Various types of artificial habitats are associated with the modified landscapes. Among them are abandoned sand and gravel pits. These sites have a varied terrain. The presence of slopes, elevations, depressions and ponds creates favorable conditions for the colonization and development of species from very different habitats. Exploitation of raw materials and the accompanying infrastructure lead to total or partial degradation of the natural vegetation cover and to the development of new short-lived unstable systems. Abandoned sites at various stages of secondary succession are characterized by remarkable species diversity and richness. The habitats these species come from also have a significant effect on species composition and richness in the abandoned sites. At 31 abandoned sand and gravel pits near wiecie, 503 species of vascular plants have been found. As many as 161 species are alien anthropophytes (archeophytes, kenophytes and ephemerophytes). The sites with the greatest number of alien species are sites near meadows growing on the slopes of the Wda valley and suburban ruderal sites. The sites with the least number of alien species are sites near re-established forest communities and sites covered with hygrophilous tall herbaceous species and shrubs.