Arctic Tundra

Soil is a complex ecosystem comprised of several and mutually interacting components, both abiotic (organo-mineral associations) and biotic (microbial and pedofaunal populations and plants), where a single parameter depends on other factors and affects the same and other factors, so that a network of influences among organisms coexists with the reciprocal actions between organisms and their environment. Therefore, it is difficult to undoubtedly determine what is the cause and what the effect within relationships between factors and processes. Soil is commonly studied through the evaluation and measurement of single parameters (e.g. the content of soil organic matter (SOM), microbial biomass, enzyme activities, pH, etc.), events (e.g. soil erosion, compaction, etc.) and processes (e.g. soil respiration, carbon fluxes, nitrification/denitrification, etc.), often carried out in laboratory conditions in order to limit the number of factors acting within the ecosystem under study, but missing the information about the global soil environment that way. In the last decade, several scientists have proposed and suggested the need for a holistic approach to soil ecosystems in different contexts. Recently, we have applied a sensing system developed in the last decades and capable of analysing complex mixtures of gases and volatiles (odours or aromas) in atmospheres, namely called electronic nose (EN). Typically, ENs are devices consisting of an array of differentially and partially specific, despite selective, sensors upon diverse coatings of sensitive films, i.e. interacting with single analytes of the same chemical class, despite not highly specific for a single substance, only, but showing also lower extent of cross-selectivity towards compounds of other chemical classes. ENs can be used in the classifications of odours by processing the collected responses of all sensors in the array through pattern recognition analyses, in order to obtain a chemical fingerprint (olfactory fingerprint) typical of the analysed air sample. Due to these features, we decided to apply such a sensing technology to the analyses of soil atmospheres, because several processes in soil, both abiotic and biotic, result in gas and/or volatile production and the dynamics of such releases may also be affected by several additional environmental factors, such as soil moisture, temperature, gas exchange rates with outer atmosphere, adsorption/desorption processes, etc. Then, the analysis of soil atmosphere may provide information about global soil conditions (e.g. soil quality and health), according to a holistic approach, where several factors are contemporarily taken into account. At the same time, the use of such a technology, if adequately trained on purpose, can supply information about a single or a pool of processes sharing similar features, which occur in soil over a certain period of time and mostly affecting soil atmosphere. According to these premises and hypotheses, we demonstrated that EN is an useful technology to measure soil microbial activity, through its correlation to specific metabolic activities occurring in soil (i.e. global and specific respiration and some enzyme activities), but also soil microbial biomass. On the basis of such evidences, we also were able to use this technology to assess the quality and health conditions of soil ecosystems in terms of metabolic indices previously identified, according to some metabolic parameters and biomass quantification of microbial populations. In other studies, we also applied EN technology, despite using a different set of sensors in the array, to analyse the atmosphere of soil ecosystems in order to assess their environmental conditions after contamination with polycyclic aromatic hydrocarbons (PAHs) (i.e. semivolatile - SVOCs - organic pollutants). In this case, EN technology resulted capable of distinguishing between contaminated and uncontaminated soils, according to the differences in a list of substances, occurring in the atmospheres of differently treated soils, which were identified through SPME-GC/MS analyses and then suggested to be responsible for the different classification. Analysing the EN responses, it was also possible to follow the degradation process of pollutants by resident microbial populations over time, on the basis of the contemporary decrease of contaminant and the increased release of CO2. Then, we suggest that EN technology may be usefully employed in the analyses of soil ecosystems in order to both supply information about global soil environment, according to the holistic approach, and about specific processes occurring therein. Furthermore, since EN technology resulted to be effective and successful in detecting processes in soil, in both natural and perturbed conditions, involving microbial populations, which are commonly considered as the most sensitive and responsive to soil environmental modifications, we suggest it might be reasonably employed in analyses concerning the assessment of soil quality and health. Consequently, such a technology may also be used to study several processes involving soil ecosystems, such as soil management practices, soil restoration, soil contamination and remediation, soil fertility, etc.

The polar tiger moth Pararctia subnebulosa (Dyar 1899) (Erebidae: Arctiinae) is one of the few conspicuous and largest Lepidoptera species in the High Arctic. However, the biology and distribution patterns of this remarkable species have not been sufficiently studied. In the present note, we summarize known data for the species localities, provide DNA barcode data and describe the immature stages and a gregarious parasitoid. The species was collected from Kolguev Island, Arctic European Russia, for the first time. This locality is situated 500 km westward from a previously known species recording in the Yugor Peninsula, which substantiates that P. subnebulosa is also a member of the European fauna. DNA barcode data revealed that the Kolguev specimen shares a close haplotype with those from Chukotka at distance ca. 5,000 km. However, a specimen from Canada has a highly divergent haplotype that indicates that the Russian populations are a separate cryptic species, P. tundrana Tshistjakov 1990. We provide the first data for an assessment of the role of Meteorus parasitoid pressure on the imago abundance of P. subnebulosa. Among 87 moth larvae collected from the Yugor Peninsula, only eight larvae (9.2 %) developed into imagoes, and all of the others (79 ind., 90.8 %) were lost due to parasitoid invasion. DNA barcode data show that this parasitoid is a sister to Meteorus acerbiavorus (Braconidae, Euphorinae). Our findings highlight the existence of multiple cryptic refugia in Beringia and an important role of parasitoids in the suppression of Arctic Lepidoptera populations.

Environmental changes are predicted to have severe and rapid impacts on polar and alpine regions. At high latitudes/altitudes, cryptogams such as bryophytes and lichens are of great importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning. This seven-year factorial experiment examined the effects of fertilizing and experimental warming on bryophyte and lichen abundance in an alpine meadow and a heath community in subarctic Sweden. The aim was to determine whether shortterm responses (five years) are good predictors of longer-term responses (seven years). Fertilizing and warming had significant negative effects on total and relative abundance of bryophytes and lichens, with the largest and most rapid decline caused by fertilizing and combined fertilizing and warming. Bryophytes decreased most in the alpine meadow community, which was bryophyte-dominated, and lichens decreased most in the heath community, which was lichen-dominated. This was surprising, as the most diverse group in each community was expected to be most resistant to perturbation. Warming alone had a delayed negative impact. Of the 16 species included in statistical analyses, seven were significantly negatively affected. Overall, the impacts of simulated warming on bryophytes and lichens as a whole and on individual species differed in time and magnitude between treatments and plant communities (meadow and heath). This will likely cause changes in the dominance structures over time. These results underscore the importance of longer-term studies to improve the quality of data used in climate change models, as models based on short-term data are poor predictors of long-term responses of bryophytes and lichens.

Two bed media were tested (gravel and Filtralite) in shallow horizontal subsurface flow (HSSF) constructed wetlands in order to evaluate the removal of ammonia and nitrate for different types of wastewater (acetate-based and domestic wastewater) and different COD/N ratios. The use of Filtralite allowed both higher mass removal rates (1.1 g NH4–N m2 d1 and 3 g NO3–N m2 d1) and removal efficiencies (>62% for ammonia, 90–100% for nitrate), in less than 2 weeks, when compared to the ones observed with gravel. The COD/N ratio seems to have no significant influence on nitrate removal and the removal of both
ammonia and nitrate seems to have involved not only the conventional pathways of nitrification–denitrification.
The nitrogen loading rate of both ammonia (0.8–2.4 g NH4–N m2 d1) and nitrate (0.6–3.2 g NO3–N m2 d1) seem to have influenced the respective removal rates.

Remote sensing is a suitable candidate for monitoring rapid changes in Polar regions, offering high-resolution spectral, spatial and radiometric data. This paper focuses on the spectral properties of dominant plant species acquired during the first week of August 2015. Twenty-eight plots were selected, which could easily be identified in the field as well as on RapidEye satellite imagery. Spectral measurements of individual species were acquired, and heavy metal contamination stress factors were measured contemporaneously. As a result, a unique spectral library of dominant plant species, heavy metal concentrations and damage ratios were achieved with an indication that species-specific changes due to environmental conditions can best be differentiated in the 1401–2400 nm spectral region. Two key arctic tundra species, Cassiope tetragona and Dryas octopetala, exhibited significant differences in this spectral region that were linked to a changing health status. Relationships between field and satellite measurements were comparable, e.g., the Red Edge Normalized Difference Vegetation Index (RENDVI) showed a strong and significant relationship (R 2 = 0.82; p = 0.036) for the species Dryas octopetala. Cadmium and Lead were below detection levels while manganese, copper and zinc acquired near Longyearbyen were at concentrations comparable to other places in Svalbard. There were high levels of nickel near Longyearbyen (0.014 mg/g), while it was low (0.004 mg/g) elsewhere.

The polar tiger moth Pararctia subnebulosa (Dyar 1899) (Erebidae: Arctiinae) is one of the few conspicuous and largest Lepidoptera species in the High Arctic. However, the biology and distribution patterns of this remarkable species have not been sufficiently studied. In the present note, we summarize known data for the species localities, provide DNA barcode data and describe the immature stages and a gregarious parasitoid. The species was collected from Kolguev Island, Arctic European Russia, for the first time. This locality is situated 500 km westward from a previously known species recording in the Yugor Peninsula, which substantiates that P. subnebulosa is also a member of the European fauna. DNA barcode data revealed that the Kolguev specimen shares a close haplotype with those from Chukotka at distance ca. 5,000 km. However, a specimen from Canada has a highly divergent haplotype that indicates that the Russian populations are a separate cryptic species, P. tundrana Tshistjakov 1990. We provide the first data for an assessment of the role of Meteorus parasitoid pressure on the imago abundance of P. subnebulosa. Among 87 moth larvae collected from the Yugor Peninsula, only eight larvae (9.2 %) developed into imagoes, and all of the others (79 ind., 90.8 %) were lost due to parasitoid invasion. DNA barcode data show that this parasitoid is a sister to Meteorus acerbiavorus (Braconidae, Euphorinae). Our findings highlight the existence of multiple cryptic refugia in Beringia and an important role of parasitoids in the suppression of Arctic Lepidoptera populations.

Abstract The fluids remaining after the digestion are a significant and growing problem as they contain large amounts of ammonia and phosphate that have high environmental impact. However, these nutrients are of considerable value replacing expensive manufactured fertiliser which typically have large carbon footprints and whose cost is linked directly to that of natural gas. Typical disposal of these fluids is by land spreading, but the capacity for this is limited as it threatens to contaminate ground and surface water causing eutrophication. Alternative practices of disposal are problematic as they need to be either integrated with AD sites or the materials be transported from digester site to a point of use. Transport soon becomes prohibitively expensive as the solutions are too dilute and bulky. Concentrating and reformulation of the nutrients as fertiliser or growth nutrient can add considerable value to these fluids so allowing transportation and distribution. As a first step ...