Transient ecosystem responses to free-air CO₂ enrichment (FACE): Experimental evidence and methods of analysis

Ecosystem responses to the perturbation generated by a step CO₂ increase in field CO₂ experiments are different from those to a gradual C_a increase as in the real world. In order to develop our ability to predict ecosystem responses to a gradual C_a increase, we need to analyse data from FACE experiments using an inversion approach to challenge the structure of existing models and derive parameter values. In order to effectively conduct the inverse analysis, we need to collect highly accurate, informative data by improving experimental design and measurement plans for the FACE studies.