Just wanted to put some concrete data from China's Cosmopolitan Empire out there. Most people know that the Tang Dynasty witness the rise of South China, defined as the Yantgze river valley and on south, as the economic and demographic engines of China (though arguably the plains around the Yellow river remained the cultural and political heart of China). There were several censuses across Chinese history.

- Between the census of 742 and 1080 the population of North China rose by ~25%. The population of South China rose by ~325%. The reasons for this are many, but one of the primary ones was the introduction and improvement upon of Champa rice (the pre-Champa strains dominant at the beginning of the Tang died out by the Song Dynasty).

- The transformation of South China from isolated cities and a few densely populated pockets of cultivation,(e.g, around lake Tai) to a region where Han agriculture was omnipresent witnessed a shift from using animals (oxen, buffalo, etc.) to human labor.

Labels: China, History