New invasive alien plant species in the forest-steppeand northern steppe subzones of European Russia: secondary rangepatterns, ecology and causes of fragmentary distribution

摘要

Recent floristic investigations in several provinces located in the northern steppe and forest-steppe subzones of European Russia have examined the naturalisation and rapid spreading of 13 annual and perennial invasive herbs. They can be considered as(potentially) dangerous neophytes in different plant formations: Eriochloa villosa, Panicum dichoto-miflorum, Eragrostis albensis, Rumex patientia, Amaranthus powellii, Papaver dubium, Erysimum repandum, Sophora alopecuroides, Galega orien-talis, Chaerophyllum aureum, Centaurea majorovii, Senecio dubitabilis, Lactuca saligna. Only a decade ago, very few of the above listed species were present in Central Russia. Chaerophyllum aureum, the most successful invader forms monodominant populations, stands atforest margins and in meadows and is transforming the existing vegetation structure. Eragrostis albensis and Amaranthus powellii have been well-established in dump sites, in contrast Galega orientalis and Rumex patientia prefer open grassland (meadows,etc.). The remaiming species occur along the railroad beds. The supposed fragmentary distribution pattern seems to be just a result of insufficient study of alien species and/or the absence of specialists in some provinces. Several species (e.g. Seneciodubitabilis, Centaurea majorovii) are recently invasive new for many parts of European Russia. The ecological attributes, respectively, the invasive status of the alien species, mentioned above, are compared between this investigation area and Central/Western Europe.