The invertebrate fauna of anthropogenic soils in the High-Arctic settlement of Barentsburg, Svalbard

The effects of different bioremediation methods on restoration of the oil-polluted peat soil (Histosol) in the northernmost taiga subzone of European Russia was studied. The population dynamics of microorganisms belonging to different trophic groups (hydrocarbon-oxidizing, ammonifying, nitrifying, and oligonitrophilic) were analyzed together with data on the soil enzyme (catalase and dehydrogenase) activities, population densities of soil microfauna groups, their structures, and states of phytocenoses during a sevenyear-long succession. The remediation with biopreparations Roder composed of oil-oxidizing microorganisms-Roder with Rhodococcus rubber and R. erythropolis and Universal with Rhodotorula glutinis and Rhodococcus sp.-was more efficient than the agrochemical and technical remediation. It was concluded that the biopreparations activate microbiological oil destruction, thereby accelerating restoration succession of phytocenosis and zoocenosis. The succession of dominant microfauna groups was observed: the dipteran larvae and Mesostigmata mites predominant at the early stages were replaced by collembolans at later stages. The pioneer oribatid mite species were Tectocepheus velatus, Oppiella nova, Liochthonius sellnicki, Oribatula tibialis, and Eupelops sp.

Oribatid mites are distinguished by high taxonomic diversity and abundance in almost all natural zones; they are used as an indicator group of microarthropods in the study of natural landscapes and anthropogenically disturbed ecosystems. In the karst landscapes of the North, the oribatid mites are very poorly studied. The aim of this study was to investigate the diversity of soil types, plant communities, and oribatid mites in karst relief forms in the conditions of the northern taiga forests. The material was collected in July 2020 in the karst landscapes of Timan Ridge, found in the European northeast of Russia. The research sites were located in the profile of the karst crater and in the profile of the slope in the Ukhta River Valley. A sedge wetland community, and pine–bilberry–green-moss forest, located in the depression between glacial hills and uplands were also examined. A total of seven sites were examined. Geobotanical descriptions were made by standard methods, descriptions of the soil profile, and samples of the soil microfauna; 12 in each site were collected. A total of 51 oribatid mite species from 39 genera and 31 families were found. The highest taxonomic diversity of oribatids was noted in forest phytocenoses located in the upper part of the karst crater slope, the lower part of the karst crater slope, and on rock outcrops in the lower part of the slope in Ukhta river valley. Ordination of the oribatid mite community by NMDS method showed the association of sites S3, S4, and S5 located on the slope of the karst crater in one group, and sites S6 and S7 located on a slope in the Ukhta River Valley, as well as S2 (pine–bilberry–green-moss forest located in the depression between glacial hills and uplands), in another group. The swamp community was located separately from other communities. Species of oribatid mites, which created the specifics of each community, were noted. The specifics of the population of oribatid mites of karst landscapes were that along with the features of fauna, characteristic for zonal north-taiga forests (the predominance of polyzonal widespread species) were found the “conditionally southern” species, the main area of distribution of which is located in lower latitudes. The study provides the basis for future studies of poorly known oribatid mites of karst landscapes of Northern Europe.

The ground (Cladina arbuscula, C. rangiferina, C. stellaris, Cetraria islandica) and epiphytic (Hypogymnia physodes and Bryoria subcana) lichens in taiga forests of the European Northeast were examined as habitats of oribatid mites. In total, in different species of lichens, 55 species of oribatids from 30 families were found. Five ecological groups of oribatid mites as inhabitants of lichens were identified. It was found that the specificity of the oribatid mite population in epiphytic lichens consisted of dominant arboricolic species also not numerous arboricolic species. Dominant hemiedaphic species and not numerous hemiedaphic species were characteristic of ground lichens. The arboricolic‒hemiedaphic group includes species that live in both ground and epiphytic lichens. The ecologically vicariating species in relation to epiphytes were identified; these are species of the genera Carabodes, Mycobates, Oribatula, and Phauloppia.

We examined 35 species of ground and epiphytic lichens, including fruticose, foliose, and crustose lichen, as habitats of oribatid mites. Observations were carried out in the taiga forests of northeast European Russia, and 87 oribatid species from 38 families were found. The Crotoniidae, Carabodidae, Oppiidae, and Suctobelbidae are the most numerous families in ground lichens and the Oribatulidae are in the epiphytes. The families Micreremidae and Licneremaeidae were only noted in epiphytes. A complex of species characteristic of epiphytic lichens as habitats of oribatid mites have been identified, these are Carabodes labyrinthicus, Oribatula (Z.) propinqua, Phauloppia nemoralis, Micreremus brevipes, Licneremaeus licnophorus, Furcoppia (Mexicoppia) dentata, Cymbaeremaeus cymba. Only in epiphytes, rarely, the species were also Jacotella frondeus, Ameronothrus oblongus, Mycobates (Calyptozetes) tridactylus, and Liebstadia humerata. Characteristic for ground lichens are species Trhypochthonius cladonicolus, Carabodes marginatus, Carabodes subarcticus. Often found in both ground and epiphytic lichens are species Eueremaeus oblongus s. str., E. oblongus silvestris, Ceratoppia quadridentata, Adoristes ovatus poppei, Graptoppia (Apograptoppia) foveolata, Suctobelbella acidens duplex, Tectocepheus velatus, Trichoribates berlesei, Chamobates pusillus, Diapterobates oblongus, Oribatula tibialis, Oribatula (Z.) exilis, Scheloribates laevigatus, Neoribates aurantiacus, Pergalumna nervosa. In epiphytic lichens, we observed species that are rare in the North (Oribatula (Z.) frisiae, O. (Z.) propinqua, P. nemoralis, L. licnophorus, F. (M.) dentata, et al.), with some noted in the taiga zone for the first time (J. frondeus).

This study presents data on the oribatid mite fauna of the Subpolar Urals for the first time. Observations were made in the Lembekoyu River valley and 35 species of oribatid mites from 24 genera and 21 families were found. The analysis of taxonomic diversity and distribution of East European tundra oribatid mite species is presented based on available literature and the author’s own research findings. The taxonomic list includes 163 species from 81 genera and 45 families. Ceratozetidae (15 species), Crotoniidae (14 species), Oppiidae (12 species), Suctobelbidae (12 species), Damaeidae (9 species), Brachychthoniidae (8 species), Phthiracaridae (5 species), Humerobatidae (5 species), Achipteriidae (5 species), Punctoribatidae (5 species), and Galumnidae (5 species) are the leading families, comprising more than 58% of all species. The zoogeographical structure of the fauna is dominated by widely distributed Holarctic, cosmopolitan, and semi-cosmopolitan species. The share of Palaearctic species is 23%. The specificity of the fauna of East European tundra manifests itself in the small group of Arctic species, both in the mainland tundra and on the Arctic islands. A complex of arctic-boreal species, widely distributed in the Eurasian sector of the Arctic, is distinguished.