Topography of Mount Sibayak is commonly wavy to steep, and some areas are flat. The liverwort specimens were collected at seven study sites Figure 1: 1
Sibolangit campground: ca. 870 m, a recreation area and for camping ground with open vegetation; 2 Jagawana: 880-980 m, has a primary forest and river, 3 Pasir
Putih: ca. 856-935 m, has river, primary and secondary forest, and some area has been open; 4 Dwiwarna waterfall: ca.1027-1152 m, with primary forest; 5
Panatapan: ca.1250-1300 m, secondary forest; 6 Lau Debuk-debuk: ca. 1421- 1572 m, has secondary forest, and planted areas; 7 Brastagi to the summit of
Mount Sibayak: ca. 1421-2000 m, with primary forest and some open areas.
3. 2 Sampling Method
The exploration for collecting liverwort specimens was carried out in November 2011, April 2012, September 2012, October 2012, and June 2013.
Survey explorations were carried out along the tracks in each study sites one track for each location.
On each track, samples were taken at 10 m to the left and 10 m to the right of track. Sample collections were also carried along the river bank and around the
waterfalls. Samples were collected used sharp knife from many substrats such as soils, tree trunks, rocks, rotten logs, and living leaves. For ephyphytes, samples
were collected from the base to 2 meters of tree trunk height. The specimen collected were packed separately as much as possible, either in the field or
directly after returning from the field when the specimens are still fresh
– unless the species are too small to allow separation in the field.
Morphological characters in the field were observed used handlens 10-20 x magnification. Samples collected were put into paper envelopes, or small plastic
bags. Each specimens received a collection number. All information gathered on the specimens were written in the field notebook. Characteristics of the living
liverworts such as color, growth form were noted. The data recorded from habitat were: the kind of substrat, localities and altitudinal measured using altimetre.
GPS Global Positioning System was used for recording the coordinates of the collecting sites.
Specimens were cleaned as well as possible. In order to dry the samples, the envelopes containing leafy liverwort sample were opened and placed on a table or
floor in a dry place without strong air currents. The envelope may also be packed in a broad weave sack or bag and hung in a well-ventilated area. Thalloid
liverworts were pressed and the paper replaced daily. Some living samples were kept for studying the oil bodies, or to facilitate the observation of several
characteristics, especially in Marchantia. For this purpose, a small portion of the sample were kept in plastic and kept cool but not frozen and examined under
the microscope as soon as possible within a few days. Dried samples were placed into clean paper envelopes. Very small samples were placed in tiny paper
envelopes and then placed into standard size herbarium envelopes to avoid loss of material Gradstein 2011. The survey yielded about 900 specimens of liverworts,
from 870 to 2000 m elevation. The specimens were deposited at Herbarium Bogoriense BO, Herbarium of Biology Department University of Sumatra
Utara, herbarium of Biology Department Bogor Agricultural University, and Herbarium SEAMEO BIOTROP BIOT.
3.3 Identification
Specimens collected were identified using both keys and descriptions from available taxonomic literatures, mainly Gradstein 2011, and other publications
of Malesian and Tropical Asian liverworts, such as Mizutani 1961, Yamada 1979, Inoue 1984, Bishler-Causse 1989, Gradstein et al. 2002, Zhu and
Gradstein 2005. Identification was done based on morphological characters using microscope in the laboratory of Plant Taxonomy, Biology Departement,
Bogor Agricultural University. Specimens were observed, measured and used a camera for documentation of species.
Some important morphological characters were used in identification of liverworts were:
Thalloid liverworts: 1 Thallus: width, margin colour, structure, median band.
2 Scales: appendage of median scales length, width, structure of margin and apex, colour, marginal cells.
3 Cupules: ciliate lobes or ciliate length of cilia, width of cilia basally. 4 Archegonium: archegoniophore stalk length, colour of scales; receptacle
diameter, lobes shape apically, structure of dorsal surface, median projection, involucres position and colour.
Leafy liverworts: 1 Shoots: width, length. Shoot width is the width between opposite leaf apices.
2 Leaf lobes: arrangement, size, shape, base, margin, apex, trigones. Leaf length is measured as the distance from the basal insertion of the leaf on the stem to
the apex of the leaf lobe. Leaf width is measured parallel to the stem and is the distance from the apical insertion of the free margin of the lobule on the
ventral lobe margin to the dorsal margin of the lobe.
Figure 2 Method of measurement in Thysananthus Sukkharak 2015. A. Leaf,
ventral view; d = dorsal leaf margin, f = lobule free margin, k = keel, l = leaf length, lb = lobule length, t1,2 = lobule teeth, u = auricle, v =
ventral leaf margin, w = leaf width, wb = lobule width. B. Underleaf, ventral view; l = underleaf length, w = underleaf width. C. Perianth,
ventral view; b = beak, l = perianth length, w = perianth width.
3 Leaf lobules: arrangement, size wide, long, shape, base, margin, apex, keel, and teeth. Lobule length is the distance from the basal insertion of leaf on the
stem to the apex of lobule. Lobule width is the widest distance from keel to free margin measured parallel to the stem Fig. 2A.
4 Underleaves: size, margin, apex. Underleaf length is the distance from the mid- basal insertion of underleaf to the middle of apex. The width is arbitrarily
chosen as the widest dimension of the underleaves Fig. 2B. 5 Androecia: position on the shoots, bracts number
6 Archegonia: position on the shoots, bracts number, size, perianth size, shape, margin, apex. Female bracts were measured as leaves while bracteoles were
measured as underleaves. Perianth length is the distance from the mid-basal insertion of perianth at the innovation to the base of the beak. Perianth width is
arbitratily chosen as the widest distance of the perianth Fig. 2C. Botanical terms used for liverworts in the study are in glossary.
3.4 Data Analysis 3.4.1 Diversity and distribution of species
1 Checklist of the species was conducted based on recently collected specimens of liverworts from Mount Sibayak and four addition specimens deposited in
BO collected from North Sumatra. 2 Distribution of species on substrate: all substrate of liverworts found were
reported. 3 Local distribution: the occurence of species in the study site, the species
diversity of study site were composed base on the number of species. 4 Altitudinal distribution: the altitudinal range based on Whitten et al. 1984:
lowland forest 0 –1200 m, lower montane forest 1200–2100 m, upper
montane forest 2100 –3000m, and sub alpine forest more than 3000 m.
5 Geographical distribution: the distribution data of species were collected from distribution note of the species in revision and floristic publications, such as
Ariyanti and Gradstein 2007, Piippo 1994, Gradstein et al. 2002, Haerida et al. 2010, Inoue 1984, Kitagawa 1977, Kitagawa 1979, Lee 2013,
Mizutani 1961, So 2001, So and Grolle 2000, Yamada 1979, Zhu and So 2001, Zhu and Gradstein 2005. The data were used to clarify species to
the geographical distribution type prepared by Hyvonen 1989.
3.4.2 Taxonomic studies of particular taxa
The study were based on the recently collected specimens of particular taxa Marchantia, subfamily Ptychanthoideae, Plagiochila and Radula collected from
Mount Sibayak and specimens collected from North Sumatra deposited in BO Siregar et al. 2013, 2014. Descriptions, nomenclatures, and identification keys
for each species of particular taxa occuring at the Mount Sibayak were provided. Descriptions were based on the morphological characters observed. Description
and identification key of Marchantia modified from Bischler-Causse 1989; subfamily Ptychanthoideae followed Gradstein et al. 2002, Zhu and Gradstein
2005, Haerida et al. 2010, and Sukkharak 2015; Plagiochila followed Inoue 1984; Radula followed Yamada 1979.
