Rozprzestrzenienie obcych gatunków drzew w lasach Nadleśnictwa Nurzec (północno-wschodnia Polska)

The paper presents and characterizes alien tree species in Polish forests in the Nurzec Forest District in the Milejczyce Forest District (northeastern Poland). The history of the spread of synanthropic plants worldwide and their classification according to their origin, the intention of introduction, manner, history of spread, degree of establishment, and type of habitats occupied are briefly mentioned. Information on the causes and methods of preventing the spread of species of alien origin were also included. The main invasive alien species in the Milejczyce Forestry were: Prunus serotina, Quercus rubra, and Robinia pseudoacacia. After the analysis, general conclusions were made regarding the occurrence of invasive species and methods of their control in the forests of the Milejczyce Forest District.