Soil Fauna Communities Research Articles (Page 1)

The characterization of soil mite (Acari) communities traditionally follows morphological identifications of specimens extracted from soil, which is a highly laborious and time-consuming process. Metabarcoding has become an increasingly utilized approach for species identification from environmental DNA (eDNA) samples, but whether the metabarcoding approaches align with the morphological identification data on soil mites has rarely been addressed. Here, we examine the congruence of soil mite communities between morphological and metabarcoding datasets. The morphological dataset was generated by extracting mite specimens from the soil samples, whereas molecular datasets represent two types of cytochrome c oxidase subunit I (COI) amplicons produced directly from soil eDNA (from 0.2 g and 2 g soil samples) and sequenced with Illumina (313 base pairs amplicons) and PacBio (658 base pairs amplicons) platforms. We found that specimen extraction from soil samples, followed by morphological identification, yielded the highest number of mite species. Despite significantly lower mite richness in the metabarcoding datasets, PacBio datasets provided more reliable community profiles that aligned strongly with the morphological data. This indicates that soil sample quantities generally used for microbial analyses are also informative in studying soil faunal communities. Furthermore, our results indicate that methodological choices (herein PacBio vs. Illumina) have a greater influence on mite community detection than the amount of input soil used for DNA extraction. Interestingly, the patterns of the entire metazoan community in the metabarcoding datasets strongly mirrored those of the morphologically identified mite communities alone, indicating that soil mites serve as a powerful ecological indicator group.

ABSTRACTIn the context of global change, mountain ecosystems are facing more threats than ever. Therefore, understanding spatial distribution patterns of diversity and their driving factors on mountains is gaining increasing attention. Although comprising an essential component of terrestrial ecosystems, the structure of soil fauna communities in mountain ecosystems and their driving factors have been little studied. Changbai Mountain harbors one of the most well‐preserved forest ecosystems in the temperate zone. Its high biodiversity provides an ideal setting for investigating biodiversity patterns along elevation gradients. We investigated the diversity, biomass, and community composition of two key soil predator taxa—centipedes and spiders—across eight elevations ranging from 800 to 1850 m a.s.l. Furthermore, we explored correlations between community characteristics and environmental factors. A total of 26 centipede species were identified among 2796 individuals, while 76 spider species were recorded from 2327 individuals. Both centipede and spider richness, biomass, as well as spider density, decreased with increasing elevation. Climatic variables and litter quality were identified as the primary drivers influencing the richness, biomass, and community composition of both taxa. Specifically, changes in temperature and precipitation associated with elevation were identified as the main drivers of changes in diversity, biomass, and community composition. Litter quality, including litter pH, total phosphorus, total carbon, total nitrogen, and N/P ratio, was of secondary importance. Overall, the results provide critical insights into the vulnerability of soil fauna to global climate change and highlight the need for conservation strategies that account for the complex interactions between biodiversity and environmental change.

ABSTRACTNematodes are versatile bioindicators of the soil food web in both agricultural and natural ecosystems. Multiple nematode‐based indices (NBIs), derived from morphological, life history and community traits, provide invaluable information on various aspects of soil health. However, a standardised approach is required to explicitly link NBIs to the soil health concept. Moreover, unifying all NBIs into a single quantitative index could offer a more comprehensive and straightforward bioindicator for soil health. The ecological foundations for individual NBIs have been well established, but a single standardised bioindicator for soil microfaunal communities including nematodes, remains absent. Here, we integrated existing knowledge on NBIs into an innovative framework for quantitatively assessing soil health and ecosystem functions. Moreover, we propose a new Nematode Soil Health (NSH) index which summarises all NBIs into a single quantitative bioindicator. The framework was tested with five case datasets covering different soil types, depths, land uses and seasonal variations. Results for Datasets 1 and 2 indicated no significant difference in NSH values among soil types (Ferrosol, Chromosol and Vertosol) but significantly greater NSH in topsoil compared to subsoil layers. Dataset 3 revealed that soil amendments with fauna significantly increased the NSH index compared to defaunated soils, supporting the role of soil faunal communities in maintaining soil health. The NSH index (in Dataset 4) was also significantly higher in perennial pastures than annual croplands and exhibited (in Dataset 5) seasonal variation, with higher values in spring compared to autumn. Although this framework requires further calibration, testing and standardisation on more nematode community datasets, it could be combined with quantitative estimations or graphical representations of NBIs to provide additional information relevant to soil health conditions. The NSH index has the potential to foster the practical application of NBIs in soil health assessment programs, enhancing their adoption by practitioners and farmers.

We quantified soil fauna communities in unoccupied Dicuspiditermes spp. mounds.Mounds supported up to nine times more soil fauna individuals than control soil.Ants were the most abundant group with active colonies within the unoccupied mounds.Many termite species create conspicuous, aboveground soil nest mounds. Once the resident termite colony disappears, the mound structure gradually disintegrates. The now empty mound, which is rich in nutrients, and stable in microclimate, potentially provides an important microhabitat for a different range of species. However, the communities in unoccupied termite mounds remain poorly explored, and the relative importance of these mounds in anthropogenically modified habitats is completely unknown. Here we quantify the invertebrate communities in unoccupied mounds of the soil-feeding termites Dicuspiditermes spp. in primary and logged lowland tropical rain forest in Malaysian Borneo and compare them to communities found in control soil. We also quantify the introgression of plant roots into the mounds. We found the unoccupied mounds support a range of invertebrate groups, with ants (Formicidae) having the highest abundances of any group across both habitats. Mounds supported significantly higher abundances of invertebrates overall in both primary forest (nine times more) and logged forest (five times more). However, the number of invertebrate taxa did not differ between mounds and control soils. Plant root mass was higher in control soils than in unoccupied mounds, possibly due to dominance of fine roots in the latter microhabitat. Using previous estimates of mound densities, we estimate that unoccupied Dicuspiditermes spp. mounds support >340 000 invertebrate individuals in primary forest and >17 000 individuals in logged forest per hectare. Our results indicate that unoccupied mounds are an important, although ephemeral, microhabitat for a range of invertebrate groups, in both pristine and anthropogenically disturbed habitats.

Impact of microplastic concentration on soil nematode communities on the Qinghai-Tibet Plateau: Evidence from a field-based microcosms experiment.

In order to establish the influence of grazing regime on soil fauna communities, a complex study was conducted on eight mountain grasslands in Romania. The grassland sites were grouped by management regime: ungrazed or intensely grazed by sheep. Eight environmental factors were measured, both abiotic (soil acidity, soil resistance at penetration, soil and air humidity, soil and air temperature, and soil electrical conductivity) and biotic (vegetation coverage). There was significant variability in the average values of these factors at the microhabitat level (between all grasslands investigated). Analysis of eighty soil samples allowed for the identification of sixteen soil fauna taxa, which constituted the database for statistical processing. The community status of these soil invertebrate faunas was mainly evaluated using three parameters: numerical abundance, taxa richness, and Shannon–Wiener index of diversity. Collembola and Oribatida were the most dominant taxa. The numerical abundance and taxa diversity recorded high values in ungrazed grasslands. Soil resistance at penetration, vegetation coverage, and soil pH influenced the numerical abundance of soil fauna communities significantly. Grassland management influenced the composition of soil invertebrates in both regimes, with Chilopoda, Staphylinidae, Diplopoda, and Enchytraeidae clearly preferring ungrazed ecosystems, whilst Mesostigmata was much commoner in grazed sites. The study revealed that correlations between the species composition of soil communities and environmental parameters under differing management regimes (ungrazed vs. grazed), demonstrated that these invertebrates can be used as bioindicators in such terrestrial ecosystems.

Microhabitat and seasonal dynamics of soil fauna communities in upper Andean successional forests

The use of chemical-based fertilizer continuously without addition of organic matter may have hazardous effects on the environment. Numerous studies have shown that chemical-based fertilizers may disrupt the balance of soil properties, including physical, chemical, and biological properties. Bio-organic fertilizers have become one of the alternative answers to oil palm sustainability and a replacement for chemical-based fertilizers to promote and provide a better service to the soil and environment. This study aims to analyze the effect of application of biofertilizers combined with different dosages of organic matter (bio-organic fertilizers), i.e. 0 kg tree-1, 6 kg tree-1, and 12 kg tree-1, respectively. The study was conducted in Cikabayan Experimental Oil Palm Plantation, Bogor, West Java with 12 year-old-plant oil palm, from May to November 2023. The study showed an increase in the population density of the soil organisms after application of bio-organic fertilizers, especially with the dose of 6 kg tree-1. The change in the soil fauna community structure was also observed in this study, where Collembola dominated the ecosystem after fertilization. These findings offer practical strategies to mitigate the negative impacts of traditional fertilizers. Moreover, the study highlights the role of bio-organic fertilizers in enhancing soil biodiversity by increasing the populations of beneficial soil organisms.

Soil fauna had little influence on decay rates, but the effect varied by species.Soil fauna richness and abundance did not influence decomposition environment.Body size traits of soil fauna were unrelated to decomposition environment.Limited macrofauna presence explained the lack of soil fauna’s effect on decay rates.Macrofauna contribution to decomposition had weak effects on succession.Recent studies and global meta-analyses suggest that soil fauna is a key driver of litter decomposition. However, most research has focused on lowland ecosystems, leaving tropical mountain regions underexplored. Our study investigated the influence of the taxonomic and functional structure of soil fauna communities on litter decomposition in successional upper Andean tropical forests. We conducted two reciprocal translocation experiments: one examining 15 litter species (2 525 litterbags) and another analyzing macrofauna exclusion (336 litterbags). We also performed extensive soil fauna sampling across four climatic seasons (6 999 individuals) and measured body size traits for 93% of the morphospecies. We analyzed the role of soil fauna attributes (richness, abundance, body size) on litter decomposition at the species and ecosystem levels in four sites of successional upper Andean tropical forests in Colombia. Our findings indicated that soil fauna has little influence on decomposition, yet the effect varies by species, suggesting specific affinities between soil fauna and litter substrates. The lack of influence of soil fauna richness, abundance, and body size can be attributed to the dominance of small-sized fauna in upper Andean tropical forests. The contribution of soil macrofauna to decomposition was higher in mature forests, but this effect was weak over time. Further studies should explore indirect effects and microbial interactions to better understand soil fauna’s role in decomposition. Our study highlights that the influence of soil fauna on decay rates is context-dependent and should not be generalized across all ecosystems.

Opposing island biogeographic effects of turnover and nestedness on beta-diversity of soil faunal communities between woodland and deforested grassland

Soil faunal community transfers nutrient cycling functionality and plant-parasitic nematode suppression from different depths of a natural soil to an agricultural soil

Global climate change is causing plants and other organisms to naturally expand their ranges to higher latitudes or altitudes. This expansion is leading to a strong reshuffling of biotic interactions with consequent ecosystem functions in the new ranges. We report here that soil fauna communities respond strongly to the cushion plants in a large-scale latitudinal gradient in the Qinghai-Tibet Plateau. Local taxonomic, functional, and phylogenetic diversity of soil nematodes increased with the presence of cushion plants independently of the latitudinal gradient, but communities became more functionally similar in the presence of cushion plants and with increasing latitude. This functional homogenization was driven by deterministic processes through which the presence of cushion plants favored some functional traits (i.e., nematode trophic groups: herbivores and bacterivores). Our study reveals functional homogenizations of soil fauna communities in response to climate warming-induced plant range expansion. Given that soil nematodes represent the most abundant and functionally diverse animal communities in terrestrial ecosystems, these findings indicate important changes in the functional dimension of biodiversity and in the delivery of ecosystem functions under climate change.

The relationship of plant diversity and several ecosystem functions strengthens over time. This suggests that the restructuring of biotic interactions in the process of a community's assembly and the associated changes in function differ between species‐rich and species‐poor communities. An important component of these changes is the feedback between plant and soil community history.In this study, we examined the interactive effects of plant richness and community history on the trophic functions of the soil fauna community. We hypothesized that experimental removal of either soil or plant community history would diminish the positive effects of plant richness on the multitrophic functions of the soil food web, compared to mature communities. We tested this hypothesis in a long‐term grassland biodiversity experiment by comparing plots across three treatments (without plant history, without plant and soil history, controls with ~20 years of plot‐specific community history).We found that the relationship between plant richness and below‐ground multitrophic functionality is indeed stronger in communities with shared plant and soil community history. Our findings indicate that anthropogenic disturbance can impact the functioning of the soil community through the loss of plant species but also by preventing feedbacks that develop in the process of community assembly.

Abstract Tropical cyclones (i.e. hurricanes, typhoons) cause large pulse fluxes of leaves that have not undergone senescence (i.e. green litter) to forest soils, with consequences for biogeochemical cycling. Energy and mineral nutrient concentrations of green litter are higher than the naturally senesced litter, likely affecting rates of decomposition and nutrient release, as well as the structure and composition of detrital food webs, but these effects have not been well quantified. During the typhoon ‘Hagubit’, we collected green and senesced litter from three common urban greening species, and then conducted a 316‐day field experiment to evaluate substrate quality affected the trophic multifunctionality of soil faunal communities and ultimately elemental release from the decomposing litter. Nitrogen (N), phosphorus (P), potassium (K), sodium (Na), calcium (Ca) and magnesium (Mg) were released at significantly higher rates from green litter than senesced litter. Aluminium (Al), manganese (Mn) and iron (Fe) displayed a net accumulation during litter decomposition, and the immobilization of these elements was significantly higher in green than senesced litter. Litter substrate chemistry directly affected the release rates of elements, but its influence was stronger in decomposing senesced litter compared to green litter. Detritivores dominated green and senesced litter faunal communities relative to predators, omnivores and herbivores, and these distinct fauna functional groups showed significantly positive correlation during decomposition, but soil fauna trophic multifunctionality was significantly higher in green litter and stimulated the release of elements. These findings suggest that typhoons dramatically alter the dynamics of nutrient release during litter decomposition, and the influences are mediated in part by its substrate quality and changes in soil fauna trophic multifunctionality, which has significant implications for the magnitude and timing of soil nutrient availability after typhoon disturbances. Read the free Plain Language Summary for this article on the Journal blog.

The widespread use of acephate, a common insecticide, raises concerns about its potential impacts on nontarget soil organisms. This study investigated the chronic effects of acephate on the reproduction of two key soil fauna species, the springtail Folsomia candida and the enchytraeid Enchytraeus crypticus. We exposed these organisms to acephate in both natural Cambisol soil and tropical artificial soil (TAS) to assess potential impacts under different environmental conditions. Our results revealed significant reductions in reproduction for both species, with effects ranging from 38% to 49% (based on control and lowest observed effect concentration values). Furthermore, the observed effects were dependent on both the organism and the soil type. Springtails exhibited greater sensitivity in TAS than in Cambisol (0.09 and 15.0 mg a.i. kg-1 soil dry wt, respectively), whereas enchytraeids were more sensitive in Cambisol than in TAS (1 and 100 mg a.i. kg-1 soil dry wt, respectively). These findings highlight the importance of considering species-specific responses and soil properties when evaluating the ecological risks of pesticides on soil fauna communities.

Soil total carbon as a key factor affects soil biota attributes in plant mixtures over time: A meta-analysis

The rapid global expansion of shale gas extraction has intensified scrutiny of its environmental impact, yet research on terrestrial ecosystems remains limited compared to aquatic systems. To address this gap, we investigated the Fuling shale gas field in China's Sichuan Basin-a region of intensive hydraulic fracturing activity-to evaluate effects on soil geochemistry and fauna. We quantified hydraulic fracturing-associated tracers (i.e., electrical conductivity (EC), chloride (Cl-), strontium (Sr), and barium (Ba)) across three distance gradients (10 m, 50 m, and 100 m) from extraction well pads. While EC, Cl-, Sr, and Ba concentrations were elevated at certain sampling sites near the extraction well pads, statistical analyses revealed no significant differences in the concentrations of these tracers across varying distance gradients. To assess ecological impacts, we integrated traditional morphological taxonomy with environmental DNA (eDNA) metabarcoding, enabling high-resolution characterization of soil fauna communities. Results indicated no significant alterations in community structure attributable to shale gas activities. A multiparameter index (MPI) synthesizing physicochemical and biological data further confirmed no measurable degradation of soil health. These findings suggest that current extraction practices in the Sichuan Basin have not yet caused serious soil contamination or ecological disruption within the studied spatial scope. However, as regional hydraulic fracturing intensifies, long-term monitoring of cumulative pressures and ecosystem resilience thresholds will be essential to mitigate latent risks.

Climate change is exacerbating a global decline in biodiversity. Numerous observational studies link rising temperatures to declining biological abundance, richness and diversity in terrestrial ecosystems, yet few studies have considered the highly diverse and functionally significant communities of tropical forest soil and leaf litter fauna. Here, we report major declines in the order-level richness and diversity of soil and leaf litter fauna following three years of experimental whole-profile soil warming in a tropical forest. These declines were greatest during the dry season, suggesting that warming effects could be exacerbated by drought. Contrary to findings from higher latitudes, total faunal abundance increased under warming, and these effects were paralleled by major shifts in community composition. These responses were driven by increased dominance of a relatively small number of thermophilic taxa, and of oribatid mites in particular. Our study provides direct experimental evidence that warming causes diversity declines and compositional shifts for tropical forest soil and leaf litter fauna, a result with potential consequences for soil functions and biogeochemical cycles, and that highlights the vulnerability of tropical biodiversity to climate change.

Biodiversity experiments revealed that plant diversity loss can decrease ecosystem functions across trophic levels. To address why such biodiversity-function relationships strengthen over time, we established experimental mesocosms replicating a gradient in plant species richness across treatments of shared versus non-shared history of (1) the plant community and (2) the soil fauna community. After 4 months, we assessed the multitrophic functioning of soil fauna via biomass stocks and energy fluxes across the food webs. We find that soil community history significantly enhanced belowground multitrophic function via changes in biomass stocks and community-average body masses across the food webs. However, variation in plant diversity and plant community history had unclear effects. Our findings underscore the importance of long-term community assembly processes for soil fauna-driven ecosystem function, with species richness and short-term plant adaptations playing a minimal role. Disturbances that disrupt soil community stability may hinder fauna-driven ecosystem functions, while recovery may require several years.

Caves represent a specific environment with a special microclimate and fauna adapted to it. However, we have still a restricted knowledge on soil fauna communities in an environments with a marked microclimate gradient at the interface between cave and surface habitats. In the present study, we investigated the community patterns of dominant soil microarthropod group, oribatid mites, and their relationship to environmental factors across the microclimate gradient along a transect with seven study sites from cold and wet cave entrance zone to warm and drier deciduous forest. The cold and wet sites showed low oribatid abundances and a high spatial clustering of individuals in comparison to the warm sites. The oribatid mites showed significantly higher abundance and species richness at warm forest sites. Indicator species analysis indicated specific cold-tolerant species that dominated at cold sites of the gradient, but which were absent at the warmest sites. Variance analysis clarified that community composition at sites were significantly driven by environmental factors: temperature, soil moisture, pH and C/N ratio. The study underlines the importance of ice cave entrances as sources of high α-diversity of soil mesofauna and thus the conservation priority of these valuable habitats.