Using six established plant community models, this study aims to understand the role of the function-dominance correlation in the biodiversity-ecosystem functioning context. I think that the topic is interesting and appropriate for the journal as it addresses an overlooked but important aspect of the biodiversity-functioning field. Basically, this study shows how the dominance-functioning correlation of species in a community can explain the sampling effect (often simplistically considered just an experimental artefact) and how it can either have positive or negative effects on ecosystem functioning and affect the variability of responses. Overall, I really like the study, but I think it should go through a revision before being ready for publication. Below a series of points that hopefully will help clarifying a few aspects and improve the paper.
1) While I think that the presented data is in line with the first hypothesis, there are additional points that need to be clarified before I am convinced that the second hypothesis can be supported by the presented data. Right now, I feel that that the authors are a bit overreaching. The authors state that “We hypothesise that reducing seed dispersal likely increases the importance of the function dominance correlation for BEF relationships since seed dispersal may decrease the abundance of the dominant species”. It is not clear to me why seed inflow may only decrease the abundance of dominant species and this postulate is further used to interpret the results. I’m not a modeler and it is not a lot of detailed on how this seed inflow is parameterized in the model, but I argue that this depends whether the species that enter from the species pool via the seed inflow are dominant species or not. If a very dominant species enters the community it could end up increasing the abundance of dominant species via its contribution.

2) Maybe I missed it, but I is not clear to me what is actually computed for the function-dominance numbers. While I understand that it’s based on the correlation between a species dominance and its performance in monoculture, for a given community it is not clear what it is. Does the number refer to the correlation of the most dominant species in that community? or is it an average of the correlations all the species in that community? …something else? Please clarify.

3) Although it is mentioned a couple of times, I feel that the authors are somewhat avoiding to use the established “positive or negative sampling effect” and prefer their own terminology. Perhaps they are afraid that it comes across less novel but I think the opposite. I think that the authors should clearly state when the results are in line with a positive or negative sampling effect. It is mentioned in the discussion a bit but it could be also introduced in the abstract and the results. Speaking of terminology, I think that “seed inflow” is perhaps a more appropriate term to use instead of “seed rain”. Also, I suggest that the authors are more consistent with the wording when describing effects “across and within species richness levels” as they use multiple ways to say the same thing throughout the text which can be tiring.

Some minor points:
- Lines 366-367, I would rephrase as it sounds like is the only possible mechanism, which is not the case.
- What do you mean by “Underlaying latent variable”? do you mean an alternative explanatory variable?
- Some correlation coefficients or coefficient of determination on the graphs would be useful.