Influence of durative drainage melioration on the soil macrofauna (The Leningrad region)

The soil-zoological research took place in 2018 on the territory of the soil-hydromeliorative station “Malinovsky” of Lisinsky educational-experimental forest farm (Tosnensky district, Leningrad region, Russia) which was drained in 1973-1974. The purpose of this research is a comparative evaluation of the density of the population and taxonometric variety of eco-functional groups of macrofauna on the Gleysols Histic Drainic after 45 year draining period and the similar biotop without drainage. The constitution of group and species and the trophic structure of soil macrofauna have been researched. 118 individuals of geobionts out of 3 types and 6 classes have been collected. It’s been stated that zoophages are the trophic dominating group. After 45 year draining period a poor groups and species constitution, a low number of large soil invertebrates and a small share of saprophages have survived which corresponds to the fauna of the soil in oligotrophic bogs.

Morphospecies Abundance of Above-Ground Invertebrates in Agricultural Systems under Glyphosate and Microplastics in South-Eastern Mexico

Soil invertebrates are important for diverse soil ecosystem services, which are jeopardized by pesticides and microplastics. In the present study, we aimed to assess above-ground invertebrates’ morphospecies abundance in the presence of glyphosate (GLY), its main metabolite aminomethylphosphonic acid (AMPA), and microplastics (MPs). Three land-use systems were analyzed: agricultural systems with and without plastic mulch and pesticides (AwPM, AwoPM) and natural unmanaged farming systems (UF). Soil GLY, AMPA, MP concentrations and above-ground invertebrates were quantified. GLY concentrations were also assessed inside invertebrate tissues. GLY, AMPA and the highest concentration of GLY in invertebrates’ tissue were found only in AwoPM at 0.14–0.45 mg kg−1, 0.12–0.94 mg kg−1 and 0.03–0.26 mg kg−1, respectively. MPs were present as follows: AwPM system (100%, 400–2000 particles kg−1) > AwoPM (70.8%, 200–1000 particles kg−1) > UF (37.5%, 200–400 particles kg−1). No significant correlations were found between soil MPs, GLY and AMPA. There was a significant correlation between MPs and morphospecies from the order Entomobrymorpha (Collembola, R = 0.61, p < 0.05). Limnophila, Mesogastropoda (Gastropoda) and Siphonaptera morphospecies were only present in the UF system. GLY in invertebrate tissue was inversely correlated with soil GLY (R = −0.73, p < 0.05) and AMPA (R = −0.59, p < 0.05). Further investigations are required to understand these phenomena.

Soil invertebrates of coniferous forests along a gradient of air pollution (Komi Republic)

The role of soil invertebrates in the cycle of substances, soil-forming processes and the provision of ecosystem services is undeniable. Therefore, soil invertebrates are valuable in bioindication studies. Comprehensive research of soil invertebrates in the production area of Mondi Syktyvkar JSC as the largest pulp and paper enterprise in the European part of Russia was initiated in 2003. A huge amount of data about composition, abundance and structure of soil macro- and mesofauna along an impact gradient was accumulated during the period from 2003 to 2019 years. These data can be used to study local biodiversity, monitor the state of soil invertebrate communities and assess the impact of the pulp and paper industry on the environment. Datasets here presented include information from a monitoring programme for soil invertebrates that inhabit coniferous forests in the production area of Mondi Syktyvkar JSC (Komi Republic). The assemblages' structure of macrofauna, collembolans and nematodes are described. Information on the number of individuals of springtail species, nematodes genera and macrofauna taxa is given. A total of 11146 sampling events of macrofauna, 6673 sampling events of Collembola, and 2592 sampling events of Nematoda are recorded along a gradient of air pollution from pulp and paper industry emissions.

New earthworm records from the Caspian Hyrcanian Forests of Iran (Oligochaeta: Megadrili)

Earthworms are the most important soil invertebrates worldwide, in terms of biomass and effects on soil processes. In this study, 21 earthworm species, including four new records were identified from Caspian Hyrcanian Forests (North of Iran). Four species; Criodrilus lacuum, Lumbricus rubellus, Metaphire californica, and Octodrilus transpadanus and the family Criodrilidae are reported for the first time. Previous studies have identified 31 earthworm species belonging to 14 genera and three families (Lumbricidae, Acanthodrilidae, and Megascolecidae) in Iran; therefore, these new records increase the number of earthworm species to a total of 35.

Potential for Interspecies Toxicity Estimation in Soil Invertebrates

Interspecies correlation estimation (ICE) models are linear regressions that predict toxicity to a species with few data using a known toxicity value in a surrogate species. ICE models are well established for estimating toxicity to fish and aquatic invertebrates but have not been generally developed or applied to soil organisms. To facilitate the development of ICE models for soil invertebrates, a database of single chemical toxicity values was compiled from knowledgebases and reports that included 853 records encompassing 192 chemicals and 12 species. Most toxicity data for single chemicals tested in soil media were for species of earthworms, with only limited data for other species and taxa. ICE models were developed for eleven separate species pairs as least squares log-linear regressions of acute toxicity values of the same chemicals tested in both the surrogate and predicted species of soil organisms. Model uncertainty was assessed using leave one out cross-validation as the fold difference between a predicted and measured toxicity value. ICE models showed high accuracy within order (e.g., earthworm to earthworm), but less prediction accuracy in the two across-taxa models (Arthropoda to Annelida and the inverse). This study provides a proof-of-concept demonstration that ICE models can be developed for soil invertebrates.

Gammaproteobacteria, a core taxon in the guts of soil fauna, are potential responders to environmental concentrations of soil pollutants

Background The ubiquitous gut microbiotas acquired from the environment contribute to host health. The gut microbiotas of soil invertebrates are gradually assembled from the microecological region of the soil ecosystem which they inhabit, but little is known about their characteristics when the hosts are under environmental stress. The rapid development of high-throughput DNA sequencing in the last decade has provided unprecedented insights and opportunities to characterize the gut microbiotas of soil invertebrates. Here, we characterized the core, transient, and rare bacterial taxa in the guts of soil invertebrates using the core index (CI) and developed a new theory of global microbial diversity of soil ecological microregions. Results We found that the Gammaproteobacteria could respond indiscriminately to the exposure to environmental concentrations of soil pollutants and were closely associated with the physiology and function of the host. Meanwhile, machine-learning models based on metadata calculated that Gammaproteobacteria were the core bacteria with the highest colonization potential in the gut, and further identified that they were the best indicator taxon of the response to environmental concentrations of soil pollution. Gammaproteobacteria also closely correlated with the abundance of antibiotic resistance genes. Conclusions Our results determined that Gammaproteobacteria were an indicator taxon in the guts of the soil invertebrates that responded to environmental concentrations of soil pollutants, thus providing an effective theoretical basis for subsequent assessments of soil ecological risk. The results of the physiological and biochemical analyses of the host and the microbial-community functions, and the antibiotic resistance of Gammaproteobacteria, provide new insights for evaluating global soil ecological health.

Trophic level drives the host microbiome of soil invertebrates at a continental scale

Background Increasing our knowledge of soil biodiversity is fundamental to forecast changes in ecosystem functions under global change scenarios. All multicellular organisms are now known to be holobionts, containing large assemblages of microbial species. Soil fauna is now known to have thousands of species living within them. However, we know very little about the identity and function of host microbiome in contrasting soil faunal groups, across different terrestrial biomes, or at a large spatial scale. Here, we examined the microbiomes of multiple functionally important soil fauna in contrasting terrestrial ecosystems across China. Results Different soil fauna had diverse and unique microbiomes, which were also distinct from those in surrounding soils. These unique microbiomes were maintained within taxa across diverse sampling sites and in contrasting terrestrial ecosystems. The microbiomes of nematodes, potworms, and earthworms were more difficult to predict using environmental data, compared to those of collembolans, oribatid mites, and predatory mites. Although stochastic processes were important, deterministic processes, such as host selection, also contributed to the assembly of unique microbiota in each taxon of soil fauna. Microbial biodiversity, unique microbial taxa, and microbial dark matter (defined as unidentified microbial taxa) all increased with trophic levels within the soil food web. Conclusions Our findings demonstrate that soil animals are important as repositories of microbial biodiversity, and those at the top of the food web harbor more diverse and unique microbiomes. This hidden source of biodiversity is rarely considered in biodiversity and conservation debates and stresses the importance of preserving key soil invertebrates.