Long‐term urbanization impacts the eastern golden frog (Pelophylax plancyi) in Shanghai City: Demographic history, genetic structure, and implications for amphibian conservation in intensively urbanizing environments

Abstract

Understanding the mechanisms of how urbanization influences the evolution of native species is vital for urban wildlife ecology and conservation in the Anthropocene. With thousands of years of agriculture‐dominated historical urbanization followed by 40 years of intensive and rapid urbanization, Shanghai provides an ideal environment to study how the two‐stage urbanization process influences the evolution of indigenous wildlife, especially of anuran species. Therefore, in this study, we used mitochondrial Cyt‐b gene, microsatellite (SSR), and single nucleotide polymorphism (SNP) data to evaluate the demographic history and genetic structure of the eastern golden frog (Pelophylax plancyi), by sampling 407 individuals from 15 local populations across Shanghai, China. All local populations experienced bottlenecks during historical urbanization, while the local populations in urban areas maintained comparable contemporary effective population sizes (Ne) and genetic diversity with suburban and rural populations. Nevertheless, the rapid modern urbanization has already imposed significant negative effects to the integrity of populations. The 15 local populations were differentiated into eight genetic clusters, showing a spatial distribution pattern consistent with the current urbanization gradient and island–mainland geography. Although moderate gene flow still occurred from the rural peripheral cluster to urban and suburban clusters, population fragmentation was more serious in the urban and suburban populations, where higher urbanization levels within 2‐km radius areas showed significant negative relationships to the Ne and genetic diversity of local populations. Therefore, to protect urban wildlife with limited dispersal ability, improving conditions in fragmented habitat remnants might be most essential for local populations living in more urbanized areas. Meanwhile, we highlight the need to preserve large unfragmented rural habitats and to construct corridor networks to connect discrete urban habitat remnants for the long‐term wildlife conservation in intensively urbanizing environments.

Genomic footprints of (pre) colonialism: Population declines in urban and forest túngara frogs coincident with historical human activity

“…Wei et al. (2021) examined the impact of long‐term urbanisation on the Eastern golden frog ( Pelophylax plancyi ) in Shanghai, China, and found that contemporary effective population sizes ( N e ) and genetic diversity remained comparable between urban, suburban and rural areas. Moreover, they detected that all populations experienced historical bottlenecks during low‐level urbanisation dominated by agriculture, 700 years ago.…”

Advertisement Call Variation of Two Frog Species along an Urban–Rural Gradient in Shanghai, China

“…To define the urbanization level of each study site, we obtained landscape data within a 2 km radius of each study site from satellite images of Formosat-2 (June 2012; 2 m resolution) and Google Earth Pro 7.3.2 (Google), and combined aerial photographs with ground surveys to distinguish the land-use types if they were hard to define [39,42]. The land-use types determined included buildings (including commercial buildings, residential buildings, parking lots, and other anthropogenic building sites) and roads (including highways, arterial roads, elevated ring-roads, and other hardened roads) (Figure 1); the percentage of each land-use type in each study site was calculated using ArcMap 10.3 (Environment Systems Research Institute) and Fragstats 4.2 [49] (Table S1).…”

“…Our previous studies indicated that habitat loss and fragmentation caused by urbanization had significant effects on the population dynamics [38][39][40], body size [41], and genetic diversity [42] of frogs in Shanghai, which is the most-urbanized city in China; however, it is less clear whether frogs have altered advertisement calls in response to anthropogenic noise and habitat change caused by urbanization. In this study, we recorded the advertisement calls of two frog species (Fejervarya multistriata and Microhyla fissipes) in 34 study sites along an urban-rural gradient from May to July of 2020 and 2021 in Shanghai, analyzing five characters of advertisement calls: temporal parameters, including CD, CI, CR, and PR; and a spectral parameter, DF.…”

Urbanization increases stochasticity and reduces the ecological stability of microbial communities in amphibian hosts

“…However, as amphibians are small-bodied animals, they can survive in small patches of forested and humid areas of ‘green spaces’, provided that these areas are not heavily polluted or disturbed ( Hamer and McDonnell, 2008 ). The impact of urbanization on the biodiversity ( Callaghan et al, 2021 ; Yang, L. et al, 2022 ) and genetic structure ( Wei et al, 2021 ) of amphibian populations has been extensively studied, but microbial data records associated with amphibian hosts in urban settings are lacking.…”

“…Symbiotic microorganisms are critical for amphibian survival ( Becker et al, 2015 ) and adaptation to rapid environmental changes ( Xu et al, 2020b ; Barnes et al, 2021 ). Consequently, it is crucial to elucidate the response of the amphibian symbiotic microbial community to rapid urbanization, which is valuable for wildlife conservation in urban settings ( Wei et al, 2021 ). However, urban ecosystems present distinctive microhabitat and microclimate conditions in comparison to wild regions ( Zhang et al, 2022 ).…”