This paper approaches the subject of soil biodiversity and of some biometrical characteristics short-term rotation hybrid poplar production from Rădăuţi area. The research was supported STRoMA project (Sustainability of short-term rotation cultures of trees on marginal lands), in a under development. The analyzis was aimed on: the influence of soil granulometry on the maximum depth of occurrence of poplars radicelar system and on the maximum depth of insects and small mammals galleries. During the research was also highlighted the influence of depth and granulometry of the alluvial deposits of these soils on height of hybridpoplar specimens.