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The aim of this study was to evaluate the effects of sludge compost (SC) in two rates and pig slurry (PS) on soil quality, in the framework of a field experiment (19-year-old) in a Mediterranean rainfed system. The treatments were compared with mineral fertilization (MF) plus a control treatment (no N fertilization). Soil microstructure and types of voids, earthworm community and its bioturbation were studied using micromorphological methods. Two earthworm species, Koinodrilus roseus and Nicodrilus trapezoides were identified; the latter was not present in the SC treatments. Earthworm abundance and biomass were not affected by fertilization. Pig slurry increased bioturbation associated with earthworm activity, improved soil microstructure (crumb type) and increased the biopore presence (compound packing voids). The control and MF plots showed a platy to massive microstructure with an absence of faunal chambers. In SC plots, non-mixed soil-organic materials were observed and soil vughs were not visible. Composition differences between SC and PS and the total amount of OM applied may have had an impact on the activity and species of earthworms; such changes can be an early indicator of further potential impacts on soil quality however, further contaminant studies are needed to validate this initial assessment. This work was supported by the Spanish Ministry of Economy and Competitiveness and the Spanish National Institute for Agricultural Research and Experimentation (MINECO-INIA) through the projects RTA2013-57-C5-5 and RTA2017-88-C3-3.

Studies comparing different land covers clearly show that land-use change commonly affects animal communities and the ecological functions they play in ecosystems. However, we lack a good understanding of the effects that more subtle changes, those occurring within a land cover type, can have on ecological functions of animals, and if these are also mediated by shifts in community attributes. We studied two important ecological functions of dung beetles in tropical planted pastures with exotic African grasses. Due to differences in management, pastures varied in grass cover, tree density, pasture age, cattle density, and in the application frequency of veterinary medical products. We sampled beetles and their functions in 24 sites to address two questions: (1) Do management variables known to strongly affect beetle communities also affect their functions?; (2) Are the dung beetle-mediated ecological functions of dung removal and soil excavation correlated, and are they influenced by community attributes? We found no influence of management variables on dung removal, while soil excavation was negatively affected by pasture age, but only weakly. Contrary to our expectations, no community attribute was correlated with either dung removal or soil excavation, but both functions were strongly and positively correlated with each other. Our results indicate that responses of dung beetle communities and their ecological functions to subtle changes within a land cover type, are decoupled, idiosyncratic and context-dependent, making predictions and generalizations difficult. We believe that there is a need of more studies investigating the effects of fine-scale changes within habitats to better understand the consequences of management decisions on ecological processes mediated by animals.

International audience; Because earthworms sustain soil functioning and fertility, there is a need to advance the knowledge of their adaptation potential to chemicals in anthropogenic landscapes. Our hypothesis is that there is acclimation to organic chemicals (pesticides) in earthworms that durably persist under conventional farming in anthropogenic landscapes. The adaptation capability of two populations of earthworms (Aporectodea caliginosa) having a different chemical exposure history, - one originating from 20 years of organic farming (naïve population) and another from 20 years of conventional farming (pre-exposed population) - to cope with soil organic pollutant (Opus®, epoxiconazole a worldwide used fungicide) were investigated. Several complementary metabolic and energetic endpoints were followed, and cast production was assessed as a behavioural biomarker related to earthworms ecological role for the soil. Basal metabolism reflected by respiration rate was increased in both fungicide-exposed worms compared to controls. Glycogen resources were decreased in the same proportion in the two populations but more rapidly for the naïve (7 days) than for the pre-exposed population (28 days). Soluble protein and most amino-acids contents increased in the pre-exposed population only, suggesting a detoxification mechanism. Metabolomic profiles showed a cut-off between fungicide-exposed and control groups in the pre-exposed earthworms only, with an increase in most of the metabolites. Exposure to a low dose of epoxiconazole increased cast production of pre-exposed earthworms, and this resulted in an increase in pesticide disappearance. As far as we know, this is the first study which evidenced there is an acclimation to an agricultural chemical in earthworms derived from conventional farming that also relates to a change in their burrowing behaviour, and for which larger consequences for the soil ecosystem need to be addressed. This original finding is of major interest in the frame of ecosystem resilience to global changes. Whether this physiological adaptation is a general pattern of response against fungicides or other pesticides would need to be confirmed with other molecules and agricultural contexts.