Spatiotemporal evolution of carbon sequestration vulnerability and its relationship with urbanization in China's coastal zone.

Carbon sequestration plays a vital role in maintaining the stability of global climate and the carbon cycle, but is undergoing significant changes due to urbanization. This study proposes the concept of carbon sequestration vulnerability (CSV), and explores the spatiotemporal evolution of CSV and its relationship between urbanization in China's coastal zone from 2000 to 2010. The study results provide a scientific basis for government management and policy-making. The results showed that the average amount of CSV in 2000 and 2010 was 0.301 and 0.279, respectively, in China's coastal zone and exhibited obvious spatial heterogeneity. Land urbanization had better interpretation strength for CSV than population and economic urbanization indexes, and could explain the 10-year change in CSV well in China's coastal zone. In China's coastal zone from 2000 to 2010, CSV response to land urbanization was proven to be positive and linearly increasing, and the slope of the linear relationship was 0.4214, cities with high land urbanization level have higher CSV; likewise, the change in land urbanization level had a significant positive and linear relationship with the change in CSV, and the slope of the linear relationship was 0.5031. When the city's land urbanization level increased by <6.8% over ten years, the CSV declined, and conversely, the CSV rose. For the goal of reduce CSV of cities, government and policy-makers should focus on land urbanization and it is possible to realize the goal by controlling land urbanization below 6.8% every ten years.