Ragweed (Ambrosia artemisiifolia L.): In weed vegetation of the Republic of Srpska

The paper presents the results of a multi-year research (1995-2015) presence of Ambrosia artemisiifolia L. in weed communities on the territory of the Republic of Srpska. Recording weed vegetation was performed by Braun-Blanquet (1964). Ambrosia artemisiifolia L. was identified in 9 communities and the most represented is in the association Panico-Galinsogetum parviflorae Tuxen et Becker (1942). Particularly significant presence is in earthed-up crops, fallow land and orchards. In the vineyards Ambrosia artemisiifolia L. was present in six of the nine communities where has the highest covering value. In the northern part of Republic of Srpska territory it was separated facies Panico-Galinsogetum ambrosiosum artemisiifoliae in which the greatest abundance and coverage has Ambrosia artemisiifolia L. Her massive expansion is the result of biological properties, entering agrophytocenosis, anthropogenic influences and many uncultivated areas.