An anthrome-based perspective of the traditional biogeographic units: Argentina as a case study

During the last few centuries, the boundaries between natural biogeographic units, that is, ecoregions and biogeographic provinces, may have shifted due to human land use in many places of the world, and entire units may have lost their diagnostic features (geomorphology, plant communities, and endemic species). These heterogeneous, fragmented, landscape mosaics are defined as anthropogenic biomes, human biomes, or anthromes. The anthromes are still not integrated into the regionalization schemes of ecoregions and biogeographic provinces. Due to the variety of natural biomes and its considerable surface covered by extensive agriculture and livestock, Argentina, in southern South America represents an interesting model for considering an anthrome-based perspective of the country traditional biogeographic units. A map of anthromes at a national analysis scale allows local patterns and heterogeneities to be captured that a global map smooths out. Thus, we constructed a detailed map of anthromes of Argentina, modeled from pre-existing information layers, and contrasted it with a map of ecoregions and a map of biogeographic provinces. Our results indicate that almost 90 % of Argentina’s surface is better classified as regional anthromes. We found great coincidences between ecoregions and biogeographic provinces regarding the major and minor anthropogenic use, suggesting an equivalent value of both types of units in conservation biogeography. Both units provide different but complementary attributes of a given area. Findings of this study highlight the need to take a more realistic view of biogeographic regionalizations.