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

URL http://dx.doi.org/10.1111/j.1365-2389.2009.01178.xSoil degradation processes have dramatically increased in their extent and intensity over the last decades. Progressively, actions have been taken in order to evaluate and reduce the major threats that have already wreaked havoc on soil conditions. Efficient and standardized monitoring of soil conditions is thus required but soil quality research is facing an important technological challenge because of the number of properties involved in soil quality. The objective of the present review is to examine critically the suitability of nearinfrared reflectance spectroscopy (NIRS) as a tool for soil quality assessment. We first detail the soil qualityrelated parameters (chemical, physical and biological) that can be predicted with NIRS through laboratory measurements. The ability of imaging NIRS (airborne or satellite) for mapping a minimum data set of soil quality is also discussed. Then we review the most recent research using soil reflectance spectra as an integrated measure of soil quality, from global site classification to the prediction of specific soil quality indices. We conclude that imaging NIRS enables the direct mapping of some soil properties and soil threats, but that further developments to solve several technological limitations identified are needed before it can be used for soil quality assessment. The robustness of laboratory NIRS for soil quality assessment allows its implementation in soil monitoring networks. However, its routine use requires the development of international soil spectral libraries that should become a priority for soil quality research.Les processus de dégradation des sols ont fortement augmenté au cours des dernières décennies. Des mesures sont progressivement mises en place afin d'évaluer et de limiter l'impact des principales menaces qui ont déjà provoqué une diminution préoccupante de la qualité des sols. Des méthodes efficaces et standardisées de suivi de la qualité des sols sont donc indispensables, mais les nombreuses propriétés impliquées dans la qualité des sols compliquent son évaluation rigoureuse. L'objectif de cette revue est d'examiner le potentiel de la spectroscopie proche infrarouge (SPIR) comme outil rapide de caractérisation de la qualité des sols. Nous dressons d'abord l'inventaire des propriétés du sol liées à sa qualité qui sont prédictibles par des mesures SPIR en laboratoire. Le potentiel de l'imagerie embarquée SPIR (satellite, avion) est également abordé. Nous réalisons ensuite une synthèse des applications utilisant la réflectance spectrale des sols comme mesure intégrée de leur qualité, depuis la classification de sites selon leur état de dégradation jusqu'à la prédiction d'indices spécifiques de qualité du sol. Nous concluons que l'imagerie SPIR permet de cartographier quelques propriétés et menaces pesant sur les sols, mais les limites technologiques relevées exigent d'importants développements pour en faire un outil robuste d'évaluation de la qualité des sols. La fiabilité de la technique SPIR ...

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Earthworms are known for their important role within the functioning of an ecosystem, and their diversity can be used as an indicator of ecosystem health. To date, earthworm diversity has been investigated through conventional extraction methods such as handsorting, soil washing or the application of a mustard solution. Such techniques are time consuming and often difficult to apply. We showed that combining DNA metabarcoding and next-generation sequencing facilitates the identification of earthworm species from soil samples. The first step of our experiments was to create a reference database of mitochondrial DNA (mtDNA) 16S gene for 14 earthworm species found in the French Alps. Using this database, we designed two new primer pairs targeting very short and informative DNA sequences (about 30 and 70 bp) that allow unambiguous species identification. Finally, we analysed extracellular DNA taken from soil samples in two localities (two plots per locality and eight samples per plot). The two short metabarcode regions led to the identification of a total of eight earthworm species. The earthworm communities identified by the DNA-based approach appeared to be well differentiated between the two localities and are consistent with results derived from inventories collected using the handsorting method. The possibility of assessing earthworm communities from hundreds or even thousands of localities through the use of extracellular soil DNA will undoubtedly stimulate further ecological research on these organisms. Using the same DNA extracts, our study also illustrates the potential of environmental DNA as a tool to assess the diversity of other soil-dwelling animal taxa.