Bryophyte flora of Gayasan Mountain National Park in Korea

Field surveys

Our collections were carried out in habitats with a high diversity of bryophytes, such as wet habitats near stream beds, more or less dry rocks, bark of forest trees, and exposed stony fields and shaded cliffs near some mountain tops (Figs. 1, 2). We conducted a total of 18 field surveys from April 2009 to November 2016 at various sites in the park (Table 1).

Fig. 1.

The position of Gayasan Mountain within Korean Peninsula and the surveyed routes in this study.

Fig. 2.

Habitats of Gayasan Mountain. A. Sangwangbong (peak). B. Northern slope of Sangwangbong. C. Cliffs near Sangwangbong. D. Low part of Hongryudong valley. E. Middle part of Hongryudong valley. F. Baegundong valley.

Table 1.

Surveyed locals and dates of Gayasan Mountain.

All specimens were collected in newspaper or acid-free paper, and collection date, geographical coordinates, field herbarium numbers, collector names, preliminary species name, substrates, and habitats were recorded in the field. The collected materials were air-dried in the laboratory, and some species were cultivated in the greenhouse. All specimens were deposited in the Jeonbuk National University Herbarium (JNU) and National Institute of Biological Resources Herbarium (KB).

Latitude and longitudinal fractional composition

The treatment of latitudinal and longitudinal types basically follows to Konstantinova (2000) and Bakalin (2010). The distribution of each species was identified in a three-dimensional grid, from the Arctic to Tropical, from East Asian to Circumpolar, and its tendency to be distributed in mountainous areas. Nine latitudinal types of elements and eleven longitudinal types of habitat (area types) were identified to classify the distribution species. For the analysis of the distribution characteristics of bryophytes, their world distribution was obtained from Noguchi (1987, 1988, 1989, 1991, 1994), Gao et al. (1999, 2003), Lawton (1999), Li et al. (2001, 2007), Wu et al. (2002, 2005, 2011), Hu et al. (2008), and Korean distribution was obtained from Choe (1980), Kim and Hwang (1991), Kim (1991), and Bakalin (2010), Park (2020).

Number of bryophyte taxa and liverwort index

The liverwort index, which is based on the character that liverworts and hornworts tend to prefer more humid conditions than mosses do, was calculated as follows (Nakanishi, 2001):

Bryophyte flora

On the basis of an inspection of 903 herbarium specimens, we found that the bryophyte flora of the Gayasan Mountain includes 204 taxa belonging to 57 families, 106 genera, 199 species, 2 subspecies, and 3 varieties (Table 2). Among these, there were 115 taxa of Bryophyta (33 families, 67 genera, 111 species, 2 subspecies, and 2 varieties) and 89 taxa of Marchantiophyta (24 families, 39 genera, 88 species, and 1 variety). This is equivalent to 18.1% of the 1,121 taxa (346 liverworts and 775 mosses) recorded on the Korean Peninsula (Kim et al., 2020). Among the species identified, 145 taxa are newly recorded in the Gayasan Mountain (Appendix 1).

Table 2.

Summary of Bryophyte flora of Gayasan Mountain National Park.

Comparison of bryophyte species richness and liverwort indices

Compared with recently studied bryophyte flora [Taebaeksan Mountain (Bum et al., 2020), Deogyusan Mountain (Yoon et al., 2011; Choi et al., 2013), Hallasan Mountain (Yim, 2012), and Sobaeksan Mountain (Choi et al., 2016)], Gayasan Mountain is characterized the lowest number of species (204 species), although the second highest number of taxa (2.67) on an area basis. The comparatively small number of species can be ascribed to the fact that although the Gayasan Mountain includes a variety of habitats, including different parent rocks (Precambrian biotite gneiss, semi-phalangeal gneiss, Ileal rock, and Cretaceous Haeinsa granite), some coniferous forests near the peaks, and small and large valleys (the Hongryudong and Baegundong valleys), the area cover covered in relatively small. Furthermore, according to the liverwort index, which indicates the degree of humidity in a surveyed area, Gayasan Mountain (43.6%) was found to be the wettest among the aforementioned areas (Sobaeksan Mountain 41.9%, Deogyusan Mountain 40.8%, and Taebaeksan Mountain 39.0%) (Table 3).

Table 3.

Comparison of the bryophyte species richness levels and liverwort indexes in other localities and Gayasan Mountain National Park.

The latitudinal and longitudinal distribution of floristic elements among bryophytes of the Gayasan Mountain

Analysis of floristic elements based on latitude (Table 4) revealed that 54 taxa (26.5%) are boreal temperate, 45 (22.1%) temperate, 39 (19.1%) temperate–subtropical, 20 (9.8%) multizonal, 14 (6.9%) subtropical, 11 (5.4%) subtropical–tropical, 9 (4.4%) boreal, 8 (3.9%) arctic–boreal, and 4 (1.9%) arctic species. Compared with the latitudinal distribution characteristics of the Korean Peninsula bryophyte flora, the bryophyte flora of the Gayasan Mountain is characterized by temperate–subtropical (+6.5%) and temperate (+1.4%) taxa, and the lowest numbers of boreal temperate taxa (−2.1%) and subtropical (−1.8%), boreal (−1.6%), arctic-boreal (−1.4%), subtropical-tropical (−0.5%), arctic (−0.4%), and multizonal (−0.1%) species. It is assumed that these distribution patterns are attributable to the geographical location of the Gayasan Mountain, as well as increases in the numbers of temperate–subtropical and temperate plants in the lower regions of the valleys within the Gayasan Mountain range.

Table 4.

The latitude fractional composition in Gayasan Mountain with Korean Bryophyte.

Analysis of the floristic elements based on longitude (Table 5) indicated that 84 taxa (41.2%) are of Eastern Asian distribution, 48 (23.5%) circumpolar, 24 (11.8%) multi-areal, 9 (4.4) Eastern Asia–American, 7 (3.4%) Asia–American, 4 (1.2) Asia–Europe and Amphipacific, and 3 (1.5%) Amphioceanic, with a further single species (0.5%) showing a disjunctive distribution. Compared with the longitudinal distribution characteristics of the Korean Peninsula bryophyte flora, that of the Gayasan Mountain is characterized by Eastern Asian and Asia–American (+1.9%), Asia–European (+1.4%), Amphipacific (+0.8), Eastern Asia–American (+0.7), and Asian mult-iareal (+0.6) taxa, with the lowest numbers of Circumpolar taxa (−5.3%), and disjunctive (−1.6%), Amphioceanic (−0.7%), and Southeast Asian (−0.1%) species. These findings thus clearly indicate that the flora of the Gayasan Mountain region of the Korean Peninsula is of an Eastern Asian type (Takhtajan, 1986).

Table 5.

The latitude fractional composition in Gayasan Mountain with Korean Bryophyte.

Comparisons with previous studies on the bryophyte flora of the Gayasan Mountain

The Gayasan Mountain were included in the areas investigated as part of an inventory of mosses distributed in the Korean Peninsula conducted by Kashimura (1939, 1940), who published a checklist on Korean mosses, which included 15 taxa (Andreaea rupestris var. fauriei, Pogonatum inflexum, Bryoxiphium norvegicum subsp. japonicum, Bryum argenteum, Plagiomnium acutum, Rhizomnium punctatum, Hedwigia ciliata, Boulaya mittenii, Myuroclada maximowiczii, Meteorium buchananii subsp. helminthocladulum, Rhytidium rugosum, Entodon flavescens, Homalia trichomanoides, Eumyurium sinicum, Anomodon rugelii) recorded in the Gayasan Mountain. Subsequently, Choe (1980) published a manual on Korean Bryophytes, which included 12 taxa (Andreaea rupestris var. fauriei, Hedwigia ciliata, Eumyurium sinicum, Anomodon giraldii, Anomodon rugelii, Boulaya mittenii, Trichocoleopsis sacculata, Jungermannia exsertifolia subsp. cordifolia, Plagiochila hakkodensis, Cephaloziella spinicaulis, Frullania diversitexta, Frullania inflata) recorded in the Gayasan Mountain, whereas Hong (1966) reported 20 taxa on Gayasan Mountain as part of an inventory of the liverworts of the Korean Peninsula. The first of the surveys described herein conducted by Song and Yamada (2009) focused on liverworts, during which 38 taxa were recorded, two (Frullania aoshimensis and Radula oyamensis) of which were recorded from the Korean Peninsula for the first time. A further analysis of records in the previous literature raised the total number of taxa to 58, and on the basis of subsequent literature and survey studies, the total number of taxa currently stands at 204 (115 mosses and 89 liverworts).

Notable species

The most noteworthy species identified during the course of surveying are Hattoria yakushimensis (Horik.) R. M. Schust., Nipponolejeunea pilifera (Steph.) S. Hatt., Drepanolejeunea angustifolia (Mitt.) Grolle, and Lejeunea otiana S. Hatt. which are rarely found in Korea, as well as Cylindrocolea recurvifolia (Steph.) Inoue, the population size of which on Gayasan Mountain is the largest among those recorded to date on Korean Mountains. Additionally, a further notable species is Pogonatum contortum (Menzies ex Brid.) Lesq., a rare bryophyte that grow in high-altitude areas (in excess of 1,000 m) (Fig. 3).

Fig. 3.

Notable species of Gayasan Mountain in Korean flora. A. Hattoria yakushimensis (Horik.) R. M. Schust. B. Nipponolejeunea pilifera (Steph.) S. Hatt. C. Drepanolejeunea angustifolia (Mitt.) Grolle. D. Lejeuena otiana S. Hatt. E. Cylindrocolea recurvifolia (Steph.) Inoue. F. Pogonatum contortum (Menzies ex Brid.) Lesq.

Hattoria yakushimensis was previously reported near the Sangwangbong Peak of Gayasan Mountain as a hitherto unrecorded species in Korea (Choi et al., 2011). This species is endemic to East Asia with a narrow distribution range (Japan and China) and is listed by the International Union for Conservation of Nature as a vulnerable (VU) species. In the present study, we also found H. yakushimensis on a cliff near the peak at an elevation of 1,313–1,350 m, where it grows with Drepanolejeunea angustifolia, Plectocolea erecta, and Marsupella tubulosa.

Nipponolejeunea pilifera, which is characterized by long cilia along the leaf dorsal lobe margin, is sparsely distributed in Japan, China, and the southernmost Russian Far East. In Korea, it has previously been recorded in Deogyusan Mountain and Jirisan Mountain (Choi et al., unpubl. data). In the present study, we found it on the edge of Abies koreana E. H. Wilson forest near the northern face between the peaks Sangwangbong and Chilbulbong. This species grows with Frullania appendiculata, Frullania usamienesis, and Bazzania denudata.

Drepanolejeunea angustifolia is mainly distributed in subtropical and tropical regions (Bhutan, Cambodia, China, India, Indonesia, Japan, New Caledonia, Papua New Guinea, The Philippines, Sri Lanka, Thailand, and Vietnam) (Zhu and So, 2001). This bryophyte was previously reported near the Sangwangbong peak of Gayasan Mountain as an unrecorded species in Korea and has more recently been found in Jirisan Mountain, Hallasan Mountain, and Sobaeksan Mountain (Choi et al., 2012; Choi et al., unpubl. data). It is characterized by bifid underleaves, curved entire leaf margins, and 1 to 2 ocelli in the dorsal leaf lobe base, and found on shaded wet cliffs covering thin soil, along with Plectocolea erecta, Marsupella tubulosa, and Hattoria yakushimensis.

Lejeunea otiana has previously been collected in small caves near the Hongryudong Valley of Gayasan Mountain, at the time of which it was an unrecorded species in Korea (Choi et al., 2012). This species is distributed in Japan and the Korean islands of Jejudo and Gageodo (Choi et al., unpubl. data). In the present study, we also found specimens in a small cave in the same area. This species grows on shaded wet cliffs along with Acanthocoleus yoshinaganus, Conocephalum salebrosum, and Conocephalum japonicum.

Cylindrocolea recurvifolia is distributed in Eastern Asian temperate regions (Japan and China), southward spreading to Indochina, and in Korea has previously been recorded in the Seolaksan, Gyeryongsan, Naejangsan, Naebyeonsan, Duryunsan, and Weolchulsan mountains and the islands of Oerarodo and Jejudo, However, the patches found near the Hongryudong Valley in the present study are, of the largest size of our knowledge, the largest that have been recorded to date. We accordingly believe that it is necessary to promote, protect, and appropriately manage the Hongryudong Valley, for example, by installing information boards in this area.

Pogonatum contortum is distributed in Eastern Asia–American temperate regions (Japan, China, India, Far East Russia, and North America) and the Keumgangsan, Seolaksan, Jirisan, and Hallasan regions of Korea at elevations greater than 1,000 m. We found it growing on slightly shaded wet soil near the northern face running from between the peaks of Sangwangbong and Chilbulbong. This species is characterized by a deep green foliage, the leaves of which are slightly curved when dried.