Reply: “Use of BIOME-BGC to simulate Mediterranean forest carbon stocks”

Abstract

The current note responds to the critical contribution of Dr. Eastaugh on Chiesi et al. (Chiesi et al. 2011). That paper did not aim at applying BIOME-BGC to simulate stand growth, which requires a thorough modification of the model functions. In contrast, only a parameter setting was changed in order to adjust the predicted carbon storages during the simulation of quasi-equilibrium conditions. The adjustment was calibrated on volume statistics derived from the Tuscany forest inventory and is suitable for regional scale applications

Simulation of Forest Carbon Fluxes Using Model Incorporation and Data Assimilation

“…Furthermore, this strategy provided the option of circumventing the problem of scarce field data describing the various forest processes in specific biomes. Previous investigations have applied this method in a Mediterranean forest ecosystem [44,48,49], but the errors caused by the uncertainties in the remote sensing-based model would there be propagated to the next calibration and the predictions of carbon fluxes; the calibration of the parameters mainly focused on the parameters related to summer drought without considering exhaustive sensitivity analysis of other crucial parameters or a global calibration. Additionally, many studies concentrating on the calibration of Biome-BGC using field measurements (e.g., dendrochronological data, eddy covariance measurements) were carried out without considering temporal continuity or spatial heterogeneity based on reliable remote sensing data [50,51].…”

“…The autotrophic respiration was separated into the maintenance respiration and growth respiration. Specifically, the former is calculated as a function of the nitrogen content and temperature of the tissues, and the latter is computed as a function of the amount of carbon allocated to the different pools [44]. The leaf onset and offset day is also described in the phenological module of Biome-BGC.…”