APPROACHES ON THE INVASIVE ALIEN TAXA IN ROMANIA - AMBROSIA ARTEMISIIFOLIA (RAGWEED) I

The aim of the present contribution was to determine the situation of Ambrosia artemisiifolia in Romania. A. artemisiifolia has a pronounced invasive character and is anemophilous, contrary to most Asteraceae. This paper is a brief summary about the researches on the alien plant Ambrosia artemisiifolia in Romania. At present, this alien plant is in the process of acclimatization and naturalization in our country. Till now it has indicated from all Romanian provinces, the spread of this taxon through our country is still incomplete known, at about a century since its first identification at Or ova. Nowadays the agricultural areas are greatly infested in Romania. However, the infestations on waste land or roadsides are rarely controlled. The annual pollen counts show an increasing tendency, indicating an increased local population. Ambrosia artemisiifolia has been studied by a high number of romanian scientists and many articles have been written on the topic. For the study of the spreading of the Ambrosia artemisiifolia L. species in the Western field of the country it was established as a study perimeter an areal which situates between the adminitrative limits of Timi county. In 2008 the presence of the species was noticed in 49 locations. In 2009 - 2011, the observations continued and it was observed the emergence of the species in 28 new locations, also the expansion and amplification in the pryor locations. In the years 2010-2011 have been made many observations in other 33 counties and Bucure ti. The determinations were made in the months of June-September. In this work were listed a number of sites across Romania, where A. artemisiifolia vegetate. Currently the biggest problem is in the lowland and hill area of macro-regions 1, 3 and 4 where the species A. artemisiifolia is found in the extensive and diverse ecosystems. The paper presents personal observations on some morphological features, anatomical and ecological aspects.