New data on aphyllophoroid fungi (Basidiomycota) in forest-steppe communities of the Lipetsk region, European Russia

The data on 150 species of aphyllophoroid fungi from the Lipetsk region, Central Russian Upland, European Russia, are presented. The annotated species list based on the herbarium collections (LE, OHHI) and observations in the Galichya Gora Nature Reserve and in the Oleniy Nature Park, including 53 newly identified species in the Lipetsk region, is provided. The species Acanthophysellum minor was registered for the first time in Russia. Athelia nivea and Vuilleminia megalospora were observed only for the second time in the whole country. New data on ecology and distribution of species, such as Ceratobasidium cornigerum, Fibrodontia gossypina, Lindtneria panphyliensis, Peniophora lilacea, Phanerochaete aculeata, Phellinus rhamni, Sistotrema alboluteum, Vararia ochroleuca, and Xylodon tuberculatus, little-known in European Russia, are reported.


Introduction
The nontaxonomic group of basidiomycetes, the central focus of our research and historically named the aphyllophoroid fungi, is characterized by nongilled hymenophores, which include several morphological types, such as polypores, hydnoids, corticioids, and clavarioids [1]. They have been confirmed to play a crucial role in dead wood degradation in forest ecosystems (the large number of known species are saproxylic), in addition to participating in trophic chains, mutualistic relationships, and the formation of microhabitats [2,3]. A number of species have been proven good indicators of oldgrowth forests and can be used as an evidence for establishing a protected area [4,5].
The forest-steppe zone of European Russia is a natural area that has not been sufficiently studied in respect of the species composition and ecological features of the aphyllophoroid fungi. The Lipetsk region is an area of the forest-steppe zone, which has a rather long history of mycobiota studies primarily devoted to diversity and phenology of macromycetes [6][7][8][9][10][11][12]. Moreover, the purposeful research of aphyllophoroid fungi has been recently initiated in this region [13]. To date, the mycobiota of the region DOI: 10.5586/am.1112 Digital signature This PDF has been certified using digital signature with a trusted timestamp to assure its origin and integrity. A verification trust dialog appears on the PDF document when it is opened in a compatible PDF reader. Certificate properties provide further details such as certification time and a signing reason in case any alterations made to the final content. If the certificate is missing or invalid it is recommended to verify the article on the journal website.
includes 204 species of aphyllophoroid basidiomycetes, of which 14 species are listed in the regional Red data book [14].
The aim of our study was to widen knowledge on the species diversity and substrate preferences of aphyllophoroid basidiomycetes in forest-steppe communities of the Lipetsk region.
Because most of the territory of the Lipetsk region has been disturbed over the last century, natural forest-steppe communities have been preserved only as local fragments with nature conservation status. Most of these fragments are included in the Galichya Gora Nature Reserve, which is the core of a network of regional protected areas. It occupies an area of 2.3 km 2 and consists of six separate parts (Fig. 1).
The landscape of the territory is quite heterogeneous. It includes upland steppe and forest zones based on Devonian limestone outcrops (Fig. 2, Fig. 3), rugged by the Bystraya Sosna River valley, its feeders and gullies, and partially by the Don River valley. The reserve is covered with deciduous forest communities formed by Quercus robur, Tilia cordata, and Acer platanoides as dominant species with Betula pendula and Populus tremula as primary species, and undergrowth, which are typical for the Central Russian Upland [15].
Besides the Galichya Gora Nature Reserve, the Oleniy Nature Park was explored and should be mentioned as one of the largest and youngest protected areas in the Lipetsk region.

Material and methods
Our results are based on field trips to a number of protected areas in the Lipetsk region with forest-steppe vegetation in the Galichya Gora Nature Reserve and the Oleniy Nature Park in September 2016.
Material was collected from five areas according to the classical route method (Fig. 1). The Morozova Gora protected area is located on the east side of the Don River valley and covers approximately 3 km 2 . The major part of it is a plain (600 m at its widest), which becomes narrower and forms a valley while going from the north to the south. The vegetation comprises fragments of upland oak and birch forests, floodplain willow forests, meadows, and stipe-herb steppe fragments.
The Plyushchan protected area was originally a forest plot on the west side of the Don River valley, rugged by the twisting Plyushchan River from the south to the east, which surrounds the limestone-cliff valley sides. The vegetation cover mostly consists of oak and birch forests, floodplain willow forests, herb-rich steppe fragments, and pine plantings.
Two areas -the Voronov Kamen and the Vorgolskoye -lie on the right side of the Vorgol River. Its valley has a canyon-like appearance and limestone-cliff outcrops are quite usual along the riverside. The typical vegetation cover types for these areas are upland lime tree and oak forests and fragments of floodplain willow forests [10].
The Oleniy Nature Park is protected separately from the Galichya Gora Reserve and is located near the villages of Nikolskoye and Sukhodol in the Krasninskiy District of the Lipetsk region. It covers over 12 km 2 and most of the territory is occupied by agricultural land, interlaced with gullies and ravines, where different meadow and steppe associations have formed. In addition, ravine oak and birch forests, blackthorn bushes, and shelter belts are widely represented. Some admixtures of garden trees are also found [10]. The identification of basidiomata specimens was made using the LOMO Micmed-6 and the Carl Zeiss AxioImager A1 light microscopes, and with the standard set of chemical solutions (5% KOH, Melzer's reagent, Cotton Blue).

Results
For each species in the annotated list, references to specimens deposited in the herbarium of Komarov Botanical Institute, St. Petersburg (LE) and the mycological collection in the Khitrovo Herbarium of the Turgenev Oryol State University (OHHI) are provided. The list was organized according to up-to-date taxonomic data [16,17]; each note contained data on the substrate and the type of forest community. Species new to the Lipetsk region were marked with an asterisk. Names of taxa and authors were given

Discussion
A total of 150 species of aphyllophoroid fungi were listed for the Lipetsk region, including 53 species registered for the region for the first time and Acanthophysellum minor as a new species in Russia. According to Bernicchia and Gorjón [19], A. minor is also known from the Mediterranean Basin (Spain, Portugal), Central Europe (Croatia), and the Caucasus (Iran). Among the species new to the region, attention was particularly attracted by Athelia nivea and Vuilleminia megalospora, which were observed only for the second time in Russia. Both species were known prior to this study only from the Leningrad region [20,21]. The species Athelia nivea is generally considered a member the A. epiphylla species complex, but is distinguished from other species of the complex (e.g., A. epiphylla s. str., A. ovata) by frequent clamps on subicular hyphae. The known distribution of A. nivea in Europe covers the Czech Republic, Germany, Slovakia, Sweden, and the United Kingdom [22]. Our finding of Vuilleminia megalospora on Quercus robur from the forest-steppe zone of European Russia is congruent with available data on occurrences and ecological requirements of the species being found on hardwoods like Quercus and Crataegus in Croatia, France, Greece, Italy, Macedonia, Slovakia, Spain, and Iran [19,23]. Two other species have been found for the second time within the European part of Russia, in particular, Fibrodontia gossypina, known from the Komi Republic [24], and Sistotrema alboluteum, reported from the Nizhny Novgorod region [25]. Both species have a widespread but scattered distribution in Europe [19,26]. Ceratobasidium cornigerum, Peniophora lilacea, Xylodon tuberculatus are also little known in the European Russia, and each species has been recorded from no more than three localities [27].
Other remarkable records of aphyllophoroid fungi revealed by this study were Phellinus rhamni and Vararia ochroleuca. Phellinus rhamni found on dry standing stems of Frangula alnus was registered for the second time in the Central Russian Upland after collection from the Bryansk Region [28]. This is a diagnostic species of forest communities in Central and Eastern Europe associated primarily with some members of the family Rhamnaceae. The recording of Vararia ochroleuca is also the second on the territory of the Central Russian Upland, where the species was collected earlier from the Oryol region [29].
The peculiarity of the biota of the revealed aphyllophoroid fungi was characterized by the findings of some species exclusively associated with broad-leaved trees and distributed in nemoral zone. Such species as Lindtneria panphyliensis and Phanerochaete aculeata listed particularly for the Oleniy Nature Park [13], were known previously in European Russia only from the forest-steppe communities of the Oryol region [30].
The highest number of aphyllophoroid fungi species was found on the woods of Quercus robur, Acer platanoides, and Betula pendula (Fig. 4). Substrate units occupied by several species of fungi were revealed simultaneously not only among large-scale forest-forming trees, but also among less frequently found substrates, for instance, dead basidiomata of polypores. In total, five species (Gloeoporus pannocinctus, Peniophorella pubera, Phanerochaete aculeata, Sistotrema brinkmannii, Trechispora cohaerens) were collected from dead basidiomata of Fomes fomentarius.
New localities for three species of aphyllophoroid fungi protected in the Lipetsk region were registered during the mycological survey: Hericium coralloides, which has an official conservation status in the Lipetsk region [14], as well as Donkia pulcherrima, and Metuloidea fragrans are included to the monitoring list and recommended for observational studies on their distribution and ecological features in the region.