The data of field observations of soil respiration (SR), or CO efflux from soil, obtained over five years (2020–2024) in four regions of the European Russia (Republic of Chuvashia, Ryazan Oblast, Tula Oblast, Kursk Oblast) within the biome of broad-leaved forests and forest-steppe were analyzed. In each region, SR measurements were carried out in the same set of natural (forests, steppes) and agricultural (arable lands, hayfields, pastures) ecosystems. SR was estimated using portable infrared gas analyzers and static chamber method in 10-fold spatial replications at the peak of vegetation seasons. In the Kursk region, gas measurements were conducted in a more intensive mode (1–2 times per month) as part of year-round monitoring. The goal was to quantify the relative contributions of spatial and temporal variability of SR for different scales of observations, which allows to increase confidence in field estimates of SR for subsequent extrapolation to larger regions or forecast. Nonparametric PERMANOVA analysis of variance was used. At the scale of a year or biotope, the contribution of temporal variability (49–59.8%) to the total variance of SR significantly exceeds the contribution of spatial variability (5.4–9%). Change the spatiotemporal scale of observations to multi-year series and regional ecosystems reduces the contribution of temporal variability to 27%, and increases the contribution of spatial variability up to 23.2%. In general, at the scales considered, temporal variability appears to be more important for the overall variation of SR. This leads to the methodological recommendation to increase the frequency of assessments of intraannual dynamics of SR rather than to increase the number of measurement points in local ecosystems.
D.V. Karelin (Wed,) studied this question.