Cartographic analysis of woodlice fauna of the former USSR

An inventory of the woodlice fauna of the former USSR yielded 190 species, 64 of them were recorded from the territory of Russia. According to the cartographic analysis, the limits of distribution of epigean terrestrial isopods over the area, excluding mountains, is explained by temperature. No woodlice records were found outside the isocline of 120 days a year with the mean daily air temperature >10°C. The highest species diversity was found between the isoclines of 180 and 210 days. These areas correspond to forest-steppe and steppe zones

Effects of prescribed forest burning on carabid beetles (Coleoptera: Carabidae): a case study in south-eastern Norway

The influence of prescribed burning on ground beetles was studied in a single 12 ha stand that was partially clear-cut, selectively-cut and retained (= standing forest), and was compared to an unburned stand in 2002 in SE Norway. Thirty-two species were collected using Barber pitfall traps. Carabids were more numerous and more diverse in the burned area, compared to the unburned forest. Overall abundance was highest in the selectively-cut treatment, followed by the clear-cut and standing forest. Species diversity tended to increase in the sequence unburned forest – burned standing forest – burned selectively-cut – burned clearcut. Species composition differed little between the burned treatments. Pterostichus adstrictus, a species associated with open habitats and which frequently colonizes burned areas, was the most abundant species collected. It was most common in the burned area, particularly in the selectively-cut treatment. Our results suggest that burning of a single stand may support some carabid species, even endangered ones, although larger forest fires are probablymore effective for conservation purposes

Markfaunans rumsliga spridning i betad och orörd stäpp i Chernozem-zonen i Ryssland

Långvarig boskapsdrift har visats ge tydliga förändringar av stäppväxtligheten samt vissa effekter på markens makrofauna. Syftet med detta arbete var att undersöka markfaunans rumsliga spridning i marken i naturreservatet i Kurskområdet, Ryssland. En parcell med orörd stäpp och en med betesmark (ko/ha) undersöktes. Prover insamlades med en jordborr (10 cm) till 15 – 20 cm djup. I varje parcell togs totalt 144 prover (6 rader om 24 prover). Proverna togs tättintill varandra. Markfaunan sorterades ut från varje jordprov för hand och analyserades tillsammans med provets vikt, stenighet, rötter och förna. Vår hypotes var att den rumsliga spridningen skulle vara mer homogen i en stäpp än i en betesmark där biocenosen är mer fragmenterad. Den orörda stäppen hade 2 gånger högre vikt av rötter och 20 gånger högre vikt av förna. Dessa skillnader medförde också skillnader i markfauna. Det totala antalet markdjur var högre i stäppen (349/m2) än i betesmarken (246/m2). I stäpp dominerade Staphylinidae (72 eks/m2), Scarabaeidae-larver(63) och Julidae (50). I betesmarken dominerade Curaelionidae-larver (40), Scarabaedae-larver (31), Elateridae larvi (39). Antalet Myriapoda var 60 gånger högre i obetad stäpp och saknades nästan i betesmarken. Vid jämförelsen av stäppytor och betesytor framgick att båda saknade daggmaskar, antagligen på grund av torkan. Markfaunas spridning var heterogenare i stäppen än i betesmarken. Heterogeniteten var hos somliga djurgrupper, t.ex. skalbaggslarver, som sped sig inom stäppytan på så sätt att de förekom med förhöjt antal samtidigt som de saknades på andra områden. I betesmarken spred sig larverna däremot jämnt. Den erhållna resultaten vederlägger hypotesen om en mer agreggerad fauna i en betesmark. Antal markdjur visade en positiv korrelation med förnans vikt, både i stäppen och i betesmarken, men korrelationskoefficienten var högre i stäppen. Förnan saknades nästan i betesmarken och där dominerade markdjur som spred sig mer homogent. Deras spridning var oberoende av förnans vikt

Revisiting global trends in freshwater insect biodiversity: A reply

Abstract Jähnig et al. make some useful points regarding the conclusions that can be drawn from our meta‐analysis; however, some issues require clarification. First, we never suggested that there was a globally increasing trend of freshwater insect abundances, but only spoke of an average increasing trend in the available data. We also did not suggest that freshwater quality has improved globally, but rather that documented improvements in water quality can explain at least some of the trends we observed. Second, as we acknowledged, our data are not a representative set of freshwater ecosystems around the world, but they are what is currently accessible. Third, there is indeed no doubt that changes in abundance or biomass need not correlate with changes in other aspects of biodiversity, such as species richness or functional composition. Our analysis was specifically focused on trends in community abundance/biomass because it has been the subject of recent study and speculation, and is a widely available metric in long‐term studies. To better understand the recent changes in freshwater insect assemblages, we encourage freshwater ecologists to further open their troves of data from countless long‐term monitoring schemes so that larger and more comprehensive syntheses can be undertaken

Evidence of a trait-specific response to burning in springtails (Hexapoda: Collembola) in the boreal forests of European Russia

© 2017 Elsevier B.V. The reaction of soil fauna to forest fires is highly variable in space across large ecoregions, the reasons for which are still not completely documented. We tested regional differences in the response of springtail (Hexapoda: Collembola) taxonomic richness, total abundance and collembolan abundance, which share combinations of the two traits (reproduction mode and vertical distribution), in a pilot study within boreal forests of European Russia. We selected four stands burned five years ago and four respective controls in each of the three boreal forest subregions: northern, middle and southern taiga. Plots were located along a 1500. km-long north-south transect covering most of the existing climatic and edaphic gradient within this ecoregion. The General Linear Model (GLM) results showed that fire had a significant effect on the abundance of collembolans that shared certain trait combinations (sexually reproducing epiedaphic species), while the total collembolan abundance depended on the forest subregion, but not burning. The abundance of sexually reproducing epiedaphic springtails decreased in burned plots by 40%, on average, in comparison with the respective controls. This reduction was positively correlated with the degree of fire severity and negatively correlated with litter thickness and soil water holding capacity. We conclude that fires induce a consistent shift in the composition of the springtail functional trait community, which is driven more by the forest stand level of litter thickness and moisture than by subregional forest differences. Our study revealed the potential of the functional trait composition to be a sensitive and informative tool for tracing the effects of fire in boreal forests, which is relatively independent from regional differences

Identifying earthworms (Oligochaeta, Megadrili) of the Southern Kuril Islands using DNA barcodes

Identificación de las lombrices (Oligochaeta, Megadrili) del sur de las Islas Kuriles utilizando códigos de barras de ADN Las Islas Kuriles forman un archipiélago volcánico situado entre Hokkaido y Kamchatka. En este estudio analizamos las lombrices de tres de las Islas Kuriles meridionales: Kunashir, Shikotan y Yuri, utilizando el análisis morfológico y los códigos de barras de ADN. Nuestros resultados ponen de relieve el potencial de los códigos de barras de ADN para estudiar las lombrices: si bien en estudios anteriores solo se habían registrado seis especies y subespecies de lombriz en las Islas Kuriles meridionales, nosotros detectamos 15 grupos genéticos. Seis de ellos son especies cosmopolitas europeas; seis, especies asiáticas; y tres, sin determinar. A pesar de que no se encontraron lombrices europeas en Yuri, que está deshabitada desde la Segunda Guerra Mundial, estas especies dominaron en las islas Kunashir y Shikotan, que son más grandes y están habitadas, lo que sugiere que se trata de especies invasoras recientes. De las seis especies asiáticas, cinco tenían secuencias cox1 idénticas o muy emparentadas con las secuencias publicadas encontradas en el continente o en las islas del Japón y, por tanto, se trata de invasoras recientes.The Kuril Islands are a volcanic archipelago located between Hokkaido and Kamchatka. In this study we investigated earthworm fauna of three of the Southern Kuril Islands, Kunashir, Shikotan, and Yuri, using both morphological analysis and DNA barcoding. Our results highlight the potential of DNA barcoding for studying earthworm fauna: while previous studies reported only six earthworm species and subspecies on the Southern Kurils, we detected 15 genetic clusters. Six of them correspond to European cosmopolites; six, to Asian species, and three, to unidentified species. While no European earthworms were found on Yuri that is uninhabited since WWII, they dominated on larger and inhabited Kunashir and Shikotan, suggesting that they are recent invaders. Of the six Asian species, five had cox1 sequences identical or very closely related to published sequences from the mainland or the Japanese islands and thus are recent invaders.Identificación de las lombrices (Oligochaeta, Megadrili) del sur de las Islas Kuriles utilizando códigos de barras de ADN Las Islas Kuriles forman un archipiélago volcánico situado entre Hokkaido y Kamchatka. En este estudio analizamos las lombrices de tres de las Islas Kuriles meridionales: Kunashir, Shikotan y Yuri, utilizando el análisis morfológico y los códigos de barras de ADN. Nuestros resultados ponen de relieve el potencial de los códigos de barras de ADN para estudiar las lombrices: si bien en estudios anteriores solo se habían registrado seis especies y subespecies de lombriz en las Islas Kuriles meridionales, nosotros detectamos 15 grupos genéticos. Seis de ellos son especies cosmopolitas europeas; seis, especies asiáticas; y tres, sin determinar. A pesar de que no se encontraron lombrices europeas en Yuri, que está deshabitada desde la Segunda Guerra Mundial, estas especies dominaron en las islas Kunashir y Shikotan, que son más grandes y están habitadas, lo que sugiere que se trata de especies invasoras recientes. De las seis especies asiáticas, cinco tenían secuencias cox1 idénticas o muy emparentadas con las secuencias publicadas encontradas en el continente o en las islas del Japón y, por tanto, se trata de invasoras recientes

Radiofrequency Hyperthermia of Cancer Cells Enhanced by Silicic Acid Ions Released during the Biodegradation of Porous Silicon Nanowires

The radiofrequency (RF) mild hyperthermia effect sensitized by biodegradable nanoparticles is a promising approach for therapy and diagnostics of numerous human diseases including cancer. Herein, we report the significant enhancement of local destruction of cancer cells induced by RF hyperthermia in the presence of degraded low-toxic porous silicon (PSi) nanowires (NWs). Proper selection of RF irradiation time (10 min), intensity, concentration of PSi NWs, and incubation time (24 h) decreased cell viability to 10%, which can be potentially used for cancer treatment. The incubation for 24 h is critical for degradation of PSi NWs and the formation of silicic acid ions H+ and H3SiO4- in abundance. The ions drastically change the solution conductivity in the vicinity of PSi NWs, which enhances the absorption of RF radiation and increases the hyperthermia effect. The high biodegradability and efficient photoluminescence of PSi NWs were governed by their mesoporous structure. The average size of pores was 10 nm, and the sizes of silicon nanocrystals (quantum dots) were 3-5 nm. Degradation of PSi NWs was observed as a significant decrease of optical absorbance, photoluminescence, and Raman signals of PSi NW suspensions after 24 h of incubation. Localization of PSi NWs at cell membranes revealed by confocal microscopy suggested that thermal poration of membranes could cause cell death. Thus, efficient photoluminescence in combination with RF-induced cell membrane breakdown indicates promising opportunities for theranostic applications of PSi NWs. © 2019 American Chemical Society

Formation of Si/SiO2 Luminescent Quantum Dots From Mesoporous Silicon by Sodium Tetraborate/Citric Acid Oxidation Treatment

We propose a rapid, one-pot method to generate photoluminescent (PL) mesoporous silicon nanoparticles (PSiNPs). Typically, mesoporous silicon (meso-PSi) films, obtained by electrochemical etching of monocrystalline silicon substrates, do not display strong PL because the silicon nanocrystals (nc-Si) in the skeleton are generally too large to display quantum confinement effects. Here we describe an improved approach to form photoluminescent PSiNPs from meso-PSi by partial oxidation in aqueous sodium borate (borax) solutions. The borax solution acts to simultaneously oxidize the nc-Si surface and to partially dissolve the oxide product. This results in reduction of the size of the nc-Si core into the quantum confinement regime, and formation of an insulating silicon dioxide (SiO2) shell. The shell serves to passivate the surface of the silicon nanocrystals more effectively localizing excitons and increasing PL intensity. We show that the oxidation/dissolution process can be terminated by addition of excess citric acid, which changes the pH of the solution from alkaline to acidic. The process is monitored in situ by measurement of the steady-state PL spectrum from the PSiNPs. The measured PL intensity increases by 1.5- to 2-fold upon addition of citric acid, which we attribute to passivation of non-radiative recombination centers in the oxide shell. The measured PL quantum yield of the final product is up to 20%, the PL activation procedure takes <20 min, and the resulting material remains stable in aqueous dispersion for at least 1 day. The proposed phenomenological model explaining the process takes into account both pH changes in the solution and the potential increase in solubility of silicic acid due to interaction with sodium cations

Description of a new species of the genus Protracheoniscus Verhoeff, 1917 and redescription of Protracheoniscus kryszanovskii Borutzky, 1957 from the southeast of European Russia (Isopoda, Oniscidea, Agnaridae)

A new species of woodlice, Protracheoniscus pokarzhevskii Gongalsky & Turbanov, sp. n. is described from Kalmykia, NE Pre-Caspian region, Russia. Protracheoniscus kryszanovskii Borutzky, 1957 from the same area is also redescribed. Diagnostic features of these species as well as affinities within the genus are provided and discussed

Disproportionate declines of formerly abundant species underlie insect loss

Studies have reported widespread declines in terrestrial insect abundances in recent years1,2,3,4, but trends in other biodiversity metrics are less clear-cut5,6,7. Here we examined long-term trends in 923 terrestrial insect assemblages monitored in 106 studies, and found concomitant declines in abundance and species richness. For studies that were resolved to species level (551 sites in 57 studies), we observed a decline in the number of initially abundant species through time, but not in the number of very rare species. At the population level, we found that species that were most abundant at the start of the time series showed the strongest average declines (corrected for regression-to-the-mean effects). Rarer species were, on average, also declining, but these were offset by increases of other species. Our results suggest that the observed decreases in total insect abundance2 can mostly be explained by widespread declines of formerly abundant species. This counters the common narrative that biodiversity loss is mostly characterized by declines of rare species8,9. Although our results suggest that fundamental changes are occurring in insect assemblages, it is important to recognize that they represent only trends from those locations for which sufficient long-term data are available. Nevertheless, given the importance of abundant species in ecosystems10, their general declines are likely to have broad repercussions for food webs and ecosystem functioning