separate monotypic sectional treatment of the east Asian A. macrostemon (subg. Allium ) and sister relationship between A. condensatum and A. chinense was suggested., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yang, Kim, Gil, Choi and Kim.)

Ulleung Island is an oceanic volcanic island in Korea, which has never been connected to the adjacent continent. Previous studies highlighted Ulleung Island as an excellent system to study the pattern and process of early stages of flowering plant evolutions on oceanic island. The predominant mode of speciation in flowering plants on Ulleung Island appears to be anagenesis. However, the potentially important role of hybrid speciation among incompletely reproductively isolated lineages cannot be ruled out. Viola woosanensis (Violaceae) is of purportedly hybrid origin between V. ulleungdoensis (i.e., formerly recognized as V. selkirkii in Ulleung Island) and V. chaerophylloides, based on morphology. To examine the origin of V. woosanensis, we sampled a total of 80 accessions, including V. woosanensis and its putative parental species and sequenced nrDNA ITS, and four highly variable chloroplast noncoding regions ( trnL- trnF, rpl16 intron, atpF- atpH, and psbA- trnH). Representative species of Viola from Korea were also included in the phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). Additive polymorphic sites in the nrDNA ITS regions were confirmed by cloning amplicons from representative species. The molecular data strongly supported the hybrid origin of V. woosanensis, and the maternal and paternal parent were determined to be V. ulleungdoensis and V. chaerophylloides, respectively. The presence of two parental ribotypes in V. woosanensis (with the exception in one population) was confirmed by cloning, suggesting V. woosanensis is primarily the F generation. No trace of backcrossing and introgression with its parents was detected due to low fertility of hybrid species. We found a multiple and unidirectional hybrid origin of V. woosanensis. Additional studies are required to determine which factors contribute to asymmetric gene flow of Viola species in Ulleung Island. [ABSTRACT FROM AUTHOR]

Documentation of diversity and assessment of cultural importance of wild edible plants gathered and consumed in Ulleung Island, South Korea was conducted in this research by asking 83 key informants (average age 70) using semi-structured interview questionnaire, and utilizing quantitative ethnobotanical indices such as use value (UV) and fidelity level (FL). A total of 66 taxa in 36 families of wild food plants were recorded, 10 of which, endemic. Asteraceae and Rosaceae were the most represented families with 10 taxa for each. Leaves, young shoots and fruits were the most collected plant parts especially in spring. The plants which recorded high UVs were Allium ochotense (0.627), Aster pseudoglehnii (0.398) and Aruncus dioicus var. kamtschaticus (0.349), indicating that these plants are considered the most important by the informants. This study also recorded 29 wild edible plant taxa with 100 % FL values. Notable plants (and their preparation) with relatively high FL and use-mentions are Vitis coignetiae (89.47 %), Anthriscus sylvestris (86.67 %) and Lilium hansonii (86.67 %) which are consumed as fruit, prepared by parboiling the shoots and by steaming the bulbs, respectively. Category 5 'Cooked' (COO) was the most preferred mode of preparation when taken as a whole recording 49 % of the total, implying that wild edible plants play a big role in the informants' regular diet despite growing modernization in the island brought about by government-led tourism and infrastructure development programs. Some social, cultural, nutritional and ecological aspects were also discussed in this paper. [ABSTRACT FROM AUTHOR]

Solar farm suitability in remote areas will involve a multi-criteria evaluation (MCE) process, particularly well suited for the geographic information system (GIS) environment. Photovoltaic (PV) solar farm criteria were evaluated for an island-based case region having complex topographic and regulatory criteria, along with high demand for low-carbon local electricity production: Ulleung Island, Korea. Constraint variables that identified areas forbidden to PV farm development were consolidated into a single binary constraint layer (e.g., environmental regulation, ecological protection, future land use). Six factor variables were selected as influential on-site suitability within the geospatial database to seek out increased annual average power performance and reduced potential investment costs, forming new criteria layers for site suitability: solar irradiation, sunshine hours, average temperature in summer, proximity to transmission line, proximity to roads, and slope. Each factor variable was normalized via a fuzzy membership function (FMF) and parameter setting based on the local characteristics and criteria for a fixed axis PV system. Representative weighting of the relative importance for each factor variable was assigned via pairwise comparison completed by experts. A suitability index (SI) with six factor variables was derived using a weighted fuzzy summation method. Sensitivity analysis was conducted to assess four different SI based on the development scenarios (i.e., the combination of factors being considered). From the resulting map, three highly suitable regions were suggested and validated by comparison with satellite images to confirm the candidate sites for solar farm development. The GIS-MCE method proposed can also be applicable widely to other PV solar farm site selection projects with appropriate adaption for local variables.

A fungal isolate EML-NCP01 was recovered from agricultural soil in Ulleung Island, Korea. Phylogenetic analysis of internal transcribed spacer and β-tubulin genes identified the isolate as the Penicillium species P. raphiae. Morphologically, the EML-NCP01 isolate was identical to the previous description of P. raphiae. The species presented here has not been reported in Korea. [ABSTRACT FROM AUTHOR]

Ulleung Island is a Quaternary volcanic island located in the mid-western part of the East Sea (Sea of Japan) back-arc basin, which has erupted from the Pliocene until the late Holocene. This study focuses on reconstructing the latest eruptive history of the island by describing the sedimentological and stratigraphic characteristics of the most recent, trachytic/phonolitic pyroclastic sequence, named the Nari Tephra Formation. This formation is preserved as a succession of unwelded pyroclastic and epiclastic deposits within an embayed margin of the Nari Caldera. The embayment acted as a topographic trap for proximal pyroclastic deposits, and contains a complete record of the past 19,000 years of eruption history. The formation includes evidence for five separate eruptive episodes (Member N-1 to N-5), with intervening weathered and/or soil horizons indicating hundreds to thousands of years of repose between each eruption. Eruption styles and depositional mechanisms varied between and during individual episodes, reflecting changing dynamics of the magma plumbing system, magmatic gas coupling, and a variable role of external water. Extra-caldera sequences show that only a few of these eruptions generated sustained eruption columns or pyroclastic density currents (PDCs) large enough to overtop the caldera wall. Thus tephra sequences outside the caldera provide an underestimate of eruption frequency, and care needs to be taken in the interpretation and correlation to distal tephra sequences recognized in marine and terrestrial records. In addition, topographic effects of caldera structures should be considered for the assessment of PDC-related hazards in such moderately sized pyroclastic eruptions. [ABSTRACT FROM AUTHOR]

Scrophularia takesimensis Nakai is a Critically Endangered plant species endemic to Ulleung Island, Republic of Korea. We provide updated information on the distribution and conservation status of this species. We located 39 subpopulations and counted a total of 443 individuals, including some reintroduced. Observations of dried and broken branches, with fruits, of S. takesimensis along the coast may indicate dispersal by sea. The construction of coastal roads is the main threat to the species. To conserve this species more effectively we recommend that: (1) the two habitats identified as a priority for conservation should be afforded special protection, (2) habitats to the seaward side of coastal roads are more suitable than habitat on the landward side for in situ conservation, and (3) the presently known subpopulations require continuous protection and monitoring. [ABSTRACT FROM AUTHOR]

The volcanic activity of Ulleung Island generated considerable amount of pyroclastic materials composed of volcanic ash, lapilli tuff, pumice, and breccia, during the period ranging from the Pleistocene to the Holocene. The Nari Formation exposed in the southern part of the Nari caldera can be divided into four units; Nari-I, Nari-II, Nari-III and Nari-IV. Nari-I, Nari-II, and Nari-III are characterized by dense gray pumice, white and gray pumices, and brown and black pumices, respectively. In this study, we dated radiocarbon ages and identified species of four charcoal fragments collected from the pumiceous deposits of Nari-I and Nari-II. Radiocarbon ages for Nari-I and Nari-II are 15,880 ± 60∼15,560 ± 100 BP and 7,660 ± 40∼7,600 ± 40 BP, respectively. Calibrated ages from these ages are 19,055 ± 95∼18,840 ± 150 cal BP for Nari-I and 8,465 ± 75∼8,400 ± 40 cal BP for Nari-II. This result indicates that the interval between Nari-I and Nari-II might be about 10,000 years. Nari-III was formed after 5,600 cal BP that records the youngest age data correlated with Nari-II. Therefore, it can be concluded that Albong lava dome, the youngest volcanic activity of the island, is more likely to cease a few thousands of years ago. On the basis of the anatomical characteristics of the charcoal fragments, they were identified to be Picea spp. and Fagus crenata. To summarize, the paleovegetation around the Nari caldera consisted of Picea spp. until 19,055∼18,840 cal BP and Fagus crenata, representing a broadleaf forest of Ulleung Island at present, flourished after about 8,465 cal BP. [ABSTRACT FROM AUTHOR]

Abstract: We investigated seasonal characteristics (concentration, enrichment factors, and correlation coefficients) of chemical constituents, including sources for sea salt-corrected metals (Al, Fe, K, Ca, Mg, S, As, Cd, Co, Cu, Li, Mn, Mo, Ni, Pb, Sn, Sr, Ti, V, and Zn), in 334 aerosol samples collected during October 2003–October 2008 at Ulleung Island in the southern East/Japan Sea. High Al concentrations were found in spring (geometric means of 1.23 and 1.28 μg m−3 in March and April, respectively) due to Asian dust (yellow sand) originating from northeastern China. The dust mineral transport by strong winds resulted in a change of metal composition showing soil-dominated condition. In the rainy period (June–September), the aerosol metal concentrations and composition were influenced largely by wet deposition and the summer monsoon, together with anthropogenic aerosol transport. The correlation coefficients in the summer period (July and August) showed a positive correlation of Al with K (r = 0.74) and As (r = 0.63), probably reflecting anthropogenic-originated Al coming from coal burning. In autumn (October and November) and winter (December and January), mixed sources of soil and anthropogenic-originated aerosols were pronounced by the development of northwesterly winds from the Asian continent. Especially, the soil-originated proportion was relatively higher in autumn than in winter when the anthropogenic-originated aerosols from heating fuels predominated. Anthropogenic As, Sn, Mo, Zn, Pb, and Cd between low- and high-dust periods that had similar air–mass movements in spring were at similar concentrations, but higher in the air masses including eastern China trajectories and/or slow movement at lower height during high-dust periods. [Copyright &y& Elsevier]

Ulleung Island is a biodiversity hot spot harboring approximately 700 species of vascular plants with high number of endemic taxa. Physocarpus insularis, one of the 41 endemic species, has an extremely restricted distribution range on the very small, geologically young oceanic island. Phylogenetic relationship of P. insularis, however, remained highly controversial whether it is conspecific with Spiraea chamaedryfolia or a distinct species in Physocarpus, making it difficult to establish necessary conservation programs. We examined comparative morphology of Physocarpus and Spiraea and reconstructed the phylogeny of the rbcL, matK, ndhF, and trnL- trnF regions from the exemplars of Rosaceae. The results strongly supported the placement of P. insularis within Spiraea. Further phylogenetic analyses of tribe Spiraeeae based on the trnL- trnF and internal transcribed spacer data showed that P. insularis is closely related to S. chamaedryfolia. Morphological analysis revealed that P. insularis differs from S. chamaedryfolia by having larger leaf blades that are subcordate or truncate at base. Results of this study suggest that P. insularis should be recognized as a distinct taxon in Spiraea and that conservation efforts on Ulleung Island should focus on protecting its natural environment to conserve evolutionary patterns and processes in addition to specific conservation programs for species in peril. [ABSTRACT FROM AUTHOR]

As part of an on-going effort to conserve endangered and endemic Scrophularia takesimensis (Scrophulariaceae), we analyzed its spatial distribution patterns by applying an index of dispersion, plant-to-all-plant distances, and the varying quadrat size method. Three indices — Dispersion, Morisita, and Standardized Morisita — all revealed clumping with small aggregates, and distances between aggregates were more or less regular. The asymptote level occurred at a distance of 20 to 30 m; the distance showing 90% of cumulative frequency coincided with 20 to 21 m; 95%, 24 to 25 m; and 99%, 31 to 32 m. The 20 m× 20 m and 40 m×40 m quadrats contained 25 and 40 plants, respectively. We conclude that this number of individuals and size of area are the minimum required for the conservation of this species. [ABSTRACT FROM AUTHOR]

Cotoneaster wilsonii Nakai is an endangered species endemic to Ulleung Island, Korea. Here we reported the first complete chloroplast gnome sequences of C. wilsonii, which is 159,999 bp in total length with the large single copy (LSC) region of 87,868 bp, the small single copy (SSC) region of 19,335 bp, and two inverted repeat (IR) regions of 26,399 bp. The plastome contains 131 genes, including 84 protein-coding, eight ribosomal RNA, and 37 transfer RNA genes. The overall GC content is 42.6% and those in the LSC, SSC, and IR regions are 34.2, 30.3, and 42.6%, respectively. Phylogenetic analysis of 21 representative plastomes within the family Rosaceae suggests strongly the monophyly of Cotoneaster and C. wilsonii being sister to the clade of Cotoneaster franchetii and Cotoneaster horizontalis. [ABSTRACT FROM AUTHOR]