Eco-friendly management of woody weeds in natural and urban areas : the case of Ailanthus altissima in Apulia Region

Among the arboreal and shrubby weeds colonizing non-crop environments in the Apulia Region (Italy), Ailanthus altissima (Mill.) Swingle (Tree of Haven), an exotic invasive fast growing species, is one of the worse. Its management is very difficult because of its fast growth and root-sucker's production, and mechanical and chemical treatments provide only shortterm control. Within a research program on the management of woody weeds, impact of A. altissima was assessed in the wide urban area of Bari and in the Alta Murgia National Park. During numerous inspections distribution was determined by mapping all plants with GPS; their size, number and density were estimated. All damages were noted down. In Bari, data were recorded along a 76 Km path, with 146 areas of plants surveyed (most with medium-high density) and 584 single plants measured; in the Park around 126 Km of roads were mapped, with a total of 92 areas surveyed and 130 single plants measured. Compared with other arboreal and shrubby weeds, in Bari A. altissima proved to be the most widespread species; in the Park it is highly threatening the ecological equilibrium of the environment. Its distribution in the studied areas confirms its ability to colonize strongly disturbed, marginal, or natural undisturbed environments. Moreover, within the project, different methods for micro injection of systemic herbicides into trunks were developed and tested, to combine the effectiveness of the herbicides at reduced rates with the safety for non target organisms and environment. The results of mapping and tests will be presented.