Circumpolar Species Research Articles

Reduced representation sequencing reveals weak genetic differentiation between Canadian and European Larus hyperboreus (Glaucous Gull)

Abstract Climate change poses a significant threat to Arctic ecosystems. Evaluation of genetic diversity within and differentiation among populations is needed to effectively conserve Arctic species and ensure genetic variation is appropriately managed. This research examined population genetic structure in Larus hyperboreus (Glaucous Gull), a circumpolar Arctic species that is declining in parts of its range. Population genetic information is needed to help delineate management units, including information on genetic differences among related species, among subspecies (currently distinguished by subtle morphometric and plumage differences), and among colonies in North America. We conducted double-digest restriction site-associated DNA sequencing for 62 L. hyperboreus, 18 L. argentatus smithsonianus (American Herring Gull), 6 L. a. argentatus (European Herring Gull), and 15 L. glaucescens (Glaucous-winged Gull) sampled across the Canadian and European Arctic. Interspecific analyses using 2,145 loci were unable to distinguish members of this species complex. Despite the geographic distance among sampling locations, molecular assignments and principal coordinates analyses based on 621 loci uncovered only weak population genetic differentiation among sampled European and Canadian colonies of L. hyperboreus. As L. hyperboreus occupying the eastern Canadian Arctic appear to be acting as a single panmictic population, conservation plans that protect Arctic habitat may help slow or reverse population declines. Proactive conservation strategies will benefit both L. hyperboreus and associated coastal Arctic ecosystems.

Growth and Fecundity of Nonnative Blue Honeysuckle Cultivars: Comparisons with Native and Invasive Congeners in a Maine Field Trial

Blue honeysuckle (Lonicera caerulea) is a circumpolar species complex with representatives in Europe, Asia, and North America. Although honeysuckles (Lonicera spp.) from Eurasia have a history of invasiveness in North America, farmers and homeowners are interested in growing nonnative blue honeysuckle hybrids because of their edible blue fruits. To assess whether these cultivars and closely related native blue honeysuckles (Lonicera caerulea subsp. villosa) might have similar growth and fecundity, we planted five nonnative cultivars of blue honeysuckle and five native genotypes in a common garden in Orono, ME, USA, along with invasive red-fruited honeysuckles [Tatarian honeysuckle (Lonicera tatarica) and European fly honeysuckle (Lonicera xylosteum)] for comparison. Rooted cuttings were planted into a field plot in Jun 2016 and fully maintained during the first season; thereafter, maintenance consisted of weeding once annually. Seventy-three percent of native blue honeysuckle plants survived to the end of the study, whereas survival and growth of nonnative cultivars were more robust. In 2021, nonnative cultivars had an average height of 81 cm and width of 86 cm, which were 2.8 times the height and 2.9 times the width of surviving native plants. The estimated canopy volumes of nonnative blue honeysuckles were an average of 20 times those of their native counterparts. The bloom periods of native and nonnative blue honeysuckles overlapped considerably. However, only seven of the 22 living native plants produced fruits in 2021, with an average of three fruits per plant among them. In contrast, nearly all plants of the nonnative cultivars produced fruits, with an average of 616 fruits per plant. In comparison, the red-fruited invasives had an average of 9739 fruits per plant. Native blue honeysuckles produced very few seeds, whereas nonnative cultivars had an average of 13,918 seeds per plant, which was approximately one-fourth the number produced by invasive red-fruited honeysuckles. We concluded that native and nonnative genotypes of blue honeysuckle differ strikingly in survival, growth, and production of fruits and seeds. However, invasive red-fruited honeysuckles grew faster with higher fecundity than nonnative blue honeysuckles in our full-sun landscape. Because bloom times overlapped substantially between native and nonnative blue honeysuckles, the potential for gene flow to occur from planted cultivars into native populations merits consideration. Several possible explanations of differences in performance among blue honeysuckles include hybrid vigor of cultivars or shallow rooting or poor adaptability of native genotypes to the environment of the common-garden trial. Our results, which demonstrated that nonnative blue honeysuckles are likely to be distinct from their native relatives in terms of competitiveness and fecundity, suggest that caution is warranted during the introduction and cultivation of agricultural genotypes.

Thermal tolerance of cultured and wild Icelandic arctic charr (Salvelinus alpinus) at self-selected flow rates

Climate change is predicted to change not only the temperature of many freshwater systems but also flow dynamics. Understanding how fishes will fare in the future requires knowing how they will respond to both extended variations of temperature and flow. Arctic charr have had their thermal tolerance measured, but never with respect to flow. Additionally, this circumpolar species has multiple populations exhibiting dramatic phenotypic plasticity which may mean that regional differences in thermal tolerance are unaccounted for. In Iceland, Arctic charr populations have experienced highly variable flow and temperature conditions over the past 10,000 years. The Icelandic climate, topography and geothermal activity have created a mosaic of freshwater habitats inhabited by charr that vary substantially in both temperature and flow. Our purpose was to test whether populations from these varied environments had altered thermal tolerance and whether phenotypic plasticity of thermal tolerance in charr depends on flow. We raised cultured Icelandic charr from hatch under a 2 X 2 matrix of flow and temperature and compared them to wild charr captured from matching flow and temperature environments. Wild fish were more thermally tolerant than cultured fish at both acclimation temperatures and were more thermally plastic. Icelandic Arctic charr were more thermally tolerant than comparison charr populations across Europe and North America, but only when acclimated to 13 °C; fish acclimated to 5 °C compared equably with comparison charr populations. Icelandic Arctic charr were also more thermally plastic than all but one other salmonine species. Neither flow of rearing or the flow selected during a thermal tolerance (CTmax) test factored into thermal tolerance. Thermal tolerance was also independent of body size, condition factor, heart and gill size. In summary, wild Icelandic Arctic charr have greater thermal tolerance and plasticity than predicted from the literature and their latitude, but artificial selection for properties like growth rate or fecundity may be breeding that increased tolerance out of cultured fish. As the world moves toward a warmer climate and increased dependence on cultured fish, this is a noteworthy result and merits further study.

Whole-genome survey reveals extensive variation in genetic diversity and inbreeding levels among peregrine falcon subspecies.

In efforts to prevent extinction, resource managers are often tasked with increasing genetic diversity in a population of concern to prevent inbreeding depression or improve adaptive potential in a changing environment. The assumption that all small populations require measures to increase their genetic diversity may be unwarranted, and limited resources for conservation may be better utilized elsewhere. We test this assumption in a case study focused on the peregrine falcon (Falco peregrinus), a cosmopolitan circumpolar species with 19 named subspecies. We used whole-genome resequencing to generate over two million single nucleotide polymorphisms (SNPs) from multiple individuals of all peregrine falcon subspecies. Our analyses revealed extensive variation among subspecies, with many island-restricted and nonmigratory populations possessing lower overall genomic diversity, elevated inbreeding coefficients (F ROH)-among the highest reported, and extensive runs of homozygosity (ROH) compared to mainland and migratory populations. Similarly, the majority of subspecies that are either nonmigratory or restricted to islands show a much longer history of low effective population size (N e). While mutational load analyses indicated an increased proportion of homozygous-derived deleterious variants (i.e., drift load) among nonmigrant and island populations compared to those that are migrant or reside on the mainland, no significant differences in the proportion of heterozygous deleterious variants (i.e., inbreeding load) was observed. Our results provide evidence that high levels of inbreeding may not be an existential threat for some populations or taxa. Additional factors such as the timing and severity of population declines are important to consider in management decisions about extinction potential.

Catalogue of specimens of Asplenium viride Huds. (Aspleniaseae, Polypodiopsida, Polypodiophyta) deposited in the State Museum of Natural History NASU, Lviv, Ukraine

Asplenium viride Huds. is known as “the Green Spleenwort, because of its green stipes and rachides. This feature easily distinguishes this species from the very similar-looking Maidenhair Spleenwort, Asplenium trichomanes. A. viride is a native species of northern and western North America and northern Europe and Asia. It is a grassy winter-green perennial, growing on calcareous rock. Asplenium viride – circumpolar boreal species. Its habitats are timed to petrophilic communities on the mesic to moist crevices in limestone and other basic rocks from the lowland and steppe to subalpine zones (up to 4,000 m above sea level). In Ukraine this species occurs mainly in Carpathians and Crimean Mountains, and also known from Roztochchia nature region (Безсмертна, Перегрим, Вашека, 2011, Вашека, Безсмертна, 2012). Outside Ukraine the species has nature protection status in Lithuania and Russian Federation (Nizhny Novgorod region). In addition A. viride is species requiring protection at the regional level for Lviv region with nature protection status as critically endangered species (CR) (Кагало, Сичак, 2014). There are 67 herbarium specimens of A. viride in the collection of vascular plants herbarium of Museum, they are all represented in the electronic database "Biodiversity of Ukraine". Geography of herbarium collections of A. viride, except modern territory of Ukraine (Zakarpattia, Ivano-Frankivsk, Lviv, Chernivtsi region), presented by Poland, Czech Republic, Slovakia, Romania and Russian Federation (North Ossetia). Chronology of collections of herbarium embraces the period from 1860 to 2009 years. Thus the oldest specimens (second half of ХІХ– beginning of ХХ century) are collected on territory of Poland, Slovakia and Romania. The list of collectors includes 30 persons, in particular: L. Tasienkevych (9 specimens), G. Kozii (7), А. Rehman (5), K. Malynovskyi (4), I. Vainahii (3), W. Dzieduszycki (3), A. Lazebna (3), M. Slobodian (3) and others. Based on literature analysis (Andrzejowski, 1869, Rehman, 1870, Tomaschek, 1862, 1866, Trusz, 1881, 1882 etc.) revealed links about findings of A. viride (Kulczyński, Kozikowski, Wilczyński, 1926), which are confirmed by herbarium specimens in Museum collection.

Genetic Introgression in Populations of Two Related Species <i>Adalia frigida</i> (Schneider, 1792) and <i>Adalia bipunctata</i> (Linnaeus, 1758) (Coleoptera: Coccinellidae) in the Zone of Sympatry

The haplotype diversity of mtDNA of the circumpolar species of ladybirds Adalia frigida collected in Yakutsk and Salekhard was studied. Based on the analysis of the nucleotide sequences of the cox1 gene, 18 mitochondrial haplotypes were identified, of which 14 were new. Of the 18 haplotypes of A. frigida, two (H32 and H9) are the most common. In the Salekhard region, the range of A. frigida overlaps with that of another closely related species, A. bipunctata. The value of divergence in the cox1 gene between A. frigida and A. bipunctata reaches 4.1–4.3% and corresponds to the level of differences characteristic of closely related species. These species are able to interbreed, the share of hybrid individuals (A. frigida and A. bipunctata) in Salekhard is 56.5%. Hybridization between A. frigida and A. bipunctata led to mutual mitochondrial introgression, which resulted in the acquisition of the H1 haplotype by the A. frigida beetles and the H9 haplotype by the A. bipunctata beetles.

Circumpolar sampling reveals high genetic connectivity of Antarctic toothfish across their spatial distribution

Antarctic Toothfish are a circumpolar species which are targeted in multiple fisheries around Antarctica covering nine statistical areas within the Convention for the Conservation of Antarctic Marine Living Resources. Despite this, it is still unclear whether the species forms a single stock across its circumpolar distribution, shows a pattern of isolation by distance, or exhibits discrete stock structure between different regions. Recent genetics studies of Antarctic toothfish have shown connectivity between two areas (Ross Sea and Antarctic Peninsula), but earlier studies with smaller number of markers produced inconsistent results with regards to genetic connectivity between other geographic locations. Here we present a range-wide population genetic study of Antarctic toothfish using > 11,000 nuclear single nucleotide polymorphisms from 715 fish collected. Our results indicate that genetic diversity of the Antarctic toothfish is very low, with only 0.1% of genetic variability associated with geographic location. Multiple clustering methods, both supervised and unsupervised, indicated no distinct breeding populations. These results are consistent with current theories of egg and larval dispersal by the predominant Antarctic currents.

Southward Migration of Arctic Ocean Species During the Last Glacial Period

AbstractThe East Asian winter monsoon (EAWM) is associated with northerly surface winds affecting crop and livestock productivity and social and economic activities across East Asia. However, the relationship between EAWM dynamics and marine biota remains poorly understood. In this study, we analyzed fossil ostracods from sediment cores collected in the northwestern Pacific Ocean to detect the appearance/disappearance of circumpolar species during the late Quaternary. We compared our ostracod records, including dating results, with ice‐rafted debris records from the Sea of Japan, and identified two southward migration events of Arctic ostracods at 120–100 ka (Marine Isotope Stage [MIS] 5d stadial) and 30–15 ka (MIS 3 and 2, peak Last Glacial), which corresponded to a strengthened EAWM system. Our results indicate that an intensified EAWM influenced the Yellow Sea Bottom Cold Water formation, lowered the winter water temperatures, and allowed Arctic ostracods to migrate southward into the Yellow Sea.

As the Goose Flies: Migration Routes and Timing Influence Patterns of Genetic Diversity in a Circumpolar Migratory Herbivore

Migration schedules and the timing of other annual events (e.g., pair formation and molt) can affect the distribution of genetic diversity as much as where these events occur. The greater white-fronted goose (Anser albifrons) is a circumpolar goose species, exhibiting temporal and spatial variation of events among populations during the annual cycle. Previous range-wide genetic assessments of the nuclear genome based on eight microsatellite loci suggest a single, largely panmictic population despite up to five subspecies currently recognized based on phenotypic differences. We used double digest restriction-site associated DNA (ddRAD-seq) and mitochondrial DNA (mtDNA) sequence data to re-evaluate estimates of spatial genomic structure and to characterize how past and present processes have shaped the patterns of genetic diversity and connectivity across the Arctic and subarctic. We uncovered previously undetected inter-population differentiation with genetic clusters corresponding to sampling locales associated with current management groups. We further observed subtle genetic clustering within each management unit that can be at least partially explained by the timing and directionality of migration events along with other behaviors during the annual cycle. The Tule Goose (A. a. elgasi) and Greenland subspecies (A. a. flavirostris) showed the highest level of divergence among all sampling locales investigated. The recovery of previously undetected broad and fine-scale spatial structure suggests that the strong cultural transmission of migratory behavior restricts gene flow across portions of the species’ range. Our data further highlight the importance of re-evaluating previous assessments conducted based on a small number of highly variable genetic markers in phenotypically diverse species.

The charophytes (Characeae, Charophyceae) from the Yenisey Siberia (Russia)

The records of new localities of charophytes from the Yenisey Siberia and confirmations for the ones known before were summarized as a result of study both available herbarium collections and field studies during 2007–2021. The twenty species, including one novel genus and five novel species records, 59 new localities (67 % of its total number), 127 new populations (83 % of its total number) were found in this region. In particular, 12 species (incl. 3 novel ones for the region) are known from the Republic of Khakassia, 17 (7) – from the Krasnoyarsk Territory, 12 (7) – from the Tuva Republic. The genus Chara is the most species-rich and frequent in the area of study. The taxonomic rank of C. arcuatifolia sensu Hollerb. et Krassavina is discussed. It seems to be a morphotype of C. globularis having clearly arcuate branchlets. Nitella tenuissima is a novel species record for Asian Russia. The charophyte northernmost locality on the continent was revealed. It belongs to C. virgata collected at Southern Taymyr. The novel locality of circumpolar species Tolypella canadensis, far distant from ones known before from Komi Republic and Republic of Yakutia, was found in this region too. The species occurrence in different ecoregions was estimated. The contemporary presence of some species after long intervals between observations from their first records was confirmed. The persistence of the same species in the same water bodies after a long period was revealed as evidence of stability of their populations, important for species protection. The loss of charophyte localities as a result of construction of large Krasnoyarskoe and Sayano-Shushenskoe water reservoirs is remarkable. The red lists for the regions studied were compiled and some species were suggested for protection. The important charophyte areas enabling protection of some species were revealed.

Genetic Structure of Native Blue Honeysuckle Populations in the Western and Eastern Eurasian Ranges.

Blue honeysuckle (Lonicera caerulea L.) is a promising berry crop producing edible early-ripening berries with a valuable chemical composition. We evaluated the genetic diversity of native L. caerulea populations from the western (Baltic states) and eastern (the Russian Far East and Japan) edges of the Eurasian range using inter-simple sequence repeat (ISSR) and chloroplast DNA (psbA-trnH and trnL-trnF) markers. The genetic relationships of populations and genotypes were analyzed using principal coordinate and cluster analyses (neighbor joining and Bayesian clustering). Sampling was carried out in two disjunct areas of this circumpolar species and the analyses showed clustering of individuals and populations according to geographic origin. The analysis of genetic structure based on ISSR markers showed that the studied populations of L. caerulea were highly differentiated. However, sequence analysis of two chloroplast DNA (cpDNA) regions revealed no phylogeographic structure among the populations. We also found that the eastern populations of blue honeysuckle had significantly greater genetic diversity parameters than the populations from the Baltic region. This finding correlates with the endangered status of blue honeysuckle in the Baltic states.

Stuckenietum subretusae — новая ассоциация водной растительности из южной части дельты р. Лена (Республика Саха (Якутия))

A nearly circumpolar hypoarctic species Stuckenia subretusa (Hagstr.) Holub is a rare species that grows in Yakuyia in lakes and reservoirs of deltaic systems of the large rivers (Lena, Kolyma, Yana, Indigirka, Anabar) mainly north of 68° N(Bobrov, Mochalova, 2014, 2017; Egorova, 2016; Opredelitel’…, 2020). The species is listed for Taymyr Peninsula as the most common in the plain part of the southern tundra and in the forest tundra (Pospelova, Pospelov, 2007) and as rarer in the typical tundra (Polozova, Tikhomirov, 1971). In general, this is a rather rare species. Besides the Taymyr Peninsula and Yakutia it occurs in the Bolshezemelskaya tundra, in the mouth of the Yenisey River, in Chukotka Peninsula and Alaska (Yurtsev et al., 2010; Bobrov et al., 2021). Stuckenia subretusa is a critical taxon associated by some authors (Kaplan, 2008; Konspekt…, 2012) with S. vaginata (Turcz.) Holub. However, both morphological and molecular genetic differences between these taxa were shown later (Volkova et al., 2017). It was also shown that S. subretusa is found in the lower reaches and estuarine areas of the large rivers in Asia, mainly north of 68° N, in Europe — of 67°, while the northern limit of the distribution of S. vaginata in Yakutia — 64°, in Europe — 66° (Bobrov, Mochalova, 2014), therefore these species are geographically separated. In July 2021, during a geobotanical survey of the islands of the southern part of the Lena River delta, thickets of S. subretusa were found on Sasyl-Ary Isl. (Fig. 1) in a shallow flow (channel) of 2 km total length, 130–150 m width and from 4–5 cm to 1.5 m depth with a very sluggish current. The bottom substrate is silty sands. Permafrost is 2–3 m depth. Thickets of S. subretusa were found only at 4–30 cm water depths. The thickets are monospecies with projective cover from 35 to 80 % (Fig. 2). Single specimens of Tephroseris palustris (L.) Rchb. were met rarely, at 4–5 cm water depths. Part of the thickets was located on wet sand along the shallows of the channel. S. subretusa was not found on neighboring islands. Five geobotanical relevés were made within the flow according to the generally accepted methodology with georeferencing using 12-channel GPS in the WGS-84 coordinate system on sample plots of 10×10 m. The classification was carried out on the principles of the ecological-floristic approach (Westhoff, van der Maarel, 1973). Estimation of the species projective cover in Table is given according to the Brown-Blanquet scale (Becking, 1957): r — single; + — less than 1 %; 1 — 1–5 %; 2 — 6–25 %; 3 — 26–50 %; 4 — 51–75 %; 5 — 76–100 %. The syntaxon name is given in accordance with the International Code of Phytosociological Nomenclature (Theurillat et al., 2021). The described communities belong to the class Potamogetonetea Klika in Klika et Novák 1941, the order Potamogetonetalia Koch 1926, and the alliance Potamogetonion Libbert 1931. We consider these as a part of a new association. The ass. Stuckenietum subretusae ass. nov. (Table). Nomenclature type (holotypus) — relevé No. L21-108а (Table, relevé 3). Republic of Sakha (Yakutia), Bulunsky district, Sasyl-Ary Isl., shallow channel in the Lena River delta, in water (N 72.35989°, E 126.41968°), 07/20/2021. N. N. Lashchinskiy is an author. Diagnostic species of the association is Stuckenia subretusa (= Potamogeton subretusus). The association includes monospecies communities of Stuckenia subretusa, sometimes with a single presence of other species. It is possible that communities of this species are floristically richer in southerner regions. These are reliably found in other parts of the Lena River delta (Nikolin et al., 2017), on Taimyr Peninsula (Krasnoyarsk Territory) in the Kha­tanga River (Pospelova, Pospelov, 2007), as well as in the Komi Republic (Chemeris, Bobrov, 2020), where their productivity is from 142 to 409 g/m2 of air-dry matter. In general, the association distribution area apparently coincides with the species range (northern regions of the Komi Republic, Krasnoyarsk Territory, Yakutia, Chukotka Autonomous District (Russia) and Alaska (USA).

Lichenomphalia umbellifera: fungible and infungible epithets and species concepts

Comparison of the protologue of Agaricus umbellifer L. with specimens and descriptions of the basidiolichen Lichenomphalia umbellifera (L.) Redhead & al. revealed that the epithet umbellifera was misapplied to the Lichenomphalia species, causing several major conflicts with Linnaeus's species concept. A felicitous match for Linnaeus's species concept was found with a species of Marasmius sect. Epiphylli. Because A. umbellifer falls in a group that arises from an evolutionary pathway divergent from that leading to Marasmius s. str., we erected a new genus, Owingsia, to accommodate it, and recombined the type species as Owingsia umbellifera. Molecular studies demonstrated that it is a widely distributed circumpolar species, prevalent in Lapland and islands of the Baltic Sea, where Linnaeus encountered it. The earliest legitimate description of the basidiolichen L. umbellifera is A. pseudoandrosaceus Bull., a name superseded by the sanctioned later synonym, A. ericetorum Pers. We recombined this basionym as L. ericetorum, and epitypified O. umbellifera and L. ericetorum with modern sequenced specimens.

North Atlantic Oscillation seesaw effect in leaf morphological records from dwarf birch shrubs in Greenland and Finland

The North Atlantic Oscillation (NAO) determines wind speed and direction, seasonal heat, moisture transport, storm tracks, cloudiness and sea-ice cover through atmospheric mass balance shifts between the Arctic and the subtropical Atlantic. The NAO is characterized by the typical, yet insufficiently understood, seesaw pattern of warmer winter and spring temperatures over Scandinavia and cooler temperatures over Greenland during the positive phase of the NAO, and vice versa during the negative phase. We tested the potential to reconstruct NAO variation beyond the meteorological record through the application of a microphenological proxy. We measured the Undulation Index (UI) in Betula nana epidermal cells from herbarium leaf samples and fossil peat fragments dating back to 1865—exceeding most meteorological records in the Arctic—to estimate imprints of spring thermal properties and NAO in Greenland and Finland. We found negative relations between Greenland UI and late winter, spring and early summer NAO, and mostly positive, but not significant, relations between Finland UI and NAO in years with pronounced NAO expression. The direction of the UI response in this common circumpolar species is, therefore, likely in line with the NAO seesaw effect, with leaf development response to NAO fluctuations in northern Europe opposing the response in Greenland and vice versa. Increased knowledge of the UI response to climate may contribute to understanding ecological properties of key Arctic species, whilst additionally providing a proxy for NAO dynamics.

Пространственное распределение Icelus bicornis (Reinhardt, 1840) и Icelus spatula Gilbert & Burke, 1912 в морях российской Арктики

This article provides data on distribution of two circumpolar species – twohorn sculpin Icelus bicornis and spatulate sculpin Icelus spatula in the Russian Arctic seas (Barents Sea, Kara Sea, Laptev Sea, East Siberian Sea) in the period from 2014 to 2019. The abundance of the twohorn sculpin varied from 2 to 18 ind/km2, and the biomass varied within 0.002–0.089 kg/km2. For the spatulate sculpin, these parameters were 2–21 ind/km2 and 0.002–0.699 kg/km2. The maximum and minimum values of these parameters for Icelus bicornis were recorded in the Laptev Sea, and for Icelus spatula in the East Siberian Sea. Information on the vertical spatial distribution of these species is also given, confirming the information given earlier that the spatulate sculpin occurs at shallower depths in contrast to the twohorn sculpin.

Ecotypic differentiation of a circumpolar Arctic-alpine species at mid-latitudes: variations in the ploidy level and reproductive system of Vaccinium vitis-idaea.

Although plant species originated from Arctic regions commonly grow in alpine habitats at mid-latitudes, some populations of these species exist also in some specific habitats below the treeline. Local populations at lower elevations may have different origins, ploidy levels, mating systems and/or morphological traits from alpine populations, but comparative studies between alpine and low-elevation populations are scarce. We aimed to reveal the ecological and genetic differentiations between higher and lower populations of Vaccinium vitis-idaea in Hokkaido, northern Japan by comparing 22 populations growing in diverse environments. We analysed the ploidy level of individual populations using flow cytometry. Genetic differentiation among populations, and genetic diversity within populations were calculated using microsatellite markers. Fruit and seed production were recorded under natural conditions, and a pollination experiment was conducted to reveal the variations in mating system across populations. Furthermore, we compared shoot growth and leaf characteristics among populations. Most of the low-elevation populations were tetraploid, whereas all but one of the alpine populations were diploid. Tetraploid populations were clearly differentiated from diploid populations. Some tetraploid populations formed huge clonal patches but genetic diversity was higher in tetraploids than in diploids. Alpine diploids were self-incompatible and produced more seeds per fruit than tetraploid populations. In contrast, tetraploids showed high self-compatibility. Leaf size and foliar production were greater in tetraploid populations. Our results indicate that the genetic compositions of low-elevation tetraploid populations are different from those of alpine diploid populations. Most populations at lower elevations contained unique ecotypes suited to persistence in isolated situations. Local, low-elevation populations of typical alpine species maintain ecologically and genetically specific characteristics and could be valuable in terms of evolutionary and conservation biology. The present study demonstrates the biological importance of small and isolated populations at the edges of species distribution.

Development of specific markers for the detection of Tolypella canadensis eDNA in water samples

Assessing the biodiversity of an ecosystem plays a major role in ecosystem management. However, proper determination on species-level is often tricky when morphological features are scarce and especially rare species require huge sampling efforts to be detected in the aquatic realm. As an alternative to conventional methods, environmental samples can be examined via the eDNA method, allowing for large-scale integration as well as taxa resolution independent from expression of morphological characters. However, to apply this technique genetic markers that are specific to a species or at least a genus are required. Such markers until now have been successfully developed only for a few well studied taxonomic groups like, e.g., fishes and amphibians, but are still missing for others, especially plants and algae (e.g. Bista et al. 2017). This project focusses on the development of species-specific markers for the macrophytic green algae Tolypella canadensis (Characeae, Charophyta), a rare alga preferring deep water and known so far mainly from remote places. Tolypella canadensis is a circumpolar species and prefers oligotrophic lakes, where it grows in depths up to 13 m (Langangen 2002; Romanov and Kopyrina 2016). In addition, proper determination of Tolypella-species is a field of a few specialists, further complicating monitoring or even detection of this rare species. The design of the species-specific primers was based on reference nucleotide sequences of the chloroplast genes rbcL, psbC and atpB and of the ribosomal internal transcribed spacer regions ITS1 and ITS2, obtained from GenBank (Perez et al. 2017). To determine the specificity of the newly designed primers, DNA isolates obtained from T. canadensis specimens collected from the Torneträsk (Sweden, 2018) and other charophyte species were prepared in different proportions. The sensitivity of the primers was experimentally assayed by using serial dilutions of T. canadensis DNA. Additionally, a mock test comprised of a sample with the DNA of several charophyte species was conducted and finally, the markers were tested on environmental samples from the Torneträsk. Tolypella canadensis-specific primers of the ITS2 region yielded positive PCR amplifications of one single band when T. canadensis was present in a sample. Cross-amplification was not found during the mock test; other charophyte species did not yield positive amplification. The eDNA samples from the Torneträsk validated the performance of the ITS2 marker. The T. canadensis-specific marker designed in this project was proven to be sensitive and accurate. It could be recommended as a useful tool to detect the presence of T. canadensis DNA, even at low concentration and in complex samples containing other charophyte species.

An open access dataset for developing automated detectors of Antarctic baleen whale sounds and performance evaluation of two commonly used detectors

Since 2001, hundreds of thousands of hours of underwater acoustic recordings have been made throughout the Southern Ocean south of 60° S. Detailed analysis of the occurrence of marine mammal sounds in these circumpolar recordings could provide novel insights into their ecology, but manual inspection of the entirety of all recordings would be prohibitively time consuming and expensive. Automated signal processing methods have now developed to the point that they can be applied to these data in a cost-effective manner. However training and evaluating the efficacy of these automated signal processing methods still requires a representative annotated library of sounds to identify the true presence and absence of different sound types. This work presents such a library of annotated recordings for the purpose of training and evaluating automated detectors of Antarctic blue and fin whale calls. Creation of the library has focused on the annotation of a representative sample of recordings to ensure that automated algorithms can be developed and tested across a broad range of instruments, locations, environmental conditions, and years. To demonstrate the utility of the library, we characterise the performance of two automated detection algorithms that have been commonly used to detect stereotyped calls of blue and fin whales. The availability of this library will facilitate development of improved detectors for the acoustic presence of Southern Ocean blue and fin whales. It can also be expanded upon to facilitate standardization of subsequent analysis of spatiotemporal trends in call-density of these circumpolar species.

Drastic changes of the amphipod fauna in northern Germany and the displacement of Gammarus lacustris G.O. Sars, 1864 to relict habitats/status

The amphipod fauna of Central Europe has changed dramatically over the last century. This change has increased dramatically over the past 30 years. This dynamic is well documented in northeast Germany. This study places it in a landscape-ecological context. An example of a displacement is Gammarus lacustris G.O. Sars, 1864, a circumpolar species with a variety of habitats, but relegated to relic habitats. The species turns out to be a very weak competitor. Already with the immigration of Gammarus roeselii Gervais, 1835 (probably in the 1960s), it became a relic species in northeast Germany. Massive waves of introduction of Pontocaspian species of the genera Dikerogammarus, Pontogammarus and Echinogammarus a few decades later intensified this process for this and other species.

Presence of King penguins (Aptenodytes patagonicus) on Elephant Island provides further evidence of range expansion

King penguins (Aptenodytes patagonicus) are a circumpolar sub-Antarctic species inhabiting most of the major sub-Antarctic island chains of the Southern Ocean, the Falkland Islands, and regions of Patagonia. Despite early suggestions to the contrary, there is no conclusive historical evidence of King penguin inhabitation of the Antarctic Peninsula or the South Shetland Islands until the past decade. After a near-complete survey of Elephant Island, we report widespread presence of this species, including documented incubation at one site and molting at another. While we found no evidence of King penguins successfully fledging a chick at any of the sites where individuals were found, their presence across numerous sites suggests the potential for future range expansion in response to warming conditions.