The work of the team of authors headed by I. N. Kurganova summarizes the data of a unique 24-year field experiment to determine the temperature sensitivity of soil respiration in two forest ecosystems in the southern Moscow region. Being a key component in assessing the carbon balance in ecosystems, soil respiration largely depends on soil temperature and moisture, which in turn are determined by weather conditions. As part of the study, we quantitatively assessed the response of respiration of forest soils of different textures (sandy and loamy) to an increase in soil temperature (temperature coefficient Q10) depending on the weather conditions of each year of research. Such a long series of observations showed significant interannual variability in Q10 values ​​and made it possible to identify significant positive correlations of the temperature sensitivity of soil respiration with the Selyaninov hydrothermal coefficient and the amount of precipitation over the summer. That is, it is shown that in dry years, the positive response of soil respiration to an increase in temperature will be weaker than in years with normal or increased moisture. At the same time, the temperature sensitivity of respiration of sandy loam soil with low water-holding capacity demonstrates a closer relationship with moisture indices, compared to loamy soils, which are able to retain moisture reserves necessary for the vital activity of microorganisms even in the driest years.

Thus, it has been shown that it is the moisture supply of soils during the growing season that is the main factor controlling the temperature sensitivity of soil respiration in forest ecosystems. Given the current trend of increasing climate aridity in many regions of Russia and the world, it is possible to predict a decrease in the emission flow of CO2 from soils, which in turn can lead to an increase in the carbon sink into forest ecosystems of boreal and temperate regions.

Today, global climate change has turned from a highly specialized natural science issue into one of the most pressing problems of the world economy and politics. The scientific community is faced with the task of finding ways to reduce the concentration of greenhouse gases in the atmosphere. To do this, it is necessary, first of all, to correctly assess the carbon-absorbing capacity of terrestrial ecosystems - one of the most important natural carbon reservoirs on our planet. The obtained estimates of the temperature sensitivity of soil respiration and the disclosure of its relationship with weather conditions will improve the quality of forecasts of the carbon-absorbing capacity of terrestrial ecosystems and competently plan environmental and climate projects as part of the decarbonization of industry.

Published in Forests 28 August 2022

https://www.mdpi.com/1999-4907/13/9/1374/htm

Kurganova, I.; Lopes de Gerenyu, V.; Khoroshaev, D.; Myakshina, T.; Sapronov, D.; Zhmurin, V. Temperature Sensitivity of Soil Respiration in Two Temperate Forest Ecosystems: The Synthesis of a 24-Year Continuous Observation. Forests 2022, 13, 1374. https://doi.org/10.3390/f13091374