Search

Different species of amphibians often breed in the same water bodies and their diets overlap. Theoretically, this might lead to a competitive elimination of either one but there are multispecies temporal larval communities persisting over the years. We hypothesized that larvae of two common European anuran species segregate their trophic niches despite their omnivorous habits and possible similarity of trophic levels. We assessed interspecific differences in food assimilation at larval and postmetamorphic stages of two anurans in an ecosystem of forest lake and an adjacent terrestrial ecosystem using a stable isotope approach. Trophic level of tadpoles of both species corresponded to those of some benthic invertebrate predators. Trophic positions of postmetamorphic juveniles corresponded to those of terrestrial invertebrate predators. The unpredictable decrease of δ15N values in anuran tissues during the transition from aquatic to terrestrial habitats corresponded to the differences between aquatic and terrestrial isotopic baselines whereas dynamics of normalized δ15N confirmed an increase in their trophic level. Finally, we detected a strong segregation of trophic niches of the two species at both larval and postmetamorphic stages. The described niche separation provides an important prerequisite for decreasing possible intraspecific competition and promoting long-term co-existence of these syntopic anurans.

The first ever list of terrestrial enchytraeids of Eastern Dagestan includes 12 species belonging to five genera. Several species from studied localities may be assigned as undescribed, therefore additional comprehensive research of enchytraeid fauna from Eastern Dagestan is required. A new enchytraeid species of the genus Fridericia Michaelsen, 1889, Fridericia samurai sp. nov., is described from Eastern Dagestan, Russia. It clearly differs from other species of the genus by short and simple oesophageal appendages, not subdivided spermathecal diverticula, and the absence of spermathecal ectal glands and clitellum on ventral side.

Disturbances alter biodiversity via their specific characteristics, including severity and extent in the landscape, which act at different temporal and spatial scales. Biodiversity response to disturbance also depends on the community characteristics and habitat requirements of species. Untangling the mechanistic interplay of these factors has guided disturbance ecology for decades, generating mixed scientific evidence of biodiversity responses to disturbance. Understanding the impact of natural disturbances on biodiversity is increasingly important due to human-induced changes in natural disturbance regimes. In many areas, major natural forest disturbances, such as wildfires, windstorms, and insect outbreaks, are becoming more frequent, intense, severe, and widespread due to climate change and land-use change. Conversely, the suppression of natural disturbances threatens disturbance-dependent biota. Using a meta-analytic approach, we analysed a global data set (with most sampling concentrated in temperate and boreal secondary forests) of species assemblages of 26 taxonomic groups, including plants, animals, and fungi collected from forests affected by wildfires, windstorms, and insect outbreaks. The overall effect of natural disturbances on α-diversity did not differ significantly from zero, but some taxonomic groups responded positively to disturbance, while others tended to respond negatively. Disturbance was beneficial for taxonomic groups preferring conditions associated with open canopies (e.g. hymenopterans and hoverflies), whereas ground-dwelling groups and/or groups typically associated with shady conditions (e.g. epigeic lichens and mycorrhizal fungi) were more likely to be negatively impacted by disturbance. Across all taxonomic groups, the highest α-diversity in disturbed forest patches occurred under moderate disturbance severity, i.e. with approximately 55% of trees killed by disturbance. We further extended our meta-analysis by applying a unified diversity concept based on Hill numbers to estimate α-diversity changes in different taxonomic groups across a gradient of disturbance severity measured at the stand scale and incorporating other disturbance features. We found that disturbance severity negatively affected diversity for Hill number q = 0 but not for q = 1 and q = 2, indicating that diversity–disturbance relationships are shaped by species relative abundances. Our synthesis of α-diversity was extended by a synthesis of disturbance-induced change in species assemblages, and revealed that disturbance changes the β-diversity of multiple taxonomic groups, including some groups that were not affected at the α-diversity level (birds and woody plants). Finally, we used mixed rarefaction/extrapolation to estimate biodiversity change as a function of the proportion of forests that were disturbed, i.e. the disturbance extent measured at the landscape scale. The comparison of intact and naturally disturbed forests revealed that both types of forests provide habitat for unique species assemblages, whereas species diversity in the mixture of disturbed and undisturbed forests peaked at intermediate values of disturbance extent in the simulated landscape. Hence, the relationship between α-diversity and disturbance severity in disturbed forest stands was strikingly similar to the relationship between species richness and disturbance extent in a landscape consisting of both disturbed and undisturbed forest habitats. This result suggests that both moderate disturbance severity and moderate disturbance extent support the highest levels of biodiversity in contemporary forest landscapes., British Ecological Society LRB20/1002, Junta de Andalucia, European Commission B-FQM-366-UGR20, Centro ANID Basal FB210015, Direccion de Investigacion Universidad de La Frontera DIUFRO DI20-0066, Federal Ministry of Education & Research (BMBF), Max Planck Society, INCT Madeiras da Amazonia, Federal Ministry of Education & Research (BMBF) 01LB1001A 01LK1602A, Brazilian Ministry of Science, Technology and Innovation (MCTI/FINEP) 01.11.01248.00, Russian Science Foundation (RSF) 21-14-00227, Ministry of Education, Youth & Sports - Czech Republic Czech Republic Government LTC 20058, Czech Academy of Sciences RVO67985939, UK Research & Innovation (UKRI), Natural Environment Research Council (NERC) GR3/11743, Greek project POL-AEGIS, Program THALES MIS 376737, Projekt DEAL TH 2218/5-1

Soil organisms drive major ecosystem functions by mineralising carbon and releasing nutrients during decomposition processes, which supports plant growth, aboveground biodiversity and, ultimately, human nutrition. Soil ecologists often operate with functional groups to infer the effects of individual taxa on ecosystem functions and services. Simultaneous assessment of the functional roles of multiple taxa is possible using food-web reconstructions, but our knowledge of the feeding habits of many taxa is insufficient and often based on limited evidence. Over the last two decades, molecular, biochemical and isotopic tools have improved our understanding of the feeding habits of various soil organisms, yet this knowledge is still to be synthesised into a common functional framework. Here, we provide a comprehensive review of the feeding habits of consumers in soil, including protists, micro-, meso- and macrofauna (invertebrates), and soil-associated vertebrates. We have integrated existing functional group classifications with findings gained with novel methods and compiled an overarching classification across taxa focusing on key universal traits such as food resource preferences, body masses, microhabitat specialisation, protection and hunting mechanisms. Our summary highlights various strands of evidence that many functional groups commonly used in soil ecology and food-web models are feeding on multiple types of food resources. In many cases, omnivory is observed down to the species level of taxonomic resolution, challenging realism of traditional soil food-web models based on distinct resource-based energy channels. Novel methods, such as stable isotope, fatty acid and DNA gut content analyses, have revealed previously hidden facets of trophic relationships of soil consumers, such as food assimilation, multichannel feeding across trophic levels, hidden trophic niche differentiation and the importance of alternative food/prey, as well as energy transfers across ecosystem compartments. Wider adoption of such tools and the development of open interoperable platforms that assemble morphological, ecological and trophic data as traits of soil taxa will enable the refinement and expansion of the multifunctional classification of consumers in soil. The compiled multifunctional classification of soil-associated consumers will serve as a reference for ecologists working with biodiversity changes and biodiversity–ecosystem functioning relationships, making soil food-web research more accessible and reproducible.

Nesting water bird colonies may act as important drivers of aquatic-terrestrial nutrient turnover in coastal ecosystems. By depositing a large amount of guano, they induce changes in the structure of soils, flora, and fauna. However, little is known about how nesting water bird colonies influence soil fauna, especially in a Mediterranean type of coastal landscape. In this study, focus was placed on how time had elapsed since the last overwintering activity of cormorant colonies, as a factor that affects the structure of springtail communities and edaphic parameters in the Black and Azov Sea coastal forest ecosystems. Black Sea coastal forests with active overwintering cormorant colonies have been characterized by a decreased total abundance, genus richness, and an abundance of certain functional groups of springtails. In contrast, in the coastal forests of the Azov Sea, where the last cormorant overwintering activity was observed 8 years ago, the total abundance of collembolans, and particularly epiedaphic species, had increased in comparison with the control sites. It was concluded that the overwintering activity of cormorants had a negative effect on springtails in previously undisturbed areas within the Mediterranean coastal forests. Nevertheless, the long-term absence of cormorant colonies may lead to the recovery of collembolan total abundance and genus richness in the previously affected areas.

A seabird (Phalacrocorax carbo) colony overwintering for three consecutive years in a pine forest near the Black Sea coast caused severe damage to the vegetation. The impact of excessive nutrients input from this colony increased soil acidity, N, P, Cu and S-content in soil and might therefore affect soil macrofauna. We compared the abundance of main functional trait guilds and the total abundance of soil macrofauna within impact and control pine forests. No significant difference between the sites was noted in taxonomic richness, total macrofauna abundance and abundance of mobile, belowground, phytophagous and predatory invertebrates. However, the abundance of poorly mobile, poorly mobile epibiontic, and these both traits of saprophagous macrofauna guilds was significantly higher in the control sites. We conclude that three-year wintering of a seabird colony in forest can lead to drastic changes in the macrofauna communities structure due to allochthonous input of nutrients.

Isotopic signatures of carbon and nitrogen are widely used for analysis of the structure of food webs in aquatic ecosystems. The study of animals raises a number of methodological questions, including choice of representative tissues and organs for sampling as well as storage of the studied organisms. Furthermore, the impacts of preservation methods can be tissue-specific, age-specific, and even taxon-specific, thus, studies of these impacts on particular taxa are necessary. We focused on the C and N isotope composition of the common toad (Bufo bufo), one of the most widespread European anuran amphibians. We hypothesized that its different tissues and organs may vary in isotopic composition, and ethanol and freezing may have different effects on isotopic values. Our results showed that both “tissue” and “storage method” factors significantly affected the δ13C values of tadpoles and postmetamorphic juveniles, whereas only the “tissue” factor had a significant effect on the δ15N values. The two stages, tadpoles and postmetamorphs, should be analyzed separately despite the brief postmetamorphic period of the juveniles. The skin, legs, muscles, and tail in tadpoles and legs, muscles and heart in juveniles can be used for δ13C and δ15N analysis regardless of the method of storage. The results will serve for the optimization of future study designs in isotopic ecology.

Communities of soil animals (meso- and macrofauna) in rice paddies tend to be fragmented, and have extremely low abundance. Nevertheless, some groups, such as enchytraeids, may become dominant in flooded conditions, as shown in tropical rice agroecosystems. However, the fauna and functional composition of enchytraeids (Annelida, Clitellata, Enchytraeidae) under such conditions have not yet been studied at temperate latitudes. We have investigated enchytraeid communities and the ratio of their functional groups in the main rice-growing regions of Russia: Krasnodar krai, Primorsky krai, and the Republic of Kalmykia. Samples were taken in summer–early autumn of 2016 in four habitat types: flooded rice paddies, drained paddies occupied by upland crops, adjacent bunds, and undisturbed grasslands (control). Generalized linear model analysis showed that the factor habitat type and its interaction with the factor region had a significant effect on the total enchytraeid abundance, with the factor region alone having no such effect. Their abundance was the highest in the control habitats and bunds (mean and standard error for all the regions: 3278 ± 1131 and 3255 ± 762 ind./m2, respectively), being insignificantly lower in the paddies under upland crops (1282 ± 850 ind./m2) and decreasing to a minimum of 415 ± 323 ind./m2 in the flooded paddies. A comparison between the last two habitat types shows that enchytraeids can relatively quickly restore their abundance in the rice paddies after draining. Principal component analysis revealed a positive correlation between the density of enchytraeids belonging to basophilous ecological group and bioavailable phosphorus content. The correlation between the abundance of acidophilous enchytraeids and this parameter was negative. Thus, the abundance ratio of enchytraeid ecological groups could be used as an informative indicator of the concentrations of nutrient elements and depends on physical and chemical characteristics of paddy soils. Despite the low abundance of enchytraeids in these soils, they can be an important component of the detrital food webs during periods of paddy-drainage in intensive rice agroecosystems at temperate latitudes.

The contribution of soil enchytraeids (potworms) to carbon cycling is often considered marginal and is therefore rarely quantified. In our experiment we aimed at evaluating the impact of the model enchytraeid species Enchytraeus buchholzi Vejdovsky, 1879 on rice straw degradation and associated CO2 release from soil. We filled 48 microcosms with soil collected in rice paddies of the Republic of Kalmykia, Russia, at 75% water holding capacity and added 0.5 g dry rice straw sealed in litterbags to each of them. Half of the microcosms were inoculated with 100 potworms. On days 3, 6, 9, 14, 21 and 31 after the start of the experiment, we measured CO2 emissions from soil. In addition, we terminated four microcosms with and four without enchytraeids at each of these dates to measure both rice straw mass loss and enchytraeid recovery rates. E. buchholzi significantly accelerated the relative rice straw mass loss (10.2 ± 1.4 and 14.2 ± 2.0%, respectively). It also significantly reduced CO2 emissions by 35% on average across the whole observation period. Though the number of potworms extracted dropped by 61% of the initial density up to day 9, it then consistently increased and reached a mean density of 365 individuals per microcosm at the end of the experiment. Considering both the rapid reproduction of E. buchholzi and the efficient mitigation of CO2 release, the promotion of enchytraeid activity may be a promising management measure for stabilizing carbon in paddy soils amended with rice straw. This opens up innovative perspectives for further research on exploiting the potential of the soil fauna for sustainable recycling of rice crop residues.

We tested for fire-induced (5–6 years post-fire) changes in the structure and functioning of the soil food web along a 3000-km north–south transect across European Russia, spanning all major forest types in the northern hemisphere outside the tropics. The total biomass of the detrital food web, including microbes and invertebrates, was not affected by fire. However, fire reduced the biomass of microfauna and mites, but had no impact on mesofauna or macrofauna. Fire also reduced rates of carbon (C) mobilisation by soil biota. Our results demonstrate that fire-induced shifts in soil food webs have significant short-term effects on forest soil C cycling, but that these effects vary across forest types and geographic locations.

We performed a mesocosm experiment with rice paddy soils of three different soil types which were collected in the three major regions of rice production in Russia: Krasnodarsky Krai, the Republic of Kalmykia and Primorsky Krai. We used the earthworm species Eisenia fetida (Savigny 1826), introduced at different densities (0, 2, 4 and 6 individuals per mesocosm with an area of 69.4 cm2 and a soil column height of approximately 10 cm) to assess rice straw decomposition and carbon stabilization in the three soil types. After 20 days of the experiment, straw amendment consistently increased CO2 release from all three soil types. The effect was highest in the soil of Krasnodarsky Krai after a straw amendment was combined with 4 earthworms per mesocosm. The effect of earthworms on CH4 release remained soil type specific but did not demonstrate any synergy with the straw amendment. We also recorded the highest enrichment of soil with carbon from the rice straw when compared with the control mesocosms without straw amendment (the difference was 31.5 mg g−1 soil dwt) under the treatment with four earthworms, and this result was independent of soil type. We conclude that the practice of rice straw reincorporation with the amendment of a certain number of earthworms provides a potentially viable way to recycle crop residue.

The impact of fires on nematode diversity, abundance and biomass was assessed in 20 burnt forests and 20 adjacent control plots across a 3000-km-long north-south transect in European Russia. The transect covered five main forest types (Mediterranean and broadleaved forests, southern, middle, and northern taiga). In spring 2015, we assessed major abiotic parameters of soil, soil microbial PLFA markers, and nematode community characteristics (genus richness, abundance, biomass and trophic structure) in the burnt and control plots. Generic richness was the highest in the southern taiga (22 genera) declining both northwards (down to 16) and southwards (down to 13 genera). The highest abundance of nematodes was recorded in the Mediterranean forests (139.4 ± 15.1 ind. g−1 soil dwt, control site) and the lowest in the northern taiga (10.8 ± 1.2 ind. g−1 soil dwt, burnt site). Biomass followed the same pattern with slight deviations. Abundance and biomass of soil nematodes was not significantly affected by fires in any ecoregion with the exception of Mediterranean forests. We detected consistent fire effects on the abundance of particular nematode feeding groups. Trophic groups abundance of soil nematode communities were considerably modified in burnt forests due to the increase in abundance of bacterial-feeding nematodes and reduced number of hyphal-feeding, plant-associated and plant-feeding nematodes. This increase in bacterial-feeding nematode biomass coincided with the growth of the ratio between bacterial and fungal biomass in pyrogenic soils. pH of soil solution and actual denitrification rate in the burnt forests correlated with the biomass of predatory nematodes. We conclude that, five years after fire, the structure of the microbial community, pH of soil solution and denitrification activity correlate with the ratio of feeding groups of belowground nematode communities in these forests. Taking into account considerable nematode biomass in soil, shifts in the ratio of trophic groups after fires induced by these factors may potentially lead to changes in the level of ecosystem functions which they deliver in burnt forests.

We assessed the impact of forest fires on macrofauna taxonomic richness, abundance and total biomass in 20 forests burnt five years ago and 20 respective control plots along a 3000-km-long north-south transect in European Russia that covered five major forest types (Mediterranean and broadleaved forests, southern, middle, and northern taiga). In parallel we assessed basic soil abiotic parameters in these stands. Within forest type, the spatial variance of macrofauna total biomass was 1.8 times higher in the burnt forests than in the controls. Due to this increase of variance in the burnt forests, the main effect of forest type on soil macrofauna parameters was generally weaker. Among different soil abiotic parameters, higher level of uniformity of macrofaunal community parameters between different forest types was explained by the labile P and N content in the soil, water-holding capacity and soil moisture. Presence of open areas within the burnt forests seems to be the leading driver of the increased similarity of soil macrofauna communities across different forest types. Forest fires thus act as a powerful force that raises within-forest-type soil macroinvertebrate beta-diversity and associated biomass fluctuations. At the same time burning reduces soil macrofauna gamma-diversity due to increased faunistic similarity between different forest types. This has potentially important implications for the functioning of soil macroinvertebate communities in the pyrogenic forests and its dependency on macroclimatic conditions.

Functionality of soil food webs after forest fires remains generally unexplored. We address this question by studying both burnt and unburnt spruce forests in Central European Russia (Tver Region). In August 2014 we sampled two spatially distant blocks consisting of forest areas burnt in 2010 and the respective unburnt controls. We analyzed biomass and structure of soil food webs as well as carbon mobilization with respect to carbon stocks in the dead wood, litter and soil after burning. The biomass of soil fauna was moderately reduced in the burnt plots. For some groups like testate amoebae and enchytraeids, however, this decrease was highly significant and corresponded with the decreased C-stock in litter. For the other taxa changes in biomass were insignificant. At the same time C-flow through the soil food web after fire was strongly reduced mainly due to the reduction of biomass of active fungi and secondary decomposers. The overall consumption rate of detritus by the soil food web strongly decreased in the burnt forests and was maintained predominantly by the decomposition activity of bacteria instead of fungi. This resulted in the reduction of the total soil food web functionality related with C-mobilization in the forests four years after a fire event. We compared rates of carbon mobilization by soil food webs in burnt and unburnt boreal forests in Central Russia. Despite of only slight decrease in soil animal biomass, consumption rate of carbon in the soil food webs after fire was considerably lower and mainly associated with soil bacteria instead of fungi.

Fires change physical, chemical and biotic conditions of forest ecosystems. They also strongly affect soil macrofauna including key soil ecosystem engineers and regulators of soil-related processes in forest soils. However, due to a wide range of traits attributable to macroinvertebrates, the effect of forest burning on the macrofauna can be quite contrasting and still has not been quantified. We assessed the impact of forest fires on macrofauna taxonomic richness, abundance, total biomass and biomass of animals belonging to different functional traits in 20 forests burnt five years ago and 20 respective controls plots along a 3000-km-long north-south transect in European Russia which covered five major forest biomes (Mediterranean and broadleaved forests, southern, middle, and northern taiga). Actual abundance, biomass and taxonomic diversity of the soil macrofauna showed remarkable stability after burning and were specific to forest biome. However, soil macrofauna trait composition was consistently affected by fire. Relatively immobile taxa inhabiting top of the forest floor and sharing saprophagy suffer most from the consequences of fire five years after burning. We have concluded that resident groups of soil macrofauna sharing saprophagy seem to avoid top soil as one of the most damaged “frontiers” of the burnt soil ecosystem possibly due to both unfavorable hydroclimatic conditions in the burnt patches and lack of suitable resources. At the same time damaged soil surface creates a barrier in the way of the resident soil macroinvertebrate taxa distribution due to their inability to quickly transit patches with harsh conditions.

Cigarette butts (CBs) represent the most common, though poorly biodegradable, type of waste on Earth. Thrown on the soil surface, they can remain unchanged for years, poisoning surrounding ecosystems with toxins accumulated during the smoking process. However, there is practically no data on the effect of smoked CBs on soil biota or soil animals in particular, nor on the potential of edaphic fauna to facilitate their decomposition. One of the most promising agents among soil animals are earthworms, which are known to be beneficial in the processes of recalcitrant organic matter degradation and stimulation of microbial activity in detrital food webs. In a microcosm experiment with the sod podzolic soil, we aimed at testing the effect of the commonly cultured epigeic earthworm Eisenia fetida (Savigny 1826) on the biodegradation rate of CBs and the possible adverse effects of this waste on the species. The experiment had a full-factorial design with three categorical predictors: CB number (0, 1 and 3 per microcosm); smoking condition (smoked and unsmoked CBs) and two levels of earthworm amendment (0 and 4 per microcosm). During 70 days of the experiment, we did not observe any smoked CB-induced mortality of earthworms. The addition of E. fetida significantly increased the CB mass loss across all treatment combinations. Specifically, earthworms improved the decomposition rate from 30 to 36% (p Summary We demonstrated that earthworms can efficiently decompose smoked and unsmoked cigarette butts regardless of their toxic potential and simultaneously reduce associated microbial activity.

Routes of aquatic allochthonous inputs (aquatic subsidies) to detrital food webs are studied, as is the effect of aquatic subsidies on the functional and taxonomic structure of soil invertebrate communities in coastal ecosystems. The study took place in the coastal zone of an oxbow lake of the Pra River in the Oka Reserve. The results indicate a strong dependence of soil animals in the coastal habitats on aquatic subsidies. Isotopic analysis shows that aquatic resources enter soil food webs not only via predators feeding on flying insects or aquatic prey, but also via saprophages decomposing organic debris of aquatic origin. The contribution of aquatic subsidies to the energy balance of soil invertebrates decreases rapidly with increasing distance from the lake. The fraction of aquatic carbon in tissues of collembolans and saprophages is negligible already a few meters from the water edge. The dependence of predatory invertebrates on aquatic resources can be traced at somewhat greater distance (tens of meters).

Relations between soil biota diversity and its contribution to the performance of some ecosystem functions were assessed based on the results obtained in undisturbed and burned spruce forests near the Central Forest Nature Biosphere Reserve (Tver oblast). In August 2014, in two 4-year-old burned areas, abiotic parameters of the soils, indicators of the state of the microbial communities, the number, taxonomic diversity, and the abundance of the main groups of soil invertebrates (testate amoebae, nematodes, enchytraeids, mites, collembolans, and the mesofauna as a whole) were determined. In the soils of the burned areas, higher CO2, CH4, and N2O emissions were observed. The number of bacterial cells remained similar, and the total length of active mycelium was not significantly different. All this implies a certain intensification of biogenic processes promoting the mobilization of carbon and nitrogen after fire. The number of most of the groups of soil animals was lower (not always significantly) in the burned area than that in the soils of the undisturbed forests. The changes in the taxonomic diversity were specific for each taxon studied. Overall, the diversity of invertebrates was related to the litter thickness. However, the high taxonomic diversity of soil fauna did not always correspond to the active functioning of the ecosystem. Thus, for some taxa, a quite close correlation was found, for instance, between the total number of species (of testate amoebae in particular) and the berry crop, as well as between the soil mesofauna population and the dead wood stock. The total diversity of the investigated taxa included in the detrital trophic web was the most reliable indicator of the carbon stock in the burned areas.

Burning is the most common practice for rice straw disposal. Due to associated negative environmental and climatic effects, development of viable alternatives, preferably based on the natural functions of soil biota are needed. In the conditions of non-tropical rice-growing systems, where periods of flooding are very short, such an approach seems to be particularly promising. We carried out a mesocosm experiment to assess the possibility of using the model earthworm species Eisenia fetida (Savigny 1826) to decompose rice residues and control associated CO2 and CH4 emissions from paddy soils at different soil moisture levels. We filled 96 mesocosms with three types (32 each) of rice paddy soils collected in key regions of rice production in Russia: Krasnodarsky Krai (the Sea of Azov lowland, Calcic Phaeozems), the Republic of Kalmykia (the Volga river valley, Haplic Phaeozems) and Primorsky Krai (Khanka lake lowland, the Russian Far East, Umbric, Histic Fluvisols). We added 2.5 g dry rice straw in each mesocosm. The experiment had a full factorial design including three categorical factors: soil type (n = 3), soil moisture level (12, 25, 50 and 75% soil water holding capacity) and E. fetida earthworm addition (none and 4 individuals per mesocosm). The integral emission of CO2 across the observation period of 10 days significantly differed between moisture classes with the highest values at 25% (p

It is not clear which mechanisms are responsible for changing soil biological activity following a fire. To address this knowledge gap, we measured such parameters of soil biological activity as flux rates of CH4, and CO2 and identified key environmental parameters that can influence soil biological activity. Soil samples were collected in burned and adjacent unburned control forests, along a 3000 km-long north-south transect in European Russia. A raw biological activity of tested soil samples varied significantly between forest types, but not between burned and control forest stands. Linear mixed effect modeling demonstrated a striking contrast in the importance of different drivers in sustaining a soil biological activity in the burned and control forests. The optimal model of basal soil respiration consisted of: “Soil moisture” (26%), “Fire treatment × Soil moisture × Labile soil N:P ratio” (21%), and “Fire treatment × Labile soil C × Labile soil N:P ratio” (13%). The model for CH4 in turn was defined by interactions of bulk and labile soil C with soil moisture and other factors. Our study clearly demonstrated that forest fires affect soil biological activity rather indirectly through modifying soil properties. The results enable forecasting post-fire effects on soil functioning in a changing climate under varied fire regimes.

Isotopic analysis has become an important tool in the study of lateral links between ecosystems. The isotopic composition of carbon in terrestrial and aquatic primary producers can differ significantly, which provides an opportunity to identify the “marine” or “freshwater” carbon in the tissues of terrestrial animals. We measured the isotopic composition of C and N in tissues of soil invertebrates and estimated the proportion of “aquatic” carbon in the energy budget of terrestrial food webs at different distances from the Black Sea and a freshwater lake. Terrestrial predators are actively subsidized with carbon from the Black Sea to distance of up to about 50 m. The carbon subsidy from the freshwater lake is significant in the zone extending no farther than the forest border (ca. 15 m). Thus, the effect of allochthonous organic matter on terrestrial communities in both cases manifests itself only in a relatively narrow coastal strip.

RATIONALE Stable isotope analysis (SIA) is used widely for reconstructing trophic links of vertebrate and invertebrate animals. Soil macrofauna form a substantial food source for a range of predators including amphibians, reptiles, birds and mammals. SIA-based estimations of their trophic niches require knowledge on the full range of isotopic signatures of potential preys. Considering the extremely high diversity of soil animals, this information is not easy to obtain. METHODS We estimated a typical range of the isotopic signatures of soil macrofauna by compiling published and original data on soil macroinvertebrates in 11 temperate forests. We examined whether the baseline correction (i.e. subtracting δ13C or δ15N values of local litter) would decrease the between-site variability in the δ13C and δ15N values of soil animals. The dataset was subsequently used to estimate the frequency distribution of δ13C and δ15N values in saprophagous and predatory soil animals. RESULTS The baseline correction reduced the between-site variability in δ15N, but not in δ13C values of soil animals. Over 95% of the taxa or individuals examined fell into an isotopic space with uncorrected δ13С values ranging from −27.9 to −22.5‰, and litter-normalized δ15N values from 0.8 to 9.6‰. Saprophagous and predatory soil animals were on average enriched in 13C relative to plant litter by 3.5 and 2.7‰, respectively, which is likely to reflect the importance of saprotrophic microorganisms as the main energy source in soil food webs. The difference in δ15N values between saprophages and predators averaged 2.8‰, which fits the anticipated trophic enrichment per trophic level. CONCLUSIONS Our results indicate that the range of possible δ15N values of soil macrofauna in temperate forest ecosystems can roughly be predicted based on the δ15N values of plant litter. On the other hand, no site-specific normalization is usually required when predicting the range of δ13C values of soil macroinvertebrates. Copyright © 2014 John Wiley & Sons, Ltd.

We compared soil nematode abundance, genus richness and feeding groups composition between four different biotope types (flooded rice paddies, upland crops planted one year after flooded rice, rice paddy bunds, and seminatural control grasslands) in temperate rice-growing systems in Russia. Our survey covered three major rice producing regions: Krasnodarsky Krai, Republic of Kalmykia in European Russia and Primorsky Krai in the Russian Far East, which have not been studied with this respect so far. Genus richness, C–P, maturiry (MI), Enrichment (EI) and Structure (SI) indices, and the total abundance of nematodes were strongly region-specific. The most of the highest values (18 genera, C–P = 2.6 ± 0.1, abundance 208.6 ± 10.1 ind. g−1 soil dwt) were found in Primorsky Krai and the lowest (6 genera, C–P = 2.1 ± 0.1, EI = 22.0 ± 1.3; SI = 55.4 ± 1.2; abundance 64.5 ± 3.3 ind. g−1 soil dwt) in Kalmykia. The highest values of enrichment and structure indices were discovered in Krasnodar Krai (EI = 53.1 ± 6.0 and SI = 82.9 ± 1.4 respectively). The abundance of the nematode feeding groups was in opposite rather driven by biotope type than the region. In the flooded rice paddies, the abundance of predatory nematodes was significantly lower than in control grasslands (2.1 ± 1.0 and 9.5 ± 3.0 ind. g−1 soil dwt, respectively). Alternatively, the abundance of fungivores increased in flooded rice paddies. We conclude that rice growing considerably alters the relative abundance of nematode feeding groups and consequently their role in detrital food webs due to alteration of the overall structure of a micro food web and specifically negative effects of flooding on predatory nematodes. Bunds act as important reservoirs of soil nematode diversity in the rice agroecosystems.

Background The Abrau Peninsula is located in northwestern Caucasus between the cities of Novorossiysk and Anapa, Krasnodar Province, Russia. This paper contains an annotated checklist of the Chilopoda and Diplopoda inhabiting the Abrau Peninsula. New information The fauna of the Abrau Peninsula comprises 17 centipede (4 orders) and 16 millipede (6 orders) species. Henia taurica, hitherto known only from the Crimea, has now been reported from several localities in the studied region. The study also reveals two possibly new millipede species. Statistical analyses showed that habitat preferences of myriapod species within the Abrau Peninsula are caused by species geographic distribution pattern and microbiotope preferences.

Stable isotope analysis (SIA) is used widely for reconstructing trophic links of vertebrate and invertebrate animals. Soil macrofauna form a substantial food source for a range of predators including amphibians, reptiles, birds and mammals. SIA-based estimations of their trophic niches require knowledge on the full range of isotopic signatures of potential preys. Considering the extremely high diversity of soil animals, this information is not easy to obtain.We estimated a typical range of the isotopic signatures of soil macrofauna by compiling published and original data on soil macroinvertebrates in 11 temperate forests. We examined whether the baseline correction (i.e. subtracting δ(13)C or δ(15)N values of local litter) would decrease the between-site variability in the δ(13)C and δ(15)N values of soil animals. The dataset was subsequently used to estimate the frequency distribution of δ(13)C and δ(15)N values in saprophagous and predatory soil animals.The baseline correction reduced the between-site variability in δ(15)N, but not in δ(13)C values of soil animals. Over 95% of the taxa or individuals examined fell into an isotopic space with uncorrected δ(13)С values ranging from -27.9 to -22.5‰, and litter-normalized δ(15)N values from 0.8 to 9.6‰. Saprophagous and predatory soil animals were on average enriched in (13)C relative to plant litter by 3.5 and 2.7‰, respectively, which is likely to reflect the importance of saprotrophic microorganisms as the main energy source in soil food webs. The difference in δ(15)N values between saprophages and predators averaged 2.8‰, which fits the anticipated trophic enrichment per trophic level.Our results indicate that the range of possible δ(15)N values of soil macrofauna in temperate forest ecosystems can roughly be predicted based on the δ(15)N values of plant litter. On the other hand, no site-specific normalization is usually required when predicting the range of δ(13)C values of soil macroinvertebrates.