As the climate warms, the frequency and area of fires are increasing, changing the composition of the atmosphere and the terrestrial carbon cycle by affecting carbon absorption and emissions. Soil carbon release responds inconsistently to fires across ecosystem types. There is also great uncertainty about the impact of time after a fire on soil carbon release. In addition, there is still a lack of direct field experimental evidence on how fires combined with nitrogen addition affect soil carbon release.
In order to analyze and answer the above questions, this study uses a fire and nitrogen addition control experiment set in coniferous and broad mixed forests in the subtropical-warm temperate climate transition zone of China, combined with the integrated analysis of the impact of fire on global forest soil carbon release. The results of field control experiments showed that fire significantly increased soil respiration, while nitrogen addition had no effect on soil respiration. The increase in soil respiration after the fire increased year by year, which was related to the change of soil temperature and the inter-annual change of woody tree species cover. Conversely, global meta-analysis showed no significant change in forest soil respiration within 1-3 years after the fire, and that negative effects were observed only in subtropical forests. This study highlights that general patterns revealed by global integration analysis may not predict the response of ecosystems to environmental change in a particular location.
On July 15, 2020, the research results were published in the classic journal "Agricultural and" in the field of ecology under the title "Understanding the effects of fire and nitrogen addition on soil respiration of a field study by combining observations with a meta-analysis" Published in Forest Meteorology. Agricultural and Forest Meteorology is an international mainstream journal of ecology published by Elsevier Publishing House in the United States.