Soil Animal Communities Research Articles (Page 1)

Abstract Plant litter harbours a wide range of organisms, such as soil animals, microbes, vascular plant seeds and seedlings, mosses and lichens. While it is well‐recognized that litter drives carbon and nutrient cycling through its traits related to the plant resource economics spectrum (PES), its explanatory power for predicting the litter‐dwelling biological community has been very low. In this era of biodiversity change, litter habitat provisioning functions should receive more research attention. A conceptual trait space defined by a physical trait axis related to the litter size and shape spectrum (SSS) and a biochemical trait axis (PES) has been proposed, to explain habitat as well as nutrition functions for soil organisms. We aim to improve the explanatory power of litter traits for the litter‐dwelling animal communities by testing this concept, and by connecting fundamental traits related to the size and shape of single litter particles with litter layer properties more directly related to habitat quality (e.g. moisture regime, habitat space). We tested the concept by using 16 woody species, and examined how different traits or trait axes determine the litter and litter layer properties directly related to habitat quality for soil animals. In addition, we assessed in a field experiment with litter layers in mesocosms how this new trait framework explains the soil invertebrate community. The two plant trait spectra together accounted for >60% of the variance in litter quality in a principal component analysis. SSS‐related traits strongly explained litter layer habitat‐related properties, such as water‐holding capacity and litter bulk density. The SSS axis and these SSS‐associated properties more strongly determined soil animal communities assembled over 7 weeks in the field experiment, surpassing the effects of the PES axis. Synthesis . This study has provided the first empirical evidence for the litter trait space defined by both SSS and PES spectra occupied by wide‐ranging plant species, and its utility to explain litter layer properties related to the physical environment and associated habitat provisioning function. We suggest that this trait‐based SSS‐PES framework will help us to disentangle mechanisms underpinning real‐world interactions between above‐ground vegetation and below‐ground communities.

Abstract Nitrogen (N) and phosphorus (P) depositions worldwide are increasing the risks of biodiversity and functionality loss in terrestrial ecosystems, particularly in tropical regions. However, the effects of increased nutrient inputs on soil biodiversity in tropical regions remain largely unknown. Here, we investigated the response of one of the most diverse groups of soil invertebrates, oribatid mites (Acari: Oribatida), to the long‐term input of moderate rates of N and P into montane rainforests along an altitudinal gradient (1000, 2000, and 3000 m) in Ecuador. The response of oribatid mites to nutrient additions was investigated after 1, 3, and 10 years. Overall, variations in oribatid mite diversity and richness due to nutrient additions were low and restricted to the 1000‐m site, where the combined addition of N and P resulted in significantly reduced density and richness of oribatid mites after 10 years. In general, oribatid mite community compositions differed strongly between the altitudinal sites and remained remarkably stable across the study period. Changes in oribatid mite community composition during the study period were driven by changes in temperature, precipitation, and relative humidity rather than by the addition of N and P. Our results suggest that oribatid mites in tropical montane rainforests are rather insensitive to moderate additional input of N and P, pointing to an outstanding stability of these soil animal communities. Shifts in climatic factors, rather than changes in resource‐associated factors such as nutrients, may pose a more significant threat to oribatid mite communities of tropical montane rainforests.

Agricultural practices affect non-target soil fauna either directly or indirectly, e.g. by altering the soil physical structure or by application of chemicals. The effects of tillage, insecticide and herbicide applications on the dominant taxon of soil microarthropods-oribatid mites was studied in two fields over three years (2020, 2021, 2022) at three seasons (spring, summer and autumn). In total 87 species were identified. Herbicide and insecticide application had negative effects on oribatid mite species numbers and abundance; however, tillage mitigated the negative effects of herbicide and insecticide applications, possibly since tillage increases the rate of pesticide degradation and thereby reduces the direct exposure to soil fauna to those chemicals. Insecticides and tillage reduced the number of parthenogenetic individuals, possibly by a decrease of available resources (dead organic matter). Oribatid species richness and density steadily declined from 2020 to 2022 likely due to increased average annual temperature and decreased precipitation associated with global warming. The species richness and density declined from spring to summer and increased again in autumn. The annual decline of the oribatid species richness was expressed by the loss of oribatids with a thin cuticle (Mixonomata, Enarthronota, Oppioidea) and those, who are sensitive towards disturbance (Liacaridae, Ceratozetidae). Dry grassland specific species (Passalozetes africanus, P. perforatus, Scutovertex sculptus) were constantly present in all samples. The study points to the effects of agricultural practices on non-target soil fauna and also on the changes in soil animal communities from meadow to dry steppe species due to global warming.

Emerging evidence suggests that microbivory prevails in soil animal communities, yet the relative importance of bacteria, fungi and plants as basal resource energy channels across taxa and forest types remains unstudied. We developed a novel framework combining stable isotope analysis of essential amino acids (eAAs) and energy fluxes to quantify basal resource contributions and trophic positions of meso- and macrofauna detritivores (Collembola, Oribatida, Diplopoda, Isopoda, Lumbricidae) and predators (Mesostigmata, Chilopoda) in 48 forest sites of different management intensity across Germany. Fungal energy channelling dominated, with the highest energy fluxes and 73% fungal eAAs across forests and regions. Chilopoda, however, acquired more energy from bacteria and plants. Energy fluxes to Lumbricidae were highest, but decreased, alongside those to other macrofauna, in acidic forests. Trophic positions varied between regions, reflecting changes in community structure linked to regional factors. Our findings highlight the stability and pivotal role of fungal energy channelling for forest soil animal communities.

Forest ecosystem management requires the conservation of associated biodiversity. Enriching native forests with economically valuable conifer species provides economic gains and meets the increasing societal demand for timber but may threaten biodiversity. Soil sustains most of forest biodiversity, but the impact of changes in tree species composition, including native and non-native species, on soil invertebrates remains little studied. We investigated the impact of different forest types on the taxonomic and functional composition of springtail communities (Collembola, Insecta), an abundant and diverse microarthropod group inhabiting litter and soil. Using native Fagus sylvatica (European beech) as reference, we compared Collembola communities with native but range-expanding Picea abies (Norway spruce) and non-native Pseudotsuga menziesii (Douglas fir) as well as beech-conifer mixtures. The abundance of Collembola was higher in Norway spruce than in European beech, with little difference among the other forest types. Further, the taxonomic and functional composition of Collembola was shifted to more parthenogenetic species at sandy sites, stressing the importance of regional factors such as soil type and climate in structuring Collembola communities. Collembola communities in Douglas fir were more pigmented and distributed to the surface, resulting in a lower proportion of euedaphic Collembola compared to European beech forests. In mixed forests, the impacts of Douglas fir on euedaphic Collembola were reduced, suggesting that negative effects of introduced tree species on soil animal communities might be alleviated by limiting Douglas fir to enrichment plantings only. Overall, the results indicate that vertical distribution in soil and morphological traits of Collembola help to better understand the changes in decomposer communities due to planting non-native tree species.

Myracrodruon urundeuva is a tree species of economic importance due to the quality of its wood and medicinal properties. As a result of its overexploitation, it is now threatened with extinction in some Brazilian regions. However, in the region of Governador Valadares, in the east of Minas Gerais, mastic trees are considered invasive, occurring in large areas in monodominance. This study aimed to test the hypothesis that the mesofauna of the monodominance mastic litter differs in its richness and abundance from that of the Atlantic Forest remnants of the region. Litter samples were collected from three locations under monodominance of mastic trees and from three locations under biodiverse vegetation, without mastic trees. Litter was sampled in three plots at each location, using a metal template (50cm in diameter). Litter was sampled four times at each site during one year, one sample per climate season. The collected animals were stored in 70% alcohol and classified by classes and orders. The data showed that the litter fauna of the forest fragments was more abundant than that of the monodominance of mastic trees, although species richness and composition were similar. The results showed that the monodominance of mastic trees is negatively interfering with the biodiversity of the litter mesofauna and that this monodominance is restrictive to more complex soil animal communities. It suggests that environmental services, such as the decomposition of organic matter and mineralization, may be deficient and that local productivity is lower than in other places with vegetation with greater biodiversity.

Urbanization profoundly impacts biodiversity and ecosystem function, exerting an immense ecological filter on the flora and fauna that inhabit it, oftentimes leading to simplistic and homogenous ecological communities. However, the response of soil animal communities to urbanization remains underexplored, and it is unknown whether their response to urbanization is like that of aboveground organisms. This study investigated the influence of urbanization on soil animal communities in 40 public parks along an urbanization gradient. We evaluated soil animal abundance, diversity, and community composition and related these measures to urban and soil characteristics at each park. The most urbanized parks exhibited reduced animal abundance, richness, and Shannon diversity. These changes were influenced by many variables underscoring the multifaceted influence of urbanization on ecological communities. Notably, contrary to our expectation, urbanization did not lead to community homogenization; instead, it acted stochastically, creating unique soil animal assemblages. This suggests that urban soil animal communities are concomitantly shaped by deterministic and stochastic ecological processes in urban areas. Our study highlights the intricate interplay between urbanization and soil animal ecology, challenging the notion of urban homogenization in belowground ecosystems and providing insight for managing and preserving belowground communities in urban areas.

Impact of naphthalene on soil fauna diversity: Consequences for ecosystem functioning and carbon cycling in grasslands

Abstract The ongoing climate change calls for managing forest ecosystems in temperate regions toward more drought‐resistant and climate‐resilient stands. Yet ecological consequences of management options such as planting non‐native tree species and mixing coniferous and deciduous tree species have been little studied, especially on soil animal communities, key in litter decomposition and pest control. Here, we investigated the taxonomic and trophic structure of soil macrofauna communities in five forest types including native European beech (Fagus sylvatica), range‐expanding Norway spruce (Picea abies) and non‐native Douglas fir (Pseudotsuga menziesii) as well as conifer‐beech mixtures across loamy and sandy sites in northern Germany. Abundance of primary decomposers (feeding predominantly on litter) was high in Douglas fir and beech forests, benefiting from less acidic soil and more favorable litter resources compared to spruce forests, while secondary decomposers (feeding predominantly on microorganisms and microbial residues) reached highest densities in spruce forests. Differences in abundance and species richness among forest types generally varied between regions and were most pronounced in Douglas fir of the sandy region. However, trophic guilds differed more between regions than between forest types, indicating that environmental factors outweigh the importance of forest type on soil macrofauna communities. The analysis of stable isotopes (δ15N and δ13C values) supported the general robustness in trophic position of macrofauna trophic guilds against variations in forest types and regions, but indicated reduced detrital shifts and food‐chain lengths in coniferous compared to European beech forests with mixtures mitigating these effects. Overall, for evaluating consequences of future forest management practices on the structure and functioning of soil animal communities, regional factors need to be considered, but in particular at loamy sites the taxonomic and trophic structure of soil macrofauna communities are resistant against changes in forest types.

Mites are among the most abundant invertebrates in subsurface ecosystems, and their community assemblages and distributions are often significantly influenced by the diversity of habitat resources. The cave ecosystem encompasses drastic changes in nonbiological factors, such as changes in lighting conditions from bright to extraordinarily dark and habitat gradients of surface plant resources from abundant to scarce or even disappearing, providing an ideal unique environment for evaluating the assembly mechanism of soil animal communities. Nevertheless, there still needs to be a sufficient understanding of the biodiversity patterns and drivers of mite communities across environmental gradients in karst caves. We conducted a comprehensive survey on the composition and diversity of soil mites in three photometric zones (dark, twilight, and light) of a typical karst cave and its adjoining extractive environments (forest scrub and farmland). Our research aimed to investigate the ecological relationships of mite communities between above- and below-ground habitats and the effects of abiotic factors on mite communities. We collected 49 families, 86 genera, and 1284 mites. In the external cave environment, we captured 1052 mites from 72 genera and 45 families; in the internal cave environment, we captured 232 mites from 46 genera and 29 families. The abundance, richness of genera, and diversity parameters of the mite community decreased from the cave entrance to the cave interior with decreasing light intensity. Oribatid mites dominated the mite community. Protoribates and Scheloribates were the dominant genera, along with Tectocepheus and 11 other genera, which primarily distinguished the mite communities among different habitats. Forty endemic taxa were found in the external cave environment, compared to 14 endemic taxa in the internal cave environment. The mite community showed a strong preference for the cave ecosystem habitat. Temperature, humidity, and soil nitrogen content significantly influenced the distribution pattern of mite communities (VIP > 0.8, p < 0.05).

Unveiling soil animal community dynamics beneath dominant shrub species in natural desert environment: Implications for ecosystem management and conservation

Abstract Biological invasion is one of the major challenges to changing ecosystems worldwide. Red fire ants are a prime example of invasive soil animals. However, the impacts of their invasion on the native soil animal communities are still poorly understood. Here, we investigated how the biomass and diversity of soil microarthropods (incl., Collembola and Acari) vary between areas affected by red fire ants at different degrees (i.e., OA, occurrence area, 0–20 m from the nest; PCA, prevention and control area, 20–50 m; POA, potential occurrence area, 50–100 m). We also tested whether the potential effects of ant invasion on other animals are associated with changes in soil properties in the invaded areas. Our results showed a decline of 64% in species richness, 74% in density, and 72% in biomass of microarthropods in OA in comparison with POA. This reduction was mainly driven by the decrease of Acari, while no reduction in Collembola biomass was observed. Despite soil properties being significantly different between ant‐impacted areas, structural equation models indicated that the direct association of invasion with microarthropod communities is stronger than the indirect association mediated by soil properties. Therefore, we consider that direct biological interaction is more likely the major mechanism behind the observed changes in microarthropod communities. The effects of red fire ants were different among taxonomic and functional groups, with litter‐dwelling Collembola, Oribatida, and Mesostigmata (Acari) affected more negatively than soil‐dwelling and surface‐dwelling Collembola. Further, red fire ants affected the turnover component of beta‐diversity (i.e., replacement of species) for both Collembola and Acari. However, the impact on the nestedness component, which is related to species local extinction and population decline, was only detected for Acari. Our study shows that red fire ant invasion is associated with the depletion of soil microarthropod community, and especially highlights that Acari are more vulnerable to this invasion compared to Collembola. The divergent response between different taxonomic and functional groups of microarthropods and the consequent shift in microarthropod communities may have important significance to soil ecological functioning in the impacted areas.

Biodiversity loss and its potential threat on ecosystem functions call for a critical evaluation of human impacts on forest ecosystems. Management practices based on stand diversification offer a possible solution to biodiversity loss due to monoculture plantations, and these practices often involve planting introduced tree species. Although introduced non-native tree species may provide high economic returns, they may also form novel ecosystems and threaten local biodiversity, but this has been little studied. Here, we combined a taxonomic and trait-based approach and investigated communities of oribatid mites (Oribatida, Acari) across forest types of both native and introduced tree species in Northern Germany. Both trophic and life-history traits of oribatid mites were evaluated using native European beech (Fagus sylvatica) as reference, compared to native Norway spruce (Picea abies), introduced Douglas fir (Pseudotsuga menziesii) and beech-conifer mixtures. The abundance and diversity of oribatid mites were generally similar among monocultures of European beech, Norway spruce and Douglas fir. By contrast, species and trait compositions of oribatid mite communities were shifted to include more primary decomposers and more surface-living oribatid mites in Douglas fir, resulting in a trophic reorganization with less predators than in European beech forests. These results suggest that oribatid mites maintain a similar level of trait diversity regardless of forest type, but the changes in trophic guild composition and vertical distribution indicate greater availability of litter-based resources in Douglas fir than in European beech forests. The similar abundance and diversity of oribatid mite communities in Douglas fir mixed stands as in native European beech forests points to mixed forests as a promising management option for future forestry. Overall, our trait-based analyses provided insights into the changes of soil biota composition, revealing the impact of introduced tree species on the structure and functions of soil animal communities.

Forest soils are a critical component of terrestrial ecosystems and host a large number of animal decomposer species. One diverse and abundant decomposer taxon is oribatid mites (Acari: Oribatida), whose species composition varies with forest type and tree species composition. We used functional traits that indicate different niche dimensions, to infer assembly processes of oribatid mite communities in monocultures and mixed forests of native and introduced tree species. We found that coexisting species differed more in the resource-related niche dimension, i.e., reproductive mode and trophic guild, than in the morphological dimension, e.g., body length and width, sclerotization and concealability. These results suggest that both filtering and partitioning processes structure oribatid mite communities. In native European beech forests, but not in non-native Douglas fir forests, oribatid mites were mainly structured by filtering processes acting via traits related both to environmental tolerance and to resources. Furthermore, oribatid mite trait diversity, but not phylogenetic diversity, differed significantly between monocultures and mixed forests, demonstrating that multidimensional diversity indices provide additional information on soil biodiversity. Overall, the study provides evidence that traits representing different niche dimensions need to be considered for understanding assembly processes in soil animal communities and thereby soil biodiversity.

Functional traits are indicators of the responses and adaptation of organisms to environmental changes and cascade to a series of ecosystem functions. The functional traits of soil animals are sensitive to environmental factors and may characterize and predict the changes of ecosystem functions. Multiple dimensions of biodiversity that combing species, phylogenetic, and functional diversity improves the understanding of distribution patterns, community assembly mechanisms and ecosystem functions of soil animals. In this review, we listed the categories of soil animal functional traits and their ecological significance, and summarized current researches on the responses of soil animal communities to environmental changes and the community assembly processes based on trait-based approaches. We proposed to strengthen the study on the impacts of eco-evolution processes of biotic interactions to soil animal functional traits, establish the database of soil animal functional traits, and apply trait-based approaches in the ecological restoration in the future, which would benefit soil biodiversity conservation and sustainability of soil ecosystems.

The implementation of the Grain for Green Project has increased vegetation coverage and provided suitable habitats and food resources for soil fauna, thereby promoting the development of soil faunal communities. Studying seasonal variations in soil fauna communities in different vegetation areas can improve our understanding of the mechanisms that drive soil fauna recovery. We selected five typical artificially restored vegetation habitats, including Populus simonii (POS), Pinus tabulaeformis (PIT), Caragana korshinskii (CAK), Stipa bungeana (STB), and Medicago sativa (MES), and one farmland (Zea mays, FAL) habitat on the Loess Plateau. In this study, soil fauna communities and environmental factors were investigated during spring (May), summer (August), and autumn (November). Among the habitats, the STB habitat had the largest seasonal variation in soil faunal density (from 1173 ind·m−2 in May to 10,743 ind·m−2 in August), and the FAL habitat had the smallest (from 2827 ind·m−2 in August to 5550 ind·m−2 in November). Among the restored vegetation habitats, Acarina (44.89–88.56%) had the highest relative abundance of all taxa. The redundancy analysis (RDA) results showed that among the factors driving seasonal variation in soil animal communities, temperature (47.41%) was the most important, followed by precipitation (22.60%). In addition, the dominant groups, Acarina and Collembola, played an influential role in seasonal variations in soil faunal density. Temperature mainly determined the seasonal variations in soil faunal communities. Seasonal factors should be considered when conducting soil fauna research, as they contribute to biodiversity conservation and regional ecological management in the Loess Plateau.

Soil animal communities include more than 40 higher-order taxa, representing over 23% of all described species. These animals have a wide range of feeding sources and contribute to several important soil functions and ecosystem services. Although many studies have assessed macroinvertebrate communities in Brazil, few of them have been published in journals and even fewer have made the data openly available for consultation and further use. As part of ongoing efforts to synthesise the global soil macrofauna communities and to increase the amount of openly-accessible data in GBIF and other repositories related to soil biodiversity, the present paper provides links to 29 soil macroinvertebrate datasets covering 42 soil fauna taxa, collected in various land-use systems in Brazil. A total of 83,085 georeferenced occurrences of these taxa are presented, based on quantitative estimates performed using a standardised sampling method commonly adopted worldwide to collect soil macrofauna populations, i.e. the TSBF (Tropical Soil Biology and Fertility Programme) protocol. This consists of digging soil monoliths of 25 x 25 cm area, with handsorting of the macroinvertebrates visible to the naked eye from the surface litter and from within the soil, typically in the upper 0-20 cm layer (but sometimes shallower, i.e. top 0-10 cm or deeper to 0-40 cm, depending on the site). The land-use systems included anthropogenic sites managed with agricultural systems (e.g. pastures, annual and perennial crops, agroforestry), as well as planted forests and native vegetation located mostly in the southern Brazilian State of Paraná (96 sites), with a few additional sites in the neighbouring states of São Paulo (21 sites) and Santa Catarina (five sites). Important metadata on soil properties, particularly soil chemical parameters (mainly pH, C, P, Ca, K, Mg, Al contents, exchangeable acidity, Cation Exchange Capacity, Base Saturation and, infrequently, total N), particle size distribution (mainly % sand, silt and clay) and, infrequently, soil moisture and bulk density, as well as on human management practices (land use and vegetation cover) are provided. These data will be particularly useful for those interested in estimating land-use change impacts on soil biodiversity and its implications for below-ground foodwebs, ecosystem functioning and ecosystem service delivery. Quantitative estimates are provided for 42 soil animal taxa, for two biodiversity hotspots: the Brazilian Atlantic Forest and Cerrado biomes. Data are provided at the individual monolith level, representing sampling events ranging from February 2001 up to September 2016 in 122 sampling sites and over 1800 samples, for a total of 83,085 ocurrences.

Asymmetric environmental selection on intraspecific body size in Collembola communities along an elevational gradient in northern Japan

Intraspecific variability and species turnover drive variations in Collembola body size along a temperate-boreal elevation gradient

Downed deadwood habitat heterogeneity drives trophic niche diversity of soil-dwelling animals