BEIJING: Chinese researchers revealed the interactions among fire, climate, vegetation and human activity on a regional scale by reconstructing the fire history of the Yangtze River Basin over the past 7,000 years, according to the Institute of Oceanology, Chinese Academy of Sciences.
The high-resolution fire history is rebuilt based on the proxy of black carbon of sediment core ECMZ on the continental shelf of the East China Sea.
Black carbon is an excellent material for fire history reconstruction because of its small particle size, light density and high chemical stability, which means it can be carried by rivers or winds over long distances. It is widely found in soil, sediments, the atmosphere and even mountains and polar ice and snow.
A comparison of fire activity with climatic and vegetation proxies suggests that changes in fire activity prior to 3,000 years ago were closely related to variations in temperature and precipitation, with more fire during warm and humid periods, suggesting climatic control on regional fire activities.
In contrast, the significant changes in the relationship between fire and climate on multi-timescales since 3,000 years ago implies an increasing human impact on regional fire activity.
The long-term reduction in regional fire activity since 3,000 years ago was caused by a general decrease in forest cover with increasing human activity, while a short-term enhancement in biomass burning usually coincides with periods characterized by increasing human activity associated with migration or technological advances. The study not only shows that human activities can change the inherent relationship between fire and climate, but also reveals that the response of fire to human activities may be completely different in different periods. – The Daily Mail-Global Times News exchange item
