Résumé
The main objective was to evaluate the impact of nurse plant species commonly found in Mediterranean areas (Lavandula dentata and Thymus satureoides) on microbial soil functions, on the native inoculum potential of AM fungi involved in the rock phosphate weathering and to measure the potential benefits to the growth of Atlas Cypress (Cupressus atlantica G.), an endemic Cupressacea of Morocco. Soils collected from an old C. atlantica forest and pre-cultivated with each of the target plant species (L. dentata and T. satureoides). After 5 months of cultivation, they were uprooted and the treated substrate was amended or not with Khouribga Rock Phosphate (KRP). Then pots were filled with the soil mixtures and planted with one pre-germinated seed of C. atlantica. The results show that pre-cultivation step with native mycotrophic plant species improves the mycorrhizal soil infectivity, modifies soil microbial functionalities and increases the impact of rock phosphate amendment on the C. atlantica growth. This low cost cultivation practice by improving forest plant development and cultural soil quality constitutes a promising ecological engineering tool to improve the performances of ecosystem restoration. (C) 2013 Elsevier B.V. All rights reserved.