Intensively used landscapes today are often very biodiversity-poor spaces. Even the smallest semi-natural sites, such as meadow paths, are increasingly disappearing and with them a variety of plant and animal species. Based on the assumption that biodiversity brings multifunctional properties to landscapes, species loss also means a loss of ecosystem functions and services, such as pollination, water, nutrient, and carbon storage. Incentives to take action to protect ecosystem functions are difficult to provide, especially in intensively used landscapes. Within the framework of the "greening" component of the CAP (Common Agricultural Policy) and the agri-environmental programs of the federal states, flower strips are currently being increasingly introduced in Europe and are also widely accepted in intensively used areas. Individual flower strips can have a positive effect on pollinators, but there are also many examples without a significant positive effect. How many flower strips would be needed to maintain pollinator diversity at the landscape level? And what properties do flowering strips bring to other ecosystem functions and resulting services at the landscape level? In a project "Ecological enhancement in arable fields in the Upper Rhine Plain" of the IFAB Mannheim (Institute for Agroecology and Biodiversity), the effect of a complex of flowering strips on an area of 10% in 50 ha landscape sections on pollinator diversity in intensively used agricultural landscapes was investigated over 6 years. In another phase of the same project, the proportion of flowering strips will now be reduced to 5% of the area and the effects on pollinator diversity will be determined. With this project, we extend the field surveys, analyses and elaborations as follows. We are examining a) the effects of such flowering strips of different ages and seeding histories from the past 8 years for their carbon, nutrient, and water storage capacity; b) the effect of turning over such flowering strips on these same ecosystem functions; c) using trait analyses, the role of distances between flowering strips and remnants of semi-natural habitats (at 10%, 5%, or control landscape) and their quality for pollinator diversity and composition of more or less specialized species of bees and butterflies; d) the relevance of such flowering strips (10%, 5%, or control plots; we d) estimate for water, carbon, and nutrient storage and pollination performance at the landscape level. This will be followed by the compilation by the partner IFAB of simple recommendations for farmers and policy makers on how to choose the arrangement and area of flower strips to promote the greatest possible pollinator diversity and other ecosystem services in the landscape.

Since flower strips are currently quite well accepted by farmers even in intensively managed areas, the inclusion of flower strip networks in the upcoming reform of the CAP, if properly promoted, could lead to broad acceptance by farmers and rapid implementation in normal landscapes. This could slow down the rapid loss of biodiversity and functionality in intensively used agricultural landscapes in the fairly short term, in order to gain time to further develop agricultural production and the use of landscapes in a sustainable way.