Trawy w procesie kolonizowania nieużytkowanych linii kolejowych w Wielkopolsce

The paper presents the results of the research on the speed and level of colonization of the unexploited railway lines by grasses. Railways tracks are an inseparable element of the human-shaped environments. These areas have specific ecological-edafical conditions and only plants of wide ecological amplitude are able to get control over them. Among grasses there is a significant number of species whose biological properties, resistance to environmental stresses and ability to survive in extreme conditions let them overrun and turf difficult terrains. These are mostly species which root deeply, creep, form a large number of diasporas and are often connected with significantly drying habitats, such as Arrhenatherum elatius, Dactylis glomerata, Festuca ovina, Festuca rubra and Poa pratensis, which grow relatively fast within peatlands. The expansion of grasses typical to ecosystems crossed by railway tracks were also identified in these areas e.g. Melica nutans, Poa nemoralis in forestry areas, Phragmites australis, Bromus inermis on wetlands and Apera spica-venti, Bromus secalinus, Echinochloa crus-galli or Setaria viridis on agricultural terrains. However, these taxons appeared usually single with a minor share. Total number of grasses was 31.