Negative effects of urbanization on terrestrial arthropod communities: A meta‐analysis

Abstract

Aim Urbanization is one of the most significant anthropogenic alterations of the surface of the Earth and constitutes a major threat to biodiversity at the global level. Arthropods are a very diverse group of organisms, with many species that provide essential ecosystem services. However, their response to urbanization is still unclear. Here, we describe the first meta‐analysis to evaluate the overall effects of urbanization on terrestrial arthropod communities and driving factors related to cities, arthropods and methods. Location Global. Time period 1979–2019. Major taxa studied Arthropods. Methods We compiled a dataset of 162 publications that have evaluated the effects of urbanization along rural–urban gradients, which yielded 196 observations for diversity and 148 for abundance of arthropods. Moderator variables related to cities (climatic region, size, age, air pollution level and vegetation cover), arthropods (taxonomic and functional group and mobility level) and methods (study duration and type of gradient) were considered. We analysed the data through a hierarchical meta‐analysis that allowed us to take into account the dependence of multiple effect sizes obtained from one study. Results Overall, urbanization had a negative effect on the diversity and abundance of terrestrial arthropods. The magnitude of the changes in diversity and abundance along the urban gradient depended on the arthropod taxonomic group. Coleoptera and Lepidoptera were the most affected groups, suggesting that not all species respond in the same way to urbanization. In addition, the age of the cities had a slightly negative influence, but only on abundance. Main conclusions Our results indicate that terrestrial arthropod communities are less diverse and abundant in more urbanized landscapes. Considering the current biodiversity crisis and the fact that urbanization is one of the most extreme forms of global environmental change, the evidence presented here could be useful to support and direct new conservation efforts in urban habitats.

Contrasting impacts of urban and farmland cover on flying insect biomass

“…The estimated effect of urban areas was still negative after accounting for potential stops during sampling ( Figure 4). Our results are consistent with a recent meta-analysis combining data from multiple studies to show an overall negative effect of urbanisation for arthropod diversity and abundance (Fenoglio, Rossetti & Videla, 2020) and the decline of insect diversity with urbanisation at multiple spatial scales (Piano et al, 2020). In large part, this may be due to the reduced biomass and productivity per unit area in urban habitats where much of the landscape is impervious surface, such as cement or rooftops, on which vegetation does not grow.…”

“…Across several insect taxa, Piano et al (2020) found that urbanisation was associated with a decline in insect diversity at multiple spatial scales in Belgium. Similarly, a recent meta-analysis combining studies from across the world found a mean negative effect of urbanisation on terrestrial arthropod diversity and abundance, although the effect may differ among insect orders (Fenoglio, Rossetti & Videla, 2020). Long-term monitoring in Britain found lepidopteran biomass to be lower in urban sites compared to woodland and grassland (Macgregor et al, 2019).…”

Insect decline in the Anthropocene: Death by a thousand cuts

“…Similarly, there is mounting evidence that light pollution is driving local declines in suburban and urban locations (45,46). Although not an emphasis of the 11 articles, urbanization is increasingly recognized as an important stressor (47,48).…”

Landscape configuration and habitat complexity shape arthropod assemblage in urban parks

“…Furthermore, urban expansion exaggerates urban heat island effects, causing temperatures in urban areas to be up to 10 °C–12 °C higher than those in the surrounding rural areas 1 , 2 . Therefore, urban habitats, with their impervious asphalt roads and buildings, are often considered disturbed habitats, hostile to arthropod survival 3 .…”