Studies on ectomycorrhizal symbionts in plant communities were developed in the experimental floodplain located in the middle reach of the Pilica River valley near Sulejów (central Poland). This area is a natural floodplain where habitats are permanently or periodically flooded. Its vegetation is highly diversified and includes haygrowing meadows (Molinio-Arrhenateretea), rush communities (Phragmitetea, Caricetea), willow shrubs (Salicetea) and pine monoculture. Samples of trees' and bushes' roots were collected using a metal probe, sporocarps of ectomycorrhizal fungi (ECMF) were collected together. Researches indicate that wet soil conditions and periodic flooding have a significant influence on mycorrhiza presence. The vast majority of ectomycorrhizal fungi were present in trees growing in dry habitats – willow bushes and pine monoculture (Salix species, Betula pendula and Pinus sylvestris). The species composition were determined - in total noted c.a. 40 species of ectomycorrhizal fungi and 15 morphological types. The number and diversity of ectomycorrhizal (ECM) morphotypes increased significantly from flooded to dry habitats. Despite the fact that extremely humid and dry soil conditions make a negative impact on mycorrhiza, symbiotic parthnership enable floodplain plant communities to tolerate water level fluctuations, eliminate water stress and provide plants tissues with e.g. phosphorous.