Earthworm Community Structure Research Articles

Spatial distribution of earthworm community structure along the wildlife sanctuaries of West Bengal, with a glimpse of parthenogenesis in Metaphire houlleti (Perrier, 1872)

Spatial distribution of earthworm community structure along the wildlife sanctuaries of West Bengal, with a glimpse of parthenogenesis in Metaphire houlleti (Perrier, 1872)

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.

Structure and diversity of earthworm communities in long-term irrigated soils with raw effluent and treated wastewater

Abstract This study was conducted in two natural meadows: first, soils were irrigated with raw wastewater (SIRWW) and in the second, soils were irrigated with treated wastewater (SITWW). Earthworms were sampled in eight soil blocks spaced 10 m apart at each site. Earthworm community was characterized and compared using density, biomass, composition, structure, species richness, and diversity parameters. At both meadows, 459 earthworm individuals from two families and seven species were collected. The highest earthworm density and species richness were recorded at SIRWW. Nicodrilus caligenus was the most abundant species. Most of earthworm community parameters decreased significantly at SITWW. Only two species (N. caligenus and Octodrilus complanatus) were common between the two grasslands. Among the seven species identified at both meadows, four (Allolobophora longa, Eisenia foetida, Allolobophora rosea, Allolobophora chlorotica) were exclusively present in SIRWW, whereas a single species (Amynthas sp.) was characterized in SITWW. Three ecological earthworm groups (epigeic, endogeic, and anectic) were represented in SIRWW, with the dominance of endogeics. Further studies are needed to quantify pollution in this soils and the accumulation of pollutant load in earthworms. It is also important to highlight the relationship between the abundance and diversity of earthworms in these two ecosystems with soil biological activity.

Структура угрупувань дощових червів в урбані­зованих біотопах Центрального Полісся

The article describes the results of the impact of urbanisation on the quantitative and qualitative structure of earthworm communities, since urbanisation is currently one of the main threats to biodiversity. Earthworms, as the most common representatives of the edaphic mesofauna, react sensitively to the level of environmental pollution. On the example of the city of Cherniakhiv, it has been established that the lumbricide fauna of the studied area includes eight species: Aporrectodea caliginosa (Savigny, 1826), A. rosea (Savigny, 1826), A. trapezoides (Dugesi, 1828), Lumbricus terrestris (Linnaeus, 1758), L. castaneus (Savigny, 1826), Octolasion lacteum (Örley, 1885), Eisenia fetida (Savigny, 1826), and Dendrobaena octaedra (Savigny, 1826). All detected worms are rather unevenly represented in the analysed samples. Background species in the study area are A. caliginosa, A. rosea, and L. terrestris. According to the analysis of the relative abundance in the samples, A. caliginosa is dominant, whereas A. rosea and O. lacteum are less common. According to the results of the spatial distribution of earthworms, a clear dominance of one species was noted in agrocoenoses and in areas with a significant recreational load, whereas in a less anthropogenically transformed zone a higher number and species diversity of lumbricides was noted. Using cluster analysis of k-means according to biodiversity estimates, two clusters of samples were selected. At the same time, such parameters as the number of species, the number of individuals in the sample, and the Brillouin index make the greatest contribution to the differentiation of clusters. A reliable correlation was found between the number of individuals in the sample and the reflectivity in the B8 band range, as well as between the indicator of the evenness of the grouping structure and the reflectivity in the B4, B5, B11, and B12 bands of the Sentinel-2 space image and the value of the NDVI vegetation index. These spectral characteristics were used to model the spatial distribution of the absolute number of lumbricides and the evenness of their groups. The model of the spatial distribution of the number of earthworms has a mosaic character: individual cells with a high number of lumbricides are replaced by areas where they are less abundant. There is a certain relationship between individual estimates of earthworm biodiversity and land cover spectral characteristics.

Effects of Hydrologic Regime Changes on a Taxonomic and Functional Trait Structure of Earthworm Communities in Mountain Wetlands.

Disturbances, both natural and anthropogenic, influence the patterning of species and species traits. The shift in species composition and distribution pattern of functional traits can demonstrate if the community is resistant, sensitive or resilient to the disturbance. Based on species- and trait-based approaches, we examined the response of the earthworm community to changing hydrologic conditions caused by the artificial drainage of mountain fens, in which cumulative effects of disturbance events over space and time are much less dynamic than in riverine wetlands. We hypothesized that the drainage-related changes of mountain fen peat soils have an effect on the earthworm community composition and its functional structure. We assume that the shift in species composition and value of community-weighted functional traits reflect changes in the resilience or resistance of the earthworm community to environmental change. Our results demonstrate that the total density of earthworms was almost three times lower under drained conditions compared to natural ones. Artificial drainage of fens had a neutral effect on the species-based diversity indices. However, there were species-specific traits that responded to hydrologic changes and which led to the species' replacements and to the co-occurrence of eurytopic, surface-browsing and more drought- and low-pH-resistant earthworm species in the drained fens. Based on these results, we conclude that abiotic-based environmental filtering was the main process responsible for sorting earthworms according to species and traits in the disturbed hydrologic conditions. The greater earthworm functional trait variations in semi-natural hydrologic conditions emphasizes the impact of transient dynamics in an altered disturbance regime on the earthworm assembly. Results also showed that in the changing hydrologic conditions of mountain fens, the functional trait approach revealed only slightly more predictive power than the taxonomic one, but it proved better with processes responsible for earthworm species filtering.

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

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

Ecological groups and isotopic niches of earthworms

Earthworms are generally categorized into three ecological groups. This categorization and its two refined versions have been widely used in studies focusing on earthworm community structure and biological invasions, as well as the effects of earthworms on vegetation, soil properties, carbon and nitrogen cycling, and ecosystem functions. We revisited this categorization system by analyzing the stable isotopes of carbon and nitrogen (13C and 15N) from 10 earthworm species commonly found in arable fields and deciduous forests in temperate North America. We showed that up to nine isotopic niches utilized by earthworms can be distinguished in the two-dimensional space delimited by δ13C and δ15N. Rather than forming distinct categories, isotopic niches of different ecological groups form a continuum, ranging from species feeding on leaf litter to those feeding on highly processed soil organic matter. Along this continuum, the three “traditional” groups are recognizable, and species of the same ecological group can exhibit considerable isotopic niche differentiation and resource partitioning. These results, together with field observations on native Lumbricidae in Europe, suggest that, despite their convenience, there are limitations to the commonly used ecological categories. We propose to incorporate stable isotopes as functional traits in studying earthworm ecology and the linkage between earthworm communities and ecosystem functions. Moreover, to fill existing knowledge gaps, the isotopic approach needs to be further expanded to native earthworm communities around the world, particularly outside Western Europe and North America, and to earthworm families and major taxonomic groups other than Lumbricidae, such as Glossoscolecidae, Acanthodrilidae, and Megascolecidae.

Earthworm community structure and diversity in different land-use systems along an elevation gradient in the Western Himalaya, India

The state Himachal Pradesh in Western Himalaya was explored to know the community structure of earthworms in agroecosystems along the elevation gradient ranges from 300 to 2500 m above sea level. The study aimed to determine the influence of climate, soil variables and the cropping pattern on species diversity and abundance. Therefore, a total of six land-use types including three crop land, and three orchards (Apple, Pear and Mango) were studied at low (300-500 m), middle (500–1500 m) and high (1500-2500 m) elevations. The results indicate that the earthworm community varies with the cropping intensity, with a greater species richness observed in the traditional cropping system including organic input vegetable field than in the cereal crop field having a high input of chemical fertilizers and using more up-to-date heavy and deep ploughing machines. The number of species significantly increased with the increasing elevation, reaching a peak at the middle but decreasing with the further elevation. The Metric-multidimensional scaling (MDS) analysis showed the highest similarity of 61% between sites of high elevation, 49% between the sites of low elevation, and 21% similarity between sites of middle and high elevations based on the density of earthworm. The Canonical correspondence analysis showed the significant positive (rainfall, soil moisture, and organic carbon) and negative (pH) relationship with earthworm density. It supports the role of physicochemical parameters in determining the earthworm community along the elevations. Except mango orchard, all sites were predominated by exotic peregrine earthworm species, which is a matter of concern for invasion and impact on the native species. While it is true that anthropogenically influenced ecosystems are more prone to invasion by alien species, further research is required in the adjacent forests to compare the impact of land-use changes on earthworm communities.

Struktura zespołów dżdżownic w uprawie kukurydzy i pszenicy

Earthworms play an important role in the soil. When digging corridors, they loosen it, aerate it and mix minerals with the organic part. They contribute significantly to the improvement of its fertility. These organisms are also commonly used in monitoring the condition of soils with varying degrees of anthropopressure. The aim of the research was to analyze the structure of earthworm communities. The research was carried out on two sites (in the cultivation of maize and wheat). Lumbricidae were harvested by the mixed method, i.e. 25 x 25 x 25 cm soil blocks were analyzed. They were sorted by hand for the extraction of earthworms. 10 liters of 0.4% formalin solution were used to rinse oligochaetes from the deeper layers of the soil. The soil under wheat was characterized by a higher Lumbricidae density. Four species of earthworms have been found here. A. rosea had the greatest share in the community of earthworms in both sites. Research should be continued over a longer period of time.

Long-term dynamics of the abundance of earthworms and enchytraeids (Annelida, Clitellata: Lumbricidae, Enchytraeidae) in forests of the Central Urals, Russia.

BackgroundSince the late 1980s, long-term monitoring of terrestrial ecosystems in metal-contaminated areas has been carried out in the Central Urals. As a part of these monitoring programmes, the data on soil macroinvertebrates in undisturbed areas as reference sites continues to be gathered. These data help study the local biodiversity and long-term dynamics of soil macroinvertebrate abundance in non-polluted areas.New informationThe dataset (available from the GBIF network at https://www.gbif.org/dataset/bf5bc7f6-71a3-4abd-8abc-861ee3cbf84a) includes information from a long-term monitoring programme for two taxa of Annelids, Lumbricidae and Enchytraeidae, which dwell in the topsoil of spruce-fir, birch, pine and floodplain forests in the Central Urals. The dataset includes information on the earthworm community structure (list of species, species abundance, number of egg cocoons, cocoon exuvia, juveniles and adults) and enchytraeid abundance. The dataset consists of 553 sampling events (= samples, corresponding to upper and lower layers of the soil monoliths) and 12739 occurrences (earthworms, mainly identified to species and earthworm cocoons and enchytraeids, identified to family) collected during 1990–1991, 2004, 2014–2016 and 2018–2020. In total, 3305 individuals of earthworms were collected, representing ten (out of twelve) species and all eight genera recorded for the fauna of the Central Urals. In addition, 7292 earthworm egg cocoons and cocoon exuvia and 6926 individuals of enchytraeids were accumulated. The presence-absence data on each of the ten earthworm species, egg cocoons, cocoon exuvia and enchytraeids are provided for each sampling event. All data were collected in undisturbed non-polluted areas and are used as a local reference for ecotoxicological monitoring. The dataset provides valuable information for estimating the composition and abundance of earthworm communities in different habitats over a long time and contributes to the study of soil fauna biodiversity in the Urals.

Assessment of Earthworm Community Structure in Industrial and Non-industrial Soils

The trend of industrialization in all over the world significantly altered the assemblages of species and their surrounding environments in the soil. In the present study, the earthworm community structures were assessed in the industrial and non-industrial soils. Total seven earthworm species i.e. Amynthas morrisi (Beddard), Lampito mauritii (Kinberg), Metaphire posthuma (Vaillant) and Polypheretima elongata (Perrier) belonging to family Megascolecidae while Eutyphoeus incommodus (Beddard), Eutyphoeus waltoni (Michaelsen) and Octochaetona beatrix (Beddard) belonging to family Octochaetidae were reported. It was also reported that the earthworm species, their abundance and biomass was significantly (p < 0.05) higher in non-industrial soils as compared to industrial soils. The Metaphire posthuma was reported as the most abundant earthworm species in both industrial and non-industrial soils. The diversity indices such as the Shannon-Wiener diversity index, Simpson index of diversity and species richness index were higher in non-industrial soils while the Simpson index and species evenness index were high in industrial soils. The soil properties such as pH, EC, TDS and heavy metals content were much higher in the industrial soils and significant negative correlation of above said soil properties with earthworm ecological characteristics. This study can be considered as indication that industrialization has much more negative effects on the earthworms and their community structures.

Distribution of earthworm communities in agroecosystems with forested riparian buffer strips: A multiscale study

Knowledge is lacking on the factors controlling the structure and spatial distribution of earthworm communities within agroecosystems. We first hypothesized that forested riparian buffer strips (FRBS) within agricultural landscapes would be a refuge for earthworms, as we predicted higher soil moisture and organic matter inputs in FRBS than in adjacent agricultural fields (treatments = FRBS vs. Field). We further hypothesized that earthworms would be most abundant where the chemical quality of above- and belowground plant litter is high, or where soil disturbance is low. We conducted a field survey to quantify earthworm species abundances in FRBS and adjacent agricultural fields in two bioregions, namely Eastern Canada and Central Europe. At each of 77 sites, we collected and identified earthworms from three plots within FRBS and within adjacent agricultural fields. In each plot, we identified the tree species, understory vegetation, soil drainage class, agricultural crop as well as five soil physicochemical properties. In each bioregion and treatment, we found proportionately more endogeic than anecic or epigeic earthworm species. In Eastern Canada, there were proportionately fewer anecic and more epigeic individuals in FRBS than in fields; in Central Europe there were fewer endogeic and more anecic earthworms in FRBS than in fields. We found significant bioregion × treatment interactions on earthworm abundance and soil moisture. More specifically, in Eastern Canada we found higher earthworm abundance and soil moisture in FRBS, whereas in Central Europe we found higher earthworm abundance in fields and no treatment effect on soil moisture. In both bioregions, we found higher organic matter in FRBS than in fields. In Eastern Canada, earthworm abundance in deciduous and mixedwood stands were higher than in coniferous stands; in Central Europe, earthworm abundance was highest in deciduous stands only. Within FRBS in Eastern Canada, the abundance of the prominent endogeic species, Apporectodea rosea, was correlated with herbaceous plants, notably ferns and graminoids. Conditional regression tree analysis revealed positive relationships between earthworms and soil clay content, pH, moisture and organic matter. Our results suggest that local and landscape patterns in earthworm diversity can be predicted by soil and vegetation attributes, however the relative importance of these factors changes across continental scales due to differences in precipitation patterns and soil moisture availability. Comparing the distributions of earthworms across different scales provides insights into the potential of different species to spread into new habitats with climate change.

Earthworm community structure along altitudinal gradients on the western slopes of Kopaonik Mountain in Serbia

The aim of this study is to examine the altitudinal patterns of earthworm community structure at different habitat types on the western slopes of Kopaonik Mountain. In total, 30 plots between 420 and 1950 m a.s.l. were sampled within two years' fieldwork. Overall, 27 earthworm taxa belonging to 11 genera were found at the study sites. A combination of Pearson's correlation, polynomial regression, and cluster analysis (UPGMA) was used for determining the effects of altitude on the earthworm community structure. The earthworm abundance and species richness monotonically decreased with the increase in altitude, showing a significant negative correlation. Cluster analysis revealed two patterns of earthworm community composition, furthermore, there are taxa with a broad altitudinal range. The mean altitudinal range size of earthworms significantly increased along the altitudinal gradients, indicating that our results support the Rapoport's altitudinal rule. Secondly, we focused on the community of earthworms in different habitat types, analyzing species richness and community composition using nonmetric multidimensional scaling (nMDS) following by analysis of similarity (ANOSIM) and an analysis of similarity percentages (SIMPER). Both altitude and habitat type had strong effects on the community structure of earthworm.

Bioturbation by endogeic earthworms facilitates entomopathogenic nematode movement toward herbivore-damaged maize roots

Entomopathogenic nematodes (EPNs) have been extensively studied as potential biological control agents against root-feeding crop pests. Maize roots under rootworm attack have been shown to release volatile organic compounds, such as (E)-β-caryophyllene (Eβc) that guide EPNs toward the damaging larvae. As yet, it is unknown how belowground ecosystems engineers, such as earthworms, affect the biological control capacity of EPNs by altering the root Eβc-mediated tritrophic interactions. We here asked whether and how, the presence of endogeic earthworms affects the ability of EPNs to find root-feeding larvae of the beetle Diabrotica balteata. First, we performed a field mesocosm experiment with two diverse cropping systems, and revealed that the presence of earthworms increased the EPN infection potential of larvae near maize roots. Subsequently, using climate-controlled, olfactometer-based bioassays, we confirmed that EPNs response to Eβc alone (released from dispensers) was two-fold higher in earthworm-worked soil than in earthworm-free soil. Together our results indicate that endogeic earthworms, through burrowing and casting activities, not only change soil properties in a way that improves soil fertility but may also enhance the biocontrol potential of EPNs against root feeding pests. For an ecologically-sound pest reduction in crop fields, we advocate agricultural practices that favour earthworm community structure and diversity.

Earthworm assemblages in urban habitats across biogeographical regions

In urban landscapes, humans are the most significant factor determining belowground diversity, including earthworms. Within the framework of the Global Urban Soil Ecology and Education Network (GLUSEEN), a multi-city comparison was carried out to assess the effects of soil disturbance on earthworms. In each of five cities (Baltimore, USA; Budapest, Hungary; Helsinki and Lahti, Finland; Potchefstroom, South Africa), covering four climatic and biogeographical regions, four habitat types (ruderal, turf/lawn, remnant and reference) were sampled. The survey resulted in 19 species belonging to 9 genera and 4 families. The highest total species richness was recorded in Baltimore (16), while Budapest and the Finnish cities had relatively low (5–6) species numbers. Remnant forests and lawns supported the highest earthworm biomass. Soil properties (i.e. pH and organic matter content) explained neither earthworm community composition nor abundance. Evaluating all cities together, earthworm communities were significantly structured by habitat type. Communities in the two adjacent cities, Helsinki and Lahti were very similar, but Budapest clearly separated from the Finnish cities. Earthworm community structure in Baltimore overlapped with that of the other cities. Despite differences in climate, soils and biogeography among the cities, earthworm communities were highly similar within the urban habitat types. This indicates that human-mediated dispersal is an important factor shaping the urban fauna, both at local and regional scales.

Plant identity control on soil food web structure and C transfers under perennial bioenergy plantations

Conversion from arable cropping systems to perennial bioenergy crops is increasing across Europe to meet market energy demands, but our understanding of how this land use change is affecting below-ground diversity and C allocation remains limited. Here, we assessed the impact of conversion from arable cropland to Miscanthus and Short Rotation Coppice (SRC) willow in UK bioenergy commercial plantations on earthworm community structure and abundance. At this same location we then conducted an in-situ 13CO2 pulse-chase labelling experiment in the two bioenergy plantations to trace the fate of recently photosynthetically assimilated carbon into roots, bulk soil, soil microbial (PLFA) and earthworm communities. Results showed that land conversion from annual arable crops to both Miscanthus and SRC willow perennial bioenergy crops led to severe reductions of soil earthworm abundance and biomass. SRC willow had higher microbial biomass relative to Miscanthus, whereas Miscanthus provided a better habitat for a more functionally diverse earthworm community. Transfer of labile C compounds to soil pools was faster under Miscanthus supporting activity of bacterial grazers in the soil food chain, whereas a fungal-driven detrital decomposition processes dominated under SRC willow plantations. Taken together, these findings indicate that plant identity in land conversions have a strong influence not only on the abundance and structure of soil communities but also on which basal resources (root exudates, dead organic matter or microbial derived compounds) are preferentially consumed, and ultimately on the rates of mobilisation of these different C pools.

Earthworm communities in conventional and organic fruit orchards under two different climates

Climate strongly influences the distribution of soil organisms in agroecosystems, but local agricultural practices can also alter the natural composition of soil communities. Conventional (CONV) practices usually cause long-term negative effects in soil agroecosystems, by reducing soil biodiversity and altering edaphic processes, while organic (ORG) practices promote soil health and the diversity and abundance of fauna. Here, we used distributional and multivariate analyses to compare the species composition and ecological structure of earthworm communities in four fruit orchards (kiwifruit, grapevine, clementine, and olive) cultivated under CONV and ORG practices and located in two different biogeographic regions of the Iberian Peninsula (Atlantic and Mediterranean). Results indicated that the interaction among the three factors studied (biogeographic region, agricultural management and fruit tree orchard) caused a significant effect on all parameters analyzed (abundance, biomass, diversity, earthworms communities, and earthworms life strategies). More earthworms were collected in Atlantic (7160 ind m−2) than Mediterranean (5576 ind m−2) region, although no differences were found between CONV and ORG practices. However, agricultural practices caused an important effect on earthworm diversity, with significant reductions in species richness (S), diversity (H′ index) and mature earthworms in the dryer and warmer climate under CONV practices. The multivariate analysis reflected those dissimilarities in ecological structure between biogeographic regions (95%) and agricultural practices (>82%). Finally, the comparison of the abundance and biomass curves confirmed that ORG practices were beneficial for earthworm populations, showing moderate or absence of ecological perturbation, and consequently, they diverted more energy to individual growth than to reproduction. Therefore, the positive effects of implementing more sustainable agricultural practices in agroecosystems will depend on their interactive effects with environmental factors, being especially useful in the dryer and warmer climates, such as in the Mediterranean region.

Effects of farming practices on the structure of earthworm communities in kiwifruit orchards

Effects of farming practices on the structure of earthworm communities in kiwifruit orchards

Influence of cadmium-contaminated soil on earthworm communities in a subtropical area of China

Research was conducted to examine the influence of historical cadmium (Cd) contamination and soil properties on the biomass, diversity and structure of earthworm communities in a subtropical area (Hunan province) of South China. Fourteen earthworm species were identified across the twelve field sampling sites. Metaphire californica was the most widespread and dominant species. Results showed that both earthworm density and the Simpson diversity index decreased inversely with increasing soil Cd concentrations. The proportion of adult earthworms was greater in soils with high levels of Cd contamination. The abundance of earthworms was also correlated with soil organic carbon and total nitrogen contents. Cd concentrations in M. californica were well predicted by both the total and available soil Cd concentrations (R2 = 0.83, R2 = 0.90, p < 0.01, respectively), and suggested that this species may have particular applications for risk assessment and use in bioremediation.

Comparisons of earthworm community structure between different ecotypes

Comparisons of earthworm community structure between different ecotypes