Sammanfattning

The negative impact of urbanization on biodiversity can be buffered by blue (e.g., rivers, ponds) and green (e.g., parks, forests) spaces. However, to prevent biodiversity loss and reduce the risk of local extinctions, blue and green spaces need to be connected by corridors, so that organisms may disperse between sites. Landscape connectivity affects local community composition and metacommunity dynamics by facilitating dispersal. The goal of this study was to test the relative roles of pond environmental properties, spatial structure, and functional landscape connectivity on differentiation of invertebrate metacommunities in urban ponds in the city of Stockholm, Sweden. We characterized functional connectivity as blue connectivity (distance to water bodies), green connectivity (land use), and combined blue-green connectivity. We estimated functional connectivity by using electrical circuit theory to identify dispersal corridors. Interestingly, while circuit theory is often used in single-taxon studies, this method has rarely been applied to multiple taxa forming a metacommunity, as we have done in this study. Indeed, our study contributes toward an increased focus on the role of dispersal at the metacommunity level. We deter-mined that functional connectivity was the most important factor in explaining community differentiation, with the local environment contributing comparatively little, and spatial structure the least. Combined blue-green functional connectivity had a major influence on structuring urban pond communities, explaining 7.8% of the variance in community composition across ponds. Furthermore, we found that increased functional connectivity was associated with an increase in the number of species. In summary, our results suggest that to preserve biodiversity in urban ponds, it is important to enhance functional connectivity, and that open green spaces could augment blue corridors in maintaining functional connectivity in urban pond metacommunities. To generalize these findings, future urban biodiversity studies should compare how functional connectivity affects meta-communities across multiple major cities. (C) 2021 The Author(s). Published by Elsevier GmbH on behalf of Gesellschaft fur Okologie.

Nyckelord

Aquatic fauna; Circuit theory; Dispersal corridors; Invertebrates; Landscape resistance; Metacommunity dynamics

Publicerad i

Basic and Applied Ecology
2021, Volym: 57, sidor: 129-145
Utgivare: ELSEVIER GMBH

SLU författare

• Bjelke, Ulf

  • SLU Artdatabanken, Sveriges lantbruksuniversitet
    

Globala målen

SDG15 Skydda, återställa och främja ett hållbart nyttjande av landbaserade ekosystem, hållbart bruka skogar, bekämpa ökenspridning, hejda och vrida tillbaka markförstöringen samt hejda förlusten av biologisk mångfald
SDG11 Göra städer och bosättningar inkluderande, säkra, motståndskraftiga och hållbara


UKÄ forskningsämne

Ekologi


Publikationens identifierare

DOI: https://doi.org/10.1016/j.baae.2021.10.004

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/114926