Gardening is one of the main sources of introduction of invasive plants into the natural environment, which may pose a danger to it. There is no danger in parks and gardens because they are artificial spaces under constant maintenance which can control or eliminate those plants considered as invasive. Parks technicians and managers and the whole gardening sector is responsible for preventing the spread of these species to the environment.
In the green spaces of Barcelona there are species which are considered to be potentially invasive for the near environment including the Natural Park of Collserola. In the future, climate change will inevitably result in planting species adapted to the new conditions in public areas. The adaptability to the new environment is precisely one of the elements which define invasive plants. For this reason, we must assess the risk of pre-invasion of these new species, whose behaviour is still unknown. A study on invasive species in Barcelona and a proposal of alternative species are necessary according to the awareness of the City Council regarding this issue.
The Council promotes continuous measures which are divided into two lines of work. The first one —which has been given priority— is identification of invasive species and use of alternative species for prevention. The second one focuses on management and possible eradication of invasive species. This document shows the work carried out since 2008 on the first line of work, which includes the Study of invasive species in Barcelona and the alternative species.