The importance of green roofs in urban macroinvertebrate biodiversity: a case study in Antwerp, Belgium.

Abstract

Abstract Urbanization has been identified as a significant anthropogenic factor in the decline of macroinvertebrate populations in terms of abundance, biomass, and species richness over the past few decades. Green roofs are commonly promoted as means of mitigating the negative impacts of urbanization. In this study we investigated twenty green roofs in the city of Antwerp, Belgium. We evaluated macroinvertebrate diversity, abundance and species richness on these roofs. We analysed the influence of roof characteristics (age, surface area, height) and plant diversity (Sedum monocultures vs a mix of Sedum, grass and herbs) on diversity, species richness and/or abundance of macroinvertebrates. We sampled 293 species in total, 151 species were found to be exclusive to a single roof, indicating their specific location-based occurrence. Our study found no correlation between physical roof characteristics, such as roof vegetation cover, and variation in diversity, richness and/or abundance of macroinvertebrates. Our results indicate that most of the species that are present on these urban environments are generalist species that have good dispersal abilities and are well adapted to the dry conditions of these green roofs. Additionally, our research discovered several species that had not previously been recorded in Belgium, which highlights that green roofs can provide suitable habitats for rare and specialized species originating from other nearby countries and different habitat types. Our study demonstrates that green roofs can provide a suitable habitat for a diverse range of species across multiple taxa, regardless of the characteristics of the roof.