Earthworm Density Research Articles

Effects of Earthworm Density on Greenhouse Gas Emissions from Constructed Wetlands with Different Plant Configurations

Effects of Earthworm Density on Greenhouse Gas Emissions from Constructed Wetlands with Different Plant Configurations

Altitude, Land Use and Soil Depth Effects on Earthworm Density and its Relationship to Soil Properties in an On-Farm Study

Abstract Purpose Earthworms play a critical role in soil ecosystem functions through the cycling of organic matter and nutrients. However, some land uses or environmental conditions are more favorable habitats for them than others. Thus, the objectives of this study were to evaluate the prevalence of earthworm density and its relationship to land uses and soil properties. Methods The study was conducted in three districts (Wangdue Phodrang, Chhukha and Dagana) in Bhutan in three land uses (organic fields - OrgF, conventional fields - ConF and natural vegetation - NatV) under three altitudes (high-, mid- and low-altitudes) and three soil depths. Results Overall, earthworm density at high-altitude was significantly (P < 0.001) higher than that at mid- and low-altitude sites. Further, across altitudes and soil depths, OrgF sites had a significantly (P < 0.001) higher earthworm density (120 earthworms m− 2) compared to that in the NatV (56 earthworms m− 2) and ConF (43 earthworms m− 2) sites, and the density decreased significantly (P < 0.001) and successively with the increase in soil depth. The coefficient of determination (R2 ≥ 0.51; P < 0.001) showed a positive and moderate relationship between the earthworm density with soil organic C and total N in OrgF sites, but the relationship was weak (R2 ≤ 0.22) in the ConF or none in the NatV sites. Conclusions Substituting chemical fertilizers with organic manures could increase earthworm density by enhancing soil health through the cycling of organic materials and nutrients in the soil. The findings demonstrate empirical evidence for earthworm prevalence in different land use types across altitudinal gradients and provide valuable decision-making insights to land users and policymakers alike.

Influence of earthworm population density on the performance of vermifiltration for treating liquid dairy manure.

The dairy industry has seen notable changes in the last couple of decades, including increased size of farms and regional concentrations of dairies. This has resulted in substantial manure production in small geographical areas, raising environmental concerns. Vermifiltration, an emerging low cost and eco-friendly technology for treating wastewater, was evaluated to assess the influence of earthworm population density on the performance of a laboratory-scale vermifilter treating liquid dairy manure. We monitored the reduction efficiencies of various components, including total nitrogen (TN), ammonium-nitrogen (NH4 +-N), nitrate-nitrogen (NO3 --N), total phosphorus (TP), orthophosphate (ortho-P), chemical oxygen demand (COD), total solids (TS), and total suspended solids (TSS), in treated dairy wastewater. This evaluation was conducted at 0; 5000; 10,000; and 15,000 earthworm densities per cubic meter (m-3) of bedding. Reduction efficiencies of 41%-89% (TN), 46%-86% (NH4 +-N), 34%-74% (NO3 --N), 3%-17% (TP), 18%-38% (ortho-P), 35%-66% (COD), 24%-54% (TS), and 50%-87% (TSS) were observed with higher earthworm densities exhibiting greater reduction efficiencies. Notably, the densities of Eisenia fetida at 10,000 and 15,000 earthworms m-3 showed no significant difference in vermifilter performance. This suggests that increasing the Eisenia fetida density beyond 10,000 earthworms m-3 may not further improve the vermifilter's performance in treating dairy wastewater. This study's findings indicate that using vermifiltration with an earthworm population density of 10,000 earthworms m-3 could effectively mitigate the negative environmental impact of liquid dairy wastewater at a low cost and sustainably.

Homogeneous earthworm communities in Southern Ontario

Earthworms are key organisms of soil ecosystems, however, the determinants of the structure and distribution of earthworm communities and their relationships with agricultural practices are not well-studied in Canada. We sampled earthworm communities from four different habitat types along a disturbance gradient: agricultural crop land, forest around crop fields (buffers), recently restored natural grassland, and forests from conservation areas. As most species living in Canada are considered exotic and because of the recent colonization of Canadian soils by mostly European species after the extinction of the native species due to the glaciation of North America during the Pleistocene, we hypothesized that the impact of agricultural practices will be similar to what is observed in Europe: for example, crop habitat showing lowest abundance, richness, and proportion of epigeic and anecic species, due to lesser soil organic matter content and higher soil disturbance. We also hypothesized that important soil variables would be associated with these habitat differences. For each habitat we sampled earthworms using a combination of two methods (quantitative + qualitative) at three replicate sites, for two years between May and July together with important environmental variables. We found lower density and diversity of earthworms in crop habitat and proportionally more epigeic species than expected. Contrary to our predictions, forest-buffer earthworm communities were more similar to crop than to forest habitats, and soil environmental variables could not explain the variations in the spatial distribution of earthworm communities. In fact, our results revealed a more homogeneous distribution of the species diversity across the habitat gradient at local scales in Southern Ontario. This was mainly associated with spatial factors, probably due to historical extinction-colonization events of earthworms in Canada and the high invasive potential of the species currently present.

The effect of soil parameters and earthworm abundance on the fine-scale nocturnal habitat use of the Eurasian woodcock (Scolopax rusticola).

The Eurasian woodcock prefers habitats where its main prey, earthworms, can be found in higher densities. Although they are forest-dwelling birds, they regularly visit pastures and natural grasslands at night, where earthworm abundance is generally higher. However, there is little information on fine-scale habitat use in relation to variation in habitat characteristics and prey availability, particularly beyond the breeding season. In our study, we investigated if the nocturnal occurrence of woodcocks during migratory stopover periods differed between two neighbouring fields, or management units, with similar vegetation structure, and if within-field variation in the spatial patterns of woodcock sightings were associated with fine-scale earthworm densities and soil parameters. Specifically, we used GPS tracking data of two tagged woodcocks and direct observation data to study patterns of occurrence of birds in a mixed forest-pasture landscape in Hungary during pre- and post-breeding periods. We compared these patterns with fine-scale soil characteristics and earthworm abundance, acquired by field sampling. We found that the field with higher earthworm abundance was visited by woodcocks more frequently, and this correlation was similarly observed at the intra-field level. Our results demonstrate that woodcocks select foraging sites with higher earthworm densities at multiple spatial scales, both between fields (coarse scale), and within fields (fine-scale). Considering that woodcocks tended to return to the same field to forage at night, the strong associations between occupancy and resources provide a basis for developing habitat management strategies at the field level for conservation. As earthworm densities and soil parameters are good indicators of woodcock foraging habitat, measuring those variables, at least at a coarse scale, could aid in predicting important habitats for the species across the landscape.

Evaluation of effects of earthworm density and species on the permeability of clay loam soils for managing stormwater in urban systems

Evaluation of effects of earthworm density and species on the permeability of clay loam soils for managing stormwater in urban systems

Forecasting Oligochaeta Abundance using the Apparent Electrical Conductivity of Irrigated Soils with Reclaimed Wastewater: Evidence from Corso, Algeria

Background: The main objective of this paper is to study the possibility of using the measurement of apparent electrical conductivity (ECa) to estimate Oligochaeta (earthworm) density in irrigated soils treated with reclaimed wastewater. Additionally, the study sought to analyze the impact of using reclaimed wastewater for irrigation on earthworm density in the study area. Methods: Earthworm sampling was carried out at thirty emplacements within the study area during two measurement campaigns. Soil ECa was measured by (EM38). Result: The results showed that irrigation with reclaimed wastewater promotes the abundance of earthworms (earthworm density). Indeed, sites irrigated with reclaimed wastewater have higher earthworm densities compared to sites irrigated with conventional water. The results also show a strong correlation between ECa and earthworm density (R2 greater than 0.7). The Wilcoxon test indicates a non-significant difference between measured earthworm densities and those predicted by ECa (p greater than 0.5). This result confirms the effectiveness of the EMI technique as a tool to evaluate the spatial variability of soil biological parameters. These results collectively suggest that ECa represents a real possibility of reducing the number of earthworm samplings, whil ensuring the reliability of the estimates of real values of earthworm density and their surface spatial distribution. ECa could therefore be a useful tool to spatialize and predict the presence of earthworms in soil irrigated by reclaimed wastewater.

Endogeic earthworms mediate aggregate formation and carbon storage in an Ultisol

The role of soil fauna in the incorporation of carbon into soil aggregates of tropical soils has been understudied. We conducted a field experiment within a secondary forest and a microcosm experiment at the University of Puerto Rico in Mayagüez to test soil aggregate formation and carbon incorporation by earthworm activity. Using 13C natural abundance in vegetation and the difference in δ13C between C3 and C4 plants, carbon sources in the soil were tracked. Maize leaves (C4 carbon isotopic signal) were used to track the carbon incorporation into soil aggregates (C3 carbon isotopic signal). Earthworms and soil samples (Typic Haplohumults) were collected at 0 to 10 cm soil depth. The treatments for microcosms were: (I) soil, (II) soil + C4 leaves, (III) soil + C4 leaves + two earthworms (low density), and (IV) soil + C4 leaves + three earthworms (high density). Aggregate size classes were separated by the wet sieving method. At the study site, we found two earthworm species belonging to epigeic and endogeic ecological categories. Over six months, our field data suggested that endogeic P. corethrurus can reorganize small macroaggregates to form large macroaggregates. The microcosm experiment corroborated that P. corethrurus consumes soil and transfers soil-derived carbon from microaggregates to macroaggregates. The treatment with the highest earthworm density did not show higher carbon incorporation (0.23 g C/kg sand-free aggregates) into the soil compared to low earthworm density (0.25 g C/kg sand-free aggregates). Our results suggest that P. corethrurus prefers consuming soil-derived carbon and can translocate it from microaggregates to macroaggregates by restructuring soil aggregates.

Bioindicators for Assessing Soil Quality in Ecuador’s Jun Jun Micro-Watershed

The evaluation of soil quality in different altitudinal gradients, with vegetative and non-vegetative subareas, is crucial for proper soil functioning and optimal crop growth, thus contributing to the sustainability of agroecosystems. Although the altitudinal gradient significantly influences soil quality, the ability to predict this quality, expressed through an index, in soils with and without vegetative cover, is still insufficiently explored. This study employed the simple additive index (SQI) method to evaluate soil quality in Ecuador’s Jun Jun micro-watershed, Tungurahua region. Three altitude categories (<2800, 2800–2900, >2900 masl) were investigated, with 24 soil samples collected across both vegetated and non-vegetated areas. The indicators used included chemical and biological parameters such as soil organic carbon (OC), earthworm density (WD), earthworm biomass (WB), organic matter (OM), pH, and total nitrogen (TN). The results revealed that in areas with altitudinal gradients below 2800 masl, the soil quality index values were higher compared to other altitudes. In vegetated areas, a decrease in index values was observed as the altitudinal gradient increased, indicating a deterioration in soil quality with increasing altitude. These findings are significant in providing a quantitative assessment of the effects of altitudinal gradient and vegetative cover influence on soil quality.

A complex relationship between cropping systems and soil macrofauna: Influence of practice intensity, taxa and traits

Larger soil organisms have often been reported as the most sensitive to disturbances caused by cropping practices. However, soil macrofauna comprises groups with a wide diversity of morphological and ecological features, which may respond differently to applied practices. In order to further assess the effect of cropping systems on soil macrofauna, macrofauna organisms were extracted from soil blocks over 21 fields (each comprising three plots) located in the Paris basin, in autumns 2020 and 2021. Fields belonged to conventional, conservation or organic systems, either long-established (≥ 7 years) or in transition (≤ 3 years). Tillage, pesticide treatment and organic matter input intensity were assessed in each field using composite indexes of practice intensity. Macrofauna density and diversity, earthworm ecological categories, species richness and functional traits were investigated. Our results showed that the density and diversity of macrofauna demonstrated few differences regarding different cropping systems, with highly variable effects across groups and years. Specific macroarthropod groups responded differently to tillage, pesticide treatment and organic input intensity, but not over the two years of the study. Regarding earthworms, high tillage intensity had a negative effect on the density and biomass of epi-anecic juveniles and on species with a small body size. Higher organic matter inputs had a negative effect on the density and biomass of endogeic earthworms, and could be related to several earthworm functional traits (body length, mass/length ratio, carbon preferences). Effects of pesticide treatments were less clear, although they could have impacted some earthworm species. More generally, taxonomic and functional trait approaches of earthworm community led to similar conclusions. Overall, our results support the need to account for (i) the actual intensity of practices in cropping systems and (ii) the different taxonomic, trophic and ecological groups of macrofauna, in order to assess the effects of cropping systems on soil biodiversity.

Enhancing productivity, soil health, and reducing global warming potential through diverse conservation agriculture cropping systems in India's Western Indo-Gangetic Plains

ContextThe rice-wheat (RW) system, spanning 13.5 million hectares in South Asia, is crucial for food security and livelihoods. However, intensive conventional tillage-based practices have harmed soil and environmental health, decreased productivity trends and increased greenhouse gas emissions. ObjectiveThis study aims to develop resilient, climate-smart cropping systems within the RW system, focusing on soil and crop productivity, economic viability, and reduced greenhouse gas (GHG) emissions. MethodsOver eight years, the study evaluated diverse parameters compared to farmer practices (FP) in seven scenarios (Sc), including one representing FP (Sc1) and six based on conservation agriculture (CA) principles. The study assessed system crop productivity, economic returns, soil quality (organic carbon; OC, nitrogen; N, phosphorus; P, potassium; K contents, bulk density; BD, soil aggregation, infiltration rates, microbial counts, and earthworm density), and GHG emissions. ResultsCA-based scenarios (Sc2 to Sc7) showed improved soil quality, lower bulk density, enhanced soil aggregation, and increased infiltration rates compared to Sc1. In the 0–15 cm layer, surface soil organic carbon (OC) and C stock were 63.7 % and 49.6 % higher, respectively, in CA-based scenarios. Additionally, available N, P and K contents in the surface layer increased by 10.2 %, 28.6 %, and 21.8 % under CA-based scenarios. Adoption of CA in intensified maize-based scenarios (Sc4 and Sc5) led to the increased system and economic yields, higher soil quality index (SQI), reduced GHG emissions and increased C stock compared to Sc1. ImplicationsThe study highlights that Conservation Agriculture (CA) practices and diversified crop rotations can address issues like falling crop productivity, reduced economic returns, soil degradation, and increasing environmental impacts in northwestern India's traditional rice-wheat system. However, widespread adoption requires government policies, including C credit payments and guaranteed markets with supportive pricing.

Assessing dietary specialization to inform the conservation of the fairy pitta (Pitta nympha), an endangered vermivore.

Quantifying the diet of endangered species is crucial for conservation, especially for diet specialists, which can be more susceptible to environmental changes. The vulnerable fairy pitta (Pitta nympha) is considered a specialist that primarily feeds its nestlings with earthworms. However, there have been few studies of the nestling diet provisioned by parents, and no assessments of earthworm proportion in the diet of adults. Our study aimed to fill these gaps, shedding light on crucial factors for conservation. Combining new observations with existing literature, we confirmed a consistent dominance of earthworms in the nestling diet, regardless of rainfall, nestling age, and time of day. We extrapolated the total earthworm consumption during a breeding event, accounting for potential variation in the availability of earthworms and their prevalence in the adult diet. We used literature-based earthworm densities in pitta habitats and our estimates of family earthworm consumption to calculate the habitat area that could provide a pitta family with the number of earthworms consumed during a breeding event. The predictions matched observed pitta home range sizes when assumed that the adult diet is comprised of approximately 70% earthworms. The results highlight the importance of earthworm-rich habitats for conservation planning of the fairy pitta. To mitigate the effects of habitat destruction, we discuss conservation practices that may involve enhancing earthworm abundance in natural habitats and providing vegetation cover for foraging pittas in adjacent anthropogenic habitats rich in earthworms. To guide conservation efforts effectively, future studies should investigate whether previously reported breeding in developed plantation habitats is due to high earthworm abundance there. Future studies should also quantify correlations between local earthworm densities, home range size, and the breeding success of the fairy pitta.

Traditional Yerba Mate Agroforestry Systems in Araucaria Forest in Southern Brazil Improve the Provisioning of Soil Ecosystem Services

Soils are a source of natural capital that provide and regulate a range of ecosystem services (ES) and play an important role in sustaining human welfare. Nonetheless, the quality and quantity of soil ecosystem services (SES) delivery over the long term depend on the use of sustainable land management practices. In the present study, we assessed seven SES using a set of soil quality indicators in four production systems based on yerba mate (Ilex paraguariensis A. St.-Hil) in the Araucaria Forest biome of Southern Brazil: two sites were under traditional agroecological agroforestry management, one was a silvopastoral system with dairy pasture, and the last one was a monoculture yerba mate production system. The SES measured were soil fertility, carbon sequestration, erosion control, nutrient cycling, plant provision, biodiversity, and health. Soil samples were collected at various depths and analysed for chemical, physical, and biological attributes. A principal component analysis on the dataset showed that the soil quality indicators that best represent the variance between the systems at the 0–10 cm layer were acidity, microbial activity (FDA), total nitrogen, (TN), structural stability index (SSI), cation exchange capacity (CEC), pH, sum of bases (SB), microbial quotient (qMic), density of earthworms (EwD), bulk density (BD), and carbon stocks (Cstock). Soil quality indicators ranging from 0 to 1 were used to graphically represent the set of SES. The indicator-based approach used to explain the differences among the four production systems was able to capture the soil functions and offered a good starting point for quantifying SES provision.

Restoring soil properties in the Hyrcanian forests from machine induced compaction: Reforestation of N2‐fixing black alder (Alnus glutinosa (L.) Gaertn.)

AbstractAmong the various species of trees, black alder (Alnus glutinosa (L.) Gaertn.) is one of the most commonly used trees for the reforestation and restoration programs of degraded forestlands in the Hyrcanian forest, particularly in the skid trails. The effects of reforestation with black alder on the recovery of litter (thickness, C, N, C/N) and soil physicochemical, biochemical, biological, and microbial properties in the skid trails with three levels of compactions were examined over a 27‐year period. Results showed that the litter characteristics such as thickness, carbon (C), nitrogen (N), and C/N were at the highest level in low intensity traffic as compared to those of medium and frequent intensities. Results showed that the values of total porosity, macroporosity, aggregate stability, silt, and clay were at the lowest level in the natural stand. The highest values of soil pH, C, C/N ratio, and C storage were recorded under the skid trail with frequent machine passages. The restoration values of soil physical and chemical properties were significantly higher in the low level of machine traffic after a period of 27 years where black alder reforestation was performed on the skid trails, as compared to the medium and frequent machine traffic levels, as well as the undisturbed area. Black alder litter affected soil nitrogen and the maximum amounts of earthworm density and dry mass. This also includes fine root biomass. These data were recorded in the trails with low machine traffic as compared to those of medium and frequent traffic. The results clearly showed that black alder is effective in reaching the objectives of restoration programs, given that it promotes soil organic matter, builds up soil structure via root‐soil feedback, and improves the soil by creating a major source of nitrogen through enhancing the nitrogen cycle.

Perbandingan Struktur Komunitas Cacing Tanah Megadrilli pada Ekosistem Alami dan Ekosistem Buatan

Earthworms are an important component of soil ecosystems. The presence of earthworms in a habitat can enhance the quality of the soil, both in its physical, chemical, and biological properties. This research has the purpose to analyze the comparison of earthworm density found in natural ecosystems and artificial ecosystems. The determination of location points is done using the Cluster Sampling method, which includes both natural and artificial ecosystems. Sampling is conducted using the line transect method along a 100-meter length in 20 plots. The earthworm collection method involves the use of square and hand sorting methods. Data analysis includes density values, frequency, diversity index, and the Morisita index, as well as statistical analysis using an independent sample T-Test to determine the significance of the difference in earthworm abundance between the two locations. Five species of megadrillic earthworms were identified, classified into two ecological categories: epigeic and endogeic. In the natural ecosystem, there were five species, namely Pheretima capensis (epigeic), P. corethururus (endogeic), Pheretima sp.1 (epigeic), Megascolex sp. (endogeic), and Pheretima sp.2 (epigeic). Meanwhile, in the artificial ecosystem, three species were found, which are P. capensis (epigeic), P. corethururus (endogeic), and Pheretima sp.2 (epigeic). The density of megadrillic earthworms in the natural ecosystem (567.8 individuals/m2) is significantly higher compared to the artificial ecosystem (242.5 individuals/m2). The relative frequency of earthworms in the natural ecosystem is divided into 3 categories: Rare (Assesory), Common (Constant), and Very Common (Absolute), whereas in the artificial ecosystem, there are 2 categories: Common (Constant) and Very Common (Absolute). The diversity index of earthworms in the natural ecosystem tends to be higher (H' = 1.236) than in the artificial ecosystem (H' = 0.885). The distribution pattern of megadrillic earthworms in the natural ecosystem is clustered, while in the artificial ecosystem, it is random.

Two aspects of earthworm bioturbation: Crop residue burial by foraging and surface casting in no-till management

In no-till agroecosystems, presence of the earthworm Lumbricus terrestris L. can be a key driver in the replenishment of soil organic matter stocks post-harvest, through surface residue foraging and incorporation. The impact on such systems under different climatic conditions is, however, still unquantified. A field experiment was designed to determine incorporation of cereal harvest residues at three no-till agricultural sites in boreal conditions (SW Finland) focusing on L. terrestris impacts over the period from autumn harvest to spring sowing. Either spring barley, wheat or oats were cultivated at the sites. Following the harvests, representative masses of residues were applied on small experimental plots (0.25 m2) with cleaned soil surfaces in areas of inherently high (LT+: 10.6 ± 2.1 ind. 0.25 m-2) and low (LT-: 1.8 ± 0.7 ind. 0.25 m-2) L. terrestris density within the fields. Residues were covered with metal mesh caging and left until spring sowing, when changes in residue mass were recorded and plots sampled for earthworms. The reduction of straw residue mass varied between sites, from no difference between the LT+ and LT- treatments to 19 % and 59 % higher mass reduction in LT+. Amount of earthworm castings on the residues was also quantified and findings indicated a positive correlation with earthworm (also endogeic) density. For L.terrestris, earthworm species abundance relationships indicated competitive interaction with epigeics and positive interaction with endogeics. Results showed that L. terrestris foraging can enhance the incorporation of cereal surface residues outside of the boreal growing season and that earthworm surface casting also has a role in residue burial. However, the increase of incorporation by L. terrestris activity, interrupted by winter conditions, was moderate and did not lead to marked exposition of the soil surface by experimental end, even at those plots with the highest L. terrestris foraging. The incorporation rate estimates may have been unrepresentative due to the exceptionally late harvest during the study period. Investigations covering the whole year from multiple growing seasons are needed for a comprehensive assessment of earthworm impacts on crop surface residue dynamics.

Soil moisture and fertility drive earthworm diversity in north temperate semi-natural grasslands

Intensive management of arable land reduces earthworm density and diversity. This may impair earthworm-mediated soil functions, such as nutrient mineralization and soil structure formation. To sustain earthworm source populations for re-colonization of cultivated soils, it is therefore important to preserve habitats with high earthworm diversity. Semi-natural grasslands, with a long continuity without soil disturbance, could serve as such earthworm diversity reservoirs. This is particularly important in mixed agricultural landscapes with elements of multiple land uses. Nonetheless, earthworm density and diversity vary greatly among grasslands. To preserve and optimally manage the most suitable grasslands, knowledge about which grassland characteristics best explain earthworm diversity is needed. Additionally, we have a limited picture of earthworm diversity in general, because previous studies have neglected juvenile earthworms and cryptic species. The juvenile fraction commonly comprises the main part of earthworm samples, whereas morphologically inseparable cryptic species account for an unknown fraction. This fraction is of particular importance, as juveniles reflect the local reproductive and regeneration potential of earthworm populations and communities. To determine the full species composition of earthworm communities, we sampled earthworms from 28 semi-natural grasslands in south-central Sweden and identified them to species by DNA barcoding. To test how grassland characteristics explain earthworm density, diversity, and community composition, we measured several characteristics of soils, vegetation, and management of the grasslands, and descriptors of the surrounding landscape. DNA barcoding revealed nearly twice as many species as were identified morphologically. Earthworm densities were higher in grasslands with higher Ellenberg moisture indicator values and lower soil C:N ratios. The diversity and occurrence of many earthworm species was also higher in grasslands with higher soil moisture indicator values and lower C:N ratios, and further increased with habitat heterogeneity. Certain species occurred more likely in grasslands with higher grazing intensity. Epigeic earthworms, which live in and feed on surface litter, were more common in grasslands with higher moisture indicator values and SOM content. Thus, dry and relatively unproductive semi-natural grasslands, which are common in Sweden, are unlikely to sustain high earthworm diversity – a pattern contrasting to previously reported plant diversity responses. Instead, earthworm diversity seems concentrated to more productive grazed grasslands, with large within-grassland heterogeneity. Therefore, we highlight the importance of considering soil animals in conservation policies for semi-natural grasslands.

Tracking earthworm fluxes at the interface between tree rows and crop habitats in a Mediterranean alley cropping field

Alley cropping is the combination of tree rows and crop alleys. The tree row is covered by an understory vegetation strip (UVS), providing a beneficial habitat for many soil fauna, which could disperse through spillover to the crop alleys. However, such movements have never been directly studied. Our experiment investigated earthworm fluxes in the tree row vicinity using a trap technique, in a Mediterranean agroforestry alley cropping field cultivated with peas and planted with walnut trees. We assessed earthworm density at different distances from the UVS (0 m, 0.3 m, 1 m and 6 m) by hand sorting soil monoliths (25*25*30 cm) in spring 2019, at the start and the end of a two-month experiment. During this period, we detected earthworm fluxes by placing directional traps at 30 cm from the UVS border. Traps consisted of three glued plastic walls placed vertically in the soil. They delimited a soil block of 25*25 cm by 20 cm depth and were open on one side. More epigeic earthworms were found in the UVS and up to 30 cm from the UVS border than in the middle of the crop alley. By contrast, the earthworm Allolobophora chlorotica presented a homogeneous distribution in the plot. Trapped earthworms were mostly of the All. chlorotica species, and 1.6 times more earthworms were found in traps open towards the crop alley than in traps open towards the UVS. These results suggest that in spring, earthworms are moving more from the crop alley towards the UVS than in the other direction, probably using the tree row and its vicinity as a refuge against adverse summer conditions in the crop alley.

Earthworm population and Community structure with reference to Soil ecological parameters from different agroecosystem in Cuddalore district, Tamil Nadu, India

Earthworms are fundamental to the dynamics of our ecosystems. The six species of earthworms (Pondoscolex corethrurus (Muller, 1856), Perionyx ceylanensis (Michaelsen, 1904), Perionyx excavates (Perrier, 1872), Lambitomauritti (Kinberg, 1867), Amynthas gracilis (Kinberg, 1867) and Drawida willsi (Michaelsen, 1907)) belonging to three families (Glossoscolecidae, Megascolecidae, Moniligastridae), five Genera (Pondoscolex, Perionyx, Lambito, Amynthas, Drawida) and three orders (Opisthopora, Heplotaxida, Moniligastrida) were identified from the study site in Cuddalore district, Tamil Nadu, India.Selected two types of cultivated lands in present study: Wet Lands (Paddy, Banana, Sugarcane), Dry Lands (Coconut, Groundnut, Oil palm).Totally six species find in the study sites, two species (Perionyx excavates, Perionyx ceylanensis) were epigeic category, one species (Pondoscolex corethrurus) were endogeic category, one species (Lambito mauritti) anecic category, one species (Amynthas gracilis) were epiendogeic and last one species (Drawida willsi) were epianecic category. The wet land cultivable fieldshave three types of earthworm category (epigeic, endogeic, epianecic) and cultivable dry land fields have two types of earthworm category (anecic and epiendogeic).The statistical analysis of data was also performed by using ANOVA software and different types of soil ecological parameters (pH, moisture, temperature, organic carbon, nitrogen, phosphorous, potassium, C:N ratio, microbial activity, earthworm density, earthworm biomass, relative density, frequency, richness index, diversity index, dominance index, evenness index, Lm/Oratioa, Pe/O ratiob).

How applied reclamation treatments and vegetation type affect on soil fauna in a novel ecosystem developed on a spoil heap of carboniferous rocks

The restoration of soil fauna on a spoil heap is a strong indicator of successful reclamation. The studies were conducted on two types of materials: bare rock (BR) and BR with topsoil (TS) which were applied during coal spoil reclamation and three vegetation types. Four variants investigated included natural forest succession on BR (Succession_BR) and TS (Succession_TS), afforestation (Reclamation_TS) and afforestation with Robinia pseudoacacia (Robinia_TS). Soil pH, soil organic carbon (SOC) and total nitrogen (TN) content, and soil texture were measured in 0–10 cm layers. Earthworms were collected using hand sorting method, and enchytraeids were collected using wet extraction with the heating method.The investigated soil had varying pH values from 5.3 in a BR to 7.2 in Robinia_TS. The highest content of SOC and TN were in Successinon_BR, and the lowest was in Succession_TS. Enchytraeids density was in the following increasing order: 275, 2982, 3001 and 4548 ind m−2 for Succession_BR, Robinia_TS, Succession_TS and Reclamation_TS, respectively. Earthworm density ranged from 0 ind. m−2 in the Succession_BR through 116 ind m−2 and 120 ind m−2 in Reclamation_TS and Succession_TS, respectively up to 162 ind m−2 in the Robinia_TS.The reclamation treatment was a major driver for soil fauna development while vegetation type was of secondary importance. Investigated soil fauna was positively related to pH value and clay content. The most stimulating variant for the development of earthworms and enchytraeids was the application of reclamation with various tree species and the planting of Robinia pseudoacacia on the topsoil.