## 2 Materials and Methods
### Field Data Collection and Analysis  
#### 2.3.1 Chamber Measurements of Carbon Dioxide Fluxes  
The carbon dioxide fluxes were measured using the static chamber method across six typical bog sites (\"Open bog\", \"Tall ryam\", \"Ridge\", \"S.hollow\", \"E.hollow\" and \"Ryam\"--further in the text, we will use the designations of the sites without quotes) in the late spring and summer of 2022: 31 May-1 June; 24-26 June; and 27 June-28 July [6; 41] using an infrared gas analyzer Li-850 (Li-COR Biogeosciences, Lincoln, NE, USA). The measurements were carried out in the daytime, from 10 am to 4 pm local time. A cube chamber made of transparent Plexiglas with the dimensions of 0.4 \(\times\) 0.4 \(\times\) 0.4 m and a built-in fan on the upper side of the chamber was used for air mixing. The chamber was installed in a stainless-steel base trough (0.4 \(\times\) 0.4 m in size) filled with settled water (to ensure the tightness of the internal space of the chamber during measurements), which was cut into the soil to a depth of 10-15 cm. In each of the six biotopes, two chambers (one down and one up) were used to capture the natural spatial variability of the ecosystems. The measurements were performed in three-time repetitions (between measurements, the chamber was ventilated for at least a minute), and the exposure time within each repetition was 2-5 min.  
Net ecosystem exchange (NEE) was measured using the transparent chambers, which characterized the net exchange of CO\({}_{2}\) between the soil, grass-moss-dwarf shrub layer (inthe presence of shrubs) and the atmosphere; opaque (covered by foiled foam propylene)--CO\({}_{2}\) emission into the atmosphere due to the heterotrophic respiration of the soil and the autotrophic respiration of the grass-mass-shrub layer (R\({}_{\rm eco}\)). Gross ecosystem exchange (GEE) characterizing the absorption of CO\({}_{2}\) from the atmosphere by the grass-mass (-shrub) layer was calculated as the difference between NEE and R\({}_{\rm eco}\). Fluxes from the ecosystem to the atmosphere are taken positive, and from the atmosphere to the ecosystem--negative (therefore R\({}_{\rm eco}\) > 0, GEE < 0) [42].  
The calculation of specific CO\({}_{2}\) fluxes was carried out in the Matlab R2016b software package (MathWorks, Inc., Natick, MA, USA) using the following formula:  
\[flux=2 aPMb\frac{H}{(T+T_{0})}\]  
The absolute error of the calculated fluxes was estimated using the following formula:  
\[\Delta flux=2 aPM\frac{1}{(T+T_{0})}\big{(}\Delta bH+\big{|}\mathrm{b}\big{|} \Delta\mathrm{H}\big{)}\]  
where _flux_ is the flux of carbon dioxide, mgC m\({}^{-2}\) h\({}^{-1}\), \(a\) is 0.12 mg \(\times\) mol \(\times\) K/(kg \(\times\) J \(\times\) ppm), \(P\) is the total pressure of the gas mixture (Pa), \(M\) is the molar mass of the gas (kg/mol: taken as 0.012 to express the flux in mgC m\({}^{-2}\) h\({}^{-1}\)), \(b\) is the rate of change in the gas concentration in the atmosphere of the chamber (ppm/h: calculated as the slope of the direct increase in concentration in the chamber based on the method of least squares, the function \"fitlm\", MatLab), \(H\) is the chamber height (m), \(T\) is the temperature in the chamber at the end of the measurement (K), T\({}_{0}\) is the temperature in the chamber at the beginning of the measurement (K), _\(\Delta b\)_ is the error in determining parameter \(b\) (ppm/h) and _\(\Delta H\)_ is the error in determining the height of the camera (m: taken as equal to 0.05 m, which is includes half the division value of the measuring tape and the error in determining the height of the chamber, due to the unevenness of the underlying surface).