Carbon capture and sequestration of the natural ecosystems is an important ecological function that partially neutralizes anthropogenic CO2 emissions and slows down global warming. Permafrost peatlands, which cover nearly 20% of the permafrost areas, store nearly 50% of the soil carbon of the permafrost ecosystem which is equal to nearly 10% of the global terrestrial soil carbon pool.
In 2019, the United Nations Environment Programme (UNEP) had been mentioned that the loss of the carbon sink function of the permafrost peatlands had become one of the five key emerging issue of environmental concern globally. Permafrost peatlands in the northern Great Khingan Mountains located at the southern edge of the global high-latitude permafrost area, and the carbon pool are highly vulnerable to climate change and other environmental disturbances.
The researchers from the Northeast Institute of Geography and Agroecology(IGA) of the Chinese Academy of Sciences focus to reveal the effects of environmental disturbances on the chemical stability of the peatland carbon pool in the northern Great Khingan Mountains at different time scales. These researches have been published on the Biogeochemistry and the Catena.
The results show the nutrients (e.g. available K, available P) are the key factors that affect the chemical properties of organic matter in the surface peat soils. The contents of these nutrient elements have a positive correlation with the contents of aromatic and total carbon, however, have a negative correlation with the carbohydrate contents.
Because the difference in nutrient contents in different vegetation communities was not significant, the changes of vegetation communities caused no significant difference of the carbohydrate and carbon contents.
During the last millennium, local precipitation and fire events may be the two major factors driving the varying stability of carbon pools in different permafrost peatlands.
Especially, at 250–200 cal yr BP, intense fire events may have promoted herb growth and high carbohydrate content in the accumulated plant litter, which ultimately produced higher carbohydrate and lower aromatic contents in the JT peatland than nearby periods, which were also higher than those in HT peatland.
“Our results suggested that the chemical stability of permafrost peatlands carbon pool have close related to the environmental disturbance factors, and the environmental disturbance cause the stability of permafrost peatlands carbon pool more vulnerable”, said Dr. GAO Chuanyu.
These work were supported by the National Natural Science Foundation of China (No. 42101108, 42171103), the Youth Innovation Promotion Association CAS (No. 2020235), the Professional Association of the Alliance of International Science Organizations (ANSO-PA-2020-14) etc.
GAO Chuanyu
Northeast Institute of Geography and Agroecology
Tel. 0431-85542274
E-mail: gaochuanyu@iga.ac.cn
Key words: permafrost peatlands, northern Great Khingan Mountain, carbohydrate, aromatic
