Table 1.
Scores of human transformation.
Fig 1.
The areas in black show with the highest human footprint values in a well-defined spatial pattern. They run along the coastal plains of the Gulf of Mexico and from there inland along an east-to-west corridor that follows the Mexican transversal volcanic ranges and the associated upland plateau. The areas in black represent the lowest values of human footprint located on Mexico’s arid northwest and its tropical southeast (chiefly the Yucatán peninsula).
Fig 2.
Mean footprint in large regions.
Biomes (a) and ecoregions (b) of Mexico grouped into categories defined by their mean human footprint (low, medium, and high human footprint, with mean HF<1; 1<HF<3, and HF>3, respectively).
Fig 3.
Ecoregional footprint nested within biomes.
Large differences in ecoregional HF values (white points) were observed within most biomes (black points). Biomes names as follow Great Plains (GP), Mediterranean California (MC), North American Deserts (NAD), Southern Semi-Arid Highlands (SSAH), Temperate Sierras (TS), Tropical Dry Forests (TDF) and Tropical Humid Forests (THF).
Table 2.
Ecoregions of Mexico ordered according to their mean footprint value.
Fig 4.
Statistical properties of the ecoregional human footprint.
(a) Relationship between the mean human footprint in each of 24 Mexican ecoregions, and the standard deviation of their footprint values (r2 = 0.99; P < 0.00001). (b) Relationship between mean human footprint in each ecoregion and the skewness of the distribution of footprint values (r2 = 0.87; P < 0.00001). (c) Relationship between mean human footprint and the mean patch size of low footprint area in each ecoregion (r2 = 0.84; P < 0.00001; in all cases the fitted curve was obtained using polynomial regression).
Table 3.
ANOVA.
Fig 5.
Distribution of the main pre-Hispanic settlements in Mexico.
Map: Archaeological pre-Hispanic sites taken INAH (http://www.geoportal.inah.gob.mx) and major pre-Hispanic settlements taken from Kellog 2011, Sharer 1994, and Whitmore and Turner 2001 mapped over the ecoregions of Mexico (exact coordinates for each site located using GoogleEarth). The ecoregions that were most densely occupied at the time of the arrival of the first Europeans are marked in color. Inserted barchart: Mean Human Footprint value for (i) central and southern Mexico, (ii) the Yucatan peninsula, and (iii) the rest of Mexico. Different letters indicate values that differ significantly (P < 0.05) from each other.
Fig 6.
Population in Mexico between 1521 and present.
Data compiled from Borah and Cook 1969, McCaa 2000, Benítez Zenteno 1961, and official population censuses available at www.inegi.gob.mx.