Biodiversity Data Journal : Data Paper (Biosciences)
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Data Paper (Biosciences)
Vascular plants occurrences in Dokdo Islands, Korea, based on herbarium collections and legacy botanical literature
expand article infoChin-Sung Chang, Shin Young Kwon, Hyun Tak Shin§, Su-Young Jung§, Hui Kim|
‡ Seoul National University, Seoul, Republic of Korea
§ Korea National Arboretum, Pocheon, Republic of Korea
| Mokpo National University, Muan, Republic of Korea
Open Access

Abstract

Background

The vascular flora of the Dokdo Islands has been reported, based on primary collections made in 2012 and 2013 and legacy botanical literature. The Dokdo Islands are the remotest islands of Korea, located in the East Sea approximately 87 km from Ulleungdo Islands. They comprise two main volcanic islands, Dongdo (east islands) and Seodo (west islands) and minor islets surrounding the two main islands. This research was conducted to document vascular plant species inhabiting Korea's most inaccessible islands. We present a georeferenced dataset of vascular plant species collected during field studies on the Dokdo Islands over the past seven decades.

New information

In the present inventory of the flora of Dokdo, there are listed 108 species belonging to 78 genera and 39 families, including 93 native species and 15 newly human-induced naturalised species for these Islands' flora. The Poaceae and Asteraceae families are the most diverse, with 22 and 15 taxa, respectively. Some of the previously-listed taxa were not found on Dokdo probably because they are rare and the limited time did not allow collectors to find rare species. The spread of introduced species, especially the invasive grass Bromus catharticus Vahl., affects several native species of Dokdo flora.

Keywords

biodiversity, Bromus catharticus, Dokdo, flora, invasive species, islands, vascular plants

Introduction

Biodiversity researchers have identified critical gaps in spatial, temporal and taxonomic coverage of biodiversity observations highlighting barriers to effective data collection, open access and analysis (Amano et al. 2016, Wetzel et al. 2018). To bridge these gaps, biodiversity data must suit the demands of multiple groups, including scientists, policy-makers and data contributors (Taylor et al. 2017). Several biodiversity data researchers have emphasised taking the lead in developing new measures. Options like open access publishing with conventional licences accessibility through major biodiversity platforms, such as GBIF, can be used (Faith et al. 2013). The next solution is offering data providers incentives, such as the option to publish in peer-reviewed data journals (Chavan and Penev 2011). Biodiversity data providers should become better data stewards, with a comprehensive understanding of metadata, best data management practices and plans for data archiving and preservation (Hartter et al. 2013, Penev et al. 2017). However, data stewardship takes time and resources and data providers cannot be data stewards without sufficient resources and support. The evolution of data stewardship culture causes biodiversity informatics challenges to emerge as data volume and precision increase. Biodiversity data scientists propose that data providers and stakeholders confront current challenges prividing them with detailed recommendations (Ariño et al. 2016).

Geographical location and security level are the main factors causing spatial gaps (Ariño et al. 2016). As biodiversity information is closely related to the temporal and spatial variation in surveying effort, Wallacean shortfall is specifically critical in remote and inaccessible areas (Hortal et al. 2008, Boakes et al. 2010). Sampling certain places better than others is inevitable given the accessibility differences between localities (Rodrigues et al. 2010); therefore, distribution data tend to be heavily biased with historical collection patterns, collation and biodiversity data accumulation (Rodrigues et al. 2010, Meyer et al. 2015). To effectively bridge spatial gaps, it is essential to comprehend the causes for data shortage in some regions. In the case of Banco de Datos de Biodiversidad de Canaris (BIOTA-Canarias, Hortal et al. 2007), it stated that the lack of completeness or large gaps in their spatial coverage compromises their future utility. The previously collected data have limited utility because the data lack detail and geographical coverage is not exhaustive (Soberón et al. 2007). Biodiversity data scientists encourage exhaustive compilation of all available information with sufficient quality and detail (Hortal et al. 2008).

The Dokdo Islands are the most inaccessible islands in Korea, located at 37°14'26.8"N and 131°52'10.4"E, belonging to an administrative district that includes the Ulleung Islands. Since the first botanical survey (Lee 1952), seventy years of sporadic observations have waited to be mobilised to accessible biodiversity data (Jung et al. 2014). This study produces an exhaustive and reliable list of vascular plants from the Dokdo Islands, based on reference herbarium specimens collected in the field and the occurrence data available in the papers (Kim and Lee 2021).

General description

Purpose: 

This research focused on the digitisation of plant distribution data on Dokdo Islands acquired by botanists on occasional expeditions to the Islands between 1947 and 2018. These data offer a promising tool to help guide the biodiversity management and conservation of these highly inaccessible island ecosystems.

Project description

Title: 

Vascular plants occurrences in Dokdo Islands, Korea, based on herbarium collections and legacy botanical literature.

Personnel: 

The datasets were digitised by Hui Kim (data manager), Su-Young Jung was the resource creator and Shin Young Kwon, Hyun Tak Shin and Chin-Sung Chang were the content providers. Chin-Sung Chang checked taxonomic changes and georeferencing. S.Y. Jung conducted the field works for two years, from April 2012 to September 2013, collaborating with members from Korea National Arboretum (Jung et al. 2014). S.Y. Jung did preliminary in situ identifications. S.Y. Jung, Hui Kim and Chin-Sung Chang conducted the final species identification.

Study area description: 

The small islands of Dokdo are volcanic rocks formed in the Cenozoic era, more specifically 4.6-2.5 million years ago, having a formation mechanism similar to underwater islands (Jo et al. 2021, Kim et al. 2013). The Dokdo Volcano rises roughly 2,100 m a.s.l. and has a diameter of more than 10 km (Song et al. 2017). The Islands have a butterfly wing shape, a relatively steep terrain, a peak elevation of 168 m a.s.l. and a surface area of 18.7 hectares (Fig. 1). The Dokdo Islands consist of two main islets, Seodo and Dongdo, with numerous surrounding rocks. Sedo has multiple berth and tracking routes access points and flora surveys and collections are possible over a comparatively large area. Since Dongdo is more difficult to access by boat, it is challenging to investigate the surface, except there are fewer primary species occurrence data in a few points. Dokdo Islands had a mean annual temperature of 13.8°C, mean annual precipitation of 589 mm, an absolute minimum temperature of -6.4°C and an absolute maximum temperature of 28.2°C. According to meteorologists, automatic weather systems underestimate the amount of snowfall, thereby resulting in missing data (Kim and Park 2017).

Figure 1.

Location and general topography of Dokdo Islands in East Sea.

aBlack arrow points to the location of Dokdo Islands.  
bTopography of Dokdo Islands.  

Sampling methods

Study extent: 

The Dokdo Islands are the most inaccessible islands in Korea, located at 37°14'26"N and 131°52'05"E, belonging to an administrative district that includes the Ulleung Islands.

Sampling description: 

The vascular plant occurrence data, treated in this study, were compiled using fieldwork from 2012 to 2013 and botanical legacy articles from 1947 to 2018. Herbarium surveys were conducted in two Herbaria, including SNUA (Seoul National University, College of Agriculture, herbarium acronym following Index Herbariorum) and KH (Korea National Arboretum). In addition to the authors’ collections, datasets on vascular plant occurrences in Dokdo Islands were digitised from several manuscripts in a heterogeneous format (Lee 1952, Lee and Joo 1958, Lee 1978, Sun et al. 2002, Hyun and Kwon 2006, Lee et al. 2007, Park and Lee 2008, Park et al. 2010, Song and Park 2012, Jung et al. 2014, Park et al. 2014, Kim and Lee 2016, Park et al. 2016, Park et al. 2017, Park et al. 2018, Table 1). References to the published literature, from which data were obtained for the occurrence data compilation, are presented in the bibliography section of the metadata.

Table 1.

Data sources for the dataset of vascular plants occurrences in Dokdo Islands.

Data source

Type of occurrence data

Number of occurrences

Field year

Lee 1952

Literature

36

1947

Lee and Joo 1958

Literature

23

1958

Lee 1978

Herbarium

37

1978

Sun et al. 2002

Literature

69

1996-1999

Hyun and Kwon 2006

Literature

49

2006

Lee et al. 2007

Literature

49

2007

Park and Lee 2008

Literature

57

2008

Park et al. 2010

Literature

58

2008-2009

Song and Park 2012

Literature

60

2008-2011

Jung et al. 2014

Herbarrium/ Literature

91

2012-2013

Park et al. 2014

Literature

65

2013-2014

Kim and Lee 2016

Literature

54

2015-2016

Park et al. 2016

Literature

56

2016

Park et al. 2017

Literature

66

2017

Park et al. 2018

Literature

68

2017-2018

Total

838

Quality control: 

The Dokdo Islands occurrence dataset was manually digitised from scanned documents of the original papers. The quality control processes of biodiversity data management were based on the principles of data quality by Chapman (2005) . Scientific names and locality names in the digitised datasets were retained exactly as in the original papers. The authors used the provisional checklist of vascular plants for the Korea Peninsula Flora to determine the accepted names (Chang et al. 2014). All scientific names were cross-checked and taxonomically updated using the taxonomic module of Botanical Research and Herbarium Management System (BRAHMS; Pouwer et al. 2008); more details on the digitisation steps, structure of the data and quality control measures are presented below.

Step description: 

1. The content providers carefully reviewed individual floristic publications to manage the irregularity in the format of historical papers. All occurrence records were merged into a spreadsheet, which contained the original species names recorded at the location. In this digitisation stage, obvious typographic errors were corrected. Accepted taxon names and taxonomic classification derived from the local checklist (Chang et al. 2014) were included in the spreadsheet. The result of the above digitisation steps was 838 records with 25 columns containing occurrence data of 108 vascular plant taxa.

2. MS Access was used to create the BRAHMS database layout. All specimen and occurrence information were recorded in the BRAHMS database of the T.B. Lee Herbarium.

3. In the literature data, we frequently encountered several uncertain dates of field works, for instance, 13 July 2017; 26 September 2017; 17 April 2018; 19-20 June 2018; 18 September 2018, for 68 collections by Park et al. (2018). When the collection date was written as “several dates,” we transcribed the last dates of field works (day, month and year) and provided the full interval date in the eventDate field and the rest of the general information in the verbatimEventDate field. Park and Lee (2008) and Park et al. (2017) published the floristic list of Dokdo Islands with many vascular plant pictures. As these authors did not provide the collection information, the publication year was used as the year of events.

4. All occurrence records without coordination were georeferenced, either from the coordinates provided in the paper or from the geographic description of the localities. The coordinate uncertainty in metres for each occurrence was estimated employing the algorithm of Wieczorek et al. (2010).

5. Occurrence data in BRAHMS could be easily exported in various formats, including Darwin Core for uploading to the EABCN IPT. The Darwin Core standard was applied to the BRAHMS extract/query file structure to accommodate the relevant information extracted from the publications.

Geographic coverage

Description: 

Dokdo Islands, Ulleung-gun, Geongsangbuk-do, the Republic of Korea (approximately 37°14'26"N, 131°52'5"E)

Coordinates: 

37.225 and 37.255 Latitude; 131.823 and 131.9 Longitude.

Taxonomic coverage

Description: 

All vascular plants were identified to infraspecific level. This dataset contains distribution information for 108 vascular plant species belonging to 39 families (Table 2).

Table 2.

Classification of species according to the criteria of Family, Habitat and Geographical origin is based on Chang et al. (2014).

Number

SPECIES

FAMILY

HABIT

Geographic Origin

1

Tetragonia tetragonoides (Pall.) Kuntze

Aizoaceae

Herb

Native

2

Achyranthes bidentata Blume

Amaranthaceae

Herb

Native

3

Achyranthes bidentata Blume var. japonica Miq.

Amaranthaceae

Herb

Native

4

Cnidium japonicum Miq.

Apiaceae

Herb

Native

5

Oenanthe javanica (Blume) DC.

Apiaceae

Herb

Native

6

Metaplexis japonica (Thunb.) Makino

Apocynaceae

Herb

Native

7

Artemisia codonocephala Diels

Asteraceae

Herb

Native

8

Artemisia indica Willd.

Asteraceae

Herb

Native

9

Artemisia japonica Thunb.

Asteraceae

Herb

Native

10

Artemisia koidzumii Nakai

Asteraceae

Herb

Native

11

Artemisia montana (Nakai) Pamp.

Asteraceae

Herb

Native

12

Artemisia scoparia Waldst. & Kit.

Asteraceae

Herb

Native

13

Aster spathulifolius Maxim.

Asteraceae

Herb

Native

14

Dendranthema naktongense (Nakai) Tzvelev

Asteraceae

Herb

Native

15

Farfugium japonicum (L.) Kitam.

Asteraceae

Herb

Native

16

Senecio vulgaris L.

Asteraceae

Herb

Introduced

17

Sonchus asper (L.) Hill

Asteraceae

Herb

Native

18

Sonchus brachyotus DC.

Asteraceae

Herb

Native

19

Sonchus oleraceus L.

Asteraceae

Herb

Native

20

Taraxacum platycarpum Dahlst.

Asteraceae

Herb

Native

21

Youngia japonica (L.) DC.

Asteraceae

Herb

Native

22

Arabis serrata Franch. & Sav.

Brassicaceae

Herb

Native

23

Arabis stelleri DC.

Brassicaceae

Herb

Native

24

Brassica juncea (L.) Czern.

Brassicaceae

Herb

Introduced

25

Capsella bursa-pastoris (L.) Medik.

Brassicaceae

Herb

Native

26

Lepidium virginicum L.

Brassicaceae

Herb

Introduced

27

Raphanus sativus L.

Brassicaceae

Herb

Introduced

28

Campanula punctata Lam.

Campanulaceae

Herb

Native

29

Lonicera morrowii A.Gray

Caprifoliaceae

Shrub

Native

30

Dianthus longicalyx Miq.

Caryophyllaceae

Herb

Native

31

Gypsophila oldhamiana Miq.

Caryophyllaceae

Herb

Native

32

Sagina japonica (Sw.) Ohwi

Caryophyllaceae

Herb

Native

33

Sagina maxima A.Gray

Caryophyllaceae

Herb

Native

34

Stellaria aquatica (L.) Scop.

Caryophyllaceae

Herb

Native

35

Stellaria media (L.) Vill.

Caryophyllaceae

Herb

Native

36

Stellaria neglecta Weihe

Caryophyllaceae

Herb

Native

37

Euonymus hamiltonianus Wall.

Celastraceae

Shrub

Native

38

Euonymus japonicus Thunb.

Celastraceae

Shrub

Native

39

Atriplex gmelinii C.A.Mey. ex Bong.

Chenopodiaceae

Herb

Native

40

Atriplex subcordata Kitag.

Chenopodiaceae

Herb

Native

41

Chenopodium album L.

Chenopodiaceae

Herb

Native

42

Chenopodium giganteum D.Don

Chenopodiaceae

Herb

Native

43

Chenopodium glaucum L.

Chenopodiaceae

Herb

Introduced

44

Chenopodium stenophyllum (Makino) Koidz.

Chenopodiaceae

Herb

Native

45

Hypericum erectum Thunb.

Clusiaceae

Herb

Native

46

Commelina communis L.

Commelinaceae

Herb

Native

47

Calystegia soldanella (L.) R.Br.

Convolvulaceae

Herb

Native

48

Ipomoea purpurea (L.) Roth

Convolvulaceae

Herb

Introduced

49

Phedimus middendorffianus (Maxim.) 't Hart

Crassulaceae

Herb

Native

50

Sedum japonicum Siebold ex Miq.

Crassulaceae

Herb

Native

51

Sedum kamtschaticum Fisch. & C.A.Mey.

Crassulaceae

Herb

Native

52

Sedum oryzifolium Makino

Crassulaceae

Herb

Native

53

Cucumis melo L.

Cucurbitaceae

Herb

Introduced

54

Cyperus microiria Steud.

Cyperaceae

Herb

Native

55

Cyrtomium falcatum (L.f.) C.Presl

Dryopteridaceae

Herb

Native

56

Elaeagnus macrophylla Thunb.

Elaeagnaceae

Liana

Native

57

Machilus thunbergii Siebold & Zucc. ex Meisn.

Lauraceae

Tree

Native

58

Allium fistulosum L.

Liliaceae

Herb

Introduced

59

Allium macrostemon Bunge

Liliaceae

Herb

Native

60

Asparagus cochinchinensis (Lour.) Merr.

Liliaceae

Herb

Native

61

Asparagus schoberioides Kunth

Liliaceae

Herb

Native

62

Lilium lancifolium Thunb.

Liliaceae

Herb

Native

63

Liriope muscari (Decne.) L.H.Bailey

Liliaceae

Herb

Native

64

Maianthemum dilatatum (A.W.Wood) A.Nelson & J.F.Macbr.

Liliaceae

Herb

Native

65

Hibiscus syriacus L.

Malvaceae

Shrub

Introduced

66

Cocculus orbiculatus (L.) DC.

Menispermaceae

Liana

Native

67

Orobanche coerulescens Stephan

Orobanchaceae

Herb

Native

68

Oxalis corniculata L.

Oxalidaceae

Herb

Native

69

Oxalis stricta L.

Oxalidaceae

Herb

Native

70

Corydalis heterocarpa Siebold & Zucc. var. japonica (Franch. & Sav.) Ohwi

Papaveraceae

Herb

Native

71

Pinus thunbergii Parl.

Pinaceae

Tree

Native

72

Plantago asiatica L.

Plantaginaceae

Herb

Native

73

Bromus catharticus Vahl

Poaceae

Herb

Introduced

74

Cleistogenes hackelii (Honda) Honda

Poaceae

Herb

Native

75

Digitaria ciliaris (Retz.) Koeler

Poaceae

Herb

Native

76

Digitaria radicosa (J.Presl) Miq.

Poaceae

Herb

Native

77

Digitaria violascens Link

Poaceae

Herb

Native

78

Echinochloa crus-galli (L.) P.Beauv.

Poaceae

Herb

Native

79

Echinochloa oryzoides (Ard.) Fritsch

Poaceae

Herb

Native

80

Eleusine indica (L.) Gaertn.

Poaceae

Herb

Native

81

Elymus kamoji (Ohwi) S.L.Chen

Poaceae

Herb

Native

82

Festuca ovina L.

Poaceae

Herb

Native

83

Festuca rubra L.

Poaceae

Herb

Native

84

Imperata cylindrica (L.) Raeusch.

Poaceae

Herb

Native

85

Miscanthus sinensis Andersson

Poaceae

Herb

Native

86

Pennisetum glaucum (L.) R.Br.

Poaceae

Herb

Native

87

Phragmites japonicus Steud.

Poaceae

Herb

Native

88

Poa annua L.

Poaceae

Herb

Native

89

Poa pratensis L.

Poaceae

Herb

Native

90

Puccinellia nipponica Ohwi

Poaceae

Herb

Native

91

Setaria faberi R.A.W.Herrm.

Poaceae

Herb

Native

92

Setaria pumila (Poir.) Roem. & Schult.

Poaceae

Herb

Introduced

93

Setaria viridis (L.) P.Beauv.

Poaceae

Herb

Introduced

94

Zoysia japonica Steud.

Poaceae

Herb

Native

95

Fallopia sachalinensis (F.Schmidt) Ronse Decr.

Polygonaceae

Herb

Native

96

Persicaria longiseta (Bruijn) Kitag.

Polygonaceae

Herb

Native

97

Polygonum aviculare L.

Polygonaceae

Herb

Native

98

Rumex crispus L.

Polygonaceae

Herb

Introduced

99

Rumex japonicus Houtt.

Polygonaceae

Herb

Native

100

Portulaca oleracea L.

Portulacaceae

Herb

Native

101

Lysimachia mauritiana Lam.

Primulaceae

Herb

Native

102

Ranunculus silerifolius H.Lév.

Ranunculaceae

Herb

Native

103

Rubus phoenicolasius Maxim.

Rosaceae

Shrub

Native

104

Lycopersicon esculentum Mill.

Solanaceae

Herb

Introduced

105

Solanum americanum Mill.

Solanaceae

Herb

Introduced

106

Camellia japonica L.

Theaceae

Shrub

Native

107

Viola kusanoana Makino

Violaceae

Herb

Native

108

Ampelopsis glandulosa (Wall.) Momiy. var. heterophylla (Thunb.) Momiy.

Vitaceae

Liana

Native

Temporal coverage

Notes: 

Sampling was conducted on several occasions in the period between 1947 and 2018.

Usage licence

Usage licence: 
Creative Commons Public Domain Waiver (CC-Zero)
IP rights notes: 

This work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License.

Data resources

Data package title: 
Vascular plant occurrences in Dokdo Islands, Korea, based on herbarium collections and legacy botanical literature.
Number of data sets: 
1
Data set name: 
Vascular plant occurrences in Dokdo Islands, Korea, based on herbarium collections and legacy botanical literature.
Data format: 
Darwin Core Archive
Description: 

The present project was focused on digitising the data on plant distribution on Dokdo Islands, collected between 1947 and 2018 by botanists taking part in occasional expeditions to the Islands. These data are expected to contribute to the biodiversity management and conservation of these highly inaccessible island ecosystems.

Column label Column description
occurrenceID An identifier for the Occurrence (as opposed to a particular digital record of the occurrence). In the absence of a persistent global unique identifier, construct one from a combination of identifiers in the record that will most closely make the occurrenceID globally unique.
recordedBy A list (concatenated and separated) of names of people, groups or organisations responsible for recording the original Occurrence. The primary collector or observer, especially the one who applies a personal identifier (recordNumber), should be listed first.
type The nature or genre of the resource.
basisOfRecord The specific nature of the data record.
institutionCode The name (or acronym) in use by the institution having custody of the object(s) or information referred to in the record.
recordNumber An identifier given to the Occurrence at the time it was recorded. Often serves as a link between field notes and an Occurrence record, such as a specimen collector's number.
day The integer day of the month on which the Event occurred.
month The integer month in which the Event occurred.
year The four-digit year in which the Event occurred, according to the Common Era Calendar.
eventDate The date-time or interval during which an Event occurred. For occurrences, this is the date-time when the event was recorded. Not suitable for a time in a geological context.
verbatimEventDate The verbatim original representation of the date and time information for an Event.
country The name of the country or major administrative unit in which the Location occurs.
countryCode The standard code for the country in which the Location occurs.
stateProvince The name of the next smaller administrative region than country (state, province, canton, department, region etc.) in which the Location occurs.
county The full, unabbreviated name of the next smaller administrative region than stateProvince (county, shire, department etc.) in which the Location occurs.
locality The specific description of the place. Less specific geographic information can be provided in other geographic terms (higherGeography, continent, country, stateProvince, county, municipality, waterBody, island, islandGroup). This term may contain information modified from the original to correct perceived errors or standardise the description.
decimalLatitude The geographic latitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic centre of a Location. Positive values are north of the Equator, negative values are south of it. Legal values lie between -90 and 90, inclusive.
decimalLongitude The geographic longitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic centre of a Location. Positive values are east of the Greenwich Meridian, negative values are west of it. Legal values lie between -180 and 180, inclusive.
geodeticDatum The ellipsoid, geodetic datum or spatial reference system (SRS) upon which the geographic coordinates given in decimalLatitude and decimalLongitude are based.
coordinateUncertaintyInMeters The horizontal distance (in metres) from the given decimalLatitude and decimalLongitude describing the smallest circle containing the whole of the Location. Leave the value empty if the uncertainty is unknown, cannot be estimated or is not applicable (because there are no coordinates). Zero is not a valid value for this term.
georeferencedBy A list (concatenated and separated) of names of people, groups or organisations who determined the georeference (spatial representation) for the Location.
identifiedBy A list (concatenated and separated) of names of people, groups or organisations who assigned the Taxon to the subject.
scientificName The full scientific name, with authorship and date information, if known. When forming part of an Identification, this should be the name in lowest level taxonomic rank that can be determined. This term should not contain identification qualifications, which should instead be supplied in the IdentificationQualifier term.
kingdom The full scientific name of the kingdom in which the taxon is classified.
phylum The full scientific name of the phylum or division in which the taxon is classified.
class The full scientific name of the class in which the taxon is classified.
order The full scientific name of the order in which the taxon is classified.
family The full scientific name of the family in which the taxon is classified.
taxonomicStatus The status of the use of the scientificName as a label for a taxon. Requires taxonomic opinion to define the scope of a taxon. Rules of priority then are used to define the taxonomic status of the nomenclature contained in that scope, combined with the expert's opinion. It must be linked to a specific taxonomic reference that defines the concept.
acceptedNameUsage The full name, with authorship and date information, if known, of the currently accepted taxon.
vernacularName A common or vernacular name.
genus The full scientific name of the genus in which the taxon is classified.
specificEpithet The name of the first or species epithet of the scientificName.
scientificNameAuthorship The authorship information for the scientificName formatted according to the conventions of the applicable nomenclaturalCode.
infraspecificEpithet The name of the lowest or terminal infraspecific epithet of the scientificName, excluding any rank designation.
taxonRank The taxonomic rank of the most specific name in the scientificName.
nomenclaturalCode The nomenclatural code (or codes in the case of an ambiregnal name) under which the scientificName is constructed.

Additional information

During the seventy years’ observation period (1947-2018), 108 taxa from 39 families were observed. Almost all were flowering plants (only one fern species and one conifer species were recorded), mostly Magnoliopsida (98%). This paper includes 91 specimens and 747 occurrence data of vascular plants recorded in Dokdo Islands regarding 108 taxa identified to infraspecific level. The confirmed species comprise 75 dicots and 31 monocots, one gymnosperm and a non-seed plant (Pteridophytes) species. Most species are native, including Cyrtomium falcatum (L.f.) C.Presl, Dianthus longicalyx Miq., Tetragonia tetragonoides (Pall.) Kuntze, Fallopia sachalinensis (F.Schmidt) Ronse Decr., Lysimachia mauritiana Lam., Sedum oryzifolium Makino, Corydalis heterocarpa Siebold & Zucc. var. japonica (Franch. & Sav.) Ohwi and Orobanche coerulescens Stephan (Fig. 2). The data collected during the last seven decades indicate continuous expansion of invasive species and increase in their richness (Fig. 3). For instance, Bromus catharticus Vahl, Sonchus asper (L.) Hill., Senecio vulgaris L., Setaria pumila (Poir.) Roem. & Schult. and Lycopersicon esculentum Mill. are the most rapidly expanding aliens in the last decade, threatening native flora (Table 2, Fig. 3). Park et al. (2017) identified increased human visitation as a major predictor of the spatial distribution of invasive species in the flora of Dokdo Islands, assuming a positive relationship between human activities and alien plant species richness. The major threatening species, especially the invasive grass, Bromus catharticus Vahl., affects several native species. Regarding the colonisation status, 14% of total species richness were invasive species and 86% were native to the Korean Peninsula and adjacent islands.

Figure 2.

Native species in Dokdo Islands.

aCyrtomium falcatum (L.f.) C.Presl  
bDianthus longicalyx Miq.  
cTetragonia tetragonoides (Pall.) Kuntze  
dFallopia sachalinensis (F.Schmidt) Ronse Decr.  
eCorydalis heterocarpa Siebold & Zucc. var. japonica (Franch. & Sav.) Ohwi  
fOrobanche coerulescens Stephan.  
Figure 3.  

Species richness (histogram, left) and percentage of invasive species (line, right) in Dokdo Islands.

Acknowledgements

We are grateful to the Korea National Arboretum for supporting and using the integrated publishing toolkit (IPT) server. This work was supported by grants of BIFA to Chin-Sung Chang (BIFA4_015).

References