Railway Tracks - Habitat Conditions, Contamination, Floristic Settlement - A Review

Apart from roads, railways are one of the principal means of transportation. The specificity of rail transportation causes some environmental problems. The study presents a review of the major environmental problems connected with railway transportation. The construction of railway tracks and properties of used materials, as well as the maintenance of railway infrastructure are responsible for the specific habitat condition with alkaline soil reaction and varying but rather high levels of nutrients, which favour plant encroachment and growth. The results of investigations described in this study show clearly that railway transportation causes typical organic and inorganic contamination. Among the most important railway pollutants are polycyclic aromatic hydrocarbons, heavy metals, and to some extent, polychlorinated biphenyls. The study also presents some information about the progress of floristic studies in operating and abandoned railway lines. In addition some trends in the transformation of the flora in abandoned railway areas are discussed: the retreat of alien species with a short life cycle, the encroachment of native perennial plants and an increase in the number of trees.