New woody alien plant species recorded in Lithuania.
Many woody plant species that originate from various regions of the world have been introduced in other regions or continents and are used in ornamental gardening, silviculture, erosion control, for fruit sources or other purposes. Woody plants selected for introduction usually originate from regions with similar climate conditions; therefore, after certain time lag they start to spread outside places of cultivation, become naturalized or even invasive. In addition to 77 woody alien plant species reported in Lithuania, ten new species were recorded and analysed in this paper. Information on the native and anthropogenic ranges, first record in Lithuania, size of populations, habitats, reproduction and naturalization of Aralia elata, Berberis thunbergii, Caragana frutex, Celastrus orbiculatus, Cornus alba, Cytisus austriacus, Hydrangea arborescens, Pinus strobus, Rhus typhina and Thuja occidentalis is presented. All these species have been introduced intentionally and are used mainly in ornamental gardening. Three of the reported species, Berberis thunbergii, Hydrangea arborescens and Thuja occidentalis, currently are casual species. Remaining seven species were recognized as naturalized in Lithuania, and five of these, i.e. Aralia elata, Celastrus orbiculatus, Cornus alba, Pinus strobus and Rhus typhina as well as Berberis thunbergii, which currently is treated as a casual, have very high or high probability of getting invasive. Constant survey of potential habitats, detection of new escaped alien plants, particularly of trees and shrubs, is the best way to reveal potentially dangerous species and make timely decisions for their control or eradication, if necessary.