Local habitat characteristics have a stronger effect than the surrounding urban landscape on beetle communities on green roofs

Abstract

Green roofs are a promising tool to return nature to cities and mitigate biodiversity loss brought about by urbanization. Yet, we lack basic information on how green roofs contribute to biodiversity and how their placement in the urban landscape affects different taxa and community composition. We studied the effects of local and landscape variables on beetle communities on green roofs. We expected that both local roof characteristics and urban landscape composition shape communities, but that their relative importance depends on species characteristics. Using pitfall traps, we collected beetles during two consecutive years from 17 green roofs in Basel, Switzerland. We evaluated the contribution of six local and six landscape variables to beetle community structure and to the responses of individual species. Communities on the roofs consisted of mobile and open dry-habitat species, with both local and landscape variables playing a role in structuring these communities. At the individual species level, local roof variables were more important than characteristics of the surrounding urban landscape. The most influential factors affecting the abundances of beetle species were vegetation, described as forb and grass cover (mainly positive), and roof age (mainly negative). Therefore, we suggest that the careful planning of green roofs with diverse vegetation is essential to increase their value as habitat for beetles. In addition, while beetle communities on green roofs can be diverse regardless of their placement in the urban landscape, the lack of wingless species indicates the need to increase the connectivity of green roofs to ground level habitats.

Keywords

Coleoptera; Green infrastructure; Landscape configuration; Patch characteristics; Pitfall traps; Vegetated roofs

Published in

Urban Forestry and Urban Greening
2018, Volume: 29, pages: 122-130
Publisher: ELSEVIER GMBH, URBAN & FISCHER VERLAG

SLU Authors

• Lehvävirta, Susanna

  • Department of Landscape Architecture, Planning and Management, Swedish University of Agricultural Sciences
    
  • University of Helsinki

Sustainable Development Goals

SDG11 Sustainable cities and communities
SDG15 Life on land


UKÄ Subject classification

Landscape Architecture
Ecology


Publication identifier

DOI: https://doi.org/10.1016/j.ufug.2017.11.009

Permanent link to this page (URI)

https://res.slu.se/id/publ/94660