Aims and Background: Ectomycorrhizal (ECM) fungi are able to produce significant amounts of phosphatases (Pases) in their environment in laboratory. These enzymes, releasing free P from organic P, may play an important role in P nutrition of trees. However, whether this release depends on the nutrient availability and/or the fungal diversity is not known in situ. We addressed this question in the field, in the mar itime pine ( Pinus pinaster) forest, planted in P limited sandy podzol. Methods : We used an experimental fertilization design, providing plots with contrasting P and N availability. We measured Pase activities released by individual ECM tips collected from soil cores through three sampling campaigns. ECM species were then identified from ITS sequencing. Results : Pase activities were more dependent on the fungal species than on soil P availability. Lactarius hepaticus and Inocybe nitidiuscula dominated the community, releasing the highest and the low est Pase activities of the whole community. Remarkably, I. nitidiuscula was dominant in plots with high mineral P availability. Conclusion : The ability for phosphatase release by ECM species may structure the community associated with the roots in response to P availability, with high phosphatase producers more successful in soil with low mineral P availability.