The flowers and the bees - Solutions and tools for integrated sustainable planning to safeguard biodiversity in urban landscapes

There is a global decline in pollinators and the main reason is that the pollinators habitats are under pressure and are being lost due to urbanization and other land use changes in the landscape. In BE(E) DIVERSE, we have studied how species diversity and the interaction between plants and pollinators are affected during urbanization as well as decision-making processes at local level and management measures. Trondheim municipality is the study area. Semi-natural grasslands are one of the most important habitats for a high diversity of plants and pollinators. The reason why this habitat provides good living conditions for so many species is due to its long continuity in extensive management and spatial variation in plant species occurrences . But as a result of this variation, more effort must be put into surveying the diversity within this habitat, and in order to maintain viable populations of important flowering plants, large areas of semi-natural habitats are needed. As semi-natural grasslands are a threatened habitat type, we have investigated whether there are other more widespread alternative habitats for the species that have semi-natural grassland as their main habitat (specialists). Roadsides are a suitable alternative habitat as they are rich in species and contain many of the semi-natural grassland specialists. The reason why roadsides are rich in species is that there is great variation between roadsides and that they contain plant species that are typical of many different habitat types such as forests and grasslands. Despite the fact that roadsides are rich in plant species, they are not necessarily as attractive to pollinators. This is because semi-natural grasslands have more flowers available throughout the season compared to roadsides. Both plant and pollinator species are more numerous in semi-natural grasslands than on roadsides and there are more interactions (large ecological network) between plants and pollinators in semi-natural grasslands compared to roadsides. The solitary bees in particular prefer semi-natural grasslands to roadsides. The roadside can thus never replace the important and species-rich semi-natural grasslands as a habitat for plants and pollinators. As roadsides are significantly more common in urban cultural landscapes than semi-natural grasslands, roadsides can nevertheless function as important alternative habitats and a link in a landscape that species can use to move between the few semi-natural grasslands that still exist. However, there are some semi-natural grassland specialists that only occur in semi-natural grasslands and not in any other habitats. These plants are particularly vulnerable when semi-natural grasslands are under pressure from land changes as they have no other alternative habitats available. In Trondheim, there are a few very species-rich semi-natural grasslands in the most urban parts of the municipality, but most are found in the surrounding agricultural landscape. Urbanization can only be positive for the abundance of pollinators if the urban semi-natural grasslands are surrounded by lots of green areas, both along the roads and in the landscape in general. Holistic land management where many species and habitats are seen in context is therefore important to safeguard biodiversity. Interviews with informants who work with the management of biodiversity in Trondheim show that competent and committed professionals in spatial planning and nature management are also crucial to ensure the long-term safeguarding of biodiversity through public administration. Cooperation between nature management and other actors in the municipality such as volunteers, residents and city management can also have a great effect when it comes to looking after pollinators and their habitats. In Norway, wild bees and especially bumblebees are considered the most important pollinators, but we have found that there are large variations in how many flowering plants the various pollinators visit. Bumblebees generally visit more flower species than solitary bees and are thus more efficient pollinators. Hoverflies have little hair on their bodies where the pollen can stick, but can still be an important pollinator as there are so many of them. A very important measure to safeguard pollinators and their flower resources is to ensure remaining habitats of high quality in both urban and rural areas. This means that both semi-natural grasslands and alternative habitats must be properly managed and included in comprehensive land use management in the municipality's spatial planning. However, to follow through on these recommendations, qualified professionals need the necessary funding and resources to do so.

Virkninger - Forskergruppa i BE(E) DIVERSE har gjennom sitt tverrvitenskapelig arbeid etablert kunnskap som er i front, både internasjonalt og nasjonalt, innen anvend vitenskap som støtter opp under forvaltningen av pollinatorer og deres leveområder som er under press. - BE(E) DIVERSE har bidratt med kapasitetsbygging for brukergrupper som jobber med forvaltning av biodiversitet. - BE(E) Diverse har utviklet ny kunnskap som kan benyttes av areal- og naturforvaltningen - Økt tverrvitenskapelig forsknings og internasjonalt samarbeid som bygger videre på nettverk etablert i prosjektet - Utdanning av en post-doc Effekter - Resultater fra BE(E) Diverse vil bidra inn i arbeidet med å stanse i tap av naturmangfold. - Resultater fra Be(E) Diverse vil bidra til å ivareta biomangfoldets av planter og pollinatorer under press fra urbanisering og andre arealendringer. - Resultater fra BE(E) diverse bidrar til kunnskapsbasert forvaltning av natur og biomangfold.

Semi-natural grasslands are biodiversity hotspot habitats for plants and pollinators but are under pressure due to urbanisation. The interaction between species are the foundation of ecosystem functions and services, such as pollination. In order to safeguard the biodiversity and ecological functions in these habitats, we need knowledge on how urbanisation processes influence the distribution and interaction of species and which habitats can act as stepping stones in the landscape. There is a call for development of tools that assist practitioners and policy makers to incorporate knowlege on the effect of urbanisation on biodiversity in planning processes. Main objective of this interdisciplinary project is therefore to provide knowledge that will be used in land use planning for maintaining and restoring biodiversity of plants and pollinators, and their interactions as an important ecosystem service in cultural landscapes during urbanisation. WP1: Establishing knowledge base on the role of biodiversity and pollinators in contemporary urban land use planning processes and land use practices. WP2: Map and model biodiversity to explore the relationship between urbanisation and biodiversity of plants and pollinators. WP3: Examine how pollinator-plant interactions and pollinator service are affected by urbanisation and develop an efficient way of establishing new species rich areas by facilitating establishment of plant species from local semi-natural grasslands. WP4: Develop easily understandable maps of ecological features, patterns and processes that can be used as tools in urban planning to safeguard biodiversity. Opportunities and challanges with implementing such tools in land use planning will be discussed and evaluated. We will cooperate closely with hands-on management authorities and stakeholders and the projects scientific output from natural and social sciences will provide an integrated foundation for land use planning.