Malmö is the third largest city in Sweden, with over 300 000 residents, and the City of Malmö Streets and Parks Department is currently responsible for around 60 000 trees. Trees are an important resource for all cities and without far-sighted planning, continual care and rejuvenation of the tree population, we risk depleting our cities of greenery.

During the mid-1980s, Malmö, just like many other cities in Europe, was struck by Dutch Elm disease and the next 20 years saw the disappearance of more than 40 000 elms growing on public and private land in Malmö. That prompted the start of deliberate planning work to create a more varied tree population and thereby an urban tree population more resistant to future diseases and pests. During recent decades, Malmö has built up one of the most varied populations of tree species in Northern Europe and every year the urban tree population continues to be expanded with new tree species.

In recent years Malmö has been affected by a number of serious diseases, for example bleeding crashers on horse chestnut, chalara dieback of ash and phytophthora in beech. The emergence of these diseases clearly demonstrates the importance of having a varied range of tree species, in Malmö as a whole and in the different city districts. These diseases have also prompted Malmö to initiate collaborations with national and international research institutes in order to increase knowledge within the City and to develop action plans for dealing with these serious diseases.

Species diversity can reduce the impact of emerging diseases – 30 years of practical work in the City of Malmö-- Malmö is the third largest city in Sweden, with over 300 000 residents, and the City of Malmö Streets and Parks Department is currently responsible for around 60 000 trees. Trees are an important resource for all cities and without far-sighted planning, continual care and rejuvenation of the tree population, we risk depleting our cities of greenery. During the mid-1980s, Malmö, just like many other cities in Europe, was struck by Dutch Elm disease and the next 20 years saw the disappearance of more than 40 000 elms growing on public and private land in Malmö. That prompted the start of deliberate planning work to create a more varied tree population and thereby an urban tree population more resistant to future diseases and pests. During recent decades, Malmö has built up one of the most varied populations of tree species in Northern Europe and every year the urban tree population continues to be expanded with new tree species.

 In recent years Malmö has been affected by a number of serious diseases, for example bleeding crashers on horse chestnut, chalara dieback of ash and phytophthora in beech. The emergence of these diseases clearly demonstrates the importance of having a varied range of tree species, in Malmö as a whole and in the different city districts. These diseases have also prompted Malmö to initiate collaborations with national and international research institutes in order to increase knowledge within the City and to develop action plans for dealing with these serious diseases and a strategy for increasing species diversity in order to create a more robust urban tree population.

 One of the latest trials involves trying to decrease the consequences of phytophthora attack on beech trees. Two years ago, various tree fertilisation trials were carried out in Malmö’s largest park in attempts to improve tree resistance to attack.

 During this joint presentation by the City of Malmö and the Swedish University of Agricultural Sciences the municipal and researcher view on the cooperation will be presentation. The presentation will thereby highlight how researchers and practitioners can work together to reduce the impact of deceases and ensure a vital urban tree population.