Instead, the landscape was dominated by a mosaic of grasses, sedges, and forbs — a diverse community of cold-tolerant plants that grew in the relatively dry, windswept conditions of the mammoth steppe.

The aridity of the Last Glacial Maximum Beringian landscape was partly a function of the reduced precipitation that characterized glacial climates globally — with more of the world’s water locked up in ice sheets, there was less water cycling through the atmosphere and delivering precipitation to land surfaces.

In Beringia, the dry conditions prevented the accumulation of the thick peat layers that insulate modern tundra soils and support the distinctive plant communities of the contemporary Arctic.

The productivity of the mammoth steppe — its ability to support enormous populations of large herbivores — was a function of this dryness as much as of anything else.