One hundred years of climate change in Mexico

set of climate surfaces in which we used the same number of weather stations for both periods. We found that differences between t2-1970 and t3-2000 were not due to the number of stations, thus we included all available stations for the second and third periods, mainly because a larger number of stations improve model signal [17,54]. Biogeographic provinces of Mexico Mexico is recognized as a megadiverse country [55]. Its extraordinary biodiversity is due to its high environmental heterogeneity and the confluence of the Nearctic and Neotropical biogeo- graphic regions connected by a transition zone (Fig 2) [56]. The Nearctic region encompasses the arid subtropical areas of the north and includes the provinces of: California, Baja Califor- nia, Del Cabo, Sonorense, Altiplano Norte, Altiplano Sur, and Tamaulipeca. The Neotropical region covers the humid and sub-humid tropical areas of the south, including the provinces: Costa del Pacı´fico, Golfo de Me´xico, Depresio´n del Balsas, Oaxaca, Altos de Chiapas, Soco- nusco, Yucata´n, and Pete´n. The Transition Zone includes the mountainous provinces in the central portion of the country: Sierra Madre Oriental, Sierra Madre Occidental, Eje Volca´nico, and Sierra Madre del Sur [56,57]. Fig 2. Biogeographic regions and provinces of Mexico: Nearctic and Neotropical regions, and the transition zone. Reprinted from [57] under a CC BY license, with permission from [CONABIO], original copyright [1997]. https://doi.org/10.1371/journal.pone.0209808.g002 PLOS ONE Historical climate change in Mexico

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