In their manuscript, the Authors assess how habitat isolation affects Odonata assemblages in Alpine regions of Italy and Austria. Their investigated these effects at three levels: species richness, species composition, and species’ occurrences. The idea is interesting, timely, and (as the authors expressed) it directly can advice conservation effort. The study design is solid and methods used are appropriate and well-thought-out, the figures are informative and elegant. In several cases the Authors needed to compromise in data collection, but these cases are well-documented and the decisions are well-reasoned. Considering all the above, in my opinion, the manuscript is a valuable piece to publish. Although I have not found any major issues, I found the text confusing, logically flawed, or vaguely written in several occasions, those should be corrected before publication (see below). The manuscript would benefit from checking the English thoroughly to spot the typos, missing comas, and awkward sentences.
Line 17: Write “occurrences of singles species”
Line 41: Write “are increasingly threatened”
Line 44: “and raising”
Lines 46-53: In my opinion this paragraph is discusses insects too broadly, and it should focus only on freshwater insects. The knowledge gap raised here also applies more to freshwater, and particularly alpine freshwater insects, rather than insects in general. Maybe even listing some of the ecosystem functions freshwater insects drive (particularly Odonata which link freshwater and terrestrial food webs) could fit into this paragraph. On the other hand, I still have the feeling that these few lines break the logical flow of the text, so may be a better option just move them completely.
Line 54: Habitat connectivity has not been mentioned earlier. In my opinion, the logic would be clearer if the three interlinked concepts, habitat connectivity, isolation/fragmentation, and species dispersal were approached from one aspect only in the Intro. This could be dispersal, which is the key point in this ms.
Line 57: “creation OF artificial...”
Line 58: delete “landscapes”
Lines 59-61: This sentence does not read well – rephrase it slightly, please.
Line 63: delete second “often”
Line 66: write “attemptS”
Line 69: “well-studied” and delete “determinates of”
Lines 71-72: Repeated. Should be deleted from here.
Lines 88 and 91 (and may be more): “kilometres” according to UK spelling (which was followed in the ms)
Line 90: Put comma after “Yet”
Line 97: “well-sampled”
Line 99: “at three different...”
Line 105: “also affected”
Line 125: “sampled by”
Line 126: “who” instead of “that”
Line 130: do you mean were “assigned to that particular site”?
Lines 153-158: Adding a few sentences for explaining/reasoning this would help readers.
Line 171: delete “other”
Line 185: “within THIS proximity”
Line 189: So, how many sites?
Line 191: Tests for alternative distances could be added to the supplementary material
Line 217: What do you mean by “Nevertheless, results not separating the two habitat types were comparable”
Line 220: Is there any particular reason for this 100m2 threshold
Line 258: What do you mean by “maximum abundances”?
Line 267: It is not clear that the “its” is linked with elevation – rephrase the sentence slightly
Line 268: delete “and”
Line 385: The bird example is rather surprising here, and not very well connected to the text either. I think some insect-related one would be better but rephrasing is definitely needed.
Line 409: “or” instead of “but other times”
Line 413: “kilometres”
Line 414: delete “a” before consistently
Line 415: “effectS”