MHA Herbarium: Collections of mosses from Yana-Indigirka Region, Yakutia, Russia

Abstract Background The Skvortsov Herbarium of the Tsitsin Main Botanical Garden, Russian Academy of Sciences (MHA) in the 1945-1980s dealt with vascular plants and only scattered occasional collections of bryophytes and lichens were accumulated there without special arrangement. Since the late 1980s, the bryophyte studies in the MHA Herbarium became permanent and several projects were started since then, including the currently conducted “Moss Flora of Russia”. There are many white spots on the map of bryophyte exploration of Russia, but one of the most conspicuous was Yakutia, the largest administrative unit of Russia, covering 3,081,000 km2. Yana-Indigirka Region, originally defined as a floristic region, includes Verkhoyansky Range and some smaller adjacent mountain areas. It is the largest amongst the bryofloristic regions in Russia, but exploration of its territory, which is difficult to access, remains far from complete. New information Several expeditions of the Institute for Biological Problems of Cryolithozone, Siberian Branch of Russian Academy of Sciences, and the Main Botanical Garden, Russian Academy of Sciences in 2000-2018 yielded in many bryophyte specimens, partly published in a number of papers. This dataset comprehensively represents the diversity of mosses of the Region. It includes 7,738 records of moss specimens preserved in the MHA Herbarium.


Introduction
Yana-Indigirka Region of Yakutia is an area defined by Karavaev (1958) for its mainly mountain region eastwards of Lena River and its largest right side tributary, the Aldan River. The original definition was only slightly modified by Kuznetsova (2005), but otherwise it remains in current use for biodiversity studies of Yakutia (Ivanova et al. 2005) and also it is used as one of subdivisions of Russian territory for the Moss Flora of Russia (Ignatov 2017, Ignatov 2018, Ignatov 2020) and its database (Ivanov et al. 2017). Covering over one million km , this floristic region is the largest amongst regions in both Yakutia and the whole of Russia. Accumulation of data on the moss flora of Yana-Indigirka Region of Yakutia started relatively late compared to its other parts, because early exploration of Yakutia was conducted either along the Arctic Ocean coast accessible by ships (Arnell 1913) or in Aldan Region in the southern Yakutia by expeditions of Kuzeneva and Prokhorov (Brotherus et al. 1916). Exploration of vegetation in many areas of Yakutia in the 1950-1980s brought scattered collections from many localities, but mostly of widespread moss species. In the 1980-1990s, bryofloristic studies became more numerous; their scope is overviewed by Ivanova et al. (2005). Collections accumulated in Herbaria of the Institute for Biological Problems of Cryolithozone, Siberian Branch of Russian Academy of Sciences (SASY) and Komarov Botanical Institute, Russian Academy of Sciences (LE). Since 2000, collаboration between Institute for Biological Problems of Cryolithozone SB RAS and the Main Botanical Garden, Russian Academy of Sciences started.

General description
Purpose: The general aim of the whole study was to fill a considerable gap in knowledge of moss diversity in the "cold pole" of the Northern Hemisphere. After preliminary studies, it turned out that many moss species in the huge permafrost area of Asia remained undescribed, being erroneously named by existing identification manuals of Europe, Japan and North America. The latter flora were based on local material and results in taxonomy, though carefully done, were inapplicable to the permafrost area of Yakutia. As usual, taxonomic studies require abundant material, from regions with as much diversity as possible. Therefore, a number of expeditions were further conducted in different areas of Yakutia in 2000-2018.  (Ignatov et al. 2001). Subsequent exploration Areas studied for moss floras in the Yana-Indigirka floristic region (Yyi). Each area includes a number of localities along 100-300 km field trips, with more exact collecting sites provided in respective publications for each of them: 1 Yudoma-Maya Plateau and Tarbagannakh Mountain (Ignatov et al. 2001); 2 Mus-Khaya Peak surroundings ( Ignatova et al. 2011); 3 Sette-Daban Range ; 4 Suntar-Khayata Nature Reserve ; 5 Ust-Nera area ; 6 Ulakhan-Chistai Range (Ignatova et al. 2020); 7 Orulgan Range around upper course of the Tumara River (Ignatov et al. 2014); 8 Yana-Adycha Plateau (Isakova 2010). resulted in a number of local moss flora, i.e. of Yana-Adycha Plateau (Isakova 2010), Mus-Khaya Peak surroundings (Ignatova et al. 2011), Orulgan Range (Ignatov et al. 2014), Suntar-Khayata Reserve , Sette-Daban Range , Ust-Nera area  and Ulakhan-Chistai Range (Ignatova et al. 2020). These main collecting localities are shown in Fig. 1. A brief description of the area is as follows. The severe continental climate of the Yana-Indigirka Region makes vegetation quite monotonous; thus, forests here are composed almost exclusively of Larix cajanderi Mayr. Picea obovata Ledeb. has just a few populations in the western part of Sette Daban Range (locality 3) and the southern part of the Region (locality 1). River banks have temporary stands of Populus suaveolens Fisch. and Salix arbutifolia Pall. and wet slopes have a limited occurrence of not very tall trees of Betula lanata (Regel) V.N. Vassil. Pinus pumila (Pall.) Regel thickets are common, but usually they are composed of shrubs lower than 1.5 m. Despite the low species diversity being found in many of the studied areas (as Larix forests are usually dry (Fig. 2), local conditions, make different areas quite distinct in their moss flora, due to different bedrock types and local climates.  Coordinates: 60°14'N -61°08'N; 135°00'E -138°18'E.

Project description
Collection localities were situated in Yudomo-Mayskoe Upland and in foothills of Sette-Daban Range; few collections were made during several short stops along Aldan River.
Habitats: Larix cajanderi forests; flood valley poplar stands; crooked birch forest communities along small creeks; rocks near waterfalls; rock-fields; soil banks, rock outcrops and cliffs; mires.  Bedrocks are mostly non-carbonate and include schists, aleurolites, sandstones, with granitoid intrusions and acid effusives. Rocks in the area are especially rich in heavy metals (Pb, Sn, As, Zn, Ag, Mn etc.), so rock fields look lifeless, with only scattered patches of mosses (Fig. 3).
Habitats: Larix cajanderi forests; mires and bogs (Sphagnum communities in wet tundra, at lake shores and in forests; springy fens and hummocks; Warnstorfia mires in wet Carex stans and Eriophorum polystachyon communities at low banks of small lakes); brook beds; dry lichen tundra; outcrops of various rocks. Steppe communities occur on S-facing steep slopes (Fig. 4).  Bedrocks: sandstones (with occasional calcareous layers), aleurolites, argillites and schists.
Habitats: Larix cajanderi forests; tundra communities; rock-fields and rock outcrops; steppe slopes; flat sedge mires with shallow water from melting permafrost (Fig. 9) and reindeer pastures (Fig. 10).  Tumara River upper course: extensive flat community of Carex stans Drejer and Eriophorum angustifolium Honck., wet due to permafrost melting, providing habitats for Saxifraga hirculus L. and Meesia hexasticha. Locality 7, 1200 m a.s.l. Photo of M.S. Ignatov (2011). and easternmost flanks are formed by pure calcareous ridges. In the west, the Setter-Daban Range faces the Lena River Valley and its main right side tributary, the Aldan River. In the east, the calcareous area, the Mramornaya (Marble) Mountain is a part of the Ulakhan-Chistai Range. Interestingly, these two calcareous regions are the only areas in Eurasia where the 'living fossil', the relic monospecific genus, family, order, class and division, Andreaeobryum macrosporum Steere & B.M. Murray (Murray 1988, Goffinet et al. 2009), has been discovered. This moss was first collected only in 1974, in Alaska and then described by Steere and Murray 1976 and later found in a few other localities in Alaska, USA and adjacent parts of Canada, in the Yukon, the westernmost Northwest Territories and northern British Columbia (Eckel 2007). In 2015, it was collected in Yakutia, ca. 3000 km from its closest localities in North America ) and subsequent intentional search elucidated its distribution in Eurasia ).
Other highly isolated populations of mosses, with disjunction more than 1000 km, expand the ranges of many species, for example, Blindiadelphus subimmersus (Lindb.  Recently described taxa and still not searchable in GBIF (https://www.gbif.org/species/ search, accessed 10 October 2021) comprise an addition to it; those are marked by asterisk (see below).
A large collection from the area allowed us to undertake taxonomic revisions, revealing previously undescribed species: Barbula jacutica Ignatova  This is not totally unexpected, but the fact that undescribed species appeared to be so numerous and some of them are common and widespread in Yakutia, exceeds our expectations. Therefore, it is obvious that further studies in the area will bring numerous very interesting additions to the present collection of data (Ignatov et al. 2021).

Data format: Darwin Core
Description: Yana-Indgrirka physiographic region of Yakutia, Russia includes Verkhoyanky Range and some smaller mountain areas; it is one of the largest regions, thus it attracted special attention of bryologists. Several expeditions in 2000-2018 yielded many bryophyte specimens; these data were partly published in a number of papers, but never summarised. This dataset comprehensively represents the diversity of the region. It includes 7,738 records of specimens preserved in the MHA Herbarium.

Column label Column description
occurrenceID An identifier for the Occurrence (as opposed to a particular digital record of the occurrence). A variable that will most closely make the occurrenceID globally unique. A barcode is used for the MHA Herbarium accessions (for example, "MHA9000139").

dcterms:type
The nature or genre of the resource. A constant ("Dataset").

dcterms:modified
The most recent date-time on which the resource was changed. A constant ("17-09-2021").

dcterms:language
A language of the resource. A constant ("en | ru"). English is used throughout and Russian verbatim text is left in "habitat", "county" and "verbatimLocality" fields.  The name of the continent in which the location occurs. A constant ("Asia"). country The name of the country or major administrative unit in which the location occurs.
A constant ("Russian Federation"). countryCode The standard code for the country in which the location occurs. A constant ("RU"). stateProvince The name of the next smaller administrative region than country (state, province, canton, department, region etc.) in which the location occurs. A constant ("Republic of Sakha (Yakutia)").

county
The full, unabbreviated name of the next smaller administrative region than stateProvince (county, shire, department etc.) in which the Location occurs. A variable, in Russian (for example, "Томпонский улус").

minimumElevationInMetres
The lower limit of the range of elevation (altitude, usually above sea level), in metres. De facto, a single figure available on the label is given. A variable (for example, "470"). decimalLatitude The geographic latitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic centre of a location. A variable (for example, "63.0417"). decimalLongitude The geographic longitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic centre of a location. A variable (for example, "137.95") geodeticDatum The ellipsoid, geodetic datum or spatial reference system (SRS) upon which the geographic coordinates given in decimalLatitude and decimalLongitude are based.
coordinateUncertaintyInMetres The horizontal distance (in metres) from the given decimalLatitude and decimalLongitude describing the smallest circle containing the whole of the location. A variable (for example, "1000").
coordinatePrecision A decimal representation of the precision of the coordinates given in the decimalLatitude and decimalLongitude. A constant ("0.0001").
georeferenceRemarks Notes or comments about the spatial description determination, explaining assumptions made in addition or opposition to the those formalised in the method referred to in georeferenceProtocol. A variable (for example, "by map by Pisarenko").
identifiedBy A list (concatenated and separated) of names of people, groups or organisations who assigned the Taxon to the subject. A variable (for example, "Ignatova E.A."). scientificName The full scientific name, with authorship and date information, if known. A variable (for example, "Abietinella abietina (Hedw.) M.Fleisch."). kingdom The full scientific name of the kingdom in which the taxon is classified. A constant ("Plantae"). phylum The full scientific name of the phylum or division in which the taxon is classified. A constant ("Bryophyta"). taxonRank The taxonomic rank of the most specific name in the scientificName. A variable (four options: "species", "subspecies", "variety", "genus"). taxonomicStatus The status of the use of the scientificName as a label for a taxon. A constant ("accepted").