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2M - Monitoring of function and structure (WEP/144) Effects of copper-enriched sludge on both soil mesofauna and decomposition of oak leaves in mesocosms. Pernin, Celine1, Krogh, Paul Henning2, Cortet, Jérôme 1, Joffre, Richard3, 1 Institut Méditerranéen d'Ecologie et de Paléoécoligie, Marseille, France, France2 National Environmental Research Institute, Silkeborg, Danmark, Danmark3 Centre d'écologie Fonctionnelle et Evolutive, Montpellier, France, France ABSTRACT- A mesocosm experiment was performed to study the effects of 2 doses of sludge (S1 = 2.74t DM ha-1, S3 = 8.22t DM ha-1) enriched with 3 doses of copper (C0, C1 and C2 respectively equal to 0, 1000 and 200mg Cu kg-1) on a mesofauna community over 12 weeks. Cork oak litter decomposition parameters (Litter Mass Remaining, nitrogen, fibres and phenol content) were also monitored using the Near Infra-red Reflectance Spectroscopy method. The mesofauna community added on each mesocosm was composed by 6 species of Collembola (Protaphorura armata, Folsomia fimetaria, Mesaphorura macrochaeta, Parisotoma notabilis, Isotomurus prasinus, Lepidocyrtus cyaneus), 2 species of Oribatida (Achipteria coleoptrata, Adoristes sp), 1 species of gamaside (Hypoapsis aculeifer) and 1 species of enchytreid (Enchytraeus crypticus). The four treatments were CONT = S1C0, S1C1, S1C2 and S3C1. Five replicates of each treatment were sampled every 3 weeks. Even though effects of treatments differed between species, the overall community abundance increased with the application of copper-enriched sludge. The changes within community parameters caused by copper affected neither decomposition process nor leaf composition parameters. Tripling the dose of sludge had a significant effect on the community and leaf nitrogen, fibres and phenol content but not on the LMR. According to results, even though Protaphorura armata and Folsomia fimetaria are usually used for ecotoxicologic tests, they did not show any answer to copper and to sludge doses. Species susceptible to be found in the field such as, Lepidocyrtus cyaneus, Parisotoma notabilis, Isotomurus prasinus and Hypoapsis aculeifer, showed more sensitive reactions to the treatments. Key words: Copper-enriched sludge, Mesocosms, mesofauna community, oak leaf litter decomposition |
