Exploring the Biodiversity and Ecological Relationships of Arthropods on Green Walls

Abstract

In urban environments, green spaces are replaced by human infrastructure. This has a negative impact on biodiversity and ecosystem services. Green walls (GWs) are suggested to aid in the biodiversity crisis by providing a habitat for arthropod species. However, the actual effects of green walls on arthropods have not been sufficiently quantified. This study investigates the arthropod metrics; abundance, richness, diversity and composition on 9 living walls (LWs) and 5 green facades (GFs) in the Randstad region of the Netherlands. We compare the wall types to each other, and investigate which local- and landscape-level variables influence these metrics. Lastly, we explore ecological relationships between arthropod species. Our findings reveal that both wall types provide unique habitats for various arthropod species. Both local- and landscape-level characteristics are important in shaping arthropod communities. Notably, the number of flowering plants positively influences arthropod diversity and abundance of flower visiting insects. Surrounding blue- and green infrastructure are positively correlated with abundance, richness and diversity. Local- and landscapelevel factors had a variable impact on different arthropod orders and families. This highlights the importance of considering lower-taxonomic relationships when developing biodiversity-conservation strategies based on GWs. Additionally, multiple intricate ecological relationships between arthropods on green walls have been found. Lastly, this study also offers recommendations for green wall design and urban planning strategies. These insights aim to effectively address the arthropod diversity crisis.