Figure 2
Observed and simulated carbon fluxes for the mature even-aged spruce stand in Harwood Forest. Panel (a) shows the monthly averages across the time-series (2015–20 for simulations using in-situ climate data and 2015–17 for Chess-Met 1 km gridded data) for GPP, tree respiration, and NPP. Black lines indicate the GPP observations while grey bands on tree respiration and NPP subplots indicate the uncertainty arising from partitioning of root respiration from the total soil respiration. Panel (b) shows both the seasonal (x-axis) and diurnal cycle (y-axis) of GPP, and difference between simulated GPP (red and blue scale) against observations. Similarly, to Fig. 1, solid and dashed dotted (Fixed 1973 CO2 concentration) olive lines are un-thinned historical simulations, while dashed and dotted (Fixed 1973 CO2 concentration) runs have been thinned.
