Fig 1.
Time courses of (a) mean soil water content at 0–30 cm depth (n = 3) and precipitation levels, (b) mean soil temperature at 2 cm depth (n = 3), (c) half-hourly mean soil respiration rates (n = 3), (d) gross primary production (GPP) according to eddy covariance tower observations during the years from 2005 to 2010.
Table 1.
Empirical equations and parameter estimates describing the relationship between soil respiration and temperature from 2005 to 2010 (n = 94904).
The Akaike information criterion (AIC) and the root mean squared error (RMSE) are used to evaluate the best fit for the models.
Fig 2.
Relationship between soil respiration and temperature during 2005–2010 as determined by the automated chamber system.
The best-fit linear relationship from the Arrhenius model is shown by the solid black line (Table 1). The rainbow color scale shows the month when the data were obtained.
Fig 3.
Relationship between daily soil respiration and gross primary production (GPP) during 2005–2010.
(a) Each point represents an individual daily observation. (b) Each point is a mean value (± SD) for samples within a month. Color distributions were convergent in the monthly data.
Fig 4.
Relationship between (a) Q10 and (b) activation energy (Ea) of soil respiration and temperature for each month. Numbers in the figure indicate months.
Table 2.
Mean soil temperature, Q10, and activation energy (Ea) for each month during 2005–2010.
Fig 5.
Diurnal variations in soil respiration and gross primary production (GPP) for each month.
Error bars represent the standard errors of the mean for each month from 2005 to 2010. Each figure shows the fixed-width from bottom to top in Y-axis in all months.
Fig 6.
Relationship between soil respiration and temperature for each month.
Each point indicates the mean value. Numbers in the figure indicate time of day of the mean for each month from 2005–2010.