Refugial ecosystems in central Asia as indicators of biodiversity change during the Pleistocene–Holocene transition

•Relict ecosystems in central Asia preserve many features of Pleistocene ecosystems.•We use them as indicators of species-richness patterns of Pleistocene landscapes.•Vascular-plant and land-snail richness was lower in Pleistocene-like landscapes.•Bryophyte and lichen richness was higher in Pleistocene-like landscapes.•Modern analogs are useful indicators of the past biodiversity changes.