Earthworm Species Composition Research Articles

Earthworms (Oligochaeta: Lumbricidae) of Georgia, Caucasus: distribution and biodiversity

The article attempts to present the species composition and distribution of earthworms in Georgia—one of the central countries of the Caucasus. According to long-term research, about 90 species of earthworms belong to 13 genera. They have been identified throughout Georgia, and most of them (47 species) were described in the nature reserves of eastern, western and central Georgia. 46 species of earthworms (51,7% of Caucasian Lumbricidae) found in Georgia have been identified as endemic species of the Caucasus. The similarities of earthworms’ dominant species in the various ecosystems within the Algeti National Park are discussed in the paper. The high level of Caucasus fauna endemism is mainly caused by the unique natural and climatic conditions of the Caucasus, which is clearly expressed in the species composition of earthworms. Among the genera which compose the Caucasian Lumbricidae fauna, the genus Dendrobaena has the most species diversity with 22 species (24.71%), followed by Eisenia (9 species, or 10%). The six genera Bimastos, Eiseniella, Imetescolex, Lumbricus, Octodrilus, and Omodeoia are represented by a single species.

Status of Soil Health Indicators after 18 Years of Systematic Tillage in a Long-Term Experiment

Long-term cultivation experiments are gaining more attention due to the possibility of following the changes in soil parameters (e.g., soil organic carbon (SOC), stock and soil health indicators, etc.). Our objective was to assess the status of soil in an 18-year-old tillage experiment after almost two decades of systematic tillage. In this research, soil physical (bulk density, moisture content), chemical (pH, SOC), and biological properties (soil microbial respiration, abundance, biomass, species composition of earthworms, yield) were used as indicators in three soil cultivation methods representing different degrees of disturbance (no-till—NT; shallow cultivation—SC; and ploughing—P). Based on our results, there were significant differences in bulk density (NT > SC, P) in 0–10 cm, and NT > P in deeper layers (10–20, 20–30, 30–40 cm), while the SOC content in 0–10 cm was the highest in NT (2.5%), followed by SC (2.4%) and P (2.0%). Soil microbial respiration was significantly greater in NT than in SC and P. The abundance and biomass of earthworms was the highest in NT (189 ind m−2, 41.26 g m−2), followed by SC (125 ind m−2, 36.9 g m−2) and P (48 ind m−2, 7.4 g m−2). We concluded that NT offered a beneficial habitat for earthworms and microorganisms and a high SOC storage capacity; however, bulk density was less convenient due to soil compaction in our experiment. Therefore, SC can be used as an alternative approach for sustainable soil tillage.

Ecological and Faunistic Analysis of Lumbricidae Species Composition of Natural Biogeocenoses and Man-made Territories

Earthworms make up the bulk of the soil mesofauna and play an important role in the transformation of organic matter, the formation of the pedosphere, the regulation of the flows of matter, energy and information in ecosystems. In this research, we have studied the species composition of earthworms in urban and suburban ecosystems of the foothills of the Trans Ili-Alatau. As a result of the work, 11 species of the Lumbricidae family of the Oligochaeta class were discovered. 6 species out of them have been discovered in our Republic: Aporrectodea rosea, Lumbricus rubellus, Lumbricus castaneus, Octolasion lacteum, Dendrobaena octaedra and Aporrectodea caliginosa are widespread. The genus Lumbricus is the most common in terms of the number of individuals in the studied territories. Significant differences have been established in the species composition of earthworms in technogenic and natural biogeocenoses. The lumbricides are the absolute dominants in two ecosystems. Along with the species composition of earthworms, seasonal dynamics were also studied, it was found that their maximum activity is observed at the most favorable ratio of temperature and humidity.

Seasonal dynamics of agricultural land use impacts on earthworm communities: Insights into diversity, abundance, and functional composition

Earthworms play a key role as soil bioengineers, but livestock farming and croplands can impact on the composition, structure, and functioning of earthworm communities. This study aimed to quantify the effects of replacing natural grasslands with crop rotations on the seasonal dynamics of key attributes of earthworm communities and explore soil physicochemical properties as mechanisms behind these effects. We conducted paired samplings on seven sites across Uruguay, comparing earthworm communities in soils under grazed natural grasslands and adjacent croplands, considering earthworm species composition, richness, diversity, and evenness, biomass, density, and mean body weight, over five consecutive seasons. Results revealed a clear negative impact of croplands on earthworm communities, showing substantial reductions in all considered attributes. Observed changes were attributed to environmental filters limiting the occurrence of larger exotic earthworm species in croplands, and variations in soil physicochemical properties were identified as potentially mediating some of these effects, including soil water regime (particularly affecting juvenile individuals) and soil organic matter content. These impacts resulted in a shift to dominance of r strategists (smaller, surface-feeding species such as Microscolex spp. in croplands compared to larger deeper-burrowing species in grasslands) and reduced functional composition of earthworm communities. Furthermore, seasonal dynamics revealed that differences between land uses were more pronounced during wetter periods, underscoring the relevance of seasonal variations when evaluating land use impacts on earthworm communities. Earthworms mean body weight resulted a useful attribute to be included in earthworm's assessments, allowing to identify impacts in community functional composition and suggesting size dependent mechanisms. Additional research is required to comprehensively understand the mechanisms behind these patterns and to develop more sustainable agricultural practices by considering soil fauna.

In‐situ tin casting combined with three‐dimensional scanner to quantify anecic earthworm burrows

AbstractEarthworms (Lumbricus terrestris) play a critical role in soil ecosystems. Analyzing the spatial structure of earthworm burrows is important to understand their effect on water flow and solute transport. The aim of this study was to quantitatively characterize structural characteristics (cross‐sectional area [A], circularity [C], diameter [D], actual length [Lt], tortuosity [τ]) of anecic earthworm burrows that were open and connected at the soil surface at two sites of different tillage treatments (no‐till at Lu Yuan [LY] and rotary tillage at Shang Zhuang [SZ]) by combining a new in‐situ tin casting method with three‐dimensional (3D) laser scanning technology. The cross‐sections of anecic earthworm burrows were almost circular, and the C values were significantly negatively correlated with D and A. Statistically, there were no significant differences in the τ values (1.143 ± 0.082 vs. 1.133 ± 0.108) of anecic earthworm burrows at LY and SZ, but D (6.456 ± 1.585 mm) and A (36.929 ± 21.656 mm2) of anecic earthworm burrows at LY were significantly larger than D (3.449 ± 0.531 mm) and A (9.786 ± 2.885 mm2) at SZ. Our study showed that burrow structures at two different sites differed from each other. Soil tillage methods, soil texture, and soil organic matter content at the two sites could have affected earthworm species composition, variation of earthworm size and the morphology of burrows. The method used in this research enabled us to adequately assess the spatial structure of anecic earthworm burrows in the field with a limited budget.

Green Corridors May Sustain Habitats for Earthworms in A Partially Converted Grassland

Permanent grasslands provide a healthy and undisturbed environment. We investigated how mulching altered the soil physicochemical parameters, earthworm abundance, biomass, species composition and vegetation cover compared to grassland and cultivated alfalfa field. Microplots (2 × 2 m) were mulched with either weed control fabric (WF) alone or WF combined with straw (WF + S) on a grassland to grow tomato in Ősagárd (Nógrád county, Hungary) between 2018 and 2021. We had two other microhabitats: a conventionally cultivated alfalfa field (CA) and grassland (GR). We measured soil parameters (physical: soil moisture content (SMC), soil penetration resistance (SPR); chemical: pH, soil organic matter; and biological: earthworm abundance, biomass, species composition and vegetation). SMC was significantly higher on covered plots (WF; WF + S) compared to CA and GR. SPR values were the highest in CA and GR at 20 cm depth. The abundance and biomass of earthworms were the highest in GR and lowest in CA in all seasons. Plant abundance was highly influenced by season and habitat. Despite the higher compaction and lower SMC figures, grass vegetation still provided a more suitable environment for earthworms than mulched plots (WF, WF + S). Therefore, where there is agricultural production on grassland, we suggest leaving uncultivated and uncovered patches as biodiversity corridors.

Species composition and phylogenetic analysis of earthworms on Hainan Island

Species composition and phylogenetic analysis of earthworms on Hainan Island

Identification of earthworm species in sand‐topdressed hybrid bermudagrass golf tees

AbstractOn golf courses, casting – the egestion of feces – by earthworms on the turfgrass surface can affect playability, growth, and maintenance. The earthworm species responsible for surface casting vary depending on location, climate and weather, soil texture, and turfgrass management practices. The objective of this study was to determine earthworm density and species composition in native soil and sand‐based golf tees managed under different sand topdressing rates (heavy at 2.54 cm yr–1 or light at 0.64 cm yr–1) in Fayetteville, AR. Earthworms were collected December 2016 by hand sorting and identified using DNA extraction and sequencing. Light sand topdressing resulted in significantly greater earthworm density. Soil rootzone did not affect earthworm density, which may have resulted from variability in earthworm populations sampled. All communities were comprised primarily of Diplocardia spp.; however, lightly topdressed treatments included Bimastos parvus (Eisen, 1874) and both topdressing treatments included Microscolex phosphoreus (Dugès, 1837). Amynthas spp. were present in all treatments except the heavily topdressed native soil treatment.

Earthworm species occurrence in agroecosystems in the Midlands, KwaZulu-Natal, South Africa

Little is known about the species composition of earthworms in agroecosystems in South Africa even though earthworms provide soil ecosystem services and are useful biological indicators of changes in the habitats. Given the land use and management impact biodiversity, the aim of this study was to document earthworm species that occur under cultivated land in the KwaZulu-Natal Midlands. A survey of nine farms that practise conservation agriculture was carried out between 2018 and 2020. Twelve earthworm species belonging to four introduced families: Acanthodrilidae (Dichogaster bolaui), Rhinodrilidae (Pontoscolex corenthrurus), Lumbricidae (Aporrectodea caliginosa,Aporrectodea rosea,Aporrectodea trapezoides,Lumbricus rubellus,Octolasion cyaneum,Octolasion lacteum), Megascolecidae (Amynthas aeruginosus,Amynthas corticis,Amynthas gracilis,Amynthas rodericensis) and juveniles from an indigenous family Tritogeniidae were recorded from cultivated fields. The type of crop (habitat) affected both species richness and abundance of earthworms significantly. However, post hoc results showed differences in species richness between the soya and the maize only, with greater species richness in the maize. Our results demonstrate that habitat type has a major influence on communities of earthworms in agroecosystems.

LUMBRICIDAE SPECIES COMPOSITION IN THE SOILS OF THE FOOTHILL BEYOND ILE ALATAU REGION

This article discusses the species composition of earthworms in the soils of the beyond Ile Alatau region. The role of earthworms in the soil is quite large. First of all, it is worth noting their loosening and structuring activities. During the movement process, these soil invertebrates mix a huge number of small fractions of soil. The loosening activity promotes moisture and sufficient oxygen. The most important is the destructive activity and enrichment of soils with active substances, as enzymes. The study of lumbricides began from the time of Charles Darwin, and is still of great importance the essence of such invertebrates in zoology. Scientific researchers had been carried out over two years (2018-2020) during the active vegetation of plants on the soils of the highest point of the beyond Ile Alatau region - in the peak of Talgar. As a result of the conducted research, the following earthworm species from the Lumbricidae family were found: Octolasium lacteum, Eisenia foetida, Eisenia nordenskioldi, Nicodrilus caliginosus, Nicodrilus longus, Lumbricus rubellus, Lumbricus terrestris, Dendrobaena octaedra. The most common species are Lumbricus rubellus and Nicodrilus caliginosus, and the rest are less common. In the seasonal dynamics of earthworm numbers, two peaks of activity were observed - in early June and at the end of August.

EARTHWORM COMMUNITIES (OLIGOCHAETA, LUMBRICIDAE) OF PINE FORESTS AND SMALL FOLIAGE FORESTS IN THE FOREST-STEPPE OB’ REGION

Earthworms form an essential group of soil macrofauna that performs a number of ecosystem functions in forests. Studies of the species composition and population density of earthworms were conducted in many regions of Russia; however, the fauna of Lumbricidae of Novosibirsk area remained unexplored for a long time. The objective of this work is to carry out a comparative analysis of earthworm population in coniferous and small foliage forests of the forest-steppe Ob region (Novosibirsk area) and to identify the correlation between the fauna composition and the basic physical and chemical properties of the soil. The study was conducted in pine forests and birch-aspen forests. The main method of registration was layer-by-layer excavation of soil with hand sorting of soil samples and analysis of forest deadwood. Some soil parameters were also measured. Data of the species composition and population density of earthworms for each habitat are given. The studied habitats were classified according to the ratio of the earthworm living forms. It was found that soil humidity is the most significant factor for the group of epigeiс and epi-endogeiс species. The diversity of epigeiс and epi-endogeiс earthworm species in forests is largely supported by deadwood. The Asian subspecies Eisenia nordenskioldi nordenskioldi was subjected to morphometric analysis confirming its characteristic polymorphism.

EFFECTS OF SOIL PHYSICOCHEMICAL PROPERTIES ON BIODIVERSITY AND DISTRIBUTION OF SOIL INVERTEBRATES

Soil invertebrates are bioindicators that characterize environmental changes due to high ecologicaland species diversity, close contact with the soil, high sensitivity and rapid response to changes inenvironmental parameters. This article presents the results of studies conducted in the biogeocenosesof the foothills of the beyond Ile Alatau in the period from 2018 to 2020. The parameters that affectthe distribution and species composition of earthworms in various biogeocenoses are determined: soilmoisture, organic matter index and pH of the environment. The family Lumbricidae is widely distributedin all biocenoses, although the predominant distribution is in the floodplain meadow. The humuscontent in the soils of this biocenosis is 3.26±0.30%, and the humidity is 14.56±2.58%. As a resultof the study, 8 species of earthworms of the family Lumbricidae were identified, belonging to 5 genera:Octolasium lacteum, Eisenia foetida, Eisenia nordenskioldi, Nicodrilus caliginosus, Nicodrilus longus,Lumbricus rubellus, Lumbricus terrestris, Dendrobaena octaedra. The ratio of invertebrate groups in thesoil varies throughout the season. Earthworms are found in the soils of biogeocenoses from June to September. Changes in environmental conditions contribute not only to the distribution and diversity of soilmesofauna, but also to their seasonal dynamics. Key words: soil mesofauna, earthworm, foothills of the beyond Ile Alatau, biogeocenosis, physical and chemical parameters.

Hidden Engineers and Service Providers: Earthworms in Agricultural Land-Use Types of South Tyrol, Italy

Earthworm activities affect the provision of many ecosystem services. Land use can strongly influence earthworm communities and, hence related soil functions. We assessed earthworm biomass, abundance, and species composition on grasslands, apple orchards, and vineyards in the context of an existing sustainability assessment tool in South Tyrol, Italy. A stratified sampling campaign revealed significant differences in earthworm distribution. We found 21 to 700 individuals m−2 in grasslands and surprisingly abundant earthworm communities in apple orchards (14 to 382 individuals m−2). Results for vineyards were ambiguous with no or very low abundance in 47% of the vineyards and a maximum of 396 individuals m−2. Mesohumic endogeic species were the most abundant functional group observed (75% of the biomass in grasslands, 50% in apple orchards and vineyards). Aporrectodea caliginosa was the most abundant endogeic species, Lumbricus rubellus the dominant polyhumic endogeic species in all land-use types. We estimated a total of 34,900 t of earthworm biomass on agricultural areas in South Tyrol corresponding to a total value of EUR 872 million. Although soil quality is a complex concept that cannot be captured with a single indicator, earthworms are suitable and feasible indicators for sustainable soil use at the landscape scale.

Do Long-Term Continuous Cropping and Pesticides Affect Earthworm Communities?

Earthworm species composition, the density of individuals, and their biomass were investigated in spring barley and faba bean fields in a long-term (52-year) experiment conducted at the Production and Experimental Station in Bałcyny, in north-eastern Poland (53°40′ N; 19°50′ E). Additionally, post-harvest residues biomass, soil organic matter (SOM), and soil pH were recorded. The above traits were investigated using two experimental factors: I. cropping system—continuous cropping (CC) vs. crop rotation (CR) and II. pesticide plant protection: herbicide + fungicide (HF+) vs. no plant protection (HF−). A total of three species of Lumbricidae were found: Aporrectodea caliginosa (Sav.) in both crops, Aporrectodea rosea (Sav.) in spring barley, and Lumbricus terrestris (L.) in faba bean. The density and biomass of earthworms were unaffected by experimental treatments in spring barley fields, whereas in faba bean CC increased and HF+ decreased earthworm density and biomass in comparison with CR and HF− respectively. Total post-harvest residues in faba bean fields were higher under CC in relation to CR and under HF+ compared with HF− treatment in both crops. Compared to CR, CC increased soil pH in spring barley fields and decreased in faba bean fields. Experimental factors did not affect SOM. Earthworm density and biomass were positively correlated with SOM content.

Phosphorus Fertilizers From Sewage Sludge Ash and Animal Blood Have No Effect on Earthworms

Soil invertebrates are crucial for agroecosystem functioning yet sensitive to agricultural practices, including fertilization. Considering the postulates of circular phosphorus economy, the use of fertilizers from secondary raw materials is likely to return and increase and may even become obligatory. The effects of recycled fertilizers on soil fauna communities, however, remain poorly understood. In this paper, the effect of phosphorus fertilizer (RecF) and biofertilizer (RecB) from sewage sludge ash and dried animal (porcine) blood on earthworm’s occurrence in soil is discussed. RecB is RecF activated by phosphorus-solubilizing bacteria, Bacillus megaterium. Waste-based fertilizers were assessed in field experiments against commercial superphosphate and no P fertilization. Three levels of P doses were established (17.6, 26.4, and 35.2 kg P ha−1). Earthworms were collected after the test crop harvest (spring or winter wheat). In the experiments two earthworm species, Aporrectodea caliginosa and Aporrectodea rosea, were identified. A large proportion of juvenile individuals were recorded in 2017. The recycled fertilizers used in the experiments used in recommended doses, similarly to superphosphate, did not alter the density, biomass, species composition, and structure of earthworms. Further long-term field research is recommended.

Comparison of the Effect of Perennial Energy Crops and Arable Crops on Earthworm Populations

The purpose of the study was to compare earthworm communities under winter wheat in different crop production systems on arable land—organic (ORG), integrated (INT), conventional (CON), monoculture (MON)—and under perennial crops cultivated for energy purposes—willow (WIL), Virginia mallow (VIR), and miscanthus (MIS). Earthworm abundance, biomass, and species composition were assessed each spring and autumn in the years 2014–2016 using the method of soil blocks. The mean species number of earthworms was ordered in the following way: ORG > VIR > WIL > CON > INT > MIS > MON. Mean abundance of earthworms decreased in the following order: ORG > WIL > CON > VIR > INT > MIS > MON. There were significantly more species under winter wheat cultivated organically than under the integrated system (p = 0.045), miscanthus (p = 0.039), and wheat monoculture (p = 0.002). Earthworm abundance was significantly higher in the organic system compared to wheat monoculture (p = 0.001) and to miscanthus (p = 0.008). Among the tested energy crops, Virginia mallow created the best habitat for species richness and biomass due to the high amount of crop residues suitable for earthworms and was similar to the organic system. Differences in the composition of earthworm species in the soil under the compared agricultural systems were proven. Energy crops, except miscanthus, have been found to increase earthworm diversity, as they are good crops for landscape diversification.

Responses of earthworm communities to crop residue management after inoculation of the earthworm Lumbricus terrestris (Linnaeus, 1758)

Earthworms are important for soil functioning in arable cropping systems and earthworm species differ in their response to soil tillage and crop residue management. Lumbricus terrestris (Linnaeus, 1758) are rare in intensively tilled arable fields. In two parallel field trials with either non-inversion (NIT) or conventional tillage (CT), we investigated the feasibility of inoculating L. terrestris under different crop residue management (amounts and placement). Simultaneously, we monitored the response of the existing earthworm communities to L. terrestris inoculation and to crop residue treatments in terms of earthworm density, species diversity and composition, ecological groups and functional diversity. L. terrestris densities were not affected by residue management. We were not able to infer effects of the inoculation on the existing earthworm communities since L. terrestris also colonized non-inoculated plots. In NIT and two years after trial establishment, the overall native earthworm density was 1.4 and 1.6 times higher, and the epigeic density 2.5 times higher, in treatments with highest residue application (S100) compared to 25% (S25) or no (S0) crop residues, respectively. Residue management did not affect earthworm species composition, nor the functional trait diversity and composition, except for an increase of the community weighted means of bifide typhlosolis in S0 compared to S100. In CT, however, crop residues did have a strong effect on species composition, ecological groups and functional traits. Without crop residues (S0), epigeic density was respectively 20 and 30% lower than with crop residues placed on the soil surface (S100) or incorporated (I100). Community composition was clearly affected by crop residues. Trait diversity was 2.6 to 3 times larger when crop residues were provided, irrespective of placement. Crop residues in CT also resulted in heavier earthworms and in a shift in the community towards species with a thicker epidermis and cuticle, a feather typhlosolis shape, and a higher average cocoon production rate. We conclude that earthworm communities under conventional tillage respond more strongly to the amount of crop residue than to its placement. Under non-inversion tillage, crop residue amounts affected earthworm communities, but to a smaller degree than under conventional tillage.

Invasive earthworm and soil litter response to the experimental removal of white-tailed deer and an invasive shrub.

Recent studies have shown that complex species interactions can regulate above- and belowground processes in terrestrial systems. Ungulate herbivory and invasive species are known to have strong effects on plant communities in some systems, but their impacts on soil biota and belowground processes are lesser known. Growing evidence suggests white-tailed deer (Odocoileus virginianus) and invasive plants facilitate increased abundance of exotic earthworms in temperate forests of the eastern United States. We conducted an experimental study that manipulated deer access and the presence of an invasive understory shrub in an eastern deciduous forest of southwestern Ohio, USA, from 2013 to 2017. Earthworm density and biomass, and standing litter biomass were measured in five paired deer access and exclosure plots, each with a split-plot removal of Amur honeysuckle (Lonicera maackii). Earthworm density declined in response to the experimental exclusion of deer, with earthworm density decreasing over time in the deer exclosure plots relative to deer access plots. Deer exclusion produced greater variation in earthworm species composition relative to access plots. Multivariate analyses indicated that larger earthworms in the genus Lumbricus were associated with deer exclosure plots, while smaller endogeic species were ubiquitous in both treatments. Standing litter biomass decreased over time in the deer-access plots. In contrast, honeysuckle removal had little effect on earthworm density and standing litter biomass. There was an interaction between deer and honeysuckle treatments on earthworm biomass, with honeysuckle removal reducing earthworm biomass when deer were excluded. Our results demonstrate strong effects of herbivores on invasive earthworms and ecosystem processes, but indicate a weaker influence of invasive shrubs. Further, our findings suggest that the effects of deer overabundance in forest ecosystems are potentially reversible with long-term intervention.

Earthworm (Oligochaeta, Lumbricidae) Populations of the Karasu River Basin (Central Caucasus)

The species composition, population structure, and synecological characteristics of earthworms inhabiting forest and meadow formations of unique beech–hornbeam woodland of the Karasu River basin have been studied. Thirteen Lumbricidae species were found. The species composition and earthworm population structure depend on phytocenosis edificators. The greatest diversity, namely, species, chorological, and ecological, was recorded in soils of relict beech phytocenosis. It was shown that in the case of forest clearing its earthworm’s fauna remains intact. In the secondary meadows, the following was noted: the lowest species diversity of Lumbricidae, domination of soil species proper, and dramatically increasing diversity indices compared to forest associations.

Intensification of pastoral systems influences earthworm populations

ABSTRACTAgriculture is becoming increasingly intensified through irrigation, increased nitrogen inputs and a change in grazing animal from sheep to cattle. These changes have the potential to affect earthworms, an important component of the soil biology. Over 4 years, this study compared earthworm populations under sheep or cattle grazing, mowing or no harvesting of pasture and with or without combinations of nitrogen fertiliser and irrigation. Irrigation had the greatest influence on both pasture production and earthworm abundance, also changing the earthworm species composition, with epigeic Lumbricus rubellus becoming more abundant. Nitrogen fertiliser increased pasture production under irrigation in both the sheep grazed and mown treatments, but not under cattle grazed treatments. The opposing influences of increasing pasture production and physical pressures mean that moving from dryland sheep to irrigated cattle grazing may have a minimal overall effect on earthworm numbers, while irrigated sheep grazing provides an ideal earthworm habitat.