This article builds on previous work by the same authors, exploring how the representation of phytoplankton evolution can affect the predictions of a plankton ecosystem model under stable and warming conditions. In a previous article (Hochfield & Hinners 2024), the authors explored a very similar model under a similar set of environmental scenarios. The article demonstrated that allowing phytoplankton to adapt to changing environmental conditions impacted projections of community composition. In the new manuscript the authors extend this analysis to include the effects of evolution on ecosystem function.

While there is significant overlap between the two articles, there are new results in the new manuscript. It is important however that the authors make a clearer distinction between the two manuscripts, explicitly noting what is repeated, what is different in terms of model setup and assumptions, and what new findings where not seen previously. It appears that the main distinction between the papers is in the additional focus on ecosystem functions (i.e. carbon export, nitrogen fixation and resource use efficiency). That said, much of the Results and Discussion sections still focus on community composition, and there is a possibility of some duplication. I would recommend that these sections are rewritten with clearer reference to the previous work, stating what was shown before and what has been added in the new manuscript. As an example, the authors note on line 126 that the original model has been "slightly extended", but it was not immediately clear to me what the differences were.

In addition to this issue, I found that the findings of the paper do not appear to be generally informative on how evolving and non-evolving plankton ecosystems might respond to climate change. Rather, we have a lot of information on how this particular configuration of this particular model responds under a very specific set of environmental forcings. Correlations and changes are presented as a long list, with little context of why the modelled changes should be of interest. It is quite difficult as a reader to understand the relevance of all these details.

I would urge the authors to develop a clearer narrative structure to the manuscript, identifying early on a small set of robust findings they want to communicate. The results can then be presented in a way that supports of refutes these ideas. Being more specific, the Results section provides a list of very precise quantitative results, but it is hard to know what these mean in a broader context. Why do we need to know how each individual model species responds in each individual experiment? This is an important issue, because I suspect that the very detailed results will be quite sensitive to the model structure and the environmental scenario. To give one example, the projected climate change scenarios only included changes in environmental temperature and neglect any long-term changes in other physical factors such as stratification/mixing. It is important to note that projected increases in productivity and biomass under future climate change might not be repeated if the model were to represent future decreases in nutrient supply in a more stratified system.

In summary, I would urge the authors to work on the paper's narrative structure, emphasising a small number of key general findings, and building the manuscript around those. 

References

Hochfeld, I. and Hinners, J. (2024), Evolutionary adaptation to steady or changing environments affects competitive outcomes in marine phytoplankton. Limnol Oceanogr, 69: 1172-1186. https://doi.org/10.1002/lno.12559