Historical pyrogenic sources of black carbon during the last 150 years in the Great Hinggan Mountains, Northeast China

Abstract

Black carbon (BC) refers to solid charred residues produced by the incomplete combustion of fossil fuels and biomass. The Great Hinggan Mountains are located on the margin of the East Asian monsoon region, and BC from fossil fuel sources could be deposited in this region through transport by westerlies and the monsoon. The overall objective of this study was to evaluate the sources and intensity of BC deposited during the last 150 years in the Great Hinggan Mountains, Northeast China. BC concentrations, stable carbon isotope values of BC (δ13C-BC), and charcoal counts in the Motianling (MP2) peatland were measured in this study. BC values measured via the chemical method were regarded as total BC concentrations, and the BC values measured via the microscope method (i.e., charcoal) represent BC from biomass burning. The results showed that BC in MP2 peatland was mainly produced from local fire events before the 1930s. After the 1930s, with the increase in European fossil fuel BC emissions, the BC produced by fossil fuels became the major BC sources in the MP2 peatland, and the total BC fluxes in the MP2 peatland were much higher than those before the 1930s. With the decrease in European BC emissions and increase in Chinese BC emissions after the 1970s, the BC emitted by China became the major fossil fuel BC source in the MP2 peatland. However, the implementation of environmentally friendly policies decreased the BC emissions from fire events, leading to the gradual decrease in BC depositional fluxes in recent years. In recent years, fossil fuels remain the major sources of BC, but the implementation of environmentally friendly policies has decreased fossil fuel BC emissions, leading to the gradual decrease in BC depositional fluxes in the Great Hinggan Mountains.