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We studied abundance, diversity, and composition of soil invertebrates along snowmelt gradients to generally understand how soil animal communities are responding to life conditions across snowbeds along a west–east transect of the European Alps and to create a reference inventory for future investigations of climate change effects on snowbed habitats. We extracted microarthropods (collembolans, oribatid mites) and macroinvertebrates (spiders, beetles, insect larvae) from soil cores taken from three sections along the snowmelt gradient: high (early snowmelt), middle, and low (late snowmelt) sections. Linear models showed no correlations between either soil conditions or time of snowmelt and densities of soil animals. A small, though statistically significant, variation in the generally high soil organic matter and sand contents and high porosity of snowbed soils seems to have no effect on soil invertebrates. Species found along the snowmelt gradient were in similar shares generalist and specialist species. Microarthropod community composition in general was driven by soil porosity and soil organic matter content; for macroinvertebrate community composition we found no specific driver. We conclude that invertebrate species assemblages in snowbeds are rather similar in the European Alps. [ABSTRACT FROM AUTHOR]

Soil macro-invertebrates play an important role in the formation and functioning of soils, which makes them indispensable for all terrestrial ecosystems, including high alpine soils. However, in the latter, knowledge on species identity, diversity, and functionality of macro-invertebrate soil communities is scarce. Here, we address this knowledge gap by investigating the structural and functional composition of soil macro-invertebrate communities in high alpine sites of the European Alps that differ in sheep grazing intensity (low, medium, and high). Abundance data were combined with the analysis of natural variations in stable isotope ratios ( 13 C/ 12 C, 15 N/ 14 N) of food sources and soil animals, allowing insight into the trophic structure of the decomposer community. The presence of sheep significantly increased the abundance of Nematocera, but reduced the abundance of most other taxa. Diplopoda were found exclusively at the low elevation site with almost no sheep grazing, while Diptera larvae increased in numbers at higher elevation sites. Lumbricidae species were abundant at all sites except the highest site, which was intensively grazed by sheep and also used as a resting place. In contrast, trophic relations were not affected by sheep grazing intensity, four trophic groups were clearly distinguished, pointing to a relatively simple food web structure: (1) primary decomposers, (2) secondary decomposers and dung feeders, (3) root and fungal feeders, and (4) predators. We suggest that the shallow soils with high organic matter do not allow the formation of more complex food webs. [ABSTRACT FROM AUTHOR]

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In glacier forelands spiders constitute a large proportion of the invertebrate community. Therefore, it is important to be able to determine the species that can be found in these areas. Linyphiid and theridiid spider identification is currently not possible in juvenile specimens using traditional morphological based methods, however, a large proportion of the population in these areas are usually juveniles. Molecular methods permit identification of species at different life stages, making juvenile identification possible. In this study we tested a molecular tool to identify the 10 most common species of Linyphiidae and Theridiidae found in three glacier foreland communities of the Austrian Alps. Two multiplex PCR systems were developed and over 90% of the 753 field-collected spiders were identified successfully. The species targeted were found to be common in all three valleys during the summer of 2010. A comparison between the molecular and morphological data showed that although there was a slight difference in the results, the overall outcome was the same independently of the identification method used. We believe the quick and reliable identification of the spiders via the multiplex PCR assays developed here will aid the study of these families in Alpine habitats. [ABSTRACT FROM AUTHOR]

On alpine pastureland the decline in large-bodied earthworm numbers and biomass after abandonment of management might be the result of a shift from highly palatable grass litter to poorly digestible leaf litter of dwarf shrubs. To test this hypothesis, we analysed nitrogen, phosphorous and total phenolic contents of fresh and aged litter of eight commonly occuring alpine plant species and compared consumption rates of these food sources in a controlled feeding experiment with Lumbricus rubellus (Lumbricidae). Furthermore, we analysed the microbial community structure of aged litter materials to check for a relationship between the microbial characteristics of the different plant litter types and the food choice of earthworms. Plant litters differed significantly in their chemical composition, earthworms, however, showed no preference for any litter species, but generally rejected fresh litter material. Microbial community structures of the litter types were significantly different, but we could find no evidence for selective feeding of L. rubellus. We conclude that L. rubellus is a widespread, adaptable ubiquist, which is able to feed on a variety of food sources differing in quality and palatability, as long as they have been exposed to wheathering. [ABSTRACT FROM AUTHOR]

Abstract: Faecal pellets of macro-decomposers form an important component of upper soil layers. It is, however, not yet specifically known which species’ faecal pellets are important in the process of humus and soil formation. Here we present a novel approach, based on the detection of short DNA fragments, to species-specifically assign faecal pellets to their detritivorous producers. Using diagnostic polymerase chain reaction (PCR), DNA of the two millipede species Cylindroiulus fulviceps and C. meinerti, abundant macro-decomposers on European alpine pastureland, could be detected in their faecal pellets. Although in both species detection was possible up to 5 days post-defecation (no longer intervals were tested), detection rates were significantly higher in C. fulviceps (81.3%) than in Cylindroiulus meinerti (60.9%) in repetitive PCRs. Employing a binomial mixture model, the probability that the producer’s DNA was present in a faecal sample which tested negative in five subsequent PCRs was estimated as 22.0% for C. fulviceps and 41.9% for C. meinerti, suggesting to adopt a flexible stopping rule for assaying this type of samples. This proof-of-concept study demonstrates that the molecular assignment of faecal pellets to their macro-invertebrate producers is possible, offering a new approach to examine the role of decomposer faecal pellets in soil formation and functioning as well as to complement molecular profiling of faunal communities. [Copyright &y& Elsevier]

This article documents the public availability of (i) microbiomes in diet and gut of larvae from the dipteran Dilophus febrilis using massive parallel sequencing, (ii) SNP and SSR discovery and characterization in the transcriptome of the Atlantic mackerel ( Scomber scombrus, L) and (iii) assembled transcriptome for an endangered, endemic Iberian cyprinid fish ( Squalius pyrenaicus). [ABSTRACT FROM AUTHOR]

Abstract: We tested whether experimental summer drought affects the transfer of recently photosynthesized carbon from plants to soil mesofauna in a subalpine meadow. From day one after 13CO2 pulse-labelling of the plant canopy, roots, collembolans and mites were enriched in δ13C in control, but not in drought plots. However, as the difference in δ13C between roots and soil animals was not affected by the drought treatment, we conclude that drought affects the tight linkage between photosynthesis and soil mesofauna primarily via functional responses of plants rather than via changes in the mesofauna. [Copyright &y& Elsevier]