The FLL Green Roof Guidelines in Germany Prof. Gilbert Lösken (D) Department of Landscape Architecture and Environmental Development, University of Hannover, head of the FLL task force "green roofs" The "FLL" (Landscape Development and Landscape Construction Research Society) is responsible for the development and publication of Green Roofs Guidelines in Germany. One of the basic documents is the Guideline for Planning, Implementation and Maintenance of Green Roofs which was first released in 1990 and just updated in 2002. This Guideline is not only a "bestseller" within the German green roof trade. Inquiries from the Netherlands, Hungary, Denmark, Japan and the USA are proofing the great interest in the settlement of international standards. Prof. Lösken will present the key criteria of the FLL guideline and discuss the possibilities to transfer the German regulations and long-lasting experiences to conditions in foreign countries and climates.
	Plants for extensive und intensive green roofs  in Germany  Tassilo Schwarz, Bavarian Institute for Viticulture and Horticulture, Veitshöchheim  in England  Dr. Nigel Dunnett, University of Sheffield Tassilo Schwarz (D) Scientific assistant at the Bavarian Regional Institute for Viticulture and Horticulture in Veitshöchheim Tassilo Schwarz is highly acclaimed for expert knowledge of plant selection criteria on green roofs in Germany. Together with Dr. Walter Kolb he has published many scientific papers and books. Subject of his presentation is basic information about the extreme environmental conditions for plants on roofs (climate, water resources, drought resistance of different plant species etc.) and plant selection from natural habitats. Dr. Nigel Dunnett (UK) Senior lecturer in the Department of Landscape, University of Sheffield, author of the book "Planting Green Roofs and Living Walls" Dr. Dunnett has done a lot of research with regard to naturalistic and ecologically informed planting of gardens and urban spaces. At the International Green Roof Congress in Nürtingen he will take a stand about plant selection criteria on green roofs in the UK.
	The effect of green roofs on the urban climate Prof. Dr. Manfred Köhler (D) Landscape architect, BDLA, University of Applied Sciences, Neubrandenburg Prof. Dr. Manfred Köhler is a green roof "cosmopolitan". He is working with research groups in Spain, Brasil, Mexico, Singapore and the USA. The "urban heat island effect effect" is a well-known problem of urban agglomerations in the tropic climates and North America. In times of climate change and continually sealing of urban areas this question gets more and more important in Europe too (cp. session 1, Dr. Bettina Menne). Green roofs are offering a high potential for the improvement of the urban climate and the reduction of the "urban heat island effect", that has not been exhausted up to now
	Water balance and run-off conditions on green roofs Prof. Dr. Stephan Roth-Kleyer (D) Director of the Institute for Landscape Construction at the Geisenheim Research Facility; lecturer at the University of Applied Sciences in Wiesbaden The Green Roof Guidelines of the FLL are containing detailed regulations with regard to the water balances and run- off conditions of green roofs. These specifications form the platform for several municipal green roof support programmes in Germany (e.g. the support programme of the federal state of North-Rhine-Westphalia). Prof. Dr. Roth-Kleyer will present standard methods to determine the water retention capacity of green roofs and discuss problems and key factors which have to be considered.
	Testing green roof substrates Martin Jauch (D) Scientific assistant at the Research Institute for Horticulture in Weihenstephan; well-versed green roof investigator In order to ensure the durable functionality of landscaped roofs and to meet the partial opposite demands of the vegetation and the building technique green roof substrates have to be chosen carefully. That’s why the FLL has defined basic requirements to the substrate characteristics for extensive and intensive green roofs vegetation. However experience and scientific experiments have shown that substrates which fulfil the FLL instructions sometimes fail to support the desired roof vegetation. Possible reasons are discussed in this presentation.
	Green roof research in the USA Dr. David J. Beattie (USA) Director of the Center for Green Roof Research at the Pennsylvania State University Presently, green roof marketing efforts in North America exceed the research knowledge and technical base, especially about the interaction of plants and media. The result is often poorly installed roofs. Therefore, educating green roof professionals "roofers, landscape contractors, and architects" is of primary importance. In addition, developing standards for green roof installation in North America is also a priority. This presentation will discuss the state of the industry and focus on the development of educational programmes and standards for green roof installation in North America.
	Green roofs as a challenge for the green trades Prof. Dr. Klaus Neumann (D) Associate professor for landscape conservation at the University of Applied Sciences in Berlin, landscape architect, BDLA and Vice-president of the FLL How about the green roof market of the future? What are the challenges, opportunities and risks for the green trades? Will the ecological green roof idea become an integral module of sustainable and environmentally-responsible urban development in a globalised world? Prof. Dr. Klaus Neumann will discuss these and further questions in his visionary presentation at the 14 September (evening "Get Together") with the audience.