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

Here, we compiled an extensive dataset of urban species richness for terrestrial vertebrates and socio-economic and ecological information for 389 municipalities across Mexico to test potential drivers of urban biodiversity. First, we evaluate whether there are differences in spe- cies richness across urban and rural settlements using different SAR models. Then, we imple- mented a machine learning model to assess the relative importance of various socio-economic and ecological drivers explaining urban biodiversity (Table 1). Finally, we explored the future exposure of Mexican municipalities to projected urban expansion, the urban heat island, and climate change. To our knowledge, this is the first study testing how socioeconomic and eco- logical factors explain urban species richness of terrestrial vertebrates across an extensive data- set for Mexican cities. Methods Datasets We obtained occurrence records for four terrestrial vertebrate groups (amphibians, reptiles, mammals, and birds) for Mexican municipalities from the SNIB (Sistema Nacional de Infor- macio´n sobre Biodiversidad) repository [47], which contains information for 2,731 species with 6,763,073 records (Fig A in S1 Appendix) (available in https://www.snib.mx). A great effort was made to sample these taxa across the country, and intensive curatorial and taxo- nomic work has been carried out for several decades [48–50]. However, this database has many taxonomic and georeferencing errors. Consequently, we eliminated duplicated, errone-

ous, and doubtful records to maintain those with approximately a spatial precision of approx. 1 km [51]. Furthermore, we harmonized the taxonomic nomenclature from this database with updated international taxonomic treatments for amphibians and mammals from the [52], rep- tiles from [53] and birds from [54]. Although the sampling effort is unbalanced across the four taxa, birds emerged as more densely sampled/observed (Fig B in S1 Appendix). We used the urban localities shapefile from the Instituto Nacional de Estadı´stica y Geografı´a (INEGI), which are denominated as a´rea geoestadı´stica ba´sica (AGEB) from the national demographic census in 2020 (available in https://www.inegi.org.mx/default.html). Urban localities are defined based on human population counts larger than 2,500 inhabitants and the municipal capital, regardless of the inhabitants’ number (Fig C in S1 Appendix). We calculated the urban areas for each municipality in Mexico as the sum of the area of their AGEB urban polygons. Only 2287 out of 2463 municipalities contain urban polygons. Municipality is the second-level administrative division in Mexico and differs from cities or towns because they are distinct entities and do not share geographical boundaries. Rural areas were defined as those that have not been urbanized. Under this definition, we included multiple human-modi- fied land uses in the rural category. We performed a spatial join between species’ occurrences and urban and rural polygons using the point.in.poly function from the spatialEco R package v

2.0.1, and we calculated the number of species for each higher taxon for urban and rural areas (Table A in S1 Data). We used the municipality as a unit of analysis due to the availability of socioeconomic data at this level, which was compiled from Haro et al. 2021 [55]. Haro et al. (2021) compiled data from several databases from Mexican institutions including Sistema Nacional de Informacio´n Municipal (http://www.snim.rami.gob.mx), Consejo Nacional de Poblacio´n (https://www.gob.mx/conapo), Secretarı´a de Agricultura y Desarrollo Rural (https://www.suri.agricultura.gob.mx:8017/buscadorBeneficiario; https://www.gob.mx/siap), and CONABIO (http://www.conabio.gob.mx/informacion/gis/) (further details in [55]). Addi- tional environmental data were collected for each municipality’s urban areas from additional multiple sources available publicly [27, 56–59] (see Table 1). PLOS ONE Urban biodiversity and anthropogenic pressures PLOS ONE | https://doi.org/10.1371/journal.pone.0308522 October 4, 2024 3 / 19