Dear authors,
Based on your response to reviewers' comments, and an additional report from a third referee, and I'm willing to accept your manuscript provided that you provide a response to comments from the third referee. You can see the comments below.

Major comment:
It is obvious that a major aim for the development of this model is to compare predictions with observations from forest inventories, e.g. RAINFOR data. However, a major application of such a model would be to incorporate it as part of a larger ESM and predict land-biosphere C exchange. From this point of view, it is not clear to me how autotrophic respiration is dealt with in this model. The main input is NPP, from which autotrophic respiration is already subtracted. However, metabolic scaling theory not only deals with size dependent growth, but also with size dependent metabolism, and therefore respiration. Why is size-dependent respiration not represented in this model? Why bother to introduce only size dependent growth while whole ecosystem metabolism is not represented? I'm not asking the authors to completely reformulate their model, but to clarify why respiratory processes are not considered relevant in this new model development effort.

Minor comments:
- Pg 4, ln 14-15. What are the limits of integration? From zero to infinity?
- Eq. 12. It seems to me that the discretization time-step can be a major source of uncertainty. Did you test the sensitivity with respect to the size of \Delta t?