Earthworm Diversity Research Articles

Vermicast Analysis with the Earthworm Species Pheretima losbanosensis (Crassiclitellata: Megascolecidae): Bacterial Profiles for Potential Applications in Agriculture

In the Philippines, the use of non-native earthworm species in vermicomposting is popular. Given that the country is a vital geographical resource for earthworm diversity, the study of earthworm species to establish the potential of their vermicasts in agricultural applications is essential. In this study, the bacteria associated with the vermicasts of the recently described indigenous species, Pheretima losbanosensis, were investigated using next-generation sequencing, community-level physiological profiling, and NPK activity screening. The results showed diverse bacterial species belonging to the phyla Proteobacteria, Bacteroidetes, Acidobacteria, Actinobacteria, Chloroflexi, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Spirochaetes, Thermodesulfobacteria, and Verrucomicrobia. Higher diversity and carbon substrate utilization (p < 0.05) of amines and amides, phenolic compounds, polymers, and carboxylic and acetic acids were exhibited by the bacterial communities of P. losbanosensis compared to those of Eudrilus eugeniae. Likewise, bacteria (n = 25) isolated from P. losbanosensis vermicasts had higher nitrogen fixation and phosphate and potassium solubilization activities (p < 0.05) than the bacteria (n = 20) isolated from E. eugeniae vermicasts. Overall, our results indicate that the diverse bacterial communities inhabiting the vermicasts of P. losbanosensis have nutrient mineralization and carbon substrate utilization activities that may have applications in sustainable agriculture as a potential organic input to promote plant growth and improve soil substrate.

Amazonian earthworm biodiversity is heavily impacted by ancient and recent human disturbance

Despite the importance of earthworms for soil formation, more is needed to know about how Pre-Columbian modifications to soils and the landscape. Gaining a deeper understanding is essential for comprehending the historical drivers of earthworm communities and the development of effective conservation strategies in the Amazon rainforest. Human disturbance can significantly impact earthworm diversity, especially in rainforest soils, and in the particular case of the Amazonian rainforest, both recent and ancient anthropic practices may be important. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by sedentary habits and intensification patterns of pre-Colombian societies primarily developed in the second part of the Holocene period. We have sampled earthworm communities in three Brazilian Amazonian (ADEs) and adjacent reference soils (REF) under old and young forests and monocultures.To better assess taxonomic richness, we used morphology and the barcode region of the COI gene to identify juveniles and cocoons and delimit Molecular Operational Taxonomic Units (MOTUs). Here we suggest using Integrated Operational Taxonomical units (IOTUs) which combine both morphological and molecular data and provide a more comprehensive assessment of diversity, while MOTUs only rely on molecular data. A total of 970 individuals were collected, resulting in 51 taxonomic units (IOTUs, MOTUs, and morphospecies combined). From this total, 24 taxonomic units were unique to REF soils, 17 to ADEs, and ten were shared between both soils. The highest richness was found in old forest sites for ADEs (12 taxonomic units) and REFs (21 taxonomic units). The beta-diversity calculations reveal a high species turnover between ADEs and REF soils, providing evidence that ADEs and REFs possess distinct soil biota. Furthermore, results suggest that ADE sites, formed by Pre-Columbian human activities, conserve a high number of native species in the landscape and maintain a high abundance, despite their long-term nature.

Earthworms Species Diversity and Populations in Initao-Libertad Protected Landscape and Seascape, Misamis Oriental, Philippines

Earthworm diversity and populations in the seaward and landward portions of Initao-Libertad Protected Landscape and Seascape (ILPLS) were assessed. Soil physico-chemical properties in the area were also assessed to explain such oc- currence. Pheretima cf. lantapanensis, Amynthas sp. and Polypheretima sp., all belonging to family Megascolecidae, were detected in the area. ILPLS has a very low diversity of earthworms and the soil physico-chemical properties had no significant relationship with earthworm species diversity. The soil physico-chemical properties between the seaward and landward portions of the protected area were not significantly different. This study was undertaken to provide baseline in- formation on earthworm species diversity in ILPLS, which will serve to help strengthen the policy on the conservation and protection of biodiversity in the protected area.

Recording earthworm diversity on the tropical island of Martinique using DNA barcoding unveiled endemic species in bromeliad plants

In a context of accelerating biodiversity loss, some species may become extinct before taxonomists have time to collect and describe them. This is an even more critical problem for taxa with poor taxonomic knowledge, such as earthworms in the tropics. To overcome this taxonomic impediment, we investigated earthworm diversity on the tropical island of Martinique using DNA barcoding. Firstly, we sampled earthworms at 81 sites evenly distributed in two categories corresponding to natural and anthropized environments. We obtained a total of 684 sequences of a fragment of the COI gene. MOTU delimitation and morphological identification suggested that this dataset corresponded to 49 putative species, of which 16 were known exotic species. The rarefaction curve suggested that the sampling effort was not sufficient to capture total earthworm diversity in the natural environment and that many more species could be discovered. Secondly, we focused on a heterogeneous landscape around the town of Morne Rouge, where arboreal earthworms were sampled using a standardized protocol. We found 8 different species in epiphytic plants, three of which were found almost exclusively in bromeliad plants that were sampled above 1.4 m from the ground. The presence of these species, probably endemic to Martinique and new to science, was significantly correlated to the proportion of forest land cover. The most common earthworm in these habitats was Dichogaster andina, an exotic species found in bromeliads and Heliconia plants that were sampled at every height from the bottom of the tree up to 6.8 m. Its presence was correlated to the proportion of total river length in the landscape, suggesting that rivers may act as a dispersal vector. This study therefore highlights the great diversity of earthworms in Martinique, while emphasizing the main threats to this biodiversity, namely the alteration of habitats and the presence of invasive species.

Evaluation of Physico-chemical Parameters of Soil in Different Cropping Systems and their Co-relation with Earthworm Diversity

Aim: The present study is an attempt to evaluate the impact of earthworm diversity on physico-chemical parameters of soil in different cropping systems (i.e. basmati-wheat, basmati-chickpea, soybean-wheat, moong-wheat) under organic and conventional farming systems.
 Place and Duration of Study: The study was conducted at the School of Organic Farming, Punjab Agricultural University, Ludhiana, Punjab, India from June, 2020 to March 2021.
 Methodology: The four earthworm species found during the study period are Metaphire posthuma, Lampito mauritti, Amynthas morissia and Travoscolides chengannure, which belong to two families i.e. Megascolicidae and Octochateidae. Out of these Travoscolides chengannure was reported for the first time in Punjab.
 Results: The results indicate that richer earthworm diversity was found in the organic farming systems as compared to the conventional farming systems. The correlation analysis of earthworm abundance with the physicochemical parameters of soil in different farming systems revealed that the abundance of earthworms in organic farming system shows positive but non-significant correlation with pH, nitrogen and potassium levels. In conventional farming system, significant positive correlation (p=0.01) was found for organic carbon, electric conductivity and nitrogen.
 Conclusion: The findings of this encourage switching from conventional to organic farming practices. These practices not only increase earthworm diversity, but enrich the soil with many major and micro-nutrients. The agriculture practices which are earthworm-friendly should be adopted for long-term soil productivity.

The mitochondrial genome of Dendrobaena tellermanica Perel, 1966 (Annelida: Lumbricidae) and its phylogenetic position.

Earthworms are an important ecological group that has a significant impact on soil fauna as well as plant communities. Despite their importance, genetic diversity and phylogeny of earthworms are still insufficiently studied. Most studies on earthworm genetic diversity are currently based on a few mitochondrial and nuclear genes. Mitochondrial genomes are becoming a promising target for phylogeny reconstruction in earthworms. However, most studies on earthworm mitochondrial genomes were made on West European and East Asian species, with much less sampling from other regions. In this study, we performed sequencing, assembly, and analysis of the mitochondrial genome of Dendrobaena tellermanica Perel, 1966 from the Northern Caucasus. This species was earlier included into D. schmidti (Michaelsen, 1907), a polytypic species with many subspecies. The genome was assembled as a single contig 15,298 bp long which contained a typical gene set: 13 protein-coding genes (three subunits of cytochrome c oxidase, seven subunits of NADH dehydrogenase, two subunits of ATP synthetase, and cytochrome b), 12S and 16S ribosomal RNA genes, and 22 tRNA genes. All genes were located on one DNA strand. The assembled part of the control region, located between the tRNA-Arg and tRNA-His genes, was 727 bp long. The control region contained multiple hairpins, as well as tandem repeats of the AACGCTT monomer. Phylogenetic analysis based on the complete mitochondrial genomes indicated that the genus Dendrobaena occupied the basal position within Lumbricidae. D. tellermanica was a rather distant relative of the cosmopolitan D. octaedra, suggesting high genetic diversity in this genus. D. schmidti turned out to be paraphyletic with respect to D. tellermanica. Since D. schmidti is known to contain very high genetic diversity, these results may indicate that it may be split into several species.

Fauna-microbe diversity coupling lost in agricultural soils: Implications from the bacteria hidden in earthworm gut

Earthworms are critical for supporting soil health and microbial diversity and simultaneously maintaining a highly diverse gut microbiome. The earthworm is predominantly vulnerable to physical disturbance, yet how changes in earthworm diversity influence the richness and ecological network of soil-gut microbiomes in response to anthropogenic disturbance is virtually unknown. Here, we investigated the richness of earthworms, and their connection with the diversity of the soil-gut microbiome using a large-scale survey covering paired agricultural and natural sites. Our results showed that earthworm diversity was positively correlated with soil and gut bacterial diversity across sites. However, the connection between soil bacterial and earthworm diversity is lost in agricultural ecosystems. We further show that earthworm richness supported greater modularity in microbial networks, being both positively correlated with the richness of earthworm gut bacteria in both land-use types. Together, we provided the first empirical evidence that agricultural practices can break the fundamental links between soil bacterial and earthworm diversity, and further identify an unreported consistent connection between the diversity of earthworms and the modularity of microbial networks in natural and managed ecosystems. These findings emphasize the primary roles of earthworms in supporting soil biodiversity and point to the wider contributions of the soil animal-microbe interactions in preserving the whole soil biodiversity in anthropogenically disturbed ecosystems.

Distribution and diversity of earthworms in different land use systems in Rio Grande do Sul, Brazil

The southernmost state of Brazil, Rio Grande do Sul, includes both the Pampa and Atlantic Forest biomes, and covers an area of around 284 thousand km2. Since the last checklist for the state, published in 2012, many additional sites have been sampled. Hence, we provide here a full list of earthworm species and their distribution in different municipalities and land use systems in the state. Data were obtained from the literature, museums, and other earthworm collections and recent sampling efforts. Records for 19 additional species are reported here for the first time, raising the total to 78 species/subspecies currently known from Rio Grande do Sul, from the families Acanthodrilidae (5), Benhamiidae (3), Lumbricidae (13), Megascolecidae (11), Ocnerodrilidae (22), Almidae (2), Glossoscolecidae (18) and Rhinodrilidae (5). Alexidrilus Righi, 1971 is synonymized with Urobenus Benham, 1886, as both species in the genus (A. littoralis Ljungström, 1972 and A. lourdesae Righi, 1971) have similar morphology to the type species Urobenus brasiliensis Benham, 1886. Most of the native species/subspecies in the state (39), including an important number of new species, were found in native vegetation with lesser disturbance, such as swamps, native forests and pastures. On the other hand, the three peregrine and 27 exotic species (especially Pontoscolex corethrurus, Eukerria spp., lumbricids, megascolecids, Dichogaster spp., and Microscolex spp.) dominated in disturbed sites, such as compost piles, urban areas, rice and other crops, and cultivated pastures. Considering the geographic extension and the many unsampled sites in the state, further collection efforts are necessary and will certainly reveal new species, as evidenced here.

New Earthworm Record from Division Muzaffarabad, Azad Kashmir, Pakistan Supported by Molecular Markers

Earthworm diversity and ecology in Pakistan is poorly known, especially in the region of Azad Jammu & Kashmir. An earthworm community survey assisted by genetic barcoding detected an unidentified species which could constitute a new record for Pakistan. Morphological study revealed its identity as Perelia kaznakovi. Additionally, Bayesian phylogenetic inference based on five mitochondrial and nuclear molecular markers was performed. Results provided a phylogenetic placement of the genus Perelia within Lumbricidae for the first time, indicating a close relationship with Eophila. This approach should be implemented to Perelia arnoldiana and further representatives of the genus in order to understand their biogeography, diversity and evolutionary history.

Earthworm richness in no-tillage farming systems and riparian forests in Southern and Southeastern Brazil

No-tillage (NT) is a soil conservation management practice that can sustain important earthworm populations due the maintenance of soil cover and absence of soil disturbance. Sites with NT can also support native earthworm species, but few studies have identified the earthworms collected under NT. Therefore, the present study evaluated earthworm diversity in 14 sites under NT and seven with riparian forest (RF) in Atlantic Forest located in Rolândia, Cambé, Toledo (Paraná), Coxilha, Sarandi (Rio Grande do Sul) and Itaí (São Paulo). The earthworms were collected by handsorting using quantitative and qualitative methods. The 1471 individuals collected were classified into 23 species belonging to five families: Glossoscolex sp.71, sp.72, sp.73 and sp.74, Fimoscolex sp.23 sp.24 and sp.25 (Glossoscolecidae); Pontoscolex corethrurus, Urobenus brasiliensis (Rhinodrilidae); Haplodrilus sp.1 and sp.2, Ocnerodrilidae sp.1, sp.15, sp.16, sp.48, sp.49 and sp.50 (Ocnerodrilidae); Amynthas gracilis, Metaphire californica (Megascolecidae); Dichogaster affinis, D. gracilis, D. bolaui and D. saliens (Benhamiidae). Of the total, 15 were native and eight were exotic species. In general NT sites had higher species richness than the forest sites (except at Itaí), mainly due to the invasion of NT fields by exotic species, particularly Ocnerodrilidae sp.1 and Dichogaster spp. Six of the seven forests had native species, but only four NT fields had native earthworms, and these were generally found in low abundance.

Assessment of Earthworm Services on Litter Mineralisation and Nutrient Release in Annual and Perennial Energy Crops (Zea mays vs. Silphium perfoliatum)

Abundant and functionally diverse earthworm communities in perennials deliver ecosystem services like increasing nutrient availability by incorporating organic matter. This study aimed to analyse the decomposition of annual and perennial energy crop residues, and the subsequent nutrient release, depending on earthworm functional diversity. In a laboratory experiment, two ecological earthworm groups—anecics (detritivorous Lumbricus terrestris (L.)) and endogeics (geophagous Aporrectodea caliginosa and A. rosea)—were incubated with wilted cup plant (Silphium perfoliatum) and maize (Zea mays) litter for 4 or 8 weeks. Decomposition and consumption rates were calculated. The C, N and P in litter and casts were analysed. Mineralisation was a function of earthworm biomass and the number of individuals. Functional diversity had no beneficial effect. Decomposition was found to be highest in treatments with detritivorous earthworms, i.e., higher earthworm biomass, yet consumption and nutrient turnover in relation to earthworm biomass were higher in treatments with geophages indicating enhanced competition. N limitation became apparent in both litter treatments and was predominant with cup plant litter. N limitation and recalcitrant cell wall compounds affected consumption rates and the egestion of total C and P. While N in casts was lower than expected, P was increased. We observed that the effects manifested at different stages of decomposition of maize and cup plant, highlighting differences in temporal development of decomposition and nutrient turnover between litter types. Our results indicate that earthworms promote decomposition of recalcitrant litter and nutrient turnover, but N limitation may hamper nutrient release. Cup plant systems offer a suitable habitat for soil-dwelling organisms, but management approaches must consider the adequate input of organic matter as an energy and nutrient source to enhance ecosystem service provision.

Comparing earthworm biodiversity estimated by DNA metabarcoding and morphology-based approaches

Conventional identification based on morphology is today's tool of choice for monitoring earthworm diversity. However, it requires skills to distinguish specific features, which can become the bottleneck in soil ecological studies. DNA-based metabarcoding is increasingly used to monitor diversity of soil organisms. Few studies have compared this method with conventional methods. The aim of the study was to compare metabarcoding based on the mitochondrial 16S rRNA region with conventional morphology-based identification, where metabarcoding captured more species (eight) than identified by conventional method (five). Additionally, we tested the effects of two commercial DNA extraction kits: PowerSoil based on 0.25 g of soil and PowerMax based on 10 g of soil (both from Qiagen), where the PowerMax covered higher richness than PowerSoil.

Earthworms are not just “earth” worms: Multiple drivers to large diversity in deadwood

Earthworms are ecosystem engineers associated with important soil functions. Despite the large amount of literature on earthworm ecology, relatively few studies have examined earthworms in deadwood or quantified their importance in this habitat. We investigated earthworm communities in decaying deadwood and disentangled how their community dynamics are influenced by variation in tree species, wood decomposition stage, and forest environment. Decaying logs (of standardised size) of ten common, temperate tree species were laid out to decay on the soil surface for four years. The experiment was carried out in the “tree cemetery” experiment LOGLIFE, in two contrasting temperate forests in the central Netherlands. The decaying logs yielded surprisingly rich earthworm populations, with on average 19 individuals per meter of log and in total belonging to 12 different species. Our findings highlighted that earthworm communities in deadwood in terms of composition and abundance were influenced by tree species, wood decomposition stage and forest type with different soil properties, as well as their interactions. After one and two years of decay, earthworm abundance was higher in the logs of Picea abies and relatively fast decomposing Populus spp. than in other trees, while this pattern changed after four years with higher earthworm abundance observed in the other tree species. Overall, Populus spp. supported the highest earthworm abundance, followed by Picea abies and Quercus robur. The earthworm community composition in the logs in the two forest sites had broadly similar dynamic trends of first becoming very dissimilar between one and two years, then relatively more similar from two to four years of decay, although the community composition differed between sites. The interacting influences of tree species, wood decay stage and forest environment on earthworm communities strongly suggest that diversity in deadwood resources contributes to earthworm diversity in forests. Thus, by mixing different tree species and logging gradually through the years, forest managers could enhance the diversity of this abundant and understudied component of deadwood invertebrate diversity. Further research should study the feedback loop between earthworm communities and decomposition of deadwood.

Earthworm Diversity and Their Influences on Soil Enzyme Activities in Organic, Sustainable and Conventional Farming Systems of Puducherry

An experiment was conducted to study the earthworm diversity and its influence on soil enzyme activities in organic, sustainable and conventional farming systems in the state of Puducherry. A total of five earthworm species namely Drawida willsi, Drawida scandens, Lampito mauritii, Perionyx excavates and Eudrilus eugeniae were present in the study sites. Four species were found in conventional and sustainable farming and five species were found in organic farming. Earthworm species diversity, population, species dominance, and biomass were significantly higher in organic farming systems compared to sustainable and conventional farming systems. In addition, soils from organic farming showed higher activity of urease, alkaline phosphatase, β-glucosidase, cellulase, invertase and xylanase activities and they had a significant positive correlation with earthworm population and biomass. Our results revealed that the presence of earthworms strongly affected enzyme activities in soil. Earthworm casts probably contributed to the enrichment of plant-available nutrients and higher soil enzyme activities in organically managed soils.

IMPACT OF HABITAT DEGRADATION ON BIODIVERSITY OF EARTHWORM IN RAEBARELI DISTRICT

The land-use pattern in the Raebareli district exhibits a gradient of increasing human-caused land-use intensification. Deforestation for agriculture causes agroecosystems to be left fallow in order to recover vegetation and enhance soil fertility. Due to extensive grazing pressure, a lack of plant cover, and soil erosion that is accelerated by a higher pH value brought on by sodicity, fallows have significantly degraded ecosystems. Using biological restoration techniques, agroecosystems have transitioned from being externally regulated to becoming an internally managed, sustainable ecosystem. Eutyphoeus nicholsoni, Eutyphoeus orientalis, and Metaphire anomala in the forest, successfully surviving there. Three species were still present in the mechanized agroecosystem; Eutyphoeus waltoni invaded and replaced Eutyphoeus orientalis due to the alteration in land use pattern from forest to agroecosystem. The fallow contained Eutyphoeus incommodus and Eutyphoeus nicholsoni. Earthworms could not thrive in the soil there because of the high pH and low nutrient value of the sodic land earthworm. As a result of the conversion of land from a forest to an agroecosystem, endemic species predominated over foreign species, and this pattern continued in fallows and reclaimed agroecosystems. Endogeic species dominated in the forest, but a change in land use caused a reduction in their population in agriculture, which allowed anacic species to take their position in the fallow. Simpson's diversity index was higher in the less disturbed reclaimed agroecosystem, whereas the earthworm diversity index declined as farming intensified.

Earthworm community structure and population dynamics at Minkong forest of Mokokchung, Nagaland, India

Aim: The present study was undertaken to assess the seasonal variations of density, biomass and community characteristics of earthworms in two different types of forest at Minkong area, Mokokchung. Methodology: The survey was conducted during the period from January 2019-February 2020 in two areas viz., mixed forest and plantation. Standard methods were followed to determine the ecological categories of earthworms, density and biomass, relative abundance and species richness as well as for determination of different soil parameters viz., pH, moisture, bulk density, organic carbon, total and available nitrogen, available phosphorus and potassium. Results: 12 number earthworm species viz., Amynthas corticis (Kinberg), Amynthus gracilis (Kinberg), Drawida assamensis (Gates), Drawida hodgarti (Stephenson), Drawida nepalensis (Michaelsen), Drawida sp., Eutyphoeus assamensis (Stephenson), Eutyphoeus festivus (Gates) Metaphire houlleti (Perrier), Perionyx excavatus (Perrier), Perionyx simlaensis (Michaelsen) and Pontoscolex corethurus (Müller) were recorded. Dominant earthworm species in both the areas were D. nepalensis, P. excavatus, Drawida sp. and E. festivus. The Shannon diversity, Simpson diversity and Pielou’s species evenness were 2.17, 0.87 and 0.87 in mixed forest and 2.05, 0.86, 0.86 in plantation. The earthworm density and biomass were greater in plantation (276.74 ind m-2 and 338.47g m-2) compared to mixed forest (230.52 ind m-2 and 254.55 g m-2). Interpretation: As earthworm community characteristics differ depending on the type of forest, therefore, earthworm’ sdiversity and its indices can be used as an ecological indicator of anthropogenic disturbances and can help designing conservation programs for reclaiming the depleted areas. Key words: Biomass, Earthworm diversity, Minkong, Relative abundance, Subtropical ecosystem

Impact of Aboveground Vegetation on Abundance, Diversity, and Biomass of Earthworms in Selected Land Use Systems as a Model of Synchrony between Aboveground and Belowground Habitats in Mid-Himalaya, India

The population status and biomass of earthworms were studied in three different land use systems of pasture (Pa), silvopasture (SP), and mixed evergreen forest (MEF) from 2019–2020 in the Solan district of Himachal Pradesh, India. The aim of this study was to assess the population status of earthworms and investigate how different land use systems influence their abundance, diversity, and biomass. Earthworms and soil were sampled using the Tropical Soil Biology and Fertility (TSBF) method in all seasons (winter, spring, summer, monsoon, and autumn). The physicochemical properties of the soil were analyzed to evaluate their effects on the diversity, biomass, and density of animals. The diversity status parameters, such as the Shannon diversity index (H′), Margalef richness index (R), evenness (J′), and dominance index (D), were computed. A total of seven earthworm species, belonging to four families, namely, Amynthas corticis, Aporrectodea rosea, Drawida japonica, Eisenia fetida, Metaphire birmanica, Metaphire houlleti, and Lennogaster pusillus, were identified from all three land use systems. The lowest Shannon diversity index (H′), Margalef index (R), and evenness (J′) index values were registered in MEF (H′ = 0.661, R = 0.762, J′ = 0.369) compared to those in Pa (H′ = 1.25, R = 1.165, J′ = 0.696) and SP (H′ = 0.99, R = 0.883, J′ = 0.552), implying that MEF is the least diversified land system. In contrast, the highest dominance index (D) value was registered in MEF (Pa = 0.39, SP = 0.53, MEF = 0.67), which again showed that MEF is the least diversified land system. The highest values of abundance and biomass were recorded in MEF (754.15 individuals m−2 and 156.02 g m−2), followed by SP (306.13 individuals m−2 and 124.84 g m−2) and Pa (77.87 individuals m−2 and 31.82 g m−2). Both the density and biomass of earthworms increased from Pa to MEF (Pa < SP < MEF). This study is novel because it revealed that the diversity and productivity (biomass and abundance) values of earthworms were negatively correlated (as diversity increased, productivity decreased; as diversity decreased, productivity increased). The total values of abundance and biomass of earthworms in the three land use systems indicated perfect synchrony between aboveground and belowground habitats, whereas the diversity values revealed that MEF was dominated by one or two species and the least diversified. Therefore, for sustainable belowground productivity, aboveground conservation is recommended, and vice versa, regardless of diversity.

Cover crops and soil ecosystem engineers

AbstractEarthworms are key to the engineering of soil ecosystem services. However, how cover crops (CCs) influence these ecosystem engineers has not been widely discussed. This paper reviews (a) CC effects on earthworm abundance, biomass, diversity, and related soil ecosystems services and (b) factors affecting CC effects on earthworms. A review of existing literature (through 29 May 2022) found 22 CC studies on earthworm abundance and 10 on earthworm biomass, but studies on earthworm diversity were few. Cover crops increased earthworm abundance in 13 of 22 studies, increased biomass in five of 10 and had no effect in the rest of studies compared with no CCs. The change (Δ increase) was 11 to 535 earthworms m–2 and 11 to 44 g of earthworm biomass m–2. Cover crop effects on earthworm diversity are mixed. Earthworm abundance was more responsive to CCs than soil C and physical properties, suggesting earthworm abundance should be included as a sensitive measurement in soil health status. Cover crops with low C/N under no‐till or reduced‐till systems promote earthworm abundance relative to CCs with high C/N under conventionally tilled systems. Cover crop mixtures do not increase earthworm abundance more than monocultures. Earthworm abundance generally increases with increasing precipitation (r = 0.45; p = .025) and temperature (r = 0.36; p = .10). Overall, CCs increase earthworm abundance but have mixed effects on earthworm biomass and diversity, although more data from different CC management scenarios and climates are needed for more robust conclusions.

Earthworm diversity and distribution in district Mandi, Himachal Pradesh of Northwest Himalaya, India

The present survey of diversity and distribution of earthworms in District Mandi of Northwest Himalayan region conducted in two year from May 2013 to April 2015. Based on study reported 17 species belonging to 4 families. Information on earthworms scientific name, family, number, locality and general habitat are given for each species discussed in the text. Out of these 17 species, 6 native and 11 exotic species are recorded. There are 3 species which are firstly recorded in the study area these includes Eisenia fetida, Argilophilus sp. and Amynthas morrisi. The study provided extended information on earthworms’ diversity in the study area with special reference to change in species along with change in vegetation and altitude.

Illuminating biodiversity changes in the ‘Black Box’

Soil is often described as a ‘black box’, as surprisingly little is known about the high levels of biodiversity that reside there. For aboveground organisms, we have good knowledge of the distribution of the species and how they might change under future human impacts. Yet despite the fact that soil organisms provide a wide variety of ecosystem functions, we have very limited knowledge of their distribution and how their diversity might change in the future. In order to create accurate and generalisable models of biodiversity, the underlying data need to be representative of the entire globe. Yet even with our recently compiled global earthworm dataset of over 11000 sites, there are gaps across large regions. These gaps are consistent across many other datasets of both above- and belowground diversity. In order to fill the gaps we propose a sampling network (SoilFaUNa), to create a comprehensive database of soil macrofauna diversity and soil functions (e.g. decomposition rates). Building on the existing dataset of earthworm diversity and early data from the SoilFaUNa project, we will investigate changes in earthworm diversity. From our current work, we know that both climate and land use are main drivers in predicting earthworm diversity, but both will change under future scenarios and may alter ecosystem functions. We will, using space-for-time substitution models, estimate how earthworm diversity and their functions might change in the future, modelling earthworm diversity as a function of climate, land use and soil properties and predicting based on future scenarios. Previous studies of aboveground diversity changes over time using time-series analysis have found no-net-loss in richness, but analyses have criticisms. We aim to use time-series data on earthworms to move this debate forward, by using data and statistical methods that would address the criticisms, whilst increasing our knowledge on this understudied soil group. Field experiments and micro-/mesocosm experiments have been used to investigate the link between a number of soil organisms and ecosystem functions under few environmental conditions. Meta-analyses, which can produce generalisable results can only answer questions for which there are data. Thus, we have been lacking on information on the link between the entire community of soil fauna and ecosystem functions and impact of changes to the soil fauna community across environmental contexts. Using data collected from the SoilFaUNa project, we will, for the first time, synthesise globally distributed specifically-sampled data to model how changes in the community composition of soil macrofauna (due to changes in land use, climate or soil properties) impact the ecosystem functions in the soil.