Research projects to improve growth and stress tolerance in the nursery and after transplanting in the urban environment, Francesco Ferrini

The urban environment constrains tree growth and survival: drought, poor soil quality, soil compaction, light heterogeneity, transplant shock, pollutants, salinity, pathogens and conflicts with human activity often cause premature plant death, thus reducing the net benefit by urban green areas. It is therefore important to better understand the dynamics leading to tree decline in the urban environment, and to develop strategies and
techniques aimed at improving the horticultural tolerance (i.e. the capacity to provide benefits, not only to survive, under stressful conditions) of urban trees. These include
nursery preconditioning techniques and post-planting management techniques, but a key role is played by species selection. Hundreds of species are used in the urban
environment, but selection criteria are frequently based upon aesthetics and whether the species are native or not, rather than on the tolerance to typical stresses imposed by
the built environment and on the capacity to provide substantial benefits therein. This has lead to only a limited knowledge about the ecophysiology of shade trees, if compared to fruit trees and crop species. Research in the area of tree selection for tolerance of urban conditions so that the service life of trees in our communities is extended
and the benefits provided by trees are maximized is limited in Europe.
Therefore, tolerance mechanisms of species with validated and potential ornamental use, and cultural techniques for either pre-conditioning plants in the nursery or
alleviating stress after planting will be reviewed in the presentation which will show some results achieved in this field