Map of the northern border of Asian elephants over the past four thousand years
A team of researchers from Nanjing University and Aarhus University in the United States reported in the Proceedings of the National Academy of Sciences that the shrinkage of China's large animal range in the past two thousand years has been mainly dominated by agriculture and the spread of agricultural intensification, which is often related to the development of human culture, and climate change has affected it with little or no impact.
Based on archival records and a graph of the distribution dynamics and social development of large animals based on archival records and a climate analysis of China from 2 to 1953 AD, the researchers ultimately confirmed that the narrowing of the range of China's five historic megafauna, Asian elephants, rhinos, tigers, Asian black bears and brown bears is mainly driven by cultural filtering (defined as the influence of cultural evolution on the existence of species).
This finding suggests that the thousands of years of farmland expansion and agricultural intensification, often accompanied by cultural expansion, were responsible for the extinction of these large animal species from much of China. In addition, cultural filtering is important for understanding the role of society in contemporary community collections from historical regional species pools.
The study also provides direct evidence that cultural evolution since time immemorial has masked the effects of climate change in shaping biodiversity patterns for large-scale megafauna, reflecting the growing importance of sociocultural processes in the biosphere.
Jens Christian Svening, a professor at Aarhus University, said: "China has preserved more than 2,000 years of written historical records, which provides a unique opportunity to reconstruct the long-term dynamics of cultural and natural interactions on a large geographical scale. ”
The Sumatran rhinoceros was historically widespread in eastern China but became extinct due to increased anthropogenic pressure
Shuqing Teng, a postdoctoral fellow at Aarhus University and Nanjing University, explains: "Ancient China once had large mammals with high biodiversity even in today's densely populated areas, such as the North China Plain and the middle and lower Yangtze River plains. But as intensive agricultural practices attributed to Han culture, which originated in northern China, expanded southward, their scope shrank or became extinct. ”
The regional extinction of these taxa from the study area is consistent with the sociocultural dynamics described above, but not with climate change. Over the past 2000 years, there have been at least two distinct cooling-warming cycles, including the Medieval Warm Period and the Xiaoice Period, with average annual temperature fluctuations of around 1 to 1.5 degrees Celsius, but neither of which had a significant effect on the fauna.