Indigenous species will often continue to be seen as the most secure basis for a long-term living system because we have scientific and practical experience of them, and they should, more than others, be hardy and trustful from a very long-term perspective—a point of major importance in ‘stressed’ urban situations. Systems with indigenous species have strong symbolic cultural values because of their familiarity to many people. Most of these experiential qualities are related to the older woodland stages, and they are therefore of crucial importance if it is possible to prolong the life of plantations into these older stages.
However, of equal importance is to increase the knowledge and the use of urban woodlands based on ornamental plants. These have, over centuries, fascinated city dwellers because of their exotic flowers, strong autumn colours, or because they are from foreign, distant countries, with all the curiosity that this can awake. And there is no sign that city people will be less fascinated about exotic plants in the future. There has been some experience in the northwestern part of Europe and Scandinavia of the hardiness and long-term survival ability of a range of exotic tree-species, but if we want to extend or deepen our knowledge and look at these species and their ability to grow in long-term systems, as well as their interactions with neighbouring individuals or their place in a succession, there is so far very limited knowledge.
