Epigeic Species Research Articles

IMPACT OF EARTHWORMS OF DIFFERENT MORPHO-ECOLOGICAL GROUPS ON CARBON ACCUMULATION IN FOREST SOILS

To date, forest ecology has not made any clear conclusions regarding the impact of large saprophagous invertebrates such as earthworms on soil carbon dynamics. Some authors claim that earthworm activities result in decreased carbon accumulation. Other studies show that earthworms contribute to soil carbon accumulation. At the same time, many studies do not take into account the differences between trophic and digging activity of different morpho-ecological groups of earthworms in different soil horizons. The objective of this study was to carry out differentiated assessment of the impact of different morpho-ecological groups of earthworms on carbon accumulation and correspondent soil parameters (nitrogen content and С/N ratio) throughout the change in forest succession status. Field operations were performed in the spring and summer of 2016 and 2018 in three regions: Bryansk Oblast (Bryansk Forest reserve), Moscow Oblast (Moskva–Oka plain, Valuyevsky urban forest) and Northwest Caucasus (Krasnodar Krai, Apsheron forestry; Republic of Adygeya, Caucasian Biosphere Reserve). Three main stages of coniferous-broadleaf forest restoration after clear cuttings were identified in each region. Three test plots 50х50 m were allocated for each stage; geobotanical and soil descriptions as well as earthworm registration were carried out on each plot. It was found out that during the change in forest succession status the species composition and the set of morpho-ecological groups of earthworms became more complicated, but there was no successive replacement of any groups with others. Ambiguous effects of different morpho-ecological groups of earthworms on carbon accumulation in forest soils were revealed. Negative correlation was found between the total biomass of earthworms feeding on the soil surface (epigeic, epi-endogeic and anecic species) and litter store. In the humus horizon, the biomass of epi-endogeic species was positively correlated with the content of carbon. C/N ratio and nitrogen content are unidirectionally correlated with the biomass of earthworms in the horizons of their activity: with an increase in the biomass of earthworms of different morpho-ecological groups, the C/N ratio decreases, and the nitrogen content increases.

Earthworm population dynamics in traditional slash and burn cultivation in Mizoram, Northeast India

Aim: This paper describes the influence of traditional slash and burn (shifting) cultivation on earthworm population structure and species diversity. Methodology: The study was conducted in a tropical hilly terrain natural forest in northeast India. The first year was taken as pre–cultivation phase. During second-year traditional slash and burn cultivation was carried out with rice (Oryza sativa) as the main crop, where local weeding practice using had hoe was done thrice. The land was left fallow in the third year. Earthworms were sampled from five random quadrats at monthly interval by digging and hand sorting method. Results: Nine species of earthworms belonging to three families were identified, out of which three epigeic species (P. excavatus, P. macintoshi and A. alexandri) were not recorded during the cultivation phase. There was a significant (p<.05) reduction in earthworm density during the cultivation phase. M. houletti was the most dominant species in terms of density, while D. nepalensis was the most versatile in seasonal distribution. Shannon Index of diversity was lowest in the cultivation phase (H ̅=0.84, 1-D=0.46) as compared to pre-cultivation (H ̅=1.67, 1-D=0.76) and post-cultivation (H ̅=1.67, 1-D=0.77). Interpretation: The reason for negative effect of traditional slash and burn cultivation on earthworm population density and diversity could be due to multiple weeding practices resulting in the disturbance of surface soil that directly or indirectly affects earthworms. Key words: Earthworms, Epigeic species, Mizoram, Slash and burn cultivation, Soil, Weeding

Studies on Cocoons of Three Epigeic Earthworm Species Perionyx excavatus (Perrier), Perionyx ceylanensis (Michaelsen) and Eudrilus eugeniae (Kinberg) with SEM Observations

Present study deals with cocoon biology of tropical epigeic earthworm Perionyx excavatus (Perrier), Perionyx ceylanensis (Michaelsen) and Eudrilus eugeniae (Kinberg). Ultra structure observed under Scanning Electron Microscope (SEM) revealed that wall of the cocoon is porous (which helps in aeration) and the terminal part of the cocoon is softer than that of middle part which facilitates the hatching process. The size of the cocoon varies among the species and is related to the diameter and length of the clitellum. All the epigeic species under study are continuous breeder with high fecundity. Among the studied species shortest incubation period, highest fecundity and highest hatching rate were observed in P. ceylanensis. Cocoon production in these three epigeic species increases in summer and monsoon season and decreases in the winter season. Temperature is the limiting factor for cocoon production as well as incubation period of cocoon. Cocoon production was affected by temperature and body weight of the earthworm. Thus it can be considered that cocoon production in epigeic earthworm species depends on biological factor (body mass), as well as, ecological factor (temperature). Continuous breeding strategy, high fecundity, high rate of cocoon production, as well as high hatching rate, indicates greater usefulness of P. ceylanensis followed by E. eugeniae than P. excavatus in the vermiculture based biotechnology in North-East India.

Subterranean biodiversity and depth distribution of myriapods in forested scree slopes of Central Europe.

The shallow underground of rock debris is a unique animal refuge. Nevertheless, the research of this habitat lags far behind the study of caves and soil, due to technical and time-consuming demands. Data on Myriapoda in scree habitat from eleven localities in seven different geomorphological units of the Czech and Slovak Republics were processed. Based on previous studies, as well as knowledge of cave and soil fauna, it was hypothesised that the occurrence of a varied and peculiar fauna would show a pattern of depth distribution with variations due to local specificities. From 2005–2016 (at least one year on each site), macrofauna was collected via sets of three long-term exposed subterranean traps consisting of 110 cm long perforated tube, with ten cups located in a gradient at 5–95 cm below the soil surface. In total, 14 symphylans (not identified to species level), 271 centipedes (23 spp.) and 572 millipedes (32 spp.) were sampled. The overall depth distribution of centipedes and millipedes appeared to have relatively similar pattern, with both groups being found at all depth levels. Nevertheless, this pattern depends on locations. The depth distribution trend lines are mostly in the form of an asymmetric ‘U’, with decreased abundance until the middle of the gradient, followed by increase in the deepest levels. Epigeic species were sporadically distributed along the whole depth gradient, but concentrated at the soil surface, while some subterranean species, such as the centipede Lithobius lucifugus and the millipedes Geoglomeris subterranea, Cibiniulus slovacus and Archiboreoiulus pallidus, were recorded in the deepest parts of the gradient. This characterises the debris community as a mixture of soil and subterranean species with an absence of species exclusively found in caves. The use of different fixation methods in traps had a significant and selective impact on samples; millipedes were either attracted by ethylene glycol or repelled by formaldehyde. Centipedes were also captured more frequently in ethylene glycol; however, the species composition varied in each of the fixatives. Depth distribution of myriapods was similar in both fixative solutions. Traps with these fixatives could be recommended for similar ecological studies.

Effect of scots pine forest management on soil properties and carabid beetle occurrence under post-fire environmental conditions - a case study from Central Europe

BackgroundFires have a fundamental impact on phytocoenoses and, depending on the size of the fire, can have a positive or negative effect. The role of fires in the formation of the species composition of plants, restoration of stands and changes in soil properties is well studied. However, the long-term relationship between forest management methods, soil properties and epigeic entomofauna assemblages in post-fire areas is still not clear. The effects of Scots pine stand management methods on biochemical soil properties and ground beetle assemblages in the largest post-fire area in Central Europe after the second World were investigated. The study was conducted in the Rudy Raciborskie Forest district in southern Poland. The soil properties and epigeic beetle community structure were analysed. The research covered areas with natural and artificial pine regeneration, which were subjected to various care treatments.ResultsThe tendency for higher accumulations of organic matter in the soil of stands that underwent natural regeneration was proven. The stimulating role of soil organic carbon on the activity of dehydrogenases in the soil of naturally renewed areas with silvicultural treatment (NRAT) was noted. Regardless of the manner of stand regeneration, the activity of β-glucosidase was higher in the areas in which breeding treatments were practised. Furthermore, managed forest stands presented a higher abundance of carabid beetles than stands without treatment practices. Thirteen epigeic beetle species from the families Geotrupidae, Carabidae, Curculionidae, Cerambycidae and Silphidae were captured, with beetles from the first two families being the most numerous. Rare epigeal carabid species in the fauna of Poland and Europe, such as Carabus glabratus (Paykull) and Carabus auronitens Fabr., found appropriate habitat conditions for survival in the post-fire areas. Compared with the other areas, in the NRAT area, there were better stand and soil properties and more features conducive to epigeic entomofaunal occurrences. The highest post-fire content of polycyclic aromatic hydrocarbons was recorded in the soils of the sites that underwent artificial regeneration. The results suggest that preparing the soil before the introduction of new vegetation affects the amount of aromatic hydrocarbons (PAHs).ConclusionsThe better performance of the NRAT stand draws attention to the positive aspects of the use of natural regeneration, both from ecological and economic perspectives. The effects of forest management on the amount of soil organic matter after fires have been proven. The natural regeneration of stands was conducive to the accumulation of organic matter. The enzymatic activity of soils is influenced by the renewal method and forest management strategy. The NRAT area was characterized by the highest number of carabid species.

An explicit definition of earthworm ecological categories – Marcel Bouché’s triangle revisited

In the early 70s, the soil biologist Marcel Bouché classified French earthworms species into defined ecological categories. This classification system was immensely successful and is still widely used to describe earthworm functional groups even outside of Europe. Bouché used morpho-anatomical traits to differentiate three main categories: epigeic, anecic and endogeic. However, the way species are assigned to a category was not explicitly described in Bouché’s work. Thus, some earthworm species can still be assigned to two categories depending on the way researchers interpret Bouché’s description. To solve these issues and avoid unnecessary controversies, we applied PCA and random forest models to the seminal data of Marcel Bouché (earthworm morpho-anatomical traits). Their assignment to Bouché’s three main categories allowed us to statistically redefine the different categories and determine which traits are the most influential. We found that the three main traits were skin pigmentation (from none to black), body length (mean of the minimal and maximal values) and skin coloration (yes or no), followed by 10 other morphological and anatomical traits. We then used this approach to assign a likely category to all of the species studied by Bouché, resulting in a new triangular graph including other categories such as epi-anecic, endo-anecic, epi-endogeic and intermediate. Finally, we calculated the percentage that each species belongs to each main ecological category. This represents a paradigm shift and may change our vision of earthworm communities enabling the computation of the percentage of anecic, endogeic and epigeic species at the community level and thus overcoming the limits and debate about fixed ecological categories for each species.

Tiger beetles (Coleoptera: Cicindelinae) of Davao Region, Mindanao, Philippines

An assessment of tiger beetles in select mountains of Davao region including Mt. Hamiguitan (MHRWS), Marilog District (MD), Davao City (DC), Sta. Cruz Davao del Sur (SCD), and Davao de Oro (DO) is herein presented. Materials were collected between December 2017 and February 2019 through a combination of opportunistic and standard light trapping methods. Twenty-two species belonging to 9 genera were recorded with 64% endemic in the Philippines. Nine (9) species are recorded from MHRWS, 6 from MD, 8 from DC, 5 SCD, and 14 from DO (formerly Compostela Valley Province). Tiger beetles showed consistent habitat preferences particularly riparian species which includes the genera Calomera, Thopeutica, Therates, Prothyma, Cylindera, and Heptodonta. Strictly arboreal species include Tricondyla, Therates, and Neocollyris. Strict epigeic species include but not limited to the genera Calomera, Tricondyla, Thopeutica, Cylindera, Heptodonta, Neocollyris, and Prothyma. Endemic species such as Heptodonta lumawigi (Wiesner, 1980), Thopeutica (Thopeutica) anichtchenkoi (Wiesner 2015), Thopeutica (Thopeutica) milanae (Wiesner, 1992), Thopeutica (Thopeutica) rolandmuelleri Cassola, 2000 and Thopeutica petertaylori (Medina, Cabras, Wiesner, 2019) prefers a more intact forests while others such as Cylindera (Ifasina) discreta elaphroides (Dokhtouroff 1882), Calomera mindanaoensis (Cassola, 2000) and Necollyris sp. could tolerate disturbed secondary forest even agricultural lands. New distribution record for Heptodonta lumawigi (Wiesner, 1980) and Thopeutica (Thopeutica) milanae (Wiesner, 1992) for Marilog District were also recorded. Ecological data and conservation status of tiger beetles are also presented. Conservation actions are deemed necessary in the remaining green spaces in Davao City that hosts tiger beetle fauna should also be conducted.

Assessment of earthworm activity on Cu, Cd, Pb and Zn bioavailability in contaminated soils using biota to soil accumulation factor and DTPA extraction.

The study aims to investigate effect of earthworm activity on metal bioavailability in soils using their BSAF-metals. Based on a microcosmic laboratory experiment, epigeic species Amynthas corticis (A. corticis) and endogeic species Amynthas robustus (A. robustus) were cultured in two types of soils contaminated by Cd, Zn, Pb and Cu for 120 days. Earthworm characteristics (i.e. numbers, biomass and BSAF), soil properties (i.e. pH, organic C and N contents along with their components such as mineralization and microbial masses) and DTPA extracted metals in soil were determined. After the incubation, the biomass and survival numbers of both earthworm species decreased significantly (P<0.05). The accumulation of Cd, Zn and Pb in earthworm tissues and BSAF-metals were earthworm species dependent. According to two-way ANOVA, BSAF-Pb clearly showed the effect of different species of earthworms while BSAF-Cu indicated an interactive effect of earthworms and soil type. Earthworms changed soil properties significantly, especially for mineralized C (Cmin), dissolved N (Ndis) and pH (P<0.05). Earthworm activity increase DTPA extracted Zn and Cu, and the effect of A. robustus were stronger than for A. corticis. Redundancy analysis (RDA) showed that BSAF-Cu and BSAF-Pb contributed for respectively 51.9% and 51.7% of soil properties and DTPA metal changes, indicating that the effects of BSAF-Cu and BSAF-Pb on soil properties and on metal bioavailability in soil were similar. BSAF-Cu, indicating the interactive effect of earthworms and soil, accounted for 38.5% and 45.1% of soil properties and soil metal bioavailability changes. BSAF-Pb, representing the effect of earthworm species, accounted for 13.3% and 6.6% of soil property and soil metal bioavailability variations. Stepwise regression indicated that earthworm might change soil properties through their activities and interactions with soil, and hence increase heavy metal bioavailability. It suggested that BSAF is an important indicator for evaluating the effect of earthworm activity on soil metal bioavailability and designing remediation strategies.

Determination of plant communities based on bryophytes: The combined use of Kohonen artificial neural network and indicator species analysis

Abstract Mosses and liverworts are good bioindicators, not only of environmental pollution and the substrates on which they develop, but also of the plant communities in which they grow. The present study classifies bryological releves and identifies epigeic species significantly associated with three forest phytocoenoses important for Central Poland: Tilio-Carpinetum with Abies alba, Abietetum polonicum and managed forests; importantly, the study takes an approach using a Kohonen artificial neural network (i.e. self-organising map, SOM), its first use in bryological studies, together with Indicator Species Analysis based on IndVal index. The number of species significantly associated with natural forests was found to be 2–3 times higher than in managed forests, which reflected the differences in the quality of forest habitats. Additionally, the approach not only confirmed that some taxa play a diagnostic role (e.g.: Pleurozium schreberi, Dicranum polysetum, Dicranum scoparium, Thuidium tamariscinum, Atrichum undulatum, Eurhynchium angustirete) but also indicated new species which may have diagnostic potential for the studied communities. Our findings demonstrate that the epigeic bryophyte layer can play an important role in separating the studied phytocoenoses, and thus in the syntaxonomy of forest communities.

Bryophyte flora of selected historical parks and gardens of Slovakia

In a cultural landscape, old historical parks feature important biodiversity refuges not only for vascular plants but also for bryophytes. Here, we surveyed a total of 14 historical parks and gardens in urban and rural areas of Slovakia to evaluate their bryophyte diversity and to find out possible correlations between species richness and habitat characteristics. Overall, 104 bryophyte species (12 liverworts and 92 mosses) were identified. Most frequently occurring species were Amblystegium serpens, Brachythecium rutabulum, Bryum argenteum and Tortula muralis, present at all studied sites. Generally, small urban parks hosted less bryophyte species compared to rural areas. In terms of substrate preference, most frequent were epigeic species, followed by epilithic, epiphytic and epixylic species. At most sites, species’ indicator values showed a dominance of semi-heliophilous, semi-heliophobic, hygrophilous, weakly acidophilous to basiphilous bryophyte taxa. Spearman rank correlation test showed that the species richness correlated with the park location (urban vs. rural area) and the number of settlement inhabitants showing that green areas in urban landscape are more isolated from each other which decreased species richness. Our results show that old parks and gardens can provide suitable habitats for some rare species such as Osculatia bornholmensis (reported recently as new for Slovakia) but even for common forest and meadow species and the study of their diversity should be given an increased attention.

A Comparative Study of the Reproductive and the Vermicomposting Ability of Three Generations of Epigeic and Anecic Earthworms When Subjected to a Toxic Weed (Ipomoea) as the Sole Feed

Recent studies by these authors have shown that the toxic and allalopathic weed ipomoea (Ipomoea carnea), gets transformed into benign organic fertilizer when subjected to vermicomposting. To derive benefit from this finding, it is necessary that a process should be made available for uninterrupted and efficient conversion of ipomoea into vermicompost. The present study has been done toward development of such a process, based on the concept of high-rate vermicomposting. It explores the relative ability to vermicompost ipomoea, and to reproduce in ipomoea-fed vermireactors, of successive generations of four species of earthworms — born and raised in ipomoea-fed vermireactors — in comparison to the first generation which had been raised to adulthood on cow-dung. Three epigeic species Eisenia andrei, Peryonix sansibaricus, Lumbricus rubillus, and one anecic Drawida willsi were explored for the purpose. The results, obtained over 480 days of uninterrupted reactor operation, show that the first generation of all four species of earthworms was slow to adapt to the ipomoea feed and took about 40 days to produce consistent quantities of vermicast. The second and the third generations didn’t need this adaptation and each generated vermicompost at significantly faster rates than it’s previous generation. Overall, the third generation of E. andrei, P. sansibaricus, L. rubellus and D. willsi produced 40, 41, 28, and 26% more vermicast, respectively, than the pioneers of the corresponding species. Similar trend was seen in fecundity as well. Each new generation produced more juveniles and cocoons than the previous generation, the increase being statistically significant at ≥ 95% confidence level. The findings reveal that earthworms can be made to adapt to ipomoea as their sole feed and the earthworm generations born and raised in ipomoea-fed vermireactors display significantly greater vermicomposting ability as well on fecundity than the earthworms which had been cultured on animal manure.

Biotopic Association of Earthworms in Intact Forests of Teberda Nature Reserve

Contribution of micromosaic structure of high mountain forests to ecological diversity of earthworms have been assessed. Intact forests of Arkhyz section of Teberda Nature Reserve were studied. The dominant types of forests have been recognized for the first time based on eco-coenotic classification. The ecological conditions of their functioning have been studied. Earthworm numbers have been studied in the recognized forest types. Diversity of earthworms was studied in soils under crowns, under fallen trees, and in mosses growing on rocks. 16 species of Lumbricidae have been found, with 4 of them being discovered for the first time. Full complexes of Lumbricidae were associated with biotopes of forest types of increased soil moisture content, low acidity, availability of nitrogen and pronounced litter. The largest abundance, diversity and biomass of Lumbricidae have been found in nitrophilous tallgrass gray alder forests. The lowest have been found in xeromesophytic pine forests with fir, spruce and birch. The most widespread dark coniferous forest with beech were inhabited by seven species of Lumbricidae, dominated by the epigeic species. There were few epi-endogeic and anecic species. The endogeic group of earthworms was represented by Crimea and Caucasus subendemic Dendrobaena schmidti. Diversity and biomass of earthworms in dark coniferous forests with beech were higher than in spruce-fir forests. During summer, dead fallen trees served as a microsite preferential for epigeic and endogeic species, while mosses growing on rocks were preferred by endogeic species.

Large variations in readily-available phosphorus in casts of eight earthworm species are linked to cast properties

Phosphorus (P) is an important nutrient for plant growth. However, P is often poorly available for uptake by roots because it strongly adsorbs to the soil mineral phase. Recent research shows that earthworms can temporally and locally increase P availability to plants. However, the pathways through which they do so are not fully understood, and it remains unclear to what extent this capacity varies among earthworm species. Here we study the variation among earthworm species with respect to readily-available P in casts as well as other physico-chemical cast properties, in a greenhouse pot experiment using a soil with a low P status. The earthworms belong to eight commonly occurring earthworm species in the Netherlands: two epigeic species (a mixture of the compost earthworms Dendrobaena veneta/Eisenia fetida; Lumbricus rubellus); four endogeic species (Allolobophora chlorotica, Aporrectodea caliginosa, Aporrectodea rosea, Octolasion lacteum); and two anecic species (Aporrectodea longa; Lumbricus terrestris). For all species, the pH in water extracts of earthworm cast (pH = 7.4–8.2) was significantly higher (p < 0.001) than for the control bulk soil (pH = 6.6) and differed significantly (p = 0.003) among earthworm species. Similarly, the dissolved organic carbon (DOC) concentration in the same water extracts was an order of magnitude higher in earthworm cast compared to the control bulk soil and varied among species (p < 0.001). The size of the total pool of reversibly adsorbed P in earthworm cast was greater than in the control bulk soil, but no significant differences were found among earthworm species. Differences among species were present for the readily-available P pools extracted from casts, including P-Olsen and water-extractable ortho-P. Water-extractable ortho-P concentrations were much higher in the casts of all species as compared to the control bulk soil (0.9–6.8 vs 0.06 mg l−1 or to 9.0–68 vs 0.6 mg kg−1). Highest ortho-P levels were measured in L. rubellus casts and the lowest in casts of A. chlorotica. A positive correlation between the concentrations of DOC and ortho-P was observed (R2 = 0.72, p < 0.001). The observed variation in all measured physico-chemical cast properties could not be explained by conventional ecological earthworm classifications. Our results show that the nature and magnitude of earthworm-induced increased P availability differs dramatically among earthworm species. This strongly suggests that, apart from its size, species composition of the earthworm community is key to optimizing P availability to plants.

Spatial distribution of the epigeic species of earthworms Dendrobaenaoctaedra andD. attemsi (Oligochaeta: Lumbricidae) in the forest belt of the northwestern Caucasus

Evaluation of the spatial distribution of 2 ecologically similar, but different, in terms of their spatial ranges, earthworm species, D. octaedra and D. attemsi, in the belt forests of northwestern Caucasus were based on our own natural data and using geographic information system (GIS) modeling of modern potential distributions. The quantitative records of earthworms were collected in beech, deciduous, dark coniferous, coniferous-deciduous, and pine forests (1028 geographic locations). Of the most important microsites inhabited by the epigeic earthworms, 2 (plant litter and deadwood) were examined. It was demonstrated that there was high correlation of the 2 species with the humidity of the habitat and the presence of deadwood at different stages of decomposition, especially for D. attemsi, which lives mainly in deadwood in all of the forest types. The high correlation of these species to coniferous-deciduous forests and dark coniferous forests was demonstrated on both the basis of the field data analysis and the GIS modeling results.

Habitat heterogeneity supports epigeic arthropods after prescribed burning of dry grasslands

Fire supports landscape openness; thus, prescribed burning could be an effective management in open landscapes. In this study we tested the response of arthropods (spider, ground beetle, rove beetle and woodlouse) to dormant-season prescribed burning in dry grassland patches. We hypothesized that the unburned patches support the arthropods recolonizing the burned patches; thus, fire causes no serious damage to the arthropod assemblages. Epigeic arthropods (spider, ground beetle, rove beetle and woodlouse) were collected by unbaited pitfall traps containing ethylene glycol as a killing-preserving solution. Altogether 60 traps worked in 3 burnt and 3 control plots (10 traps/plot). Traps were emptied monthly from May to October in the year after burning. Collected arthropods were identified at species level using standard keys. We found no significant difference between the burned and control plots for the abundance, species richness, and Shannon diversity of spiders, ground beetles, rove beetles and woodlice. Differences in total abundance, species richness and diversity of arthropods were also not significant between the burned and control plots. Among from 12 most abundant species, ten species was not affected by burning, while the abundance of Titanoteca veteranica spider species increased and the abundance of Trochosa robusta spider species decreased in the burnt plots. Microcaves and other unburned microhabitats in and around the burned patches serve as refuge for epigeic arthropods supporting the fast recolonization after prescribed burning, although the abundance of some epigeic spider species (Titanoteca veteranica, Trochosa robusta) was affected by burning. Our findigs revealed that prescribed burning is a potentially promising conservation method. We also highlighted that preservation of unburned microhabitats and surroundings of the managed patches is essential during the prescribed burning.

Risk element accumulation in Coleoptera and Hymenoptera (Formicidae) living in an extremely contaminated area-a preliminary study.

The risk element accumulation ability of two groups of epigeic species, insects from families Coleoptera and Hymenoptera (namely Formicidae), was determined and related to soil risk element content and bioaccessibility. The study was conducted in the district of Příbram, Czech Republic, which was characterised by extremely high aged pollution in the soils, including risk elements, especially As, Pb, Zn and Cd, due to the former mining and smelting activity. Four sampling sites differing in their pseudo-total risk element contents were selected and composite samples of individuals representing either Coleoptera or Formicidae were sampled at the individual sampling points. The results indicate the ability of Coleoptera and Formicidae organisms to accumulate risk elements, especially at the location with extremely high soil risk element content. In soil containing up to 841mg As kg-1, 84.6mg Cd kg-1, 4250mg Pb kg-1 and 8542mg Zn kg-1, contents in insect bodies reached 239mg As kg-1 As, 24.2mg Cd kg-1, 70.4mg Pb kg-1 and 335mg Zn kg-1 in beetles and up to 20.9mg As kg-1, 29.9mg Cd kg-1, 111mg Pb kg-1 and 657mg Zn kg-1 in ants. Therefore, bioaccumulation factors (BAFs) varied between 0.02 and 0.55. Increasing Cd content in Coleoptera bodies with increasing soil pseudo-total element content was observed only among the investigated elements. However, the results indicate increasing BAF values with decreasing soil element levels, especially for Cd, Pb and Zn, indicating limited uptake of elements by the organisms living in contact with extremely contaminated soil.

Tree species identity governs the soil macrofauna community composition and soil development at reclaimed post-mining sites on calcium-rich clays

We tested the effect of main soil characteristics and tree species on earthworm community composition and abundance in reclaimed spoil heaps planted with five different tree species. Earthworm and soil macroarthropod abundance and biomass were highest in alder plantations, followed by oak plantations. The numbers of soil macrofauna were positively correlated with the total soil N content, which was highest in alder plantation. The correlation was strongest for endogeic earthworms (genus Aporrectodea and Octolasion). Soil moisture, measured in top 10 cm, affected only endogeic species. Other soil variables (pH, Ca) did not have a strong effect on earthworms. The earthworm community composition was similar in alder and oak, with most species occurring at both types of forest; however, in alder forest the epigeic species Dendrobaena octaedra was more common, whilst in oak forest the epigeic earthworms form genus Lumbricus were more abundant (L. rubellus and L. castaneus). The anecic species Aporrectodea longa was more abundant at alder sites, but L. terrestris was more abundant under oak. The alder forest was characteristic by a thick humus layer (10–15 cm), which at oak and larch sites was thinner (4–7 cm) and at pine and spruce stands was absent. Soil compaction was lower under the deciduous trees (alder, oak, larch), than under spruce and pine. We conclude that the alder plantations have most palatable litter and lowest C/N ratio and therefore support the highest numbers of soil macrofauna, which affects the humus layer thickness and soil compaction in the surface layers.

Ecotoxicological assessments of biochar additions to soil employing earthworm species Eisenia fetida and Lumbricus terrestris

Biochar is the degradation-resistant product generated by the pyrolysis of organic materials and is produced for the intended use of land application in order to promote carbon sequestration and soil improvement. However, despite the many potential benefits biochar application offers, it is important to quantify any ecological impacts that may result from soil amendment in order to avoid potentially causing negative effects upon soil biota which are crucial in the many ecosystem services provided by soil. Any impacts on earthworms in particular are important to evaluate because of their pivotal role in organic matter breakdown, nutrient cycling and soil formation. In this study, we conducted a series of ecotoxicological assays to determine lethal and sublethal (avoidance, mass change and moisture content) effects of heavy biochar applications that reflect levels that may be used in soil restoration efforts. Two earthworm species, Eisenia fetida, an epigeic species, and Lumbricus terrestris, an anecic species, were utilised as test organisms. Two types of biochar, produced from wheat straw and rice husk feedstocks, respectively, were applied to OECD artificial soil and to a natural soil (Kettering loam) at rates of up to 20% w/w. The influence of biochar application on soil porewater chloride, fluoride and phosphate concentrations was also assessed. The biochar applications induced only a subtle level of avoidance behaviour while effects on survival over a 4-week exposure period were inconsistent. However, death and physical damage to some individual earthworms at high biochar application rates were observed, the mechanisms and processes leading to which should be investigated further. Earthworm development (mean mass change over time) proved to be a more sensitive measure, revealing negative effects on L. terrestris at 10% and 20% (w/w) wheat biochar applications in OECD soil and at 20% (w/w) applications of both biochars in Kettering loam. The moisture content of E. fetida remained remarkably consistent across all treatments (~ 82%), indicating that this is not a sensitive measure of effects. The high rates of biochar application resulted in increased chloride (2 to 3-fold) and phosphate (100-fold) concentrations in simulated soil porewaters, which has important implications for soil fertility and production but also for environmental management.

CURRENT UNDERSTANDING ON INDUSTRIAL ORGANIC WASTE MANAGEMENT BY EMPLOYING Eisenia fetida

Earthworms have the inherent capability of stabilising different organic waste materials of industrial as well as domestic origin. This review paper depicts the potential of epigeic earthworm species Eisenia fetida in the vermistabilisation of various industrial organic wastes such as silk industry waste, herbal pharmaceutical industry sludge, food industry sludge, milk processing industry sludge, tea factory coal ash, sugar mill sludge, cotton industrial waste, paper mill waste, and bio sludge of beverage industry. The analysis of results obtained clearly indicates the suitability of vermicomposting over conventional composting as an alternative technology for management, stabilisation and nutrient recovery from industrial organic waste.

The impact of cattle dung pats on earthworm distribution in grazed pastures

BackgroundGrazed grassland management regimes can have various effects on soil fauna. For example, effects on earthworms can be negative through compaction induced by grazing animals, or positive mediated by increases in sward productivity and cattle dung pats providing a food source. Knowledge gaps exist in relation to the behaviour of different earthworm species i.e. their movement towards and aggregation under dung pats, the legacy effects of pats and the spatial area of recruitment. The present study addressed these knowledge gaps in field experiments, over 2 years, using natural and simulated dung pats on two permanent, intensively grazed pastures in Ireland.ResultsDung pats strongly affected spatial earthworm distribution, with up to four times more earthworms aggregating beneath pats, than in the control locations away from pats. In these earthworm communities comprising 11 species, temporally different aggregation and dispersal patterns were observed, including absence of individual species from control locations, but no clear successional responses. Epigeic species in general, but also certain species of the anecic and endogeic groups were aggregating under dung. Sampling after complete dung pat disappearance (27 weeks after application) suggested an absence of a dung pat legacy effect on earthworm communities. Based on species distributions, the maximum size of the recruitment area from which earthworms moved to pats was estimated to be 3.8 m2 per dung pat. Since actual grazing over 6 weeks would result in the deposition of about 300 dung pats per ha, it is estimated that a surface area of 1140 m2 or about 11% of the total grazing area can be influenced by dung pats in a given grazing period.ConclusionsThis study showed that the presence of dung pats in pastures creates temporary hot spots in spatial earthworm species distribution, which changes over time. The findings highlight the importance of considering dung pats, temporally and spatially, when sampling earthworms in grazed pastures. Published comparisons of grazed and cut grasslands probably reached incorrect conclusions by ignoring or deliberately avoiding dung pats. Furthermore, the observed intense aggregation of earthworms beneath dung pats suggests that earthworm functions need to be assessed separately at these hot spots.