The cryosphere (i.e. glaciers and permafrost) and its related landforms offer a wide range of ecosystem services, thus they have strong relationships with human population. Even if these harsh ...environments have often been regarded as inhospitable, there is a growing amount of literature on glacial biodiversity, specifically concerning European mountains. Glaciers and permafrost-related landforms (e.g. rock glaciers) host a variety of cold-adapted taxa, from bacteria to vertebrates. They have been included in the Natura 2000 network, specifically in the habitat type: Permanent Glaciers (code 8340), but their biodiversity is still poorly known. Even if local extinctions and population reductions of cold-adapted species due to glacier and permafrost shrinking have been already documented, none of the species living in this habitat type are listed in the Habitat Directive Annexes. With this commentary, we call for urgent actions for an ecological characterization of this habitat type in order to plan monitoring and management of the biodiversity hosted by them. An increased knowledge of this no longer permanent habitat appears particularly urgent, because it is not replaceable and is likely to go extinct in the next decades.
The invasive tiger mosquito Aedes albopictus is a serious nuisance for people due to its biting and potential for disease transmission, even in Italian mountain regions. In this work, we examined its ...occurrence dynamic from the first invasion in two Alpine cities, Rovereto and Trento, only 25 km apart. Mosquito's distribution was assessed using ovitraps, from mid-May to end-October, from its first reported occurrence, i.e. 2001 in Rovereto and 2010 in Trento. In both cities, ovitraps were located in seven habitat types: gathering places, residential areas, urban parks, car parks, near watercourses, industrial areas and croplands. The annual average temperature and precipitation were similar in the two cities from 2001 to 2020. We had hypothesized that the seasonal and annual differences in egg number between both cities would be limited. Significant linear and positive relationship was found between the average number of eggs and air temperature in both the cities, but with a steeper slope in Trento. In addition, the average number of eggs per ovitrap was higher in Trento than in Rovereto (average 50.3 vs 14.2). None of the considered risk factors (climate, habitat type) explained such difference in abundance between cities. Indeed, based on the temperature, the expectation was to find fewer eggs in Trento being cooler than Rovereto during 2010-2020 (the average in the period of activated traps was, respectively, 19.2 vs 19.7°C). Thus, we argue that other anthropogenic factors, such as different control activities (adulticide treatments were carried out solely in Rovereto), might explain the difference in egg abundance found between cities. A specific experimental design to evaluate treatment effect might validate our hypothesis (e.g. apply adulticides during the surveillance period, with treatments applied at regular distances from the ovitraps and with a specific periodicity to compare adult and egg abundance).
Ae. albopictus invaded two alpine cities 25 km apart with a lag of 12 yrs
Temporal trend of egg abundance was positively correlated with temperature in both cities
Ae. albopictus was more abundant in gathering places in urban areas
The colder city (Trento) was the more infested
Control activities carried out in Rovereto might explain difference in abundance between the two cities
A key to species belonging to the genus Diamesa Meigen, 1835 (Diptera, Chironomidae) well known as adult males and pupal exuviae from European Alps, is presented; the characters useful in species ...identification are pictured.The key considers both qualitative and quantitative characters.Thirteen morpho-species are distinguished, probably more species have a very similar larva and can be separated only in the adult or pupal stage. The most discriminant quantitative characters are the length and thickness of anal setae, among qualitative characters the most discriminant ones are the head capsule colour and the split of setae anteriores of labrum. The shape of mental and mandibular teeth are good taxonomic characters, but can be rarely used because teeth are often worn out in samples collected in the field. Quantitative characters show variability within each species, differing according to the sampled site and season, and must be used with caution.The following species groups can be easily separated in the larval stage: i) dampfi, including D. dampfi and D. permacra; ii) latitarsis including D. modesta and D. latitarsis; iii) zernyi including D. zernyi and D. vaillanti. D. starmachi, D. steinboecki, D. goetghebueri, D. bertrami, D. aberrata, D. incallida, D. cinerella, D. tonsa and D. insignipes can be separated from all the other known species in larval stage, but some of them, D. cinerella and D. insignipes for example, have a very similar larva, so are better separated on the basis of their distribution and collection of adults and pupae are strongly recommended to support identifications. A new character bound to head capsule colour is proposed to separate D. insignipes, D. cinerella, D. tonsa and D. zernyi.
Issue Title: Theme: Ecology of High Altitude Aquatic Systems in the Alps The results of a study of littoral chironomid communities from 89 lakes in the Alps are presented. The lakes are located on ...the northern and southern sides of the Alps from the western Bernese to the eastern Julian Alps. Due to the different origins of the data set here considered, different sampling years and sampling methodologies were adopted. All of the lakes were sampled during the ice-free season, but 79/89 lakes were sampled mainly in autumn 2000, while for a few of them the sample dated back to 1996 or the early 90s. Samples were taken by kicking the different substrata or a stretch of lakeshore (10-30 m) for at least 2-5 min with a standard net and were then preserved in alcohol. Larvae and pupal exuviae were sampled by skimming the lake surface with the same net, to extend identification to species level. Notwithstanding the large altitudinal gradient, almost all of the lakes are situated above the timberline, and show a wide range of morphological (depth, watershed and lake area) and chemical characteristics. Chironomids were the most abundant insects represented in these lakes, with highest abundances at pH between 6.0 and 7.5. In particular, Orthocladiinae and Chironominae were the two subfamilies with the widest distribution. Altitude and temperature played an important role in determining their distribution, the higher altitudes were dominated by the former, whereas the latter were more numerous in lower lakes. The prevalence of Orthocladiinae and Tanytarsini at high altitudes was regarded as a general pattern of taxonomic composition in harsh climatic areas. A reverse condition occurred only in the Julian Alps, where Tanytarsini dominate, followed by Tanypodinae and rare Orthocladiinae. Although our results demonstrated that the composition of chironomid assemblages was also determined by pH, the pattern was unbalanced. Due to the fact that no cases of strong water acidification were present, taxa restricted to very low pH were poorly represented (only three taxa--Limnophyes, Endochironomus and Orthocladius (O.) spp.) compared with circumneutral (8) and alkaline (14) taxa, which occurred in slightly acid and non-acidified soft water lakes. As regard conductivity and altitude, we found that almost all the taxa present at higher pH were contemporary present at conductivity higher than 100 μeq l^sup -1^ and altitude lower than 2100 m a.s.l. At species level, Pseudodiamesa branickii, Corynoneura arctica, Heterotrissocladius marcidus and Paratanytarsus austriacus resulted to be the most ubiquitous and abundant species in the Alps. When the west to east distribution of taxa was taken into account, Chironomini (particularly the genera Chironomus and Dicrotendipes) and Tanypodinae (Larsia and Paramerina) were more typical of the eastern lakes (JA). They may be better indicators of more alkaline waters. Assembling all the existing data and presenting a comprehensive panorama of lake-littoral chironomid taxa of the Alps was one of the aims of this paper. Further monitoring, but also harmonization of the sampling methodologies and taxonomical identification including inter-calibration exercises among laboratories are recommended, to provide reliable basis and more knowledge for future studies of comparative biogeography, and to preserve these environments where global climatic changes may cause abrupt shifts in the faunal assemblages with a loss of taxa typical of these mountainous areas.PUBLICATION ABSTRACT
The response to high temperatures in adults of two cold stenothermal cave-dwelling leptodirins,
Neobathyscia mancinii and
Neobathyscia pasai (Coleoptera, Cholevidae) was evaluated by determinating ...levels of gene expression of two members of the family of heat shock proteins 70
kDa by qPCR. In both species,
hsc70 mRNA level was constant with increasing temperature, whereas a significant increase in the inducible member (
hsp70) mRNA was observed, higher in
N. pasai. This difference could be due to their in-cave distribution:
N. pasai colonizes the cave entrance where the temperature is more variable than the internal part where
N. mancinii is confined. These results demonstrated for the first time the occurrence of a heat shock response in troglobite insects and suggest the correlation between the intensity of this response and the adaptation to the cave environment.
Glaciers cover ∼10% of the Earth’s land surface, but they are shrinking rapidly across most parts of the world, leading to cascading impacts on downstream systems. Glaciers impart unique footprints ...on river flow at times when other water sources are low. Changes in river hydrology and morphology caused by climate-induced glacier loss are projected to be the greatest of any hydrological system, with major implications for riverine and near-shore marine environments. Here, we synthesize current evidence of how glacier shrinkage will alter hydrological regimes, sediment transport, and biogeochemical and contaminant fluxes from rivers to oceans. This will profoundly influence the natural environment, including many facets of biodiversity, and the ecosystem services that glacier-fed rivers provide to humans, particularly provision of water for agriculture, hydropower, and consumption. We conclude that human society must plan adaptation and mitigation measures for the full breadth of impacts in all affected regions caused by glacier shrinkage.
Due to their sensitivity, remote mountain lakes and streams are not only vulnerable to environmental change but also excellent sensors of such changes. Notwithstanding their importance as an ultimate ...resource of unpolluted waters, the alpine biome remains one of the less studied ecosystems in the world. This study involved the analysis of a database of zoobenthic communities collected in 36 inlets and 44 outlets of Swiss (Canton Bern) and Italian (Piedmont, Trentino-Alto Adige) Alpine lakes. All the streams are above the tree line and were sampled qualitatively in September/October (mostly in 2000) by disturbing the substrate and concentrating the dislodged animals with a standard pond net (250 μm mesh size). Generally higher population densities and taxon richness were found in the outlets than in the inlets. Fifty-seven per cent of taxa were common to the two stream types, with 17% found exclusively in the inlets and 26% in the outlets. Piedmont had the highest number of taxa found only in the region, Trentino-Alto Adige the lowest number. Insects represented 89% and 81% of the zoobenthic community of inlets and outlets, respectively. Among the insects, Diptera prevailed, with Chironomidae accounting for 68% of the mean inlet communities and 45% of those found in the outlets. The subfamily of Diamesinae was far more abundant in the inlets (16%) than in the outlets (1%). In contrast, the outlets hosted more Ephemeroptera, Trichoptera, Plecoptera, Oligochaeta and Tricladida. Some significant differences regarding the distribution of some species were found along the West–East and South–North gradients. The lakes appeared to affect the structure of the stream zoobenthic community by ameliorating the harsh physico-chemical conditions of the tributaries but no evidence was found indicating an increase in organic matter. In fact, filter-feeding invertebrates did not show any significant increase in the outlets, though the number of these taxa was higher downstream of the lakes.
1. A study on glacial stream ecosystems was carried out in six regions across Europe, from Svalbard to the French Pyrenees. The main aim was to test the validity of the conceptual model of Milner & ...Petts (1994) with regard to the zonation of chironomids of glacier‐fed rivers along altitudinal and latitudinal gradient.
2. Channel stability varied considerably, both on the latitudinal and altitudinal scale, being lowest in the northern regions (Svalbard, Iceland and Norway) and the Swiss Alps. Water temperature at the upstream sites was always <2 °C.
3. There was a prominent difference in taxonomic richness between the Alpine and the northern European regions, with a higher number of taxa in the south. In all regions, the chironomid community was characterized by the genus Diamesa and the subfamily Orthocladiinae. Of a total of 63 taxa recorded, two (Diamesa bertrami and Orthocladius frigidus) were common in all the regions except Svalbard.
4. On the basis of cluster analysis, seven distinct groups of sites were evident amongst glacial‐fed systems of the five regions (Pyrenees excluded). This classification separated the glacier‐fed streams on geographical, latitudinal and downstream gradients.
5. Canonical Correspondence Analysis (CCA) of environmental variables was carried out using 41 taxa at 105 sites. Slope, water depth, distance from source, water temperature and the Pfankuch channel stability index were found to be the major explanatory environmental variables. The analysis separated Diamesinae and typical upstream orthoclads from the other chironomids by low temperature and high channel instability.
6. In all six regions, Diamesa was present closest to the glacier. Within 200 m of the glacier snout, other genera of Diamesinae were found together with Orthocladiinae. Pioneer taxa like Diamesa species coexisted with later colonizers like Eukiefferiella minor/fittkaui in relatively unstable channels.
7. The longitudinal succession of chironomid assemblages across altitudinal and latitudinal gradients in glacial streams followed the same pattern, with similar genera and groups of species. The general aspects of the conceptual model of Milner & Petts (1994) were supported. However, Diamesa species have wider temperature limits than predicted and other Diamesinae as well as Orthocladiinae colonize metakryal habitats.
•Long-term Chironomidae response to chemical stressors have been hardly addressed.•Model predicts Chironomidae response across generations, stages, and latitudes.•Emergence reduction stronger with ...prevalence of early-instar larvae.•Emergence reduction twice as severe in the 2nd year of Bti application.•Model adaptable to other insects, chemicals, latitudes via adjusted parameterisation.
Chironomidae are the most abundant aquatic insect group and are important in providing energy and nutrients to aquatic and terrestrial food webs. The stress response of Chironomidae can vary with environmental conditions and time of pollutant exposure, making it difficult to understand the underlying mechanisms. Here, we use a dynamic population model to predict the potential effects of anthropogenic stressors on Chironomus riparius larvae and adult emergence for up to two years. We employed the non-chemical larvicide Bacillus thuringiensis var. israelensis (Bti) as a case study, as this stressor has been shown to reduce larval survival of C. riparius. To predict the responses of C. riparius adapted to variable geographic conditions, we simulated scenarios in which Bti is applied at three different latitudes in Europe. For each latitude, we also simulated a varying Bti application timing corresponding to a higher or a lower density of early-instar larvae, for which a higher sensitivity to Bti is documented. While acute exposure to Bti did not alter the patterns of larval development and adult emergence, in all scenarios and latitudes considered, the predicted reduction was stronger when Bti was applied to populations with a prevalence of early-instar larvae. Moreover, in all simulated scenarios, the reduction in the second year of Bti application was approximately twice as large as in the first year, revealing cumulative effects. Our model can be used to develop new hypotheses and test them through either empirical or in silico experiments to project the long-term effects of Bti on Chironomidae populations. The model can be theoretically applied to other insect groups and toxicants, and to different latitudinal scenarios by changing input parameters.
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