The present study aims to disentangle the direct effects of temperature on vital rates and the indirect effects mediated by the temperature-size rule on the community structure of a food chain model across temperature and productivity gradients. The authors furthermore explore the effects of thermal asymmetries between warm/cold-adapted consumers and predators. They find that the direct effects of temperature on vital rates have a much stronger impact than the imposed temperature size rule, revealing that in combination, temperature mostly affects community structure via direct effects on vital rates. They also highlight the effect of thermal asymmetries on community structure for consumers/predators facing cold/warm adapted predators/consumers.

The study combines multiple ecologically important mechanisms of temperature responses (direct + indirect effects, direct + indirect + thermal mismatches) and evaluates the relative impacts of each of these mechanisms; I appreciate the efforts that went into dissecting the relative importance across mechanisms, effects on consumers and predators or both, as well as different rates (presented in the appendix); the question posed is therefore timely and of interest to a broad readership of population and community ecologists. The results are well presented both in writing and using informative figures.

Although the research question is timely and interesting, I doubt whether the modelling approach is the most suitable to address the question. The reason for this is that the TSR and temperature-dependent vital effects are imposed as independent effects in isolation or jointly rather than the TSR emerging due to feedback between the size structure of the consumer and its interaction with the resource and the predator. I think the authors have to justify what kind of biological scenarios this could represent.

Alternatively, Audzijonyte et al. 2022 used an individual physiological model to study how life histories expressing the TSR can arise. This can be due to differential effects of temperature on vital rates across size classes, that is, during development. It would be valuable to provide an additional scenario(s) where the TSR emerges naturally from the temperature effects on vital rates and species interactions and compare it to the other scenarios shown.

I also wondered whether the direct effects of temperature on vital rates do not result in any change in size structure in the consumer (an emerging TSR in scenarios 2-4)? Ohlberger et al. 2011 for instance report changes in consumer length with warming as an emergent effect when modelling the response of a size-structured fish population to warming. Can you show the changes in consumer length for the scenarios with temperature effects on vital rates in the appendix?

Related to my previous points, I find the terminology of direct and indirect effects of temperature incongruent with the modelling approach chosen. It is common practice to call temperature effects mediated by species interactions indirect. However, here the TSR effects are imposed without any clear link to the trophic interactions in the food chain (except for the vulnerability size threshold to predation). If you stick with the original modelling approach, it seems preferable not to use direct/indirect effect terminology.

A large portion of the results is dedicated to describing the direct effects of temperature on vital rates and subsequent effects on food chain community structure. I understand this is an important reference point for the comparison with the effects of imposed TSR and thermal asymmetry, however, this has been addressed previously for instance by Lindmark et al 2019. Are imposing TSR and thermal mismatch the novel aspects in comparison to this study? It may be better to focus on these aspects of the analysis then, especially the thermal asymmetry results, which I found particularly interesting.

In some places, the introduction is too vague to understand how this work expands on previous work. For instance, line 72 cites the Lindmark study, but does not specifically list what we don't understand yet (save listing sudden regime shifts, which also require more explanation in the introduction). Also lines 74-75 should be more clear about which aspects of thermal asymmetries we do not understand yet since they have been a focus of recent research in ecological modelling (Álvarez-Codesal et a. 2023, Bideault et al. 2020, Dell et al. 2014, Gibert et al. 2022)

Minor issues:
l 87: something missing at the end of the line
l 116: something missing between estimated mean mass-specific aquatic ectotherms
l 125: explain what a Rosso function is and does
l 155: Figs SS <- add numbers
l 263: delete the first occurrence of "consumer"
l 368: is body size really a currency? Suggest to replace it with " .... determinants of ecological processes ..."

References:

Audzijonyte, A., Jakubavičiūtė, E., Lindmark, M., & Richards, S. A. (2022). Mechanistic Temperature-Size Rule Explanation Should Reconcile Physiological and Mortality Responses to Temperature. _The Biological Bulletin_, _243_(2), 220–238.

Lindmark, M., Ohlberger, J., Huss, M., & Gårdmark, A. (2019). Size-based ecological interactions drive food web responses to climate warming. _Ecology Letters_, _22_(5), 778–786.

Ohlberger, J., Edeline, E., Vøllestad, L. A., Stenseth, N. C., & Claessen, D. (2011). Temperature-Driven Regime Shifts in the Dynamics of Size-Structured Populations. _The American Naturalist_, _177_(2), 211–223.

Thank you for the careful revision addressing all of my concerns.