A 5,500-Year Model of Changing Crop Niches on the Tibetan Plateau

Three thousand years of farming strategies in central Thailand

“…Our analysis confirms that millets were probably the earliest crops introduced to the Khao Wong Prachan Valley, arriving by c. 2300 cal BC (following Weber et al 2010). Foxtail millet cultivation was practised along the margins of the Tibetan Plateau in China as early as c. 3500 BC (d'Alpoim Guedes 2011;d'Alpoim Guedes et al 2016). Millets appear in our samples by c. 2300 cal BC, shortly after appearing on the Chengdu Plain (c. 2700 BC) and in Yunnan Province (c. 2600 cal BC), where they are coupled with finds of rice (d'Alpoim Guedes et al 2013;Jin et al 2014;Dal Martello et al 2018).…”

Climate change stimulated agricultural innovation and exchange across Asia

“…Wheat and barley appear on the SETP several hundred years after millet-producing sites had already been abandoned—not giving farmers an opportunity to integrate these new grains into the diet ( 8 ). On the NETP, however, wheat and barley arrived before the 4000 cal.…”

“…To examine how changing temperatures could have affected the ability of farmers to grow each crop, we used a global record of Holocene temperatures ( 44 ) to reconstruct available growing degree-days (GDDs) following the methods of d’Alpoim Guedes et al . ( 8 ). We derived daily modern temperatures from Global Historical Climatology Network weather stations across East, South, and Central Asia ( 45 ).…”

“…During this period of time, broomcorn and foxtail millet made their way from China to Central Asia, and wheat and barley moved from Central Asia to the Far East. Who spread these crops across Asia—when, how, and by what routes—has been a topic of increasing debate ( 2 , 3 ), as have the social and economic motivations behind their adoption ( 4 – 8 ). There is an increasing interest in how changes in precipitation and temperature may (or may not) have affected agricultural production in past societies ( 9 – 12 ).…”

“…We use this niche model to examine the impact that changing temperatures had on human’s ability to subsist on these crops and to reveal the strategies they used to cope with these potential challenges. This model covers a wider geographic scope and temporal depth and more crop varieties than previously published thermal niche models ( 8 ), allowing us to make several general observations about the nature of grain crop farming across early-mid Holocene Eurasia.…”