Unexpected Links between Communities of a Freshwater–Cropland Mediterranean Metanetwork

Round 1

Reviewer 1 Report

Review of Unexpected links between communities of a freshwater-cropland Mediterranean metanetwork.

 This paper develops a qualitative model that utilises network metrics to examine the role of a large set of participants in the trophic and non-trophic system within this defined ecosystem. The paper is very well written and the and approach is worthwhile and robust. The findings are interesting and highly relevant to ecosystem management. I thank the authors for providing an excellent advancement in this field.

 

My comments are minor.

1.      Line 60 the term metanetwork is first used here but given the broad use this term needs to be given some context and description here too.

2.      Line 133 the term function unit is an interesting one in network science. See Turnbull et al 2018 (Connectivity and complex systems: learning from a multi-disciplinary perspective, Journal of Applied Network Science, 3:11.) for discussion. Only a suggestion.

3.      Introduction: the concepts of interaction and scale can be complex and there are recent attempts at generating some clarity here. See Metaecology framework such as Schiesari, L et al. 2019. Towards an applied metaecology. Perspectives in Ecology and Conservation,  https://doi.org/10.1016/j.pecon.2019.11.001

4.      Line 147 there might be merit in also introducing the Pulse stress here (Anthony et al. 2015 Glob Chang Biol. 2015 Jan; 21(1): 48–61.)

5.      Line 199 the use of classic statistics such as Spearman rank correlations within a highly dependent environment is questionable. Possibly the use of Kendall's rank correlation might be more suited but even then I doubt it. There are numerous discussion about this problem and I touch on this a bit further down.

6.      Figure 4 make the use of the absolute values more prominent in the description.

7.      Line 307. This comment about the relevance is interesting and raises the question about dependency and stationary models. Would the same result be observed if a different system state was observed? In some cases only when some FU are depressed do we see other FU come to prominence. See Kininmonth et al. 2021, Is Diversity the Missing Link in Coastal Fisheries Management?  Diversity 14 (2), 90 whilst noting the change in some benthic classes.

8.      Line 323 A key aspect missing here is the spatial interactions and configurations. For example, riparian buffer zones and the effect that has on ecosystem function etc. The topological influences generated from landscape features is important for this discussion.

9.      Line 349 fix the sentence ‘Despite…”

10.   Line 363 fix the sentence ‘cascades due…”

11.   Line 411 the notion of what is random in the world of networks is fundamentally important.  Extensive exploration of this topic has yielded many recent tools and comments about the application of networks to ecology. With some adoption from Social Sciences the use of ERGMs and the derivatives provides significant promise in being able to understand the impact of statistics to this science. While I am satisfied in the use of centrality measures etc within the context of this study there is exciting scope to apply newer methods to this type of study.

12.   Line 424 I look forward to seeing this work in ‘entire bounded solutions’.

13.   Figure 2 provide some extra description here of the negative and positive relevance to your study from line 459

 

 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The article is devoted to a relevant topic and is based on the analysis of a large amount of data.

Comment:

It is necessary to pay more attention to the formulation of the problem and the comparison of the applied method with other data - the assessment of the diversity of ecosystem components, the degree of overlap of diets, the food web, and the assessment of biomass.

The description of the study area is incomplete, the scale of the territories is also not given, I believe that a schematic map of the assessed territory, the type of economic activity, the proportion of transformed habitats, and the degree of invasion of invasive organisms are needed.

It is necessary to structurally supplement a large array of information that is poorly perceived and consider the interaction inside: "Freshwater ecosystem" and "Cropland ecosystem". The degree of internal and external interaction should be compared (according to the number of positive and negative links).

Also consider in more detail the ecosystems-linking species "Link" component, which includes the elements: 25 "Amphibian Ecosystems-linking", 26 "Birds (FCI) Ecosystems-linking" 27 Odonata "Ecosystems-linking", perhaps this list is incomplete as it is species of insects with aquatic larvae, with subsequent development at the adult stage in the terrestrial environment.

The manuscript provides an analysis of the significance of the role of invasive organisms, but this point needs to be finalized taking into account their role in ecosystem interaction and the degree of damage.

The design of "Figure 1. Signed directed graph of the ecological interactions metanetwork composed of the freshwater community, systems-linking module, and the cropland community" needs to be finalized.

At the end of the manuscript, it is necessary to give a conclusion  on the presented material.

Author Response

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Round 2

Reviewer 2 Report

The authors have done a great job of editing the manuscript.

 

Key notes have been corrected. Improved problem statement, analysis of data used for research.

The design and presentation of study results needs to be improved.

 

At the same time, the scale is (line 669) “Figure 1. Signed directed graph of the ecological interactions metanetwork composed of the freshwater community, systems-linking module, and the cropland community.” also requires a larger size.

Probably, in additional materials it is necessary to give a generalized analysis of the interaction between the blocks - aquatic birds (A), fish (B), aquatic invertebrates (C), diatoms (D), macrophytes (E), ecosystems-linking species (F), cropland birds (G), pests' natural enemies (H), pests (I), pollinators (J), crops (K) in general for a generalized characteristic - scheme and to analyze the relationships within the block in more detail.

 

These corrections will improve the understanding of the information "Figure 1" .

In conclusion, it is necessary to provide information on the key points for monitoring the biodiversity of ecosystems of this type, with the choice of a key block through which the main connections between ecosystem components pass, with justification in percentage or relative share. The authors note (line 657) "We found weak-to-moderate relationships between standard centrality measures and the measures of node importance based on the net effect matrix." . I think it is necessary to specify these key nodes. The results (line 378) state, "The strength of responses of cropland ecosystem were influenced positively by the presence of omnivores-TP birds 379

(freshwater), omnivores-C birds (cropland), carnivore birds (freshwater) and amphibians.” It is probably possible to imagine the distribution of blocks according to the degree of importance for the metanetwork.

 

It is also necessary to indicate the influence of the alien component for each block of the metanet, since agricultural lands are a channel for the introduction of alien organisms - invasive species. Previously, the authors state (line 32-34) “These services are currently seriously threatened by climate change, habitat loss, pollution, biological invasions, and other anthropogenic pressures (Schröter et al. 2005, Pereira 2020), imposing troubling uncertainties on food production. » But the topic of aliens is not disclosed, even on separate examples known for the study area. At the same time, the control of the number of alien organisms is the main measure for the management of ecosystems and the management of bioresources.

 

Important. I consider it necessary to indicate alien species (taxa) for each block (A-K) for the next stage of the study.

Author Response

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