IMPACT OF FERTILISATION ON VEGETATION DEVELOPMENT AND WATER QUALITY

Vegetated roofs are known to have an important impact on the urban water balance. How they influence the storm water quality is not well known. Vegetated roofs might act as filters and have a positive effect on storm water quality by the uptake of airborne particles and nutrients. There is also a possibility that the vegetated roofs might leak nutrients to the storm water system since vegetated roofs are generally fertilised when they are constructed. The nutrient dynamic of an extensive green roof is important both for the storm water quality, survivability of the plants and the aesthetic qualities of the roof. Maintenance of vegetated roof is dependent on the goal of the vegetation and it is important to increase the knowledge about how green roofs can be maintained and how different maintenance regimes influence the vegetation. This paper discusses fundamental concepts and some preliminary results