Birds can be an important agent of environmental change in High Arctic ecosystems, particularly due to the role of seabirds as a vector transferring nutrients from the marine to terrestrial realms. The soils of bird nesting sites are known to host distinct plant communities but the consequences of bird modification for microorganisms are much less clear. Our focus here is testate amoebae: a widelydistributed group of protists with significant roles in many aspects of ecosystem functioning. We compared the testate amoeba assemblages of a site on Spitsbergen (Svalbard archipelago) affected by nesting birds, with nearby control sites. We found differences in assemblage between sites, typified by reduced relative abundance of Phryganella acropodia and Centropyxis aerophila in birdmodified soils. These changes may reflect a reduced availability of fungal food sources. We found no evidence for differences in assemblage diversity or test concentration between bird-modified and control soils. Our dataset is small but results provide the first evidence for the potential effect of bird modification of soils on testate amoebae in the Arctic. Results show only limited similarity to experimental studies of nutrient addition, implying that response mechanisms may be more complicated than simply additional nutrient supply through faeces.
Testate amoebae have proved a useful group of species to understand the biogeography of larger microorganisms. The Arctic has attracted particular interest in such studies but there are large geographic gaps in current knowledge. Here we present what we believe is the first ever study of testate amoebae from the Novaya Zemlya archipelago in Arctic Russia. We investigated testate amoebae from the northernmost island of Novaya Zemlya proper and two smaller islands to the south: Dolgii Island and Matveev Island. We found that testate amoebae were present and active even in the extreme physical environment of northern Novaya Zemlya. Further south in the tundra zone of Dolgii and Matveev islands, testate amoebae were notably abundant and diverse. There were distinct differences in assemblage between all three islands and particularly between Novaya Zemlya and the two more southerly islands. The assemblage of Novaya Zemlya was distinctive with a surprising abundance of larger taxa. Comparisons to previous data suggest that the testate amoeba assemblages of these islands may show more affinity to those further west in Greenland and Svalbard than those further east in Siberia. Results highlight the limited knowledge of the abundance and diversity of these functionally-significant protists in large areas of the globe.
The role of human activity as a vector in the movement of soil microorganisms is uncertain and disputed. It is increasingly clear that some larger microorganisms have restricted distributions and plausible to imagine that many human activities could lead to exotic species introductions, but concrete examples are lacking. We investigated an unusual case study: the former mining settlement of Pyramiden on the island of Spitsbergen in the Svalbard archipelago. In around 1983 large quantities of chernozem soils were imported from the southern USSR as part of an urban greening initiative, bringing large numbers of soil organisms to a very different physical environment. Focusing on a readily-identifiable group of protists with documented regional endemism (testate amoebae), we assessed morphospecies assemblages after thirty years. We analysed communities from Pyramiden imported soils and conducted comparisons to: i) nearby locations with nonimported near-natural soils; ii) previously-established datasets from near-natural Svalbard soils and chernozem soils in southern Russia, and iii) regional species inventories from both regions. Our aims were to assess how the community has adapted to the change in physical conditions and identify any evidence for the import of exotic taxa. Our results show significant differences between the assemblages of imported soils and those of nearby reference sites but strict comparisons are complicated by the different treatment of soils in different locations. No taxa were identified which can be unambiguously identified as atypical for the region. Assemblages of imported soils were more similar to those of other sites on Svalbard than to assemblages from southern Russia. Our data are equivocal but suggest that the testate amoeba assemblages of soils transported more than 3000km northwards have substantially acclimated to the new conditions, contrasting with microinvertebrates in the same site. A P opportunities for long-term, large-scale, soil biological research.
The subject for the research was Phytoadditive containing extracts from herbs: Rhaponticum carthamoides, Serratula coronata, Filipendula ulmaria. There has been studied the effect of Phytoadditive on biochemical parameters of blood (total protein, albumins, aminotransferases, urea, total cholesterol, reserve alkalinity, calcium), indicators of milk fat, protein and average daily milk yield of lactating cows at the age of 3 years, which were divided into experimental (Phytoadditive + basic diet) and control (basic diet only) groups of 10 animals per group. Phytoadditive in powder form was administered individually to the diet of animals of the experimental group daily, once at a dose of 10 grams per head per day during 90 days. Analysis of Phytoadditive for the presence of biologically active substances showed that the major compounds in it are ecdysteroids (mainly hydroxyecdysone) and flavonoids (rutin) in a total concentration of 13.5 g/kg. At the end of the experiment in cows of the experimental group, in comparison with the initial indicators, significantly (p < 0.05) increased the amount of albumin by 16.7 % (up to 45.3±2.4 g/l), calcium by 21.7 % (2.3±0.01-2.8±0.02 mmol/l). Other studied markers of the biochemical status did not change significantly (p> 0.05) and after the final blood test they were: aminotransferases (AST − 30.1±1.2 U/l, ALT − 35.0±2.8 U/l), urea (5.9±0.1 mmol / l), reserve alkalinity (20.2±2.6 vol.% CO2), cholesterol (2.8±0.1 mmol/l). All studied blood parameters did not go beyond the reference values throughout the experiment, which indicated the absence of any negative properties of Phytoadditive. At the end of the experiment, the milk indicators of cows in the experimental group had the following values: milk yield (19±0.2 kg), fat (4.3±0.4 %), protein (3.3±0.1 %), which exceeded the result in control by 5.5 %; 0.1 and 0.2 %, and in comparison with the beginning of the experiment by 18.7 %, 0.6 and 0.2 %, respectively. Thus, as the result of use of Phytoadditives in cows during lactation, a positive trend was noted in terms of its effect on milk yield, milk quality and the absence of any negative effect on the studied blood parameters.
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