The contribution of constructed green infrastructure to urban biodiversity: A synthesis and meta‐analysis

Abstract

The development of buildings and other infrastructure in cities is viewed as a threat to local biodiversity and ecosystem functioning because natural habitat is replaced. However, there is momentum for implementing green infrastructure (GI), such as green roofs, wetland detention basins and community gardens, that partially offset these impacts and that benefit human health. GI is often designed to explicitly support ecosystem services, including implied benefits to biodiversity. The effects of GI on biodiversity have been rarely quantified, but research on this topic has increased exponentially in the last decade and a synthesis of the literature is needed. Here, we examined 1,883 published manuscripts and conducted a meta‐analysis on 33 studies that were relevant. We determined whether GI provides additional benefits to biodiversity over conventional infrastructure or natural counterparts. We also highlighted research gaps and identified opportunities to improve future applications. We determined that GI significantly improves biodiversity over conventional infrastructure equivalents, and that in some cases GI had comparable measures of biodiversity to natural counterparts. Many studies were omitted from these analyses because we found GI research has generally neglected conventional experimental design frameworks, including controls, replication or adequate sampling effort. Synthesis and applications. Our synthesis identified that taxa specificity is an important consideration for green infrastructure (GI) design relative to the more common measurements at the community level. We also identified that ignoring multi‐trophic interactions and landscape‐level patterns can limit our understanding of GI effects on biodiversity. We recommend further examination of species‐specific differences among infrastructures (i.e. green, conventional or natural equivalents) or using functional traits to improve the efficacy of GI implementation on urban biodiversity. Furthermore, we encourage policy makers and practitioners to improve the design of GI to benefit urban ecosystems because of the potential benefits for both humans and global biodiversity.

Roadside diversity in relation to age and surrounding source habitat: evidence for long time lags in valuable green infrastructure

“…This loss, together with the high value of grassland habitat in terms of biodiversity and ecosystem services (Bengtsson et al., 2019; Billeter et al., 2008; Wilson, Peet, Dengler, & Pärtel, 2012), means that it is important to understand the role of alternative, marginal habitats in the landscape that are also able to support grassland communities. Such habitat elements – forming part of a landscape's green infrastructure – can make significant contributions to biodiversity, providing both valuable habitat area and landscape connectivity, which are vital for facilitating species‐ and community‐level responses to ongoing environmental change (Auffret et al., 2017c; Filazzola, Shrestha, & MacIvor, 2019; Hodgson, Moilanen, Wintle, & Thomas, 2011). As such, green infrastructure is a key component of the European Union's long‐term environmental strategy (European Commission, 2013).…”

Shading enhances plant species richness and diversity on an extensive green roof

“…Green roofs are increasingly popular in urban areas since they provide a range of benefits including retention of rainwater, cooling of buildings and promoting biodiversity (Oberndorfer et al 2007;Berardi et al 2014;Filazzola et al 2019). Biodiversity is promoted on green roofs by the higher presence and abundance of native plant species and arthropods compared to conventional roofs (Madre et al 2013(Madre et al , 2014Schrader and Böning 2006).…”

Articulating the new urban water paradigm

“…This type of management approaches also aligns with so-called naturebased ("green") solutions for water (WWAP, 2018), which utilize ecosystems that can potentially deliver any water-related service that humans might require (MEA, 2005;Schuch et al, 2017)-for example, flood risk management and natural drainage (Pappalardo et al, 2017), water purification (Everard & McInnes, 2013), urban cooling (Norton et al, 2015;Schmidt, 2010), support of biodiversity (Filazzola et al, 2019), or even enhancement of physical and psychological health (Tzoulas et al, 2007)often with lower costs and higher efficiencies than those of the "grey" solutions. Context-sensitive management requires then a local management style that benefits from intimate knowledge of local characteristics (like ecology, geomorphology, infrastructures, urban form, demographics, rules, standards and cultural characteristics) seen from an integrated perspective Marlow et al, 2013;Mitchell, 2006;Rygaard et al, 2014).…”