Local Management and Landscape Effects on Diversity of Bees, Wasps and Birds in Urban Green Areas

Today almost all ecosystems on Earth are directly or indirectly influenced by human activity. Most species occur in ecosystems that are managed by humans and only a small fraction of biodiversity exists in protected areas. Therefore, human dominated areas must also be considered for conservation of biodiversity. I have studied the effect of urbanization and green area management on bumble bees, compared the effects of urbanization and agriculture on trap-nesting insects, and also included how management practices and landscape changes through urbanization affect birds. Further, the social drivers behind management practices of three different types of urban green areas (cemeteries, city parks and allotment gardens) were studied through interviews with managers. I also interviewed local managers of allotment gardens to get their perspective on the management. I found that diversity of bumble bees, trap-nesting insects, and birds decreased with urbanization, whereas bumble bee abundance and species composition, and bird species composition, were most affected by local management and habitat quality. Allotment gardens had much higher abundances of bumble bees than city parks and cemeteries. Management practices differed among the three types of green areas and were most affected by social organization, local ecological knowledge and sense of place of the managers. Both local ecological knowledge and sense of place were more pronounced among allotment gardeners. Among the allotment gardeners the most important social drivers were that the management was meaningful and very important for their well-being. To favour bumble bees, trap-nesting insects, and birds within cities it is important to improve the qualities of urban green areas as habitat for these species. Further, it is important to maintain a variety of green areas within the city, and to enhance the connectivity among green areas within the city and with habitats in the hinterlands. Planners should recognize urban green areas that are normally overlooked in green plans of the city, such as allotment gardens. These areas have a large potential for biodiversity conservation within cities.