This study was designed to evaluate the supposed changes in the terrestric ecosystem in the area between the channelized Danube river and its bypassed section. The shift occurred at the end of October 1992. The comparison of the background period (1990-1992), with the alterations which followed mainly in the hydrological regime, displays different adaptive changes in plant, mollusc, spider, mite and springtail communities. The common features of these changes are distributed in the following groups: changes in alpha-diversity, retreat of demanding species of the floodplain forest, re-casting of the guilds, retreat of hygrophilous species connected with the drive of euryoecic species, penetration of flood intolerant species, changes in species composition identity rate, changes in relative representation of life forms, drying of the site resulting in canopy thinning and loss of foliage, and ecomorphoses.