Biodiversity in cities needs space: a meta‐analysis of factors determining intra‐urban biodiversity variation

Abstract

Understanding varying levels of biodiversity within cities is pivotal to protect it in the face of global urbanisation. In the early stages of urban ecology studies on intra-urban biodiversity focused on the urban-rural gradient, representing a broad generalisation of features of the urban landscape. Increasingly, studies classify the urban landscape in more detail, quantifying separately the effects of individual urban features on biodiversity levels. However, while separate factors influencing biodiversity variation among cities worldwide have recently been analysed, a global analysis on the factors influencing biodiversity levels within cities is still lacking. We here present the first meta-analysis on intra-urban biodiversity variation across a large variety of taxonomic groups of 75 cities worldwide. Our results show that patch area and corridors have the strongest positive effects on biodiversity, complemented by vegetation structure. Local, biotic and management habitat variables were significantly more important than landscape, abiotic or design variables. Large sites greater than 50 ha are necessary to prevent a rapid loss of area-sensitive species. This indicates that, despite positive impacts of biodiversity-friendly management, increasing the area of habitat patches and creating a network of corridors is the most important strategy to maintain high levels of urban biodiversity.

Urban stress is associated with variation in microbial species composition—but not richness—in Manhattan

“…Saito and Koike, 2013;Concepción et al, 2015), we re-acknowledge that many macroorganisms decline in diversity in cities relative to rural areas and that some species are absent in cities, resulting in changes in composition. Recent work (Beninde et al, 2015) has surveyed the causes of intra-urban biodiversity variation for a range of macroorganisms and found that, to a great extent, shifts in composition and declines in diversity in cities are due to the effects of habitat area and connectivity, with the most affected green spaces in cities being both small and disconnected.…”

“…Species-area relationships, with fewer species in smaller sites, have been observed for microbes (Green et al, 2004;Horner-Devine et al, 2004;Bell et al, 2005) in habitats such as tree holes owing to the greater potential for colonization and quantity and diversity of available resources and habitats. At least for macroorganisms, urban, habitat area has a positive influence on biodiversity (Basham et al, 2010;Shanahan et al, 2011;Beninde et al, 2015). If urban habitat patches act analogously to tree holes, we expect to find fewer microbial species in smaller habitats in cities.…”

How small cities affect the biodiversity of ground-dwelling mammals and the relevance of this knowledge in planning urban land expansion in terms of urban wildlife

“…Apart from urbanization gradient analysis, there are other ecological frameworks that are also useful in understanding the ecology of urbanized landscapes, e.g. patch dynamics or meta-analysis (McDonnell and Hahs 2008;Beninde et al 2015).…”

Determining the Sensitive Conservative Site in Kolah Ghazi National Park, Iran, in Order to Management Wildlife by Using Gis Software

“…Inverse distance weighing (IDW) method was used to zone the dispersion of the birds and mammals. In order to set conservational priorities, topographic, plant life and birds and mammals' dispersion maps were overlaid and the region was divided into three conservation levels (high, medium and low) by using Spatial analyst tool in ARCGIS software [8][9][10][11].…”