The Temporal Variability of Respiration of a Soddy-Podzolic Soil in Forest and Meadow Coenoses of the South-Taiga Zone.

Autor: Kurganova, I. N., Lopes de Gerenyu, V. O., Myakshina, T. N., Sapronov, D. V., Khoroshaev, D. A., Zhmurin, V. A.
Zdroj: Moscow University Soil Science Bulletin; Jun2022, Vol. 77 Issue 2, p74-82, 9p
Abstrakt: Soil respiration is one of the main fluxes in the global carbon cycle and has high temporal and spatial variability. Respiration of a soddy-weakly-podzolic soil (Entic Podzol Arenic) in forest and meadow coenoses of the south-taiga zone was continuously monitored on a year-round basis for 21 years; the collected data allows us to assess the temporal variability of CO2 fluxes from soils at different temporal levels: monthly, seasonal, and annual. The total respiration of the soddy-weakly-podzolic soil varies most significantly at the monthly averaging level (coefficient of variation, CV = 25–56%); while the annual respiration variability is 20–22%. At the seasonal averaging level, winter CO2 fluxes from soils have the highest variability (CV = 39–44%); in contrast, during other calendar seasons, soil respiration variability remains roughly at the same level: 26–29%. The effect of the coenosis type on total CO2 fluxes from the soddy-weakly-podzolic soil is statistically significant both at the annual averaging level and in all calendar seasons of the year, except for winter. The most stable parameter that characterizes the seasonal distribution of CO2 fluxes throughout the year is the contribution of the warm period (May–October) to the total annual CO2 flux from soils (73–77% on average). In both studied coenoses, its variability over the 21-year observation period was 8%. This parameter can be used to estimate annual CO2 fluxes from soils based on field measurements performed during the growing season. Results of numerical experiments show that continuous measurements of CO2 emissions from soils for 5 consecutive years reduce the variability of annual and seasonal CO2 fluxes from soils by more than half compared with 1‑ or 2-year measurement periods. Accordingly, a 5-year observation period can be recommended as the optimal one: its duration is sufficient to obtain adequate values of annual and seasonal CO2 fluxes from soils in the south-taiga zone. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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