Is the noxious Ambrosia artemisiifolia L. going to invade Belgium?

Ambrosia artemisiifolia L. is an invasive species from North America, causing a health crisis in Europe due to its highly allergenic pollen. In France, there is a zone where the A. artemisiifolia populations are naturalized and invasive. Outside this area, populations are more rare and do not seem to expand. We tested if the performances of A. artemisiifolia are varying with competition level, and among geographical zones. The results show that populations from Belgium and Netherlands are not less efficient than invasive populations for the measured traits.