Biodiversity is responsible for the provision of many ecosystem services; human well-being is based on these services, and consequently on biodiversity. In soil, earthworms represent the largest component of the animal biomass and are commonly termed ‘ecosystem engineers’. This review considers the contribution of earthworms to ecosystem services through pedogenesis, development of soil structure, water regulation, nutrient cycling, primary production, climate regulation, pollution remediation and cultural services. Although there has been much research into the role of earthworms in soil ecology, this review demonstrates substantial gaps in our knowledge related in particular to difficulties in identifying the effects of species, land use and climate. The review aims to assist people involved in all aspects of land management, including conservation, agriculture, mining or other industries, to obtain a broad knowledge of earthworms and ecosystem services

A critical review of biological parameters used to indicate pollutant impact on soi! quality was conducted. These param eters mention some soi! invertebrates. The value of an indicative organism depends on its life expectancy, life style and specific importance. Nematodes, mites, collembolans, enchytraeids, earthworms, isopods and molluscs are good potential biological indica tors. Biological indicators of bioaccumulation and biological indicators of effects (toxicological and ecological) can be distin guished. Bioaccumulation studies are difficult to interpret, as wide variations could be found, depending on taxonomie group, habitat, organ studied, soi) type or even pollutant type. Sorne groups, such as Collembola, require in depth bioaccumulation studies. It is suggested to use a pool of macro-concentrators, including at least some earthworm, isopod and gastropod species. Toxicological indicators have been well studied and their lethal and sublethal pollutant effects are well known. However, studies have focused on only a few species, such as the earthworm Eiseniafoetida or the collembolan Folsomia candida. These studies should be extended to other zoological groups, as well as to several species from the same group, to generate a representative test battery. Exposure biom arkers and physiological change studies should be emphasised, as they act as very early warning systems of contamination. Data are currently lacking on how soil biological processes malfunction due to pollution. We need to explore the links between pollutant effects on soi! fauna and pollutant effects on soi! functioning. Concerning ecological indicators, studies should develop sampling techniques and parameters, which are specific to ecotoxicological goals. Before-after impact contrai procedures should be carried out, to eliminate the background noise of the study site and only evaluate the influence of pollutants. On the other hand, ecological indices, such as taxonomie diversity or richness, should be used carefully especially concerning chronic pollution. Effects of pollut ants on biological cycle studies seem very promising, but need further information on the life history strategies of many species. Furthermore, the pollutant tolerance of rare species should be considered. The different types of biological indicators yield comple mentary information on pollutant effects. They ail need standard procedures. In this context, studies should be extended and diversi fied, and associate bioaccumulation, toxicological and ecological indicators to provide better information on soi! quality.Ecotoxicology / bioindicators of effects / bioaccumulation / soit ecology / soit quality / soit inv ertebrates / soit fauna / earthworms / microarthropods / mites / collembolans / isopods / enchytraeids / snails / soit pollution Résumé -Utilisation de la faune invertébrée du sol comme bio-indicateur des effets des polluants. Une liste critique des para mètres biologiques utilisés dans certains travaux pour indiquer l'impact des polluants sur la qualité des sol...

International audienceSoil invertebrates are assumed to play a major role in ecosystem dynamics, since they are involved in soil functioning. Functional traits represent one of the main opportunities to bring new insights into the understanding of soil invertebrate responses to environmental changes. They are properties of individuals which govern their responses to their environment. As no clear conceptual overview of soil invertebrate trait definitions is available, we first stress that previously-described concepts of trait are applicable to soil invertebrate ecology after minor modification, as for instance the inclusion of behavioural traits. A decade of literature on the use of traits for assessing the effects of the environment on soil invertebrates is then reviewed. Trait-based approaches may improve the understanding of soil invertebrate responses to environmental changes as they help to establish relationships between environmental changes and soil invertebrates. Very many of the articles are dedicated to the effect of one kind of stress at limited spatial scales. Underlying mechanisms of assembly rules were sometimes assessed. The patterns described seemed to be similar to those described for other research fields (e.g. plants). The literature suggests that trait-based approaches have not been reliable over eco-regions. Nevertheless, current work gives some insights into which traits might be more useful than others to respond to a particular kind of environmental change. This review also highlights methodological advantages and drawbacks. First, trait-based approaches provide complementary information to taxonomic ones. However the literature does not allow us to differentiate between trait-based approaches and the use of a priori functional groups. It also reveals methodological shortcomings. For instance, the ambiguity of the trait names can impede data gathering, or the use of traits at a species level, which can hinder scientific interpretation as intra-specific variability is not taken into account and may lead to some biases. To overcome these shortcomings, the last part aims at proposing some solutions and prospects. It concerns notably the development of a trait database and a thesaurus to improve data management

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Background and aims Soil aggregate stability depends on plant community properties, such as functional group composition, diversity and biomass production. However, little is known about the relative importance of these drivers and the role of soil organisms in mediating plant community effects. Methods We studied soil aggregate stability in an experimental grassland plant diversity gradient and considered several explanatory variables to mechanistically explain effects of plant diversity and plant functional group composition. Three soil aggregate stability measures (slaking, mechanical breakdown and microcracking) were considered in path analyses. Results Soil aggregate stability increased significantly from monocultures to plant species mixtures and in the presence of grasses, while it decreased in the presence of legumes, though effects differed somewhat between soil aggregate stability measures. Using path analysis plant community effects could be explained by variations in root biomass, soil microbial biomass, soil organic carbon concentrations (all positive relationships), and earthworm biomass (negative relationship with mechanical breakdown). Conclusions The present study identified important drivers of plant community effects on soil aggregate stability. The effects of root biomass, soil microbial biomass, and soil organic carbon concentrations were largely consistent across plant diversity levels suggesting that the mechanisms identified are of general relevance

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