Emissions of CO2, CH4, and N2O Fluxes from Forest Soil in Permafrost Region of Daxing’an Mountains, Northeast China

Abstract

With global warming, the large amount of greenhouse gas emissions released by permafrost degradation is important in the global carbon and nitrogen cycle. To study the feedback effect of greenhouse gases on climate change in permafrost regions, emissions of CO2, CH4, and N2O were continuously measured by using the static chamber-gas chromatograph method, in three forest soil ecosystems (Larix gmelinii, Pinus sylvestris var. mongolica, and Betula platyphylla) of the Daxing’an Mountains, northeast China, from May 2016 to April 2018. Their dynamic characteristics, as well as the key environmental affecting factors, were also analyzed. The results showed that the flux variation ranges of CO2, CH4, and N2O were 7.92 ± 1.30~650.93 ± 28.12 mg·m−2·h−1, −57.71 ± 4.65~32.51 ± 13.03 ug·m−2·h−1, and −3.87 ± 1.35~31.1 ± 2.92 ug·m−2·h−1, respectively. The three greenhouse gas fluxes showed significant seasonal variations, and differences in soil CO2 and CH4 fluxes between different forest types were significant. The calculation fluxes indicated that the permafrost soil of the Daxing’an Mountains may be a potential source of CO2 and N2O, and a sink of CH4. Each greenhouse gas was controlled using different key environmental factors. Based on the analysis of Q10 values and global warming potential, the obtained results demonstrated that greenhouse gas emissions from forest soil ecosystems in the permafrost region of the Daxing’an Mountains, northeast China, promote the global greenhouse effect.

Increased Litter Greatly Enhancing Soil Respiration in Betula platyphylla Forests of Permafrost Region, Northeast China

“…In this region, snowpack covers the land more than half the year (from October to April). This region has a mean annual sunshine of 2594 h and a frost-free period of 89 days, typically from June to September [32]. The soil type belongs to brown coniferous forest soil.…”

“…The Daxing'an Mountains area is not only the southern margin of the Eurasian permafrost region [30,31], but is also the largest natural forest area in China, and has an area of 8.35 million ha with a forest coverage rate of 84.32% [32,33]. The dominant species of trees in this region are Larix gmelinii, Betula platyphylla, Populus davidiana and Pinus sylvestris var.…”

Effect of Losing Nitrogen Fertilizers on Living Organism and Ecosystem, and Prevention Approaches of their Harmful Effect

“…The concentration of this gas in the atmosphere was 268 ppb in 1750 and reached to 329.9 ppb in 2017. The concentration of greenhouse gases has a close relationship to carbon and nitrogen cycles of the ecosystems, the three (CO 2 , CH greenhouse gas fluxes have become a significant cause of global climate change [16,17]. The fertilization rate, annual and perennial crops, cultivated mineral soils, soil moisture, temperature, and tillage affect nitrous oxide emission rate [18].…”

Analyzing Similarities between the European Union Countries in Terms of the Structure and Volume of Energy Production from Renewable Energy Sources

“…The source of this energy involves most often fossil fuels, the extraction and combustion of which (in the process of energy production) causes the formation of many harmful substances that enter the natural environment [9]. The greenhouse gases and other gaseous and dust pollutants generated in this process disturb the balance of the natural environment and pose a greater and greater threat to the entire terrestrial ecosystem [10,11]. At present, this threat is already so great that it becomes necessary to take very decisive and global-wide actions to limit the negative impact of the development of our civilization on the environment.…”