Abstract

Maintaining biodiversity in urban landscapes requires a well-functioning green infrastructure for the landscape to remain ecologically functional. However, city planners often lack knowledge to identify how well different parts of the green infrastructure are connected, and tools to estimate the accessibility to important habitats for different species in urban areas are strongly needed. We compared the ability of three measures of available food resources, with increasing complexity, for explaining species richness and abundance of bees and wasps at 23 locations in an urban landscape in Sweden. Specifically, we tested (1) the summed amount of food habitat within a buffer circle, (2) the amount of food habitat weighted by distance, and (3) the summed amount of food habitat within an area created by cost-weighted distance based on the surrounding landscape friction. We tested two spatial scales (200 and 400 m). The results show that both the summed (1) and the weighted measures (2) were very poor in explaining species richness and abundance regardless of spatial scale, while we found significant relationships for both species richness and abundance with the friction-based measure (3) at both scales. For the friction-based measure, the relationships with both response variables were strongest at the smallest spatial scale (200 m). We conclude that bees and wasps are sensitive to barriers such as large roads and built-up areas when foraging in urban environments. This is important to consider when assessing the functionality of urban green infrastructure in order to not overestimate the available amount of habitat and how well different parts of the landscape are connected for these important pollinators.

Keywords

Aculeata; green infrastructure; habitat fragmentation; landscape friction/resistance; road ecology; wild bees

Published in

Ecosphere
2018, Volume: 9, number: 10, article number: e02486
Publisher: WILEY

SLU Authors

• Johansson, Victor

  • Department of Ecology, Swedish University of Agricultural Sciences
    
  • Calluna AB

• Hedblom, Marcus

  • Department of Forest Resource Management, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology
Landscape Architecture


Publication identifier

DOI: https://doi.org/10.1002/ecs2.2486

Permanent link to this page (URI)

https://res.slu.se/id/publ/97290