Rice exposure to cold stress in China: how has its spatial pattern changed under climate change?

Extreme cold events have always been great threats to the major rice-cultivation areas across China. The spatial pattern of rice exposure to cold stress (ECS) is critical to develop countrywide adaptation strategies. Under climate change, whether and how ECS spatial pattern has changed? These answers are urgently required for adaptation optimization, but regrettably remain unclear. Here, we examined the changes in rice-planted area exposed to cold stress across mainland China, and historical movements of the geographical centroids of rice ECS over 1980-2015. The results showed that in the single rice cultivation of northeast China and the Yunan-Guizhou plateau, the area exposed to cold stress has shrunk significantly and the centroid moved northward since the 1980s. The southern parts of the mid-lower reaches of Yangtze River witnessed a continuous decrease in the area exposed to cold stress from the 1980s to 2000s, but a large expansion over the 2010s. In south China, the areas exposed to cold stress mainly gathered in the northern parts and showed large variations since the 1980s. These two regions dominant by double rice have witnessed westward movements of ECS centroids over the past decades.