Meta-analysis reveals that the effects of precipitation change on soil and litter fauna in forests depend on body size

Anthropogenic climate change is altering precipitation regimes at a global scale. While precipitation changes have been linked to changes in the abundance and diversity of soil and litter invertebrate fauna in forests, general trends have remained elusive due to mixed results from primary studies. We used a meta-analysis based on 430 comparisons from 38 primary studies to address associated knowledge gaps, (i) quantifying impacts of precipitation change on forest soil and litter fauna abundance and diversity, (ii) exploring reasons for variation in impacts and (iii) examining biases affecting the realism and accuracy of experimental studies. Precipitation reductions led to a decrease of 39% in soil and litter fauna abundance, with a 35% increase in abundance under precipitation increases, while diversity impacts were smaller. A statistical model containing an interaction between body size and the magnitude of precipitation change showed that mesofauna (e.g. mites, collembola) responded most to changes in precipitation. Changes in taxonomic richness were related solely to the magnitude of precipitation change. Our results suggest that body size is related to the ability of a taxon to survive under drought conditions, or to benefit from high precipitation. We also found that most experiments manipulated precipitation in a way that aligns better with predicted extreme climatic events than with predicted average annual changes in precipitation and that the experimental plots used in experiments were likely too small to accurately capture changes for mobile taxa. The relationship between body size and response to precipitation found here has far-reaching implications for our ability to predict future responses of soil biodiversity to climate change and will help to produce more realistic mechanistic soil models which aim to simulate the responses of soils to global change.

Effects of plant taxonomic position on soil nematode communities in Antarctica

Antarctica terrestrial ecosystems are facing the most threats from global climate change, which is altering plant composition greatly. These transformations may cause major reshuffling of soil community composition, including functional traits and diversity, and therefore affect ecosystem processes in Antarctica. We used high-throughput sequencing analysis to investigate soil nematodes under 3 dominant plant functional groups (lichens, mosses, and vascular plants) and bare ground in the Antarctic region. We calculated functional diversity of nematodes based on their diet, life histories, and body mass with kernel density n-dimensional hypervolumes. We also calculated taxonomic and functional beta diversity of the nematode communities based on Jaccard dissimilarity. The presence of plants had no significant effect on the taxonomic richness of nematodes but significantly increased nematode functional richness. The presence of plants also significantly decreased taxonomic beta diversity (homogenization). Only mosses and vascular plants decreased nematode functional beta diversity, which was mostly due to a decreased effect of the richness difference component. The presence of plants also increased the effect of deterministic processes potentially because environmental filtering created conditions favorable to nematodes at low trophic levels with short life histories and small body size. Increasing plant cover in the Antarctic due to climate change may lead to increased diversity of nematode species that can use the scarce resources and nematode taxonomic and functional homogenization. In a future under climate change, community restructuring in the region is possible.

Linking nematodes and ecosystem function: a trait-based framework

Trait-based approaches are being increasingly adopted to understand species' ecological strategies and how organisms influence ecosystem function. Trait-based research on soil organisms, however, remains poorly developed compared with that for plants. The abundant and diverse soil nematodes are prime candidates to advance trait-based approaches belowground, but a unified trait framework to describe nematode ecological strategies and assess their linkages with ecosystem function is lacking. We categorized nematode traits as morphological, physiological, life history, and community clusters, and proposed the nematode economics spectrum (NES) to better understand nematode ecological strategies and their association with ecosystem function. We argue that bridging the NES and the plant economics spectrum will facilitate a more holistic understanding of ecosystem carbon and nutrient cycling under global change.

Glyphosate Disorders Soil Enchytraeid Gut Microbiota and Increases Its Antibiotic Resistance Risk

Pesticides promote the stable development of intensive global agriculture. Nevertheless, their residues in the soil can cause ecological and human health risks. Glyphosate is a popular herbicide and is generally thought to be ecologically safe and nontoxic, but this conclusion has been questioned. Herein, we investigated the interaction among soil fauna (Enchytraeus crypticus) exposed to glyphosate and found that glyphosate induced oxidative stress and detoxification responses in E. crypticus and disturbed their lipid metabolism and digestive systems. We further demonstrated that glyphosate disordered the gut microbiota of E. crypticus and increased the abundance of resistance determinants with significant human health risks. Empirical tests and structural equation models were then used to confirm that glyphosate could cause E. crypticus to generate reactive oxygen species, indirectly interfering with their gut microbiota. Our study provides important implications for deciphering the mechanisms of the ecotoxicity of pesticides under the challenge of worldwide pesticide contamination.

Taxonomic diversity and abundance of enchytraeids (Annelida, Clitellata, Enchytraeida) in the Northern Palaearctic. 1. Asian part

Background

Enchytraeids, or potworms, are tiny oligochaetes that are distributed worldwide in many terrestrial, freshwater and marine ecosystems. Despite their key role in the functioning of ecosystems, the diversity and abundance of Enchytraeidae are rarely studied due to the laborious process of species identification. The present study addresses this gap and sheds some light on the distribution and abundance of enchytraeids in the lands of the Northern Palearctic. The provided dataset constitutes the latest and comprehensive field sampling of enchytraeid assemblages across the Asiatic part of the Northern Palearctic, encompassing an original set of soil samples systematically collected throughout the region from 2019 to 2022.

New information

The dataset includes occurrences from 131 georeferenced sites, encompassing 39 species and 7,074 records. This represents the first dataset providing species-specific information about the distribution and abundance of terrestrial enchytraeids across an extensive geographic area covering the Asian sector of the Northern Palaearctic. The compiled dataset is the key for exploring and understanding local and regional enchytraeid diversity. It may also serve as a valuable resource for monitoring and conserving the entire soil biodiversity.

Exploring Collembola Diversity in the Green Open Spaces of Baruga Forest, Kendari City, Indonesia

<b>Background and Objective:</b> The rapid development of Kendari City as the capital of Southeast Sulawesi Province has led to changes in land use patterns, particularly an increase in built-up areas, which threaten environmental stability. Rapid population growth contributes to rising carbon dioxide emissions, impacting air quality. Green spaces like Baruga Forest are ideal for environmental balance and bioservation. This study aims to identify the diversity of Collembola species in Baruga Forest, Kendari and understand the environmental factors influencing their presence. <b>Materials and Methods:</b> Collembola was collected in the Baruga Forest using a Berlese funnel, then identified and classified based on the family by counting the number of individuals in each taxonomic group. The diversity of Collembola was measured using the Shannon-Wiener index, while the evenness of individual distribution in each family was assessed using an evenness index. Additionally, environmental parameters such as air temperature, air humidity and soil pH were measured. The collected data were analyzed using descriptive statistical analysis. <b>Results:</b> The research results indicate that there are 75 individuals of Collembola belonging to the class Entognatha. The dominant order observed is Entomobryomorpha, consisting of three families: Oncopoduridae with 60 individuals, Isotomidae with 7 individuals and Orchesellidae with 5 individuals. Additionally, there is the order Symphypleona, represented by a single family, Bourletiellidae, with one individual. The biodiversity index (H') yielded a moderate value of 0.622, where the most significant contribution comes from the genus Isotomidae. Meanwhile, the evenness index (E) indicates a uniform distribution among the various genera of Collembola. <b>Conclusion:</b> Observed variations in temperature, humidity and soil pH changes underscore the need for ongoing management and conservation of Baruga Forest to maintain the diversity of Collembola species and the sustainability of the ecosystem in Baruga Forest.

Cessation of grazing causes biodiversity loss and homogenization of soil food webs

There is widespread concern that cessation of grazing in historically grazed ecosystems is causing biotic homogenization and biodiversity loss. We used 12 montane grassland sites along an 800 km north-south gradient across the UK, to test whether cessation of grazing affects local α- and β-diversity of below-ground food webs. We show cessation of grazing leads to strongly decreased α-diversity of most groups of soil microbes and fauna, particularly of relatively rare taxa. By contrast, the β-diversity varied between groups of soil organisms. While most soil microbial communities exhibited increased homogenization after cessation of grazing, we observed decreased homogenization for soil fauna after cessation of grazing. Overall, our results indicate that exclusion of domesticated herbivores from historically grazed montane grasslands has far-ranging negative consequences for diversity of below-ground food webs. This underscores the importance of grazers for maintaining the diversity of below-ground communities, which play a central role in ecosystem functioning.

Ecosystem type drives soil eukaryotic diversity and composition in Europe

Soil eukaryotes play a crucial role in maintaining ecosystem functions and services, yet the factors driving their diversity and distribution remain poorly understood. While many studies focus on some eukaryotic groups (mostly fungi), they are limited in their spatial scale. Here, we analyzed an unprecedented amount of observational data of soil eukaryomes at continental scale (787 sites across Europe) to gain further insights into the impact of a wide range of environmental conditions (climatic and edaphic) on their community composition and structure. We found that the diversity of fungi, protists, rotifers, tardigrades, nematodes, arthropods, and annelids was predominantly shaped by ecosystem type (annual and permanent croplands, managed and unmanaged grasslands, coniferous and broadleaved woodlands), and higher diversity of fungi, protists, nematodes, arthropods, and annelids was observed in croplands than in less intensively managed systems, such as coniferous and broadleaved woodlands. Also in croplands, we found more specialized eukaryotes, while the composition between croplands was more homogeneous compared to the composition of other ecosystems. The observed high proportion of overlapping taxa between ecosystems also indicates that DNA has accumulated from previous land uses, hence mimicking the land transformations occurring in Europe in the last decades. This strong ecosystem-type influence was linked to soil properties, and particularly, soil pH was driving the richness of fungi, rotifers, and annelids, while plant-available phosphorus drove the richness of protists, tardigrades, and nematodes. Furthermore, the soil organic carbon to total nitrogen ratio crucially explained the richness of fungi, protists, nematodes, and arthropods, possibly linked to decades of agricultural inputs. Our results highlighted the importance of long-term environmental variables rather than variables measured at the time of the sampling in shaping soil eukaryotic communities, which reinforces the need to include those variables in addition to ecosystem type in future monitoring programs and conservation efforts.

[Community structure of soil fauna under different tree species in subtropical forests]

Soil fauna play an important role in key functions of ecosystem such as material cycling. Litter quality and microenvironment of different tree species may regulate soil fauna community structure. In this study, we investigated soil fauna community structure, the differences of taxonomic and functional groups, and the regulatory factors under eight dominant tree species in August 2022. We captured 567 soil fauna (except for termites and ants), belonging to 3 phyla, 10 classes, 26 orders, and 99 families, with Achipteriidae, Trygoniidae, Poduridae, and Isotomidae as the dominant species. Tree species significantly affected soil fauna abundance, following an order: Michelia macclurei > Elaeocarpus decipiens > Castanopsis carlesii > Cunninghamia lanceolata > Lindera communis > Schima superba > Pinus massoniana > Liquidambar formosana. However, the richness, evenness, and diversity of soil fauna under different tree species were significantly different. Richness and diversity of M. macclurei, C. lanceolatas soil fauna were relatively high, while L. formosana, C. carlesii were relatively low. The evenness of meso-microfauna of L. formosana was the highest, which was significantly higher than that of M. macclureis and E. decipiens. The evenness of macrofauna and total soil fauna was not significantly different among the eight tree species. In addition, the abundance of omnivores and herbivores soil fauna was relatively high under M. macclurei, but relatively low under E. decipiens. The abundance of saprophages and predators soil fauna of E. decipiens, M. macclurei was higher than L. formosana, while saprophages was mainly meso-microfauna. Results of redundancy analysis showed that litter N, C:N, and K were the main factors affecting soil fauna community structure. The results indicated that the tree species with thicker litter layer and higher N and K contents may be conducive to enhancing the diversity of soil fauna community and affecting the distribution of different functional groups, thus contributing to the maintenance of forest biodiversity.

A new jewel-like species of the pill-millipede genus Sphaerobelum Verhoeff, 1924 (Diplopoda, Sphaerotheriida, Zephroniidae) from Thailand

A new species of the giant pill millipede genus Sphaerobelum is described: Sphaerobelumturcosasp. nov. from the northeastern part of Thailand. Species delimitation is based on morphological characters and COI sequence data. The new species can be clearly discriminated from congeners by its greenish-blue body color, the face mask-like appearance of the thoracic and anal shields jointly when rolled up, and the combination of the following four characters: (1) the coxa of the second leg laterally with a sharp and long process, (2) the tarsi of legs 4-21 with 6-7 ventral spines, (3) the anterior telopods consisting of four conspicuous telopoditomeres, and (4) the immovable, slender (not strongly humped) and distally curved finger of the posterior telopods without a membranous spot. The interspecific COI sequence divergence between the new species and other Sphaerobelum species ranges from 17% to 23% (mean 20%). The intergeneric COI sequence divergence between the new species and Zephronia species ranges from 18% to 21% (mean 20%). The relationships among Sphaerobelum and Zephronia species based on the COI sequence data were not resolved in this study. Sphaerobelumturcosasp. nov. is restricted to limestone habitat in Loei province and is probably endemic for the Thai fauna.

Overview of Direct and Indirect Effects of Antibiotics on Terrestrial Organisms

Antibiotics (ABs) have made it possible to treat bacterial infections, which were in the past untreatable and consequently fatal. Regrettably, their use and abuse among humans and livestock led to antibiotic resistance, which has made them ineffective in many cases. The spread of antibiotic resistance genes (ARGs) and bacteria is not limited to nosocomial environments, but also involves water and soil ecosystems. The environmental presence of ABs and ARGs is a hot topic, and their direct and indirect effects, are still not well known or clarified. A particular concern is the presence of antibiotics in agroecosystems due to the application of agro-zootechnical waste (e.g., manure and biosolids), which can introduce antibiotic residues and ARGs to soils. This review provides an insight of recent findings of AB direct and indirect effects on terrestrial organisms, focusing on plant and invertebrates. Possible changing in viability and organism growth, AB bioaccumulation, and shifts in associated microbiome composition are reported. Oxidative stress responses of plants (such as reactive oxygen species production) to antibiotics are also described.

Brand-Specific Toxicity of Tire Tread Particles Helps Identify the Determinants of Toxicity

The widespread occurrence of tire tread particles (TPs) has aroused increasing concerns over their impacts. However, how they affect the soil fauna remains poorly understood. Here, based on systematically assessing the toxicity of TPs on soil model speciesEnchytraeus crypticusat environmentally relevant concentrations through both soil and food exposure routes, we reported that TPs affected gut microbiota, intestinal histopathology, and metabolites of the worms both through particulate- and leachate-induced effects, while TP leachates exerted stronger effects. The dominant role of TP leachates in TP toxicity was further explained by the findings that worms did not ingest TPs with a particle size of over 150 μm and actively avoided consuming TP particles. Moreover, by comparing the effects of different brands of TPs as well as new and aged TPs, we demonstrated that it was mainly TP leachates that resulted in the ubiquity of the disturbance in the worm's gut microbiota among different brands of TPs. Notably, the large variations in leachate compositions among different brands of TPs provided us a unique opportunity to identify the determinants of TP toxicity. These results provide novel insights into the toxicity of TPs to soil fauna and a reference for toxicity reduction of tires.

Can Grasslands in Photovoltaic Parks Play a Role in Conserving Soil Arthropod Biodiversity?

Under the increasing global energy demand, the new European Union Biodiversity Strategy for 2030 encourages combinations of energy production systems compatible with biodiversity conservation; however, in photovoltaic parks, panels shadowing the effects on soil health and biodiversity are still unknown. This study (location: Northern Italy) aimed to evaluate the effect of ground-mounted photovoltaic (GMPV) systems on soil arthropod biodiversity, considering two parks with different vegetation management: site 1-grassland mowed with tractor; site 2-grassland managed with sheep and donkeys. Three conditions were identified in each park: under photovoltaic panel (row), between the panel rows (inter-row), and around the photovoltaic plant (control). The soil pH and organic matter (SOM), soil arthropod community, biodiversity, and soil quality index (e.g., QBS-ar index) were characterised. Differences between the two GMPVs were mainly driven by the SOM content (higher values where grazing animals were present). No differences were observed in site 1, even if a high heterogeneity of results was observed for the soil biodiversity parameters under the panels. In site 2, SOM and pH, as well as arthropods biodiversity and QBS-ar, showed low values in the row. Soil fauna assemblages were also affected by ground-mounted panels, where Acarina, Collembola, Hymenoptera, and Hemiptera showed the lowest density in the row. This study suggests that ground-mounted solar panels had significant effects on below-ground soil fauna, and was more marked depending on the system management. Furthermore, the results obtained for the inter-row were similar to the control, suggesting that the area between the panel rows could be considered a good hotspot for soil biodiversity.

Toxicity of Per- and Polyfluoroalkyl Substances to Nematodes

Per- and polyfluoroalkyl substances (PFASs) are a class of compounds that persist in the environment globally. Besides being transported to the soil and sediments, which act as their sinks, PFASs can be transferred to several species of higher organisms directly or via bacteria, eliciting a wide range of adverse effects. Caenorhabditis elegans has been widely used in toxicological studies and life science research owing to its numerous advantages over traditional vertebrate models; notably, C. elegans has 65% conserved human-disease-associated genes and does not require ethical approvals for experimental use. This review covers a range of topics, from reported accumulation characteristics and lethal concentrations of PFAS in C. elegans to the mechanisms underlying the toxicity of PFAS at different levels, including reproductive, developmental, cellular, neurologic, oxidative, metabolic, immune, and endocrine toxicities. Additionally, the toxicity levels of some PFAS substitutes are summarized. Lastly, we discuss the toxicological mechanisms of these PFAS substitutes and the importance and promising potential of nematodes as in vivo models for life science research, epidemiological studies (obesity, aging, and Alzheimer's disease research), and toxicological investigations of PFASs and other emerging pollutants compared with other soil animals or model organisms.

Exogenous carbon turnover within the soil food web strengthens soil carbon sequestration through microbial necromass accumulation

Exogenous carbon turnover within soil food web is important in determining the trade-offs between soil organic carbon (SOC) storage and carbon emission. However, it remains largely unknown how soil food web influences carbon sequestration through mediating the dual roles of microbes as decomposers and contributors, hindering our ability to develop policies for soil carbon management. Here, we conducted a 13 C-labeled straw experiment to demonstrate how soil food web regulated the residing microbes to influence the soil carbon transformation and stabilization process after 11 years of no-tillage. Our work demonstrated that soil fauna, as a "temporary storage container," indirectly influenced the SOC transformation processes and mediated the SOC sequestration through feeding on soil microbes. Soil biota communities acted as both drivers of and contributors to SOC cycling, with 32.0% of exogenous carbon being stabilizing in the form of microbial necromass as "new" carbon. Additionally, the proportion of mineral-associated organic carbon and particulate organic carbon showed that the "renewal effect" driven by the soil food web promoted the SOC to be more stable. Our study clearly illustrated that soil food web regulated the turnover of exogenous carbon inputs by and mediated soil carbon sequestration through microbial necromass accumulation.

Bamboo invasion alters Collembola community composition varying with life-forms

BACKGROUND

Plant invasions are a global concern. In eastern China, bamboo is rapidly expanding, negatively influencing neighbouring forest communities. However, studies on how bamboo invasion affects belowground communities, especially for soil invertebrates, are still lacking. In the present study, we focused on a highly abundant and diverse fauna taxon - Collembola. Collembola communities have three typical life-forms (i.e., epedaphic, hemiedaphic, and euedaphic) inhabiting different soil layers and playing distinct roles in ecological processes. Specifically, we studied their abundance, diversity, and community composition at the three stages of bamboo invasion: uninvaded secondary broadleaf forest, moderately invaded mixed bamboo forest, and completely invaded bamboo (Phyllostachys edulis) forest.

RESULTS

Our results showed that bamboo invasion negatively influenced Collembola communities by decreasing their abundance and diversity. Moreover, Collembola life-forms differed in their responses to bamboo invasion, with surface-dwelling Collembola being more vulnerable to bamboo invasion than soil-living Collembola.

CONCLUSION

Our findings indicate differential response patterns to bamboo invasion within Collembola communities. The negative effects of bamboo invasion on soil surface-dwelling Collembola may further influence ecosystem functioning. © 2023 Society of Chemical Industry.

Diversity of medium and small-sized soil fauna community in different urban-rural green spaces and its influencing factors in Nanchang, China

Urbanization is one of the important factors leading to biodiversity loss and habitat fragmentation. As an important component of urban ecosystem, soil fauna community plays a key role in improving soil structure and fertility, and promoting material circulation of urban ecosystem. To investigate the distribution characteristics of medium and small-sized soil fauna community in green space and the mechanisms underlying their responses to environmental change during urbanization, we selected 27 green space plots with a gradient of urban, suburban, and rural areas in Nanchang City as study objects, and measured plant parameters, soil physicochemical properties, and distribution characteristics of soil fauna community in these plots. The results showed that a total of 1755 soil fauna individuals were captured, belonging to 2 phyla, 11 classes, and 16 orders. The dominant groups were Collembola, Parasiformes, and Acariformes, which accounting for 81.9% of total soil fauna community. The density, Shannon diversity index, and Simpson dominance index of soil fauna community were significantly higher in suburban area than those in rural area. In the green space of the urban-rural gradient, there were large structure variations in different trophic levels of medium and small-sized soil fauna community. Herbivores and macro-predators occupied the largest proportion in rural area, and less in other areas. Results of the redundancy analysis showed the crown diameter, forest density, soil total phosphorus contents were the main environmental factors affecting soil fauna community distribution, with interpretation rate of 55.9%, 14.0% and 9.7%, respectively. Results of the non-metric multidimensional scale analysis showed that there were variations in soil fauna community characteristics in green space of the urban-rural gradient, and that the aboveground vegetation was the dominant factor for this change. This study improved our understanding of urban ecosystem biodiversity in Nanchang, and provided basis for maintaining soil biodiversity and urban green space construction.

Patterns and drivers of soil surface-dwelling Oribatida diversity along an altitudinal gradient on the Changbai Mountain, China

Distribution patterns of biodiversity and environmental interactions are dominant themes in ecology. In montane ecosystems, biodiversity is closely associated with altitudinal gradients. However, studies of biodiversity in montane ecosystems are focused on plants and vertebrates, with relatively less on invertebrates. Here, the present study used a Vortis arthropod suction sampler to explore the biodiversity patterns of soil surface-dwelling Oribatida and their drivers along an altitudinal gradient (600, 800, 1600, 2000, and 2300 m) from typical temperate forests, evergreen coniferous forests, subalpine birch forests to alpine tundra on the north slope of Changbai Mountain, Northeast China. Trichoribates berlesei, Platynothrus peltifer, and Oribatula tibialis were the dominant soil surface-dwelling species on Changbai Mountain. Generally, alpha diversity and beta diversity of soil surface-dwelling Oribatida decreased with the rising altitude, with a peaking density value at 2000 m. The result of beta diversity showed that the structures of community were more influenced by the species turnover component than the nestedness component. Nonmetric multidimensional scaling (NMDS) ordination showed that the community structure of soil surface-dwelling Oribatida varied significantly along the altitudinal gradient. The variance partitioning showed that the elevation and climatic conditions determined the soil surface-dwelling Oribatida community. Spatial filtering represented by geographic and elevation distances was particularly associated with soil surface-dwelling Oribatida community variation between altitudes on Changbai Mountain. However, the variation of the Oribatida community between adjacent altitudes was only associated with geographic distance. Our study provides supportive evidence for the biodiversity analyzing of soil surface-dwelling Oribatida in montane ecosystems along an altitudinal gradient.

Individual and combined toxicity of imidacloprid and two seed dressing insecticides on collembolans Folsomia candida

The aim of this study was to examine the chronic toxicity of imidacloprid (IMI), clothianidin (CLO) and fipronil (FIP) as a single exposure, as well as binary mixtures of IMI with CLO or FIP toward collembolans Folsomia candida, which are fauna present in the soil. Chronic toxicity assays were performed following an ISO guideline in a Tropical Artificial Soil (TAS), and the influence on the number and growth of the juveniles produced were determined. The range of nominal concentrations used in the tests with the individual compounds was 0.08-1.28 mg/kg (IMI), 0.079-1.264 mg/kg (FIP) and 0.007-0.112 mg/kg (CLO), whereas the mixture assays were performed with half the value used in the tests with individual compounds. Based upon single exposures, IMI produced a similar impact of reducing reproduction by 50% (EC₅₀ ranging from 0.74 to 0.85 mg/kg) compared to FIP (EC₅₀ = 0.78 mg/kg), whereas CLO was the most toxic to F. candida (EC₅₀ = 0.08 mg/kg). Their mixtures generally resulted in a diminished effect on reproduction, as evidenced by the higher EC₅₀ values. In contrast, in the case of the IMI+FIP combination at high concentrations at the EC₅₀ level, a synergistic effect on toxicity was observed. The single exposure to the three insecticides and the mixture of IMI-FIP also decreased the size of generated juveniles, which was evidenced by the reduction in the proportion of large juveniles and increased proportion of small juveniles. However, both binary mixtures (IMI-FIP and IMI-CLO) presented antagonistic effects as evidenced by less than expected reductions in growth. Data on the toxic effects of IMI in a mixture with other seed dressing insecticides to collembolans provides useful information to environmental risk assessors by diminishing the uncertainties on the ecological risk of exposure to pesticides, enabling soil management degradation by utilizing multiple insecticides.

Plant roots fuel tropical soil animal communities

Belowground life relies on plant litter, while its linkage to living roots had long been understudied, and remains unknown in the tropics. Here, we analysed the response of 30 soil animal groups to root trenching and litter removal in rainforest and plantations in Sumatra, and found that roots are similarly important to soil fauna as litter. Trenching effects were stronger in soil than in litter, with an overall decrease in animal abundance in rainforest by 42% and in plantations by 30%. Litter removal little affected animals in soil, but decreased the total abundance by 60% in rainforest and rubber plantations but not in oil palm plantations. Litter and root effects on animal group abundances were explained by body size or vertical distribution. Our study quantifies principle carbon pathways in soil food webs under tropical land use, providing the basis for mechanistic modelling and ecosystem-friendly management of tropical soils.

Nematodes and their bacterial prey improve phosphorus acquisition by wheat

Plant growth is greatly influenced by the rhizosphere microbiome, which has been traditionally investigated from a bottom-up perspective assessing how resources such as root exudates stimulate microbial growth and drive microbiome assembly. However, the importance of predation as top-down force on the soil microbiome remains largely underestimated. Here, we planted wheat both in natural and in sterilized soils inoculated with the key microbiome predators - bacterivorous nematodes - to assess how plant performance responds to top-down predation of the soil microbiome and specific plant growth-promoting bacteria, namely phosphate-solubilizing bacteria. We found that nematodes enriched certain groups (e.g. Actinobacteria, Chloroflexi, and Firmicutes) and strengthened microbial connectance (e.g. Actinobacteria and Proteobacteria). These changes in microbiome structure were associated with phosphate-solubilizing bacteria that facilitated phosphorus (P) cycling, leading to greater P uptake and biomass of wheat in both soils. However, the enhancement varied between nematode species, which may be attributed to the divergence of feeding behavior, as nematodes with weaker grazing intensity supported greater abundance of phosphate-solubilizing bacteria and better plant performance compared with nematodes with greater grazing intensity. These results confirmed the ecological importance of soil nematodes for ecosystem functions via microbial co-occurrence networks and suggested that the predation strength of nematodes determines the soil bacteria contribution to P biogeochemical cycling and plant growth.

Coevolutionary legacies for plant decomposition

Coevolution has driven speciation and evolutionary novelty in functional traits across the Tree of Life. Classic coevolutionary syndromes such as plant-pollinator, plant-herbivore, and host-parasite have focused strongly on the fitness consequences during the lifetime of the interacting partners. Less is known about the consequences of coevolved traits for ecosystem-level processes, in particular their 'afterlife' legacies for litter decomposition, nutrient cycling, and the functional ecology of decomposers. We review the mechanisms by which traits resulting from coevolution between plants and their consumers, microbial symbionts, or humans, and between microbial decomposers and invertebrates, drive plant litter decomposition pathways and rates. This supports the idea that much of current global variation in the decomposition of plant material is a legacy of coevolution.

Sympatry of genetic lineages of Parisotomanotabilis s. l. (Collembola, Isotomidae) in the East European Plain

Parisotomanotabilis (Schaeffer, 1896) is one of the most abundant eurytopic species of springtails in temperate regions of the northern hemisphere, and is often used as a model species for studies on the genetics of soil microarthropod populations. Six genetic lineages (L0, L1, L2, L3, L4-Saltzwedel, L4-Hebert) are known which are distributed mainly parapatrically in Western and Central Europe. Individuals of P.notabilis from 21 locations on the East European Plain were analyzed. Three genetic lineages were found: L1, L2, L4-Hebert. In contrast to Western and Central Europe, the coexistence of two or three lineages was revealed in about half of the locations on the East European Plain. The most diverse genetic composition of P.notabilis populations was noted in natural forests and slightly disturbed habitats, while the least diverse was in places with a high anthropogenic influence.

Microbial Multitrophic Communities Drive the Variation of Antibiotic Resistome in the Gut of Soil Woodlice (Crustacea: Isopoda)

Multitrophic communities inhabit in soil faunal gut, including bacteria, fungi, and protists, which have been considered a hidden reservoir for antibiotic resistance genes (ARGs). However, there is a dearth of research focusing on the relationships between ARGs and multitrophic communities in the gut of soil faunas. Here, we studied the contribution of multitrophic communities to variations of ARGs in the soil woodlouse gut. The results revealed diverse and abundant ARGs in the woodlouse gut. Network analysis further exhibited strong connections between key ecological module members and ARGs, suggesting that multitrophic communities in the keystone ecological cluster may play a pivotal role in the variation of ARGs in the woodlouse gut. Moreover, long-term application of sewage sludge significantly altered the woodlice gut resistome and interkingdom communities. The variation portioning analysis indicated that the fungal community has a greater contribution to variations of ARGs than bacterial and protistan communities in the woodlice gut after long-term application of sewage sludge. Together, our results showed that changes in gut microbiota associated with agricultural practices (e.g., sewage sludge application) can largely alter the gut interkingdom network in ecologically relevant soil animals, with implications for antibiotic resistance, which advances our understanding of the microecological drivers of ARGs in terrestrial ecosystem.

New records of Trachelipusvespertilio (Budde-Lund, 1896) (Isopoda, Oniscidea) with a description of the male

Background

The existing descriptions of the woodlouse Trachelipusvespertilio are based on a single female collected in Croatia in the nineteenth century. No further information on the occurrence of this species has been reported in published literature and the morphology of the male, which may offer additional reliable diagnostic characters, has remained unknown.

New information

On the basis of new material collected in Slovenia, a description of the male morphology of T.vespertilio is provided along with a species diagnosis. The rediscovery of this woodlouse after more than a century extends its distribution range to Slovenia.

Characterizing Fragmentation of Polystyrene Foam Debris by Isopods Oniscus asellus (Isopoda: Oniscidae) and Trachelipus rathkii (Isopoda: Trachelipodidae)

Microplastics present a novel and potentially unique threat to soil ecosystems, one whose effects may be mediated by soil organisms themselves. We investigated fragmentation of polystyrene (PS) foam into microplastic particles by two isopods, Oniscus asellus L. and Trachelipus rathkii Brandt, in laboratory arena experiments. First, we examined the temporal dynamics of fragmentation across a time span of 96 h. O. asellus produced more fragments than T. rathkii, and neither species significantly fragmented the PS foam until 48 h had passed. Second, we asked whether O. asellus would still fragment PS foam in the presence of an alternate, more natural substrate like wood. Wood did not significantly affect fragmentation rates, in line with the few other studies examining the effect of alternate food on soil invertebrates' propensity to consume and/or fragment plastics. Our results provide additional characterization of PS foam fragmentation by isopods and indicate that laboratory experiments involving soil invertebrates and plastic debris can take place over relatively short timespans of four or fewer days, but do not necessarily need to provide alternate food to prove that plastic consumption would still occur in its presence.

Northward range expansion of rooting ungulates decreases detritivore and predatory mite abundances in boreal forests

In the last few decades wild boar populations have expanded northwards, colonizing boreal forests. The soil disturbances caused by wild boar rooting may have an impact on soil organisms that play a key role in organic matter turnover. However, the impact of wild boar colonization on boreal forest ecosystems and soil organisms remains largely unknown. We investigated the effect of natural and simulated rooting on decomposer and predatory soil mites (total, adult and juvenile abundances; and adult-juvenile proportion). Our simulated rooting experiment aimed to disentangle the effects of (i) bioturbation due to soil mixing and (ii) removing organic material (wild boar food resources) on soil mites. Our results showed a decline in the abundance of adult soil mites in response to both natural and artificial rooting, while juvenile abundance and the relative proportion of adults and juveniles were not affected. The expansion of wild boar northwards and into new habitats has negative effects on soil decomposer abundances in boreal forests which may cascade through the soil food web ultimately affecting ecosystem processes. Our study also suggests that a combined use of natural and controlled experimental approaches is the way forward to reveal any subtle interaction between aboveground and belowground organisms and the ecosystem functions they drive.

Northward range expansion of rooting ungulates decreases detritivore and predatory mite abundances in boreal forests

In the last few decades wild boar populations have expanded northwards, colonizing boreal forests. The soil disturbances caused by wild boar rooting may have an impact on soil organisms that play a key role in organic matter turnover. However, the impact of wild boar colonization on boreal forest ecosystems and soil organisms remains largely unknown. We investigated the effect of natural and simulated rooting on decomposer and predatory soil mites (total, adult and juvenile abundances; and adult-juvenile proportion). Our simulated rooting experiment aimed to disentangle the effects of (i) bioturbation due to soil mixing and (ii) removing organic material (wild boar food resources) on soil mites. Our results showed a decline in the abundance of adult soil mites in response to both natural and artificial rooting, while juvenile abundance and the relative proportion of adults and juveniles were not affected. The expansion of wild boar northwards and into new habitats has negative effects on soil decomposer abundances in boreal forests which may cascade through the soil food web ultimately affecting ecosystem processes. Our study also suggests that a combined use of natural and controlled experimental approaches is the way forward to reveal any subtle interaction between aboveground and belowground organisms and the ecosystem functions they drive.

Northward range expansion of rooting ungulates decreases detritivore and predatory mite abundances in boreal forests

In the last few decades wild boar populations have expanded northwards, colonizing boreal forests. The soil disturbances caused by wild boar rooting may have an impact on soil organisms that play a key role in organic matter turnover. However, the impact of wild boar colonization on boreal forest ecosystems and soil organisms remains largely unknown. We investigated the effect of natural and simulated rooting on decomposer and predatory soil mites (total, adult and juvenile abundances; and adult-juvenile proportion). Our simulated rooting experiment aimed to disentangle the effects of (i) bioturbation due to soil mixing and (ii) removing organic material (wild boar food resources) on soil mites. Our results showed a decline in the abundance of adult soil mites in response to both natural and artificial rooting, while juvenile abundance and the relative proportion of adults and juveniles were not affected. The expansion of wild boar northwards and into new habitats has negative effects on soil decomposer abundances in boreal forests which may cascade through the soil food web ultimately affecting ecosystem processes. Our study also suggests that a combined use of natural and controlled experimental approaches is the way forward to reveal any subtle interaction between aboveground and belowground organisms and the ecosystem functions they drive.

Co-Exposure of Nanopolystyrene and Other Environmental Contaminants-Their Toxic Effects on the Survival and Reproduction of Enchytraeus crypticus

Plastics in all shapes and sizes have become widespread across ecosystems due to intense anthropogenic use. As such, they can interact with other contaminants that accumulate in the terrestrial environment, such as pharmaceuticals, metals or nanomaterials (NMs). These interactions can potentiate combined toxic effects in the exposed soil organisms, with hazardous long-term consequences to the full ecosystem. In the present study, a terrestrial model species, Enchytraeus crypticus (oligochaeta), was exposed through contaminated soil with nanopolystyrene (representative of nanoplastics (NPls)), alone and in combination with diphenhydramine (DPH, representative of pharmaceuticals), silver nitrate (AgNO₃, representative of metals) and vanadium nanoparticles (VNPs, representative of NMs). AgNO₃ and VNPs decreased E. crypticus reproduction at 50 mg/kg, regardless of the presence of NPls. Moreover, at the same concentration, both single and combined VNP exposures decreased the E. crypticus survival. On the other hand, DPH and NPls individually caused no effect on organisms' survival and reproduction. However, the combination of DPH (10 and 50 mg/kg) with 300 mg NPls/kg induced a decrease in reproduction, showing a relevant interaction between the two contaminants (synergism). Our findings indicate that the NPls can play a role as vectors for other contaminants and can potentiate the effects of pharmaceuticals, such as DPH, even at low and sub-lethal concentrations, highlighting the negative impact of mixtures of contaminants (including NPls) on soil systems.

[Effects of cultivating Coptis chinensis and Paris polyphylla on soil microarthropod communities]

In recent years, the area of herbal medicine planting is rapidly increasing. The effects of planting herbal medicines on soil invertebrate communities are still unclear. To reveal the effects of planting different herbal medicines on the soil microarthropod communities, soil microarthropods in two fields of planting Coptis chinensis and Paris polyphylla for 3-year and 5-year, respectively, were investigated in Pengzhou, Chengdu in July 2020. A total of 526 individuals of soil microarthropods were recorded and classified into 4 classes, 17 orders, 69 families, and 98 genera or taxonomic groups. The communities were dominated by Isotoma, Piatynothrus, Folsomia, and Paranura. The community structure of soil microarthropods differed obviously among the two herbal medicine fields, with the main influencing taxonomic groups of Proisotoma, Ocesobates and Epicridae. The total taxonomic group richness of soil microarthropods were richer in C. chinensis field than P. polyphylla field. There was no significant difference in the abundance and diversity index between the two fields. With the increases of cultivating years, the abundance of soil microarthropods in C. chinensis field declined significantly, and Shannon index increased significantly in P. polyphylla field. The redundancy analysis showed that the community structure of soil microarthropods was mainly affected by soil available N, pH, total K, and available K. It suggested that the effects of cultivating herbal medicines on soil microarthropod communities differed between herbal medicine species. Therefore, we recommended to intercrop C. chinensis and P. polyphylla for maintaining the stability of soil microarthropod diversity and promoting ecosystem function.

Precipitation effects on nematode diversity and carbon footprint across grasslands

Free-living nematodes are one of the most diverse metazoan taxa in terrestrial ecosystems and are critical to the global soil carbon (C) cycling through their role in organic matter decomposition. They are highly dependent on water availability for movement, feeding, and reproduction. Projected changes in precipitation across temporal and spatial scales will affect free-living nematodes and their contribution to C cycling with unforeseen consequences. We experimentally reduced and increased growing season precipitation for 2 years in 120 field plots at arid, semiarid, and mesic grasslands and assessed precipitation controls on nematode genus diversity, community structure, and C footprint. Increasing annual precipitation reduced nematode diversity and evenness over time at all sites, but the mechanism behind these temporal responses differed for dry and moist grasslands. In arid and semiarid sites, there was a loss of drought-adapted rare taxa with increasing precipitation, whereas in mesic conditions increases in the population of predaceous taxa with increasing precipitation may have caused the observed reductions in dominant colonizer taxa and yielded the negative precipitation-diversity relationship. The effects of temporal changes in precipitation on all aspects of the nematode C footprint (respiration, production, and biomass C) were all dependent on the site (significant spatial × temporal precipitation interaction) and consistent with diversity responses at mesic, but not at arid and semiarid, grasslands. These results suggest that free-living nematode biodiversity and their C footprint will respond to climate change-driven shifts in water availability and that more frequent extreme wet years may accelerate decomposition and C turnover in semiarid and arid grasslands.

The extremely high diversity of Collembola in relict forests of Primorskii Krai of Russia

Background

The diversity of soil animals of relict forest ecosystems in East Asia continues to be insufficiently studied and almost not represented in international databases, including GBIF. This article is based on 7550 records of 175 species which were collected in Ussuriiskii, Sikhote-Alinskii and Kedrovaya Pad’ natural reserves of Russian Far East in 2016–2017. A multi-scale sampling design allowed us to estimate population densities and local species richness of Collembola at areas of different sizes. The work continues the digitization of the collections of the Moscow Pedagogical State University (MPSU) and their publication through GBIF.org, which began in 2019. This article is based on original data including 2377 specimens of springtails from eight forests and 648 soil cores.

New information

Within the framework of modern taxonomy, this work represents the first publication of lists of Collembola species of forests of Primorsky Krai. The work focused on the relict protected cedar-deciduous forests. Nine species new to science were described and data on the fauna of the region were significantly revised. Considerable contribution was made to the biogeography of Collembola of East Asia. The design of the sampling allowed us to draw conclusions about the species saturation of springtails at various spatial scales within the habitat: from a few square cm to 100 sq. m. Number of species reached record high values reflecting the benchmark state of Collembola communities of undisturbed old temperate forest ecosystems.

[Scaling laws of altitudinal pattern of soil fauna diversity in Dongling Mountain, Beijing, China]

Identifying the complexity of diversity pattern of various taxa within a community is a challenge for ecologist. Scaling law is one of the suitable ways to detecting the complex ecological structure. In this study, we explored the scaling laws of soil fauna diversity pattern along an altitudinal gradient by multifractal analysis, and compared the difference of multifractal spectra between the litter and the soil layers. Consistent with results from plant communities in previous studies, there was power law scaling law for soil fauna diversity, i.e., richness, the exponential of Shannon's Diversity Index, and the inverse Simpson's Diversity Index. Moreover, power law scaling law also existed for the richness changes of different relative abundance species in both litter and soil layers. Although multifractal characteristics existed for both litter layer and soil layer of soil fauna diversity, the fractal structure of the diversity in the litter layer was more even than that in the soil layer, and the scaling properties of dominant and rare species showed different patterns in multifractal spectra between litter layer and soil layer. In conclusion, there were power law scaling laws for soil fauna diversity which had high richness and abundance along the altitudinal gradient, which would help us uncovering the spatial distribution mechanism of belowground biodiversity.

A "Dirty" Footprint: Macroinvertebrate diversity in Amazonian Anthropic Soils

Amazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia.

Radiocarbon signature reveals that most springtails depend on carbon from living plants

Terrestrial carbon cycling is largely mediated by soil food webs. Identifying the carbon source for soil animals has been desired to distinguish their roles in carbon cycling, but it is challenging for small invertebrates at low trophic levels because of methodological limitations. Here, we combined radiocarbon (¹⁴C) analysis with stable isotope analyses (¹³C and ¹⁵N) to understand feeding habits of soil microarthropods, especially focusing on springtail (Collembola). Most Collembola species exhibited lower Δ¹⁴C values than litter regardless of their δ¹³C and δ¹⁵N signatures, indicating their dependence on young carbon. In contrast with general patterns across all taxonomic groups, we found a significant negative correlation between δ¹⁵N and Δ¹⁴C values among the edaphic Collembola. This means that the species with higher δ¹⁵N values depend on C from more recent photosynthate, which suggests that soil-dwelling species generally feed on mycorrhizae to obtain root-derived C. Many predatory taxa exhibited higher Δ¹⁴C values than Collembola but lower than litter, indicating non-negligible effects of collembolan feeding habits on the soil food web. Our study demonstrated the usefulness of radiocarbon analysis, which can untangle the confounding factors that change collembolan δ¹⁵N values, clarify animal feeding habits and define the roles of organisms in soil food webs.

The impact of invertebrate decomposers on plants and soil

Soil invertebrates make significant contributions to the recycling of dead plant material across the globe. However, studies focussed on the consequences of decomposition for plant communities largely ignore soil fauna across all ecosystems, because microbes are often considered the primary agents of decay. Here, we explore the role of invertebrates as not simply facilitators of microbial decomposition, but as true decomposers, able to break down dead organic matter with their own endogenic enzymes, with direct and indirect impacts on the soil environment and plants. We recommend a holistic view of decomposition, highlighting how invertebrates and microbes act in synergy to degrade organic matter, providing ecological services that underpin plant growth and survival.

Deciphering Potential Roles of Earthworms in Mitigation of Antibiotic Resistance in the Soils from Diverse Ecosystems

Earthworms are capable of redistributing bacteria and antibiotic resistance genes (ARGs) through soil profiles. However, our understanding of the earthworm gut microbiome and its interaction with the antibiotic resistome is still lacking. Here, we characterized the earthworm gut and soil microbiome and antibiotic resistome in natural and agricultural ecosystems at a national scale, and microcosm studies and field experiments were also employed to test the potential role of earthworms in dynamics of soil ARGs. The diversity and structure of bacterial communities were different between the earthworm gut and soil. A significant correlation between bacterial community dissimilarity and spatial distance between sites was identified in the earthworm gut. The earthworm gut consistently had lower ARGs than the surrounding soil. A significant reduction in the relative abundance of mobile genetic elements and dominant bacterial phylotypes that are the likely hosts of ARGs was observed in the earthworm gut compared to the surrounding soil, which might contribute to the decrease of ARGs in the earthworm gut. The microcosm studies and field experiments further confirmed that the presence of earthworms significantly reduced the number and abundance of ARGs in soils. Our study implies that earthworm-based bioremediation may be a method to reduce risks associated with the presence of ARGs in soils.

No evidence for increased loss of old carbon in a temperate organic soil after 13 years of simulated climatic warming despite increased CO2 emissions

Determining the temperature sensitivity of terrestrial carbon (C) stores is an urgent priority for predicting future climate feedbacks. A key aspect to solve this long-standing research gap is to determine whether warmer temperatures will increase autotrophic activities leading to greater C storage or promote heterotrophic activities that will drive these systems to become C sources. We experimentally addressed this critical question by subjecting intact plant-soil systems in a UK upland ecosystem to simulated climate warming under natural field conditions. We report the results of a 13-year field-based climate manipulation experiment combining in situ respiration measurements with radiocarbon (¹⁴ C) analyses of respired CO₂ , dissolved organic carbon (DOC), soil and the tissue contents of the dominant soil fauna (enchytraeids). We found that warming during the growing season produced the largely expected increases in ecosystem respiration (63%) and leaching of DOC (19%) with no evidence for thermal acclimation or substrate exhaustion over the whole 13-year experimental period. Contrary to expectations, we found no evidence to support an increased release of old soil C after more than a decade of simulated climatic change, and indeed, ¹⁴ C analyses indicated that warming caused a significant shift towards mineralisation of more recent plant-derived C inputs. Further support came from the radiocarbon analyses of the enchytraeid tissues, which showed a greater assimilation of the more recent (plant-derived) C sources following warming. Therefore, in contrast to subarctic ecosystems, our results suggest that changes in C storage in this UK upland soil are strongly coupled to plant activities and that increasing temperatures will drive the turnover of organic material fixed only within recent years, without resulting in the loss of existing old carbon stores.

Incorporation of mineral nitrogen into the soil food web as affected by plant community composition

Although nitrogen (N) deposition is increasing globally, N availability still limits many organisms, such as microorganisms and mesofauna. However, little is known to which extent soil organisms rely on mineral-derived N and whether plant community composition modifies its incorporation into soil food webs. More diverse plant communities more effectively compete with microorganisms for mineral N likely reducing the incorporation of mineral-derived N into soil food webs. We set up a field experiment in experimental grasslands with different levels of plant species and functional group richness. We labeled soil with 15NH4 15NO3 and analyzed the incorporation of mineral-derived 15N into soil microorganisms and mesofauna over 3 months. Mineral-derived N incorporation decreased over time in all investigated organisms. Plant species richness and presence of legumes reduced the uptake of mineral-derived N into microorganisms. In parallel, the incorporation of mineral-derived 15N into mesofauna species declined with time and decreased with increasing plant species richness in the secondary decomposer springtail Ceratophysella sp. Effects of both plant species richness and functional group richness on other mesofauna species varied with time. The presence of grasses increased the 15N incorporation into Ceratophysella sp., but decreased it in the primary decomposer oribatid mite Tectocepheus velatus sarekensis. The results highlight that mineral N is quickly channeled into soil animal food webs via microorganisms irrespective of plant diversity. The amount of mineral-derived N incorporated into soil animals, and the plant community properties affecting this incorporation, differed markedly between soil animal taxa, reflecting species-specific use of food resources. Our results highlight that plant diversity and community composition alter the competition for N in soil and change the transfer of N across trophic levels in soil food webs, potentially leading to changes in soil animal population dynamics and community composition. Sustaining high plant diversity may buffer detrimental effects of elevated N deposition on soil biota.

Two new species of the genus Anillinus Casey (Coleoptera, Carabidae, Anillini) from the southern United States

Two new species of blind ground beetles are described from the southern United States. One species, Anillinusrelictussp. nov. (type locality: E of Oneonta, Blount County, Alabama), based on the structure of male genitalia, is similar to Texan Anillinus, in particular to the endogean A.sinuatus Jeannel. The second species, A.felicianussp. nov. (type locality: 4 mi SW Jackson, West Feliciana Parish, Louisiana), is superficially similar to the endogean A.sinuaticollis Jeannel from Roane County, Tennessee, and represents the first record of the genus for the state of Louisiana. All species are illustrated with digital images of habitus, body parts, and male and female genitalia. Biogeographical and evolutionary implications of the new findings are discussed.

A history of study and new records of terrestrial enchytraeids (Annelida, Clitellata, Enchytraeidae) from the Russian Far East

A list of terrestrial enchytraeids of the Russian Far East is compiled based on literature and extensive field data collected by the authors in 2019. A database has been created consisting of geographic coordinates, habitat type, species, and data source. For some species collected by the authors, barcoding using COI, 16s, and 12s rRNA genes has been performed. In total, there are at least 62 species of enchytraeids belonging to 12 genera. Seven species (Achaeta macroampullacea, Cognettia sphagnetorum, Enchytraeus dichaetus, Fridericia cusanica, Globulidrilus riparius, Marionina southerni, Mesenchytraeus gigachaetus) are reported in the Russian Far East for the first time. Cognettia sphagnetorum and F. cusanica are most probably introduced. Taxonomic and biogeographical remarks on some of the species found and differences from the original descriptions are provided. Some of the specimens may be undescribed species, but this requires a more in-depth examination. The Russian Far East, especially its southeastern part, is of great interest as a possible location for new species of enchytraeids.

Soil functional biodiversity and biological quality under threat: intensive land use outweighs climate change

Climate change and land use intensification are the two most common global change drivers of biodiversity loss. Like other organisms, the soil meso-fauna are expected to modify their functional diversity and composition in response to climate and land use changes. Here, we investigated the functional responses of Collembola, one of the most abundant and ecologically important groups of soil invertebrates. This study was conducted at the Global Change Experimental Facility (GCEF) in central Germany, where we tested the effects of climate (ambient vs. 'future' as projected for this region for the years between 2070 and 2100), land use (conventional farming, organic farming, intensively-used meadow, extensively-used meadow, and extensively-used pasture), and their interactions on the functional diversity (FD), community-weighted mean (CWM) traits (life-history, morphology), and functional composition of Collembola, as well as the Soil Biological Quality-Collembola (QBS-c) index. We found that land use was overwhelmingly the dominant driver of shifts in functional diversity, functional traits, and functional composition of Collembola, and of shifts in soil biological quality. These significant land use effects were mainly due to the differences between the two main land use types, i.e. cropland vs. grasslands. Specifically, Collembola functional biodiversity and soil biological quality were significantly lower in croplands than grasslands. However, no interactive effect of climate × land use was found in this study, suggesting that land use effects on Collembola were independent of the climate change scenario. Overall, our study shows that functional responses of Collembola are highly vulnerable to land use intensification under both climate scenarios. We conclude that land use changes reduce functional biodiversity and biological quality of soil.

Climate change and intensive land use reduce soil animal biomass via dissimilar pathways

Global change drivers, such as climate change and land use, may profoundly influence body size, density, and biomass of soil organisms. However, it is still unclear how these concurrent drivers interact in affecting ecological communities. Here, we present the results of an experimental field study assessing the interactive effects of climate change and land-use intensification on body size, density, and biomass of soil microarthropods. We found that the projected climate change and intensive land use decreased their total biomass. Strikingly, this reduction was realized via two dissimilar pathways: climate change reduced mean body size and intensive land use decreased density. These findings highlight that two of the most pervasive global change drivers operate via different pathways when decreasing soil animal biomass. These shifts in soil communities may threaten essential ecosystem functions like organic matter turnover and nutrient cycling in future ecosystems.

Effects of historical legacies on soil nematode communities are mediated by contemporary environmental conditions

Both contemporary and historical factors are documented to be crucial in regulating species diversity and distribution. Soil fauna contribute substantially to global biodiversity and ecosystem functioning, while it is unclear whether and to what extent historical factors shape their diversity patterns. Here, we used soil nematodes as a model organism to test historical effects on soil fauna and to investigate the relative importance of climatic, soil, and historical factors. Based on nematode distribution data in 16 natural sites at a large scale (ranging from 22 to 40°N) in mainland China, we conducted elastic net regression model to test the effects of climatic (e.g., mean and seasonality of temperature/precipitation), soil (e.g., soil carbon, nitrogen, and pH), and historical (e.g., temperature/precipitation anomaly and the velocity of the change since the Last Glacial Maximum) variables on nematode genus richness and Shannon's diversity. Additionally, variation partitioning was used to determine the contribution of the three predictor sets to the explanation of both Jaccard and Bray-Curtis community dissimilarity. We found that climate generally explained more variations in both diversity and composition than soil and historical predictors in our samples. We also showed that although historical factors (e.g., temperature change velocity) were correlated with nematode diversity and composition, the pure effects of these historical factors were negligible. In other words, the historical effects were commonly represented by their interactions with current climatic and soil factors within our selected sites. Our results indicated that contemporary factors, especially climate, may outperform historical factors in regulating soil nematode diversity patterns at large scales.

Living Litter: Dynamic Trait Spectra Predict Fauna Composition

Understanding what drives soil fauna species composition through space and time is crucial because we should preserve soil fauna biodiversity and its key role in ecosystem functioning in this era of fast environmental change. As plant leaf litter provides both food and habitat for soil fauna, a focus on litter traits that relate to these two functions will help in understanding soil invertebrate community structure and dynamics comprehensively. To advance this agenda, we propose a conceptual framework to explicitly link the invertebrate community composition to the temporal dynamics of the litter trait space defined by two axes: a food-quality axis related to plant resource economics and chemistry and a habitat-quality axis related to litter particle size and shape.

Vegetation Pattern Modulates Ground Arthropod Diversity in Semi-Arid Mediterranean Steppes

The ecological functioning of dryland ecosystems is closely related to the spatial pattern of the vegetation, which is typically structured in patches. Ground arthropods mediate key soil functions and ecological processes, yet little is known about the influence of dryland vegetation pattern on their abundance and diversity. Here, we investigate how patch size and cover, and distance between patches relate to the abundance and diversity of meso-and microarthropods in semi-arid steppes. We found that species richness and abundance of ground arthropods exponentially increase with vegetation cover, patch size, and patch closeness. The communities under vegetation patches mainly respond to patch size, while the communities in the bare-soil interpatches are mostly controlled by the average distance between patches, independently of the concurrent changes in vegetation cover. Large patches seem to play a critical role as reserve and source of ground arthropod diversity. Our results suggest that decreasing vegetation cover and/or changes in vegetation pattern towards small and over-dispersed vegetation patches can fast lead to a significant loss of ground arthropods diversity in drylands.

Nutrient scarcity strengthens soil fauna control over leaf litter decomposition in tropical rainforests

Soil fauna is a key control of the decomposition rate of leaf litter, yet its interactions with litter quality and the soil environment remain elusive. We conducted a litter decomposition experiment across different topographic levels within the landscape replicated in two rainforest sites providing natural gradients in soil fertility to test the hypothesis that low nutrient availability in litter and soil increases the strength of fauna control over litter decomposition. We crossed these data with a large dataset of 44 variables characterizing the biotic and abiotic microenvironment of each sampling point and found that microbe-driven carbon (C) and nitrogen (N) losses from leaf litter were 10.1 and 17.9% lower, respectively, in the nutrient-poorest site, but this among-site difference was equalized when meso- and macrofauna had access to the litterbags. Further, on average, soil fauna enhanced the rate of litter decomposition by 22.6%, and this contribution consistently increased as nutrient availability in the microenvironment declined. Our results indicate that nutrient scarcity increases the importance of soil fauna on C and N cycling in tropical rainforests. Further, soil fauna is able to equalize differences in microbial decomposition potential, thus buffering to a remarkable extent nutrient shortages at an ecosystem level.

Conversion of rainforest to oil palm and rubber plantations alters energy channels in soil food webs

In the last decades, lowland tropical rainforest has been converted in large into plantation systems. Despite the evident changes above ground, the effect of rainforest conversion on the channeling of energy in soil food webs was not studied. Here, we investigated community-level neutral lipid fatty acid profiles in dominant soil fauna to track energy channels in rainforest, rubber, and oil palm plantations in Sumatra, Indonesia. Abundant macrofauna including Araneae, Chilopoda, and Diplopoda contained high amounts of plant and fungal biomarker fatty acids (FAs). Lumbricina had the lowest amount of plant, but the highest amount of animal-synthesized C20 polyunsaturated FAs as compared to other soil taxa. Mesofauna detritivores (Collembola and Oribatida) contained high amounts of algal biomarker FAs. The differences in FA profiles between taxa were evident if data were analyzed across land-use systems, suggesting that soil fauna of different size (macro- and mesofauna) are associated with different energy channels. Despite that, rainforest conversion changed the biomarker FA composition of soil fauna at the community level. Conversion of rainforest into oil palm plantations enhanced the plant energy channel in soil food webs and reduced the bacterial energy channel; conversion into rubber plantations reduced the AMF-based energy channel. The changes in energy distribution within soil food webs may have significant implications for the functioning of tropical ecosystems and their response to environmental changes. At present, these responses are hard to predict considering the poor knowledge on structure and functioning of tropical soil food webs.

Fast attrition of springtail communities by experimental drought and richness-decomposition relationships across Europe

Soil fauna play a fundamental role on key ecosystem functions like organic matter decomposition, although how local assemblages are responding to climate change and whether these changes may have consequences to ecosystem functioning is less clear. Previous studies have revealed that a continued environmental stress may result in poorer communities by filtering out the most sensitive species. However, these experiments have rarely been applied to climate change factors combining multiyear and multisite standardized field treatments across climatically contrasting regions, which has limited drawing general conclusions. Moreover, other facets of biodiversity, such as functional and phylogenetic diversity, potentially more closely linked to ecosystem functioning, have been largely neglected. Here, we report that the abundance, species richness, phylogenetic diversity, and functional richness of springtails (Subclass Collembola), a major group of fungivores and detritivores, decreased within 4 years of experimental drought across six European shrublands. The loss of phylogenetic and functional richness was higher than expected by the loss of species richness, leading to communities of phylogenetically similar species sharing evolutionary conserved traits. Additionally, despite the great climatic differences among study sites, we found that taxonomic, phylogenetic, and functional richness of springtail communities alone were able to explain up to 30% of the variation in annual decomposition rates. Altogether, our results suggest that the forecasted reductions in precipitation associated with climate change may erode springtail communities and likely other drought-sensitive soil invertebrates, thereby retarding litter decomposition and nutrient cycling in ecosystems.