Drivers of urban biodiversity in Mexico and joint risks from future urban expansion, climate change, and urban heat island effect

concomitant habitat loss, which drives negative consequences on biodiversity, such as popula- tion decline and local extinction [4–7]. However, some species are favored by urbanization insomuch by increasing their abundance (e.g., non-native species) [8], whereas others exhibit traits that allow a successful establishment in these new settings [9, 10]. The ecological, evolutionary, and socioeconomic processes driving urban biodiversity pat- terns are relatively well-known in cities from higher-income countries [6, 7, 11–15]. By con- trast, in lower-income countries, mainly located in biodiversity hotspots, there is a lack of understanding of how these processes shape biodiversity across rural-urban gradients [14, 15]. As urban areas in these countries are projected to increase notably in the following decades [16–18], it is necessary to develop a research agenda about the mechanisms underlying urban biodiversity [15, 19]. Eco-evolutionary research on urban biodiversity is critical to design spe- cific conservation actions. Such strategies should help reduce further biodiversity loss and improve the sustainable agendas of emerging Latin American cities. Mexico is one of the megadiverse countries with a high number of endemism and threat- ened species [20–22]. The topographical complexity, geological history, and climatic variation favor elevated alpha and beta taxonomic diversity for several taxa, including terrestrial verte- brates, across the country [23, 24]. Although several human stressors impact biodiversity in

Mexico at different spatial scales, habitat loss, and climate change are considered the main extinction drivers in the past and the projected future [25–28]. However, the impacts of urban- ization on biodiversity across Mexican cities are poorly understood, and how the interplay of ecological and socioeconomic processes plays a role in maintaining the current levels of urban species richness. Environmental, geographical, and socioeconomic factors directly influence urban species richness across cities in high-income countries [15, 29, 30]. The ongoing urban sprawl, regional climate change, pollution, and urban heat island (UHI) are the most critical threats to urban biodiversity in Latin American cities [14, 31–33]. However, there is a lack of studies evaluating how these threats act synergistically to impact urban biodiversity in Mexican municipalities. Recent studies have found that size of urban settlements strongly predicts urban develop- ment and intensive resource consumption in Mexico [34]. The urban area also plays a signifi- cant role in species richness, since larger metropolitan areas will have more extensive green spaces [14]. The area effects on urban species richness derive from theoretical expectations from species-area relationships (SAR) models [35] and the equilibrium theory of island bioge- ography [36]. For instance, there is a positive relationship between the size of urban areas and bird species richness at local and regional scales in some Mexican municipalities [37–39].

However, whether the same effects are maintained in other taxonomic groups (e.g., amphibi- ans, reptiles, and mammals) is unknown. In addition, the type of SAR models can inform us about the interplay of different ecological and evolutionary processes (e.g., stochastic, immi- gration-extinction dynamics, and adaptive evolution [35, 36, 40]. Inspecting SAR curves across an urban-rural dichotomy is one of the first steps to establish whether urban assemblages are unique or an extension of those observed in other less transformed landscapes [41, 42]. For instance, Uchida [42] proposed theoretical scaling relationships between biodiversity and city size, which should vary between urban and non-urban settings exhibiting different slopes and intercepts. SAR for the urban environment usually has more alpha diversity than rural areas, and species increase quickly with city size (i.e., high intercepts and slopes). However, few stud- ies are known across multiple municipalities in the same country or region [41, 43]; therefore, the expected pattern in cities, particularly which is the best SAR model describing the observed data, is poorly understood. In addition, recent work has shown that no single best model fits different datasets. Therefore, an approach that tests several models is likely the best strategy for analyzing this information [44–46]. PLOS ONE Urban biodiversity and anthropogenic pressures PLOS ONE | https://doi.org/10.1371/journal.pone.0308522 October 4, 2024 2 / 19 https://figshare.com/articles/dataset/Mexican_ urban_biodiversity/14881755.

Funding: We have removed the Programa de Investigacio´n en Cambio Clima´tico at UNAM (PINCC-UNAM) acknowledgment from the manuscript. Funding Statement should be updated as: 1. Universidad Nacional Auto´noma de Me´xico 2. The Programa de Investigacio´n en Cambio Clima´tico at UNAM (PINCC-UNAM), grant number “n/a” The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist.