Automated high resolution soil respiration campaign data from Climoor fieldsite in Clocaenog Forest (2013 - 2014)

Automated soil respiration measurements were carried out as daily-weekly campaigns 2013 and 2014. Therefore, one soil collar (20.3 cm diameter) was installed (6-8 cm deep) per plot on top of one out of three permanent soil respiration collars in June 2013. Areas were chosen where vegetation (mostly C. vulgaris) could be tied back and removal of vegetation could be avoided. Following installation, the vegetation surrounding the collars was not visually affected suggesting limited or no disturbance to the plants, however, the soil became visibly drier with time. Collars remained in the soil and re-grown vegetation was removed regularly throughout the years.

Automated soil respiration chambers (8100-104, LI-COR, Bad Homburg, Germany) were coupled via a multiplexer (LI-8150, LI-COR) to an infrared CO2 analyser (LI-8100A, LI-COR) in each plot (n = 9). Automated measurements (120 sec) were taken every hour for at least 24 hours.

The HMR-package for R was used to calculated soil respiration rates from CO2 concentrations measured by the infrared gas analyser. For each point, the CO2 concentration was plotted against time, taking the chamber area and volume into account. An acclimation phase of 25 sec was applied where respiration rates are likely to be disturbed by the closure of the chambers. Rs was estimated by linear regression because it provided a better fit over suggested non-linear regressions. Fits of linear regressions were checked visually. The slope of the regression equals the soil CO2 efflux per m2 and unit time. Values are reported in µmol CO2 m-2 sec-1.