Intensification of Human Land Use Decreases Taxonomic, Functional, and Phylogenetic Diversity of Macroinvertebrate Community in Weihe River Basin, China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript shows a high number of graphic and statistical elaborations. It would be useful to reduce these elaborations to the essential and explanatory ones. Furthermore, the manuscript is too long, due to the fact that many ecological concepts are repeated several times. 

I recommend to revise the manuscript according to these indications: 

a) insert the list of taxa identified by season/station/impacted and non-impacted sites; 

b) try to display the meaning of the observed seasonal differences; 

c) utilize the most useful taxa as bioindicators. This aspect is too less treated.

d) reduce the number of indices and statistical analyses to the most significant ones; 

e) considerably shorten the text of all chapters;

Comments on the Quality of English Language

English need minor editing

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

A worthy paper.  Just a few corrections in English and to the legends of the box plot diagrams (in red in the returned ms).

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Author Response

This has been done. Changes are marked in red. Please see revised manuscript for details.

Answer to question1：on the taxonomic diversity of the macroinvertebrate → macroinvertebrate taxonomic diversity. See line 25.

Answer to question2：Consequently, this diminishes the number or eradicates native species while introducing alien species, exacerbating biodiversity decline →Consequently, this diminishes the number of, or eradicates native species while introducing alien species, exacerbating biodiversity decline. See line 38.

Answer to question3：in→for. See line 44.

Answer to question4： size→area. See line 141.

Answer to question5：bottom→top. See line 242.

Answer to question6：strategies. And→strategies and. See line 562.

Answer to question7：restoration. Formulate→restoration, formulate. See line 566.

Answer to question8：This also requires the joint efforts and cooperation of the government, social organizations, scientific research institutions and local communities to focus on the ecological restoration of key habitats and damaged ecosystems, establish ecological corridors and natural connecting channels, and promote ecosystem connectivity and establish a sound ecological monitoring system and so on→This also requires the joint efforts and cooperation of the government, social organizations, scientific research institutions and local communities. Focus on restoring key habitats and damaged ecosystems, establishing ecological corridors and natural connecting channels, and promoting ecosystem connectivity. And establish a sound ecological monitoring system and so on. See lines 574-575.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors,

I do not have many substantive comments on your manuscript. You will find all doubts marked in the PDF file that I am attaching. In general, your research confirms the general state of knowledge regarding the impact of the intensity of land use near rivers and other water bodies. As you have noticed, these are not very representative results because the research was conducted in only one season, and additionally, it was separated by winter, not summer. It would be much more interesting to compare several seasons, with the possibility of taking into account some anomalies, in order to better understand the constant trend.

My comment, which I would like to share with you, is that there are too many repetitions in the text. I feel as if I were reading the same sentences several times, only in a different word order. The descriptions in the results are also quite repetitive and the same as in the tables or figures.

I wish you all the best and I hope that the comments and suggestions included in the file will be useful.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Just a few minor language errors and a few suggestions for changing the wording of some sentences

Author Response

This has been done. Changes are marked in blue. Please see revised manuscript for details.

Answer to question1：This intensification of land use is also causing water quality degradation and water environmental factors change, evidenced

→ This intensification of land use is also causing water quality degradation and changes in water environmental factors, evidenced. See line 12-13.

 

Answer to question 2：leading to reduce → reducing. See line 23.

Answer to question 3：The hydrological → Hydrological. See line 24.

Answer to question 4：have a significant impact on the taxonomic diversity of the macroinvertebrate. → have a significant impact on macroinvertebrate taxonomic diversity. See line 25.

Answer to question 5: the impact of → the effects of. See line 25.

Answer to question 6: for developing →delete for. See line 27.

Answer to question 7: aimed at →for. See line 27.

Answer to question 8: the introduction of toxic compounds →toxic compounds input. See line 52.

Answer to question 9: all of which have a negative effect on aquatic → all negatively affecting. See lines 64-65.

Answer to question 10: can lead to increased nutrients  → can increase nutrients. See line 66.

Answer to question 11: (FD) and  → (FD), and. See line 90.

Answer to question 12: the hypothesis tested → the hypothesis was tested. See line 98.

Answer to question 13: This leads to the decrease of classification,  → This leads to a decrease in the classification. See line 101-102.

Answer to question 14: Please note that all paragraph numbering starts with "2.1". → This has been done. For details, see lines 124,137,163,178,219,264,297,316,361,381.

Answer to question 15: its tributaries make up the majority of  → its tributaries comprise most of. See line 108.

Answer to question 16: is 7.8 to 13.5 °C and has 113 about 500 to → is 7.8 to 13.5 °C, with about 500 to. See line 112.

Answer to question 17: carries a significant amount of silt due to →carries significant silt due to. See line 115.

Answer to question 18: Lines 143-153 → This has been done. For details, see lines 220-230.

And (Fig. 2A), whereas in spring, PC1 → (Fig. 2A). In contrast, in spring, PC1. See lines 221.

Answer to question 19: under an anatomical microscope. → under microscope. See line 146.

Answer to question 20: while a portable pH indicator →while a portable pH indicator (HANNA instruments, model: HI 98130). See lines 152-153.

Answer to question 21: was classified into two categories. →was classified into low and high intensity. See line 180.

Answer to question 22: genus, family, order, class, phylum, and border. →genus, family, order, class, phylum, and kingdom. See line 204.

Answer to question 23: the fall exerted a notable impact on both→the fall notably impacted both. See line 254.

Answer to question 24: with autumn having greater species richness than spring→Delete. See lines 299.

Answer to question 25: Autumn had 341 a slightly higher Simpson's diversity index compared to spring →Delete. See line 307.

Answer to question 26: There were significant differences in the functional richness index between the high- 378 intensity group and the low-intensity group. →Significant differences existed in the functional richness index between the high-intensity and low-intensity groups. See lines 339-340.

Answer to question 27: land use intensity→land use intensities. See line 389.

Answer to question 28: land use intensity→land use intensities. See line 397.

Answer to question 29: Additionally, we also observed differences in hydrological factors under different human land use intensity

→We also observed different in hydrological factors under different human land use intensities in autumn. See line 389.

Answer to question 30: These findings indicate that the increase of land use intensity will increase the concentration of total nitrogen and may also decrease the level of dissolved oxygen

→These findings indicate that the increase of land use intensities will augment the concentration of total nitrogen and may also decrease the dissolved oxygen level. See lines 426-427.

Answer to question 31: a. Notably, no significant difference was observed in the dominant species between spring and autumn.

→Notably, no significant difference between spring and autumn was observed in the dominant species. See lines 436-437.

Answer to question 32: species richness showed a significant decline→species richness significantly declined. See line 448.

Answer to question 33: hypothesis that an increase in human n land use intensity leads to a reduction in taxonomic diversity

→hypothesis that increased human land use intensity reduces taxonomic diversity. See line 453.

Answer to question 34: Notably, Limnodrilus and Branchiura species were significantly more abundant in the high-intensity group compared to the low-intensity. Diversity group. These findings highlight the role of functional traits in mediating the relationship between macroinvertebrate populations and their environment. Environmental factors, influenced by varying levels of human land use, can alter the primary traits of functional groups, thereby affecting the composition of macroinvertebrates.

→Delete. See line 457.

Answer to question 35: such as multivoltinism →such as multivoltine. See line 459.

Answer to question 36:It is assumed that functional diversity is significantly affected by human activities→Delete. See line 471.

Answer to question 37:the hypothesis suggesting that→the hypothesis suggested that. See line 486.

Answer to question 38: land use intensity had significant effects on the taxonomic diversity of macroinvertebrate communities. The result is consistent with the previous research, strong man-made interference will cause hydrological changes, which will have an impact on the river ecosystem.

→land use intensities significantly affected the taxonomic diversity of macroinvertebrate communities. The result is consistent with the previous research, which states that strong man-made interference will cause hydrological changes that will impact the river ecosystem. See lines 496-499.

Answer to question 39: In the study area with great human disturbance, hydrological factors such as discharge and depth reduce the richness and diversity of macroinvertebrate community. In addition to the above factors, the point distribution of high-intensity group is close to the main river compared with that of low-intensity group. River width, Diversity water depth and discharge is large.

→In addition to the above factors, the point distribution of the high-intensity group is close to the main river compared with that of the low-intensity group. River width, water depth and discharge are large. See lines 499-502.

Answer to question 40: the content of→The content of. See line 511.

Answer to question 41: From the above research results, it can be seen that→ The above research results show that. See line514.

Answer to question 42: in order to predict→to predict. . See line 545.

Answer to question 43: take into account→consider . See line 546.

Answer to question 44: Focus on the ecological restoration of key habitats and damaged ecosystems, establish ecological corridors and natural connecting channels, and promote ecosystem connectivity. →Focus on restoring key habitats and damaged ecosystems, establishing ecological corridors and natural connecting channels, and promoting ecosystem connectivity. See lines574-575.

Reviewer 4 Report

Comments and Suggestions for Authors

The Authors concentrated on calculating various indices so intently, that they seem to have neglected the object of their study, i.e. the Weihe River Basin. The structure of the manuscript should be reconsidered.

1. Problems appear already in the description of the investigated area. The sampling sites are not described, only marked on a map. Lack of proper description results in some gaps requiring elucidation, e.g.:

   1. Figure 4 – why the difference in the width of rivers flowing through the high‑intensity land-use areas between autumn and spring is bigger than the same difference in rivers flowing through the low-intensity land-use areas? One would expect more extensive channel regulations in the former, and, consequently, fewer changes in the river width.

   2. Table S2 – why the altitude changed between autumn and spring? In the case of the high‑intensity land-use areas it amounts to over 300 meters. Mountain-building processes are rarely that quick.

2. Sampling:

   1. The substratum from which the Surber samples were taken should be characterised, and possible differences in the type of substratum among the sampling sites should be reported. Type of substratum has bearing upon the composition of macrobenthic assemblage.

   2. l. 191 – measuring water velocity with an anemometer does not look like a good idea. Measurements would not be reliable.

   3. Throughout the text, traits (Table 1) look completely detached from the animals collected. How did the Authors assign traits to the collected macroinvertebrates? Did they use literature data, or carried out their own investigations?

3. Data analysis:

   1. Generally, the paper is far too long, overloaded with theory, as if the Authors were writing a handbook. About a third of the text should be left out. Two examples:

      • l. 135-142 – description of the PCA.

      • l. 249-263 – theory of the phylogenetic diversity.

   2. The Authors employed a couple of software packages to carry out their analyses. None of the packages is properly cited! Please, go to appropriate manuals/web pages and find out how to cite the software.

   3. How have the Authors defined the “frequency of occurrence” (l. 223) – as number or as percentage?

4. Technical remarks:

   1. l. 45 – Earth.

   2. l. 105 – subchapter number 2.1 appears here, and also in the lines: 126, 174, 200, 215, 276, 297, 330, 354, 416, 440.

   3. l. 107 – 134.766 km² is not that much. Probably the Authors mean 134,766 km².

   4. Figure 1, inset – the lines delimiting the provinces of China should be thinner.

   5. ll. 143-157 – this part should be moved to the Results section.

   6. Figure 2 – why have not the high- and low-intensity land-use areas been marked differently in the graphs.

   7. Figures 3, 4, 6, 8, 9 – remove grid from within graphs.

   8. l. 168/169 – “the bottom and bottom” – something wrong here.

   9. Table 1 – introducing horizontal lines between traits would make the table clearer.

   10. Table 2 – the column “Latin name” is redundant. The same Latin names appear in the column “Genus”.

   11. Figure 7 – consider the “Autumn High” swapping place with the “Spring Low”.

   12. l. 597 – what does “citation of alien species” mean?

   13. All the figures – use bigger font at axes and legends.

Comments on the Quality of English Language

generally good

Author Response

Please see revised manuscript for details.

Question 1a: Problems appear already in the description of the investigated area. The sampling sites are not described, only marked on a map. Lack of proper description results in some gaps requiring elucidation, e.g. Figure 4 – why the difference in the width of rivers flowing through the high‑intensity land-use areas between autumn and spring is bigger than the same difference in rivers flowing through the low-intensity land-use areas? One would expect more extensive channel regulations in the former, and, consequently, fewer changes in the river width.

Answer to question 1a: The Weihe River basin is an important industrial hub in China. The Yellow River basin has high sediment concentration and high soil and water loss rate. Heavy rainfall in autumn, strong human interference, and then the river embankment broken seriously. The above combined factors lead to the increase of flow and the increase of river width. In spring, the rainfall is low, and the hydrological factors are reduced, so there is no significant difference. For details, see lines 418-426.

 

Question 1b. Table S2 – why the altitude changed between autumn and spring? In the case of the high‑intensity land-use areas it amounts to over 300 meters. Mountain-building processes are rarely that quick.

Answer to question 1b: Two sample surveys were conducted in this study, namely autumn and spring. However, due to the uncertainty of field sampling, there are several points in spring that do not completely coincide with autumn, but the land use intensity of the points is consistent with that of the previous points. This paper explored the relationship between land use intensity and macrobenthic diversity, but did not focus on seasons and macrobenthic diversity. Only two field surveys were used as parallel experiments. Despite the difference in elevation, the land use intensity under the two surveys was basically consistent with the main influencing factors in the analysis of macroinvertebrate fauna diversity. See Fig 4. Fig 10 for details.

 

Question 2a: Sampling:The substratum from which the Surber samples were taken should be characterised, and possible differences in the type of substratum among the sampling sites should be reported. Type of substratum has bearing upon the composition of macrobenthic assemblage.

Answer to question 2a: In general, the composition of macrobenthic communities is affected by the type of substrate. However, in this experiment, the matrix data of low intensity and high intensity land use classification were calculated and analyzed, and no significant difference was found. Substrate type was not a factor in the change of macrobenthic communities under different land use intensities. Therefore, the effect of substrate type on macrobenthic communities is not discussed in detail.

 

Question 2b. l. 191 – measuring water velocity with an anemometer does not look like a good idea. Measurements would not be reliable.

Answer to question 2b: Thank you for your guidance on the measuring instrument. We will use the measuring instrument more strictly in the investigation and research to ensure more accurate measurement results.

 

Question 2c. Throughout the text, traits (Table 1) look completely detached from the animals collected. How did the Authors assign traits to the collected macroinvertebrates? Did they use literature data, or carried out their own investigations?

Answer to question 2c: In this investigation, a large number of books and literature on macrobenthos were consulted, and macrobenthos were classified and identified according to the life history and other characteristics of the organisms in the books and literature, and relevant experts were consulted for further confirmation. Try to identify the species, if the characteristics are not obvious, then identify the family, genus, to ensure the accuracy of identification.

 

Question 3a: Data analysis: Generally, the paper is far too long, overloaded with theory, as if the Authors were writing a handbook. About a third of the text should be left out. Two examples:

1. 135-142 – description of the PCA.
2. 249-263 – theory of the phylogenetic diversity.

Answer to question 3a: This has been done. Delete lines 135-142 – description of the PCA. And 249-263 – theory of the phylogenetic diversity. See lines 132,193-205.

 

Question 3b. The Authors employed a couple of software packages to carry out their analyses. None of the packages is properly cited! Please, go to appropriate manuals/web pages and find out how to cite the software.

Answer to question 3b: This has been done. For details, see lines 179,190-192,196,205,214.

 

Question 3c. How have the Authors defined the “frequency of occurrence” (l. 223) – as number or as percentage?

Answer to question 3c: The dominant species is determined according to the dominant value Y of each species, that is, the occurrence frequency of species and the number of individuals. fi is the occurrence frequency of the species i. Fi is the occurrence frequency of the species i. Numbers, not percentages. See line 186.

 

Question 4a: Technical remarks:. l. 45 – Earth.

Answer to question 4a: This has been done. earth→Earth. For details, see line 45.

 

Question 4b. l. 105 – subchapter number 2.1 appears here, and also in the lines: 126, 174, 200, 215, 276, 297, 330, 354, 416, 440.

Answer to question 4b: This has been done. For details, see line 124,137,163,178,219,264,297,316,361,381.

 

Question 4c. l. 107 – 134.766 km2 is not that much. Probably the Authors mean 134,766 km2.

Answer to question 4c: This has been done. For details, see line 106.

 

Question 4d. Figure 1, inset – the lines delimiting the provinces of China should be thinner.

Answer to question 4d: This has been done. For details, see Figure 1.

 

Question 4e. ll. 143-157 – this part should be moved to the Results section.

Answer to question 4e: This has been done. For details, see lines 220-230.

 

Question 4f. Figure 2 – why have not the high- and low-intensity land-use areas been marked differently in the graphs.

Answer to question 4f: This has been done. For details, see Figure 2.

 

Question 4g. Figures 3, 4, 6, 8, 9 – remove grid from within graphs.

Answer to question 4g: This has been done. For details, see Figure 3, 4, 6, 8, 9.

 

Question 4h. l. 168/169 – “the bottom and bottom” – something wrong here.

Answer to question 4h: This has been done. For details, see line 242.

 

Question 4i. Table 1 – introducing horizontal lines between traits would make the table clearer.

Answer to question 4i: This has been done. For details, see Table 1.

 

Question 4j. Table 2 – the column “Latin name” is redundant. The same Latin names appear in the column “Genus”.

Answer to question 4j: This has been done. For details, see Table 2.

 

Question 4k. Figure 7 – consider the “Autumn High” swapping place with the “Spring Low”.

Answer to question 4k: This has been done. For details, see Figure 7.

 

Question 4l. l. 597 – what does “citation of alien species” mean?

Answer to question 4i: Proposed factors that may affect land use intensity and macroinvertebrate biodiversity. The citation of alien species may change the structure and function of river ecosystems, creating competitive pressure and predation pressure on macroinvertebrates. These factors may interact with each other and jointly affect the biodiversity of macroinvertebrates. For details, see lines 527-530.

 

Question 4m. All the figures – use bigger font at axes and legends

Answer to question 4i: This has been done.

Round 2

Reviewer 4 Report

Comments and Suggestions for Authors

 

The paper was improved, yet some minor problems remain. Please, find below comments to the Authors’ reply.

1. Answer to question 1b: Two sample surveys were conducted in this study, namely autumn and spring. However, due to the uncertainty of field sampling, there are several points in spring that do not completely coincide with autumn… This should be clearly stated in the Methods section. The statement in lines 138/139 suggests that all the 34 sites were visited during both surveys.

2. Answer to question 2b: We will use the measuring instrument more strictly. I would start with visiting the following web pages:

   1. https://en.wikipedia.org/wiki/Anemometer

   2. https://www.ysi.com/File%20Library/Documents/Specification%20Sheets/FP111-Flow-Probe-Specification-Sheet.pdf

3. Question 3c. How have the Authors defined the “frequency of occurrence” (l. 223) – as number or as percentage? Answer to question 3c: […] . fi is the occurrence frequency of the species i. Fi is the occurrence frequency of the species i. Numbers, not percentages. Explanation stating that “the frequency of occurrence” is “the occurrence frequency” is no explanation. The Authors have to clearly state, how did they calculate this parameter.

4. Answer to question 4d: For details, see Figure 1. The Authors misunderstood me here. In my opinion the inner administrative division of China should have been made less conspicuous as it adds nothing to this paper. In the present version this division has been made more detailed, which actually lessens the clarity of the map.

5. Question 4l. l. 597 – what does “citation of alien species” mean? Answer to this question is yet another misunderstanding. What I have meant is the word “citation” being out of place there. Both, in their reply and in the text the Authors mean “invasion/arrival” or something along these lines.

6. Figure 5. In the graph illustrating the density of macrofauna there are two problems with the Y axis:

   1. Instead of “Density” there is “Densitv” – word ending with “v”, unless it is “y”. the bottom of which has been obscured by axis labels.

   2. In the axis labels use “×” instead of “x”.

.

Comments on the Quality of English Language

Generally English is acceptable, yet the language needs polishing by a native speaker.

Author Response

Question 1: Answer to question 1b: Two sample surveys were conducted in this study, namely autumn and spring. However, due to the uncertainty of field sampling, there are several points in spring that do not completely coincide with autumn… This should be clearly stated in the Methods section. The statement in lines 138/139 suggests that all the 34 sites were visited during both surveys.

Answer to question 1: This has been done. Two sample surveys were conducted in October 2011 and April 2012 as parallel experiments. Due to the uncertainty of field sampling, the two survey points were not exactly the same, but their land use intensity was consistent. 34 sampling points were selected in the whole Weihe River basin. For details, see lines 139-142.

Question 2: Answer to question 2b: We will use the measuring instrument more strictly. I would start with visiting the following web pages:

https://en.wikipedia.org/wiki/Anemometer

https://www.ysi.com/File%20Library/Documents/Specification%20Sheets/FP111-Flow-Probe-Specification-Sheet.pdf

Answer to question 2: This has been done. For details, see lines 156-160. Insitu measurements of water depth (Depth) and velocity (Velo) were conducted using a digital handheld water velocity meter (FP111). Used the measuring instrument more strictly, we would start with visiting the following web pages: https://www.ysi.com/File%20Library/Documents/Specification%20Sheets/FP111-Flow-Probe-Specification-Sheet.pdf.

Question 3: How have the Authors defined the “frequency of occurrence” (l. 223) – as number or as percentage? Answer to question 3c: […] . fi is the occurrence frequency of the species i. Fi is the occurrence frequency of the species i. Numbers, not percentages. Explanation stating that “the frequency of occurrence” is “the occurrence frequency” is no explanation. The Authors have to clearly state, how did they calculate this parameter.

Answer to question 3: This has been done. fi is the occurrence frequency of species i, that is, the ratio of the sample number of species i occurrence to the total sample number under different land use intensity. For details, see lines 192-194.

Question 4: Answer to question 4d: For details, see Figure 1. The Authors misunderstood me here. In my opinion the inner administrative division of China should have been made less conspicuous as it adds nothing to this paper. In the present version this division has been made more detailed, which actually lessens the clarity of the map.

Answer to question 4: This has been done. For details, see Figure 1.

Question 5: Question 4l. l. 597 – what does “citation of alien species” mean? Answer to this question is yet another misunderstanding. What I have meant is the word “citation” being out of place there. Both, in their reply and in the text the Authors mean “invasion/arrival” or something along these lines.

Answer to question 5: Thank you for correcting the unreasonable part, and the unreasonable part has been deleted in the manuscript. 533-534.

Question 6: Figure 5. In the graph illustrating the density of macrofauna there are two problems with the Y axis:

 Instead of “Density” there is “Densitv” – word ending with “v”, unless it is “y”. the bottom of which has been obscured by axis labels.

 In the axis labels use “×” instead of “x”.

Answer to question 5: This has been done. For details, see Figure 5.