Peer review of: Extreme rainfall events alter the trophic structure in bromeliad tanks across the Neotropics (2020)

Reviewers' Comments: 
 
Reviewer #1: 
Remarks to the Author: 
This is a very interesting study that adds to previous publications by the same group on the effects of 
rainfall on aquatic communities in bromeliads. Overall the manuscript is solid and provides information 
that will advance our understanding of aquatic ecosystems. However, some specific issues need to be 
addressed: 
 
- The title seems too broad, the study makes a good case for a particular type of freshwater 
ecosystem, but to stretch to “freshwater ecosystems across the Neotropics” is not appropriate. 
 
- The authors argue that hydrology was not affected by manipulated precipitation. I am not clear at 
what they mean by hydrology and it is difficult to assess their statement, as it is based on unpublished 
data. Also, it seems that it might be a point specific for bromeliads. Streams, ponds, and all respond 
quickly to precipitation. This needs further clarification. 
 
- The authors talk about drought, but as far as I was able to understand from the manuscript, they did 
not reduce rainfall. How were drought conditions achieve? Systems with low or infrequent precipitation 
are expected to be adapted to those regimens. Plus, there are different definitions of drought and 
some do not include seasonal environments where a dry period is expected and organisms are fully 
adapted to it. 
 
- It would be good to get more details about how they assigned taxa to trophic levels. Identification of 
aquatic organisms is rather difficult in tropical regions and there is limited information on their biology. 
Plus, some degree of omnivory is also expected. The methods section lists a very small list of taxa, 
studies with Neotropical bromeliads often list over 20 taxa. 
 
- Line 246 – there is something wrong here. Allochthonous subsidies and biomass turnover are not 
related concepts. 
 
 
 
Reviewer #2: 
Remarks to the Author: 
This is an interesting paper with lots of potential. While I like the paper, think it is well written, and 
find the results interesting the paper to me, as it currently stands, lacks data to make this a more 
powerful contribution -- as it is, it feels light. Specifically, the results point to the role rainfall 
frequency may play in mediating trophic structure but it would aid this contribution enormously if 
there was some more mechanistic data to go with the changing biomass pyramid structure across this 
gradient. As an example: 
 
i) are nutrients actually lower in more frequent rainfall scenarios? if so, this natural experiment is 
showing something very consistent with theory, one trophic level is apparently held in check while the 
other increases as per Rosenzweig-MacArthur or the paradox of enrichment (a signature of which is 
increased top heaviness). I know the authors suggest things like this but without some mechanistic 
details on what is driving their results it seems insufficient for a journal like Nat. Comm. 
 
ii) are interactions truly stronger (e.g., greater per capita consumption rates) in less frequent rainfall? 
again their results are consistent with theory on top heaviness. Note, this increased interaction 
strength in smaller spaces has been also argued to occur in floodplains during their dry season just 

prior to migration (check out flood pulse concept) 
 
iii) are both i and ii occurring? 
 
Anything to support one or both of the above or neither would aid this finding. 
 
In summary, I think this paper is moving in a good direction but is light for a significant journal like 
Nat. Comm. without a more mechanistic underpinning.