One hundred years of climate change in Mexico

surfaces to evaluate to what extent Mexico and its biogeographic regions and provinces have been exposed to climate change during the 20th and early 21st centuries. Significance for ecological studies Mexico has been projected to maintain medium to high climate stability [36], but, as expected, historically the magnitudes of change have not been geographically uniform across Mexico. Understanding the history of climate change at the regional level can provide useful informa- tion for analyzing how climate change impacts biodiversity [62]. Our results show that, on average, minimum and maximum temperatures decreased and precipitation increased coun- trywide from t1-1940 to t2-1970, whereas from t2-1970 to t3-2000, average minimum and maxi- mum temperatures rose and precipitation decreased. Similar results were obtained for temperature by Pavia et al. [19] and Englehart and Douglas [18] from analysis of weather sta- tions’ data. Furthermore, these authors found that warming has not been consistent Fig 4. Seasonal precipitation changes in % (♦) and millimeters (bars) from t1-1940 to t2-1970 (Δt1-t2) and from t2-1970 to t3-2000 (Δt2-t3) in the biogeographic provinces of Mexico. Negative values indicate a decrease in precipitation from the previous period and positive values indicate an increase. DB: Depresio´n del Balsas, SMOr: Sierra Madre Oriental, DC: Del Cabo, C: California, Sse: Sonorense, SMOcc: Sierra Madre Occidental; AN: Altiplano Norte, T: Tamaulipeca, BC: Baja California,

CP: Costa del Pacı´fico, AS: Altiplano Sur, EN: Eje Neovolca´nico, GM: Golfo de Me´xico, O: Oaxaca, Y: Yucata´n, P: Pete´n, AC: Altos de Chiapas, Ssc: Soconusco, and SMS: Sierra Madre del Sur. Stations used were not corrected for inhomogeneities and densities vary between periods, especially between t1-1940 to t2-1970. Biogeographic provinces reprinted from [57] under a CC BY license, with permission from [CONABIO], original copyright [1997]. https://doi.org/10.1371/journal.pone.0209808.g004 PLOS ONE Historical climate change in Mexico PLOS ONE | https://doi.org/10.1371/journal.pone.0209808 July 16, 2020 11 / 19