Earthworm Sampling

Earthworm migration in significant quantities is an extremely rare event in nature. The probable cause for such migration and associated mortality is generally obscure without additional information on the bio-ecology of the region. The present study was conducted as a result of public reporting of mass migration and mortality of earthworms in two hilly districts of Kerala, namely Idukki and Wayanad (part of Western Ghats biodiversity hotspot) following the worst deluge for decades in Kerala, 2018 (August-September). The major aim of the study was to find the species involved and probable cause for this mass migration and death of earthworms in the reported regions. Dead and dying earthworms were collected from the sites of mass death by hand picking, digging and hand sorting methods. Our examination revealed that a total of four species of earthworms viz., Amynthas alexandri Beddard, 1901, A. corticis (Kinberg, 1867), Metaphire houlleti (Perrier, 1872) and Pontoscolex corethrurus (Müller, 1857), belonging to Megascolecidae and Rhinodrilidae families were found migrating and dead in masses at these sites. All the species that underwent mass migration and mortality were naturalised exotic species. It can be inferred that the native species are more accustomed to the changing weather pattern in the region. The physical characteristics and the sudden change in moisture content of the soil seem to have triggered the mass migration and associated mortality of earthworms in the Western Ghats of Kerala.

Soil is fundamental for the functioning of terrestrial ecosystems, but our knowledge about soil organisms and the habitat they provide (shortly: Soil biodiversity) is poorly developed. For instance, the European Atlas of Soil Biodiversity and the Global Soil Biodiversity Atlas contain maps with rather coarse information on soil biodiversity. This paper presents a methodology to map soil biodiversity with limited data and models. Two issues were addressed. First, the lack of consensus to quantify the soil biodiversity function and second, the limited data to represent large areas. For the later issue, we applied a digital soil mapping (DSM) approach at the scale of the Netherlands and Europe. Data of five groups of soil organisms (earthworms, enchytraeids, micro-arthropods, nematodes, and micro-organisms) in the Netherlands were linked to soil habitat predictors (chemical soil attributes) in a regression analysis. High-resolution maps with soil characteristics were then used together...

<p>The protection of soil biodiversity is essential for ensuring soil functioning and provisioning of related ecosystem services, but also the conservation of species <em>per se</em>. For this purpose, it is essential to know what soil organism is where and how it is influenced by environmental, climate and human activities. </p><p>Numerous studies (there are over 1400 published articles) have been elaborated in Europe regarding soil fauna. A data platform to store data on soil fauna already exists and is currently under further development to become a pan-European data warehouse for soil biodiversity (https://www.eudaphobase.eu/). Though, the data stored in this database until now comprises only a small percent of the available data. Hence, it is evident that a compiled dataset providing an overall understanding of the distribution of several taxa across European biomes and under different land use still is missing.</p><p>Attempting to fill this gap, we start a new initiative within the framework of the Cost Action EUdaphobase CA18237: the creation of the <strong>first European Atlas of Soil Fauna. </strong> We aim to map, summarize and upscale the current knowledge on soil fauna to help in providing support to the scientific community and directions to stakeholders and policymakers. We seek collaboration (data holders and experts) to identify, collect and analyze data of all groups of micro-, meso- and macrofauna in Europe. </p><p>This presentation will focus on the aims of this initiative and the way we plan to collect data and involve people.</p>

Highlights-A new method is proposed to measure allyl isothiocyanate concentration in mustard-AITC concentration in mustard varied five-fold, depending on its use by date-AITC concentration was about 4 times higher in the AITC solution than in the mustard one-AITC and commercial mustard solutions had the same earthworm extracting efficiency

Existing data sets on earthworm communities in Europe were collected, harmonized, collated, modelled and depicted on a soil biodiversity map. Digital Soil Mapping was applied using multiple regressions relating relatively low density earthworm community data to soil characteristics, land use, vegetation and climate factors (covariables) with a greater spatial resolution. Statistically significant relationships were used to build habitat-response models for maps depicting earthworm abundance and species diversity. While a good number of environmental predictors were significant in multiple regressions, geographical factors alone seem to be less relevant than climatic factors. Despite differing sampling protocols across the investigated European countries, land use and geological history were the most relevant factors determining the demography and diversity of the earthworms. Case studies from country-specific data sets (France, Germany, Ireland and The Netherlands) demonstrated the importance and efficiency of large databases for the detection of large spatial patterns that could be subsequently applied at smaller (local) scales. 2015 Elsevier B.V. All rights reserved.

Highlights-A new method is proposed to measure allyl isothiocyanate concentration in mustard-AITC concentration in mustard varied five-fold, depending on its use by date-AITC concentration was about 4 times higher in the AITC solution than in the mustard one-AITC and commercial mustard solutions had the same earthworm extracting efficiency

Existing data sets on earthworm communities in Europe were collected, harmonized, collated, modelled and depicted on a soil biodiversity map. Digital Soil Mapping was applied using multiple regressions relating relatively low density earthworm community data to soil characteristics, land use, vegetation and climate factors (covariables) with a greater spatial resolution. Statistically significant relationships were used to build habitat-response models for maps depicting earthworm abundance and species diversity. While a good number of environmental predictors were significant in multiple regressions, geographical factors alone seem to be less relevant than climatic factors. Despite differing sampling protocols across the investigated European countries, land use and geological history were the most relevant factors determining the demography and diversity of the earthworms. Case studies from country-specific data sets (France, Germany, Ireland and The Netherlands) demonstrated the importance and efficiency of large databases for the detection of large spatial patterns that could be subsequently applied at smaller (local) scales.

Earthworms are a key group of detritivores and ecosystem engineers in many ecosystems worldwide, yet we have a limited understanding of how their diversity varies globally. Synthesis of global data on earthworms would allow a range of important ecological, evolutionary, and applied questions to be addressed. We conducted a survey on global earthworm data at the 10th International Symposium on Earthworm Ecology (ISEE10) and sent an electronic survey to additional earthworm researchers. Respondents were asked about existing databases, research interests, required data, and research locations. Most researchers were aware of at least one database with earthworm data, with a total of 19 current databases being identified. Most of the top questions listed by researchers related to distributions and diversity at global scales, but traits, evolution, genetics, taxonomy, invasions, ecosystem functioning/impacts, ecotoxicology, and bioindicators were also key themes of interest. Correspondingly, distributional, environmental, and trait data were the primary data types required. Global data coverage was poor, with research being especially concentrated in Europe and the United States. Encouragingly, all researchers who currently had data indicated they would be willing to contribute it to a global database. While there are a number of key challenges associated with synthesis of earthworm data on a global scale (data limitations, taxonomic inconsistencies, logistical issues), the wide range of questions involving global data listed by researchers, and their willingness to contribute their own data, suggests there is strong interest in developing a comprehensive global database on earthworms. 2015 Elsevier B.V. All rights reserved.

Quantitative sampling for earthworms by hand sorting was carried out in different habitats of Sirohi district of Rajasthan. Seasonal changes in population of earthworm species viz. Pontoscolex corethrurus and Octochaetona beatrix were studies in different fields. Population of the earthworm Pontoscolex corethrurus varied in different seasons in agricultural, forest and grasslands. Similarly, the population of Octonochaetona beatrix changed in agricultural, garden and orchard lands. Highest population of Pontoscolex corethrurus was recorded in agricultural land in July, whereas its population was lowest in forest land. The earthworm Octochaetona beatrix was abundant in garden but poor in agricultural land. The highest population of both species was observed in the rainy season but it was meagre in the summer and winter seasons. Both the species of earthworms (Pontoscolex corethrurus, Octochaetona beatrix) showed their population peak twice i.e. one in July-August and another in February-March. Our aim was to understand the effect of seasonal changes on population density of these two earthworms.

The French programme Réseau de Mesures de la Qualité des Sols e Biodiversité was carried out at a regional scale (Brittany, west part of France) i) to produce a first statement regarding soil biodiversity, ii) to identify bioindicators of anthropic constraints, and iii) to determine baseline values for several biological groups depending on land uses. In this study, 109 monitoring sites were investigated using a systematic framework (a 16 km  16 km regular grid). Six biological groups were studied within four major categories, i.e., macrofauna (all soil macro-invertebrate taxa and earthworms), mesofauna (Acari and Collembola), microfauna (nematodes), and microorganisms (microbial biomass and functional genes). The abundances of earthworms, nematodes, Acari and the bacterial community (assessed by their encoded 16S rRNA) as well as microbial biomass and earthworm species richness discriminate land uses (crops from meadows from forests). Macro-invertebrate abundance, Collembola abundance and richness, and nematode richness are only relevant for the discrimination of agricultural practices (e.g., management system or fertilisation intensity). Most of the soil biological groups (except Collembola) exhibit lower values of abundance and community richness in croplands than in meadows. This programme allows us to set up a first reference database for soil biological data for France covering microflora and fauna. This substantial reference database will be used to calibrate future research results and to develop management baseline values for stakeholders to assess the status of soil biodiversity under several policies, e.g., the Common Agricultural Policy, Soil Framework Directive, EU and national biodiversity strategies, and policies related to contaminated land management. Therefore it should assist stakeholders in the choice of good agricultural practices.

Highlights-A new method is proposed to measure allyl isothiocyanate concentration in mustard-AITC concentration in mustard varied five-fold, depending on its use by date-AITC concentration was about 4 times higher in the AITC solution than in the mustard one-AITC and commercial mustard solutions had the same earthworm extracting efficiency

Soil is fundamental for the functioning of terrestrial ecosystems, but our knowledge about soil organisms and the habitat they provide (shortly: Soil biodiversity) is poorly developed. For instance, the European Atlas of Soil Biodiversity and the Global Soil Biodiversity Atlas contain maps with rather coarse information on soil biodiversity. This paper presents a methodology to map soil biodiversity with limited data and models. Two issues were addressed. First, the lack of consensus to quantify the soil biodiversity function and second, the limited data to represent large areas. For the later issue, we applied a digital soil mapping (DSM) approach at the scale of the Netherlands and Europe. Data of five groups of soil organisms (earthworms, enchytraeids, micro-arthropods, nematodes, and micro-organisms) in the Netherlands were linked to soil habitat predictors (chemical soil attributes) in a regression analysis. High-resolution maps with soil characteristics were then used together...

Exotic earthworms have previously been recorded in the UK. Many of those records are from the Royal Botanical Gardens, Kew. Earthworms were collected from Kew on two separate occasions in 2007 (March and August). In total 6 species were found, of which two are new species records for the British Isles. When updating the British earthworm species list it became apparent that many species are not inhabitants of UK soils but are transitory visitors in greenhouses. Their status in soils is currently unknown. A new system of recording earthworm species in the British Isles is proposed and consists of two parts. Part 1 lists those species found living freely in soils, part 2 lists those species whose status is unknown, many of which are likely to be imported visitors found in greenhouses. The need for systematic sampling of earthworms throughout the UK is highlighted and the possible effects of climatic change on earthworm populations are commented on.

Earthworms are target organisms both for scientists studying the biological component of soils and for farmers concerned with monitoring the quality of their soils. Different expellants are used to extract earthworms from the soil but differences in chemical properties and efficiency between commercial mustard and allyl isothiocyanate (AITC) solutions remain unknown. The objectives of this study were to compare (i) the concentration of irritating product (allyl isothiocyanate AITC) in two expellant solutions (diluted mustard or AITC solution) and (ii) their efficiency in extracting earthworms from the soil.

Earthworms are target organisms both for scientists studying the biological component of soils and for farmers concerned with monitoring the quality of their soils. Different expellants are used to extract earthworms from the soil but differences in chemical properties and efficiency between commercial mustard and allyl isothiocyanate (AITC) solutions remain unknown. The objectives of this study were to compare (i) the concentration of irritating product (allyl isothiocyanate AITC) in two expellant solutions (diluted mustard or AITC solution) and (ii) their efficiency in extracting earthworms from the soil.

Existing data sets on earthworm communities in Europe were collected, harmonized, collated, modelled and depicted on a soil biodiversity map. Digital Soil Mapping was applied using multiple regressions relating relatively low density earthworm community data to soil characteristics, land use, vegetation and climate factors (covariables) with a greater spatial resolution. Statistically significant relationships were used to build habitat–response models for maps depicting earthworm abundance and species diversity. While a good number of environmental predictors were significant in multiple regressions, geographical factors alone seem to be less relevant than climatic factors. Despite differing sampling protocols across the investigated European countries, land use and geological history were the most relevant factors determining the demography and diversity of the earthworms. Case studies from country-specific data sets (France, Germany, Ireland and The Netherlands) demonstrated the importance and efficiency of large databases for the detection of large spatial patterns that could be subsequently applied at smaller (local) scales.

Earthworms play an important role in the functioning of many terrestrial ecosystems, and while their importance is frequently acknowledged significant challenges still remain in determining their operant roles within the soil. This lack of knowledge becomes increasingly important as the spatial scale of
analysis increases from individuals to populations within the landscape. To effectively develop understanding,
research techniques must be able to determine the effects that earthworms have on the soil system, as well as to establish how many and which species are present. A range of techniques are required to facilitate meaningful analysis from the micro-scale within a soil profile (e.g. drilosphere
effects) to a field scale or landscape scale. Furthermore, an additional framework of understanding is required to investigate the role of earthworms in the biogeochemical cycles.
By critically evaluating recent advances in methods and data analysis techniques in three areas of earthworm research we highlight that combinations of common approaches often offer the most significant insights into the functional roles of earthworms within a soil system. Through particular reference to earthworm sampling and identification, biochemical functions and persistent pollutant ecotoxicology of
temperate ecosystems we emphasise how a range of investigation methods can be a hindrance to developing
a whole-system level understanding. The complex and diverse nature of soil systems means that a traditional compartmentalised approach studying single species using a single research technique is no longer sufficient to gain further insights into the earthworm contribution to ecosystem goods and services delivered at the whole landscape scale. The integration of technologically advanced methods in combination with systems based modelling will be critical to develop landscape scale understanding of the functions of earthworms as individuals and as populations within in their ecosystems.