Tests of Hexazinone and Tebuthiuron for Control of Exotic Plants in Kauai, Hawaii
Round 1
Reviewer 1 Report
This report describes an applied study of the impacts of two herbicides on target invasive species and non-target native species in two Hawaiian ecosystems. Certainly, invasive species are a significant ecological issue and their management could benefit native species and help to restore native systems. While potentially informative to land managers within the context of invasive species control and native plant management, the research design was not comprehensively described, data do not appear to have been analyzed statistically, and the results were difficult to discern from more speculative discussion of those results.
Abstract:
‘Hawaii’s delicate…ecosystem’ is redundant in the first two sentences.
Lines 21-21: This assessment is confusing because first you saw that the herbicides were not effective on the species tested, but then you say that they did affect the non-native species included in your study.
It would be helpful for the abstract and/or keywords to contain names of species included in the study so that they would be searchable by other researchers and land managers interested in those species. And it should be made very clear which species are non-native and which were native. Without this basic information, this isn’t clear.
Line 23: Was transplantation a part of your study? Or were species previously transplanted? This isn’t clear. Was this mortality caused by the herbicide? What reasons do you have to suspect the list of potential causes listed in line 24?
Introduction:
The first paragraph of the introduction starts very broad. I think that it would improve the manuscript to narrow the scope of the first paragraph. I would suggest a quicker introduction to the focus of the research.
Was there a reason to think that the herbicides would potentially impact native species differently than invasive species? Was the research hypothesis driven? Or only exploratory?
Materials and Methods:
In subsection 2.1 on ‘Study Sites’ could you provide specific information about the presence of the various species in each of the sites (both native and invasive species) in terms of percent cover or relative abundance? Without this information, it is difficult to envision the sites. In addition, could you provide temperature data for each site? Also, information about soils?
Line 90 is confusing. Was average rainfall 1651 mm or 1092 mm?
Line 113: How many plots were located in each site? How were plot locations within each site
determined?
Line 115: Manufacturer locations should be provided in parentheses.
Line 118: How does hand spreading ensure uniformity of application? Wouldn’t equipment ensure more uniform application? And what does ‘in four increments’ mean? If each application covered half of the plot, why were there four applications instead of two?
Line 119: Why were these herbicide application rates used? Were there replicate plots? Or was there only one plot per application rate?
Lines 119:121: Why did evaluation occur a full year after herbicide application? Would defoliation still be expected at that time?
Line 124: Were ‘plots’ from which soil was collected the same ‘plots’ are used for the herbicide application? If so, why were there so many more plots for soil sampling than for herbicide application?
Overall, in both subsections 2.2 and 2.3, it is difficult to figure out how many plots, subplots, replicates, etc. were used in the experimental design. Information is needed to clarify the experimental design.
Line 136: What were the ‘outplantings’ specifically? Did these differ from transplants? Why were only two individual plants used per plot? Is this enough for robust experimental design?
Line 143: Where were these ‘various parts of Kauai’ exactly? Detail in methods should provide for the ability to replicate the experiment.
Were results analyzed statistically? For example were differences in defoliation percentages (as a dependent variable determined for herbicide type, application rates, and species origin (native vs. non-native)? This information needs to be included in the methods section.
Results:
Overall, discussion of results needs to be presented separately. As written the Results section contains much discussion and this makes it difficult to ascertain the results of the research from more speculative information that is presented. If this section is intended to be a ‘Results and Discussion’, then I would still suggest that results be presented first in paragraphs and then discussed later in those paragraphs to help distinguish between what was studied and what was speculated.
It is very difficult as a reader to see the results in an organized way when they are all presented in text that goes quickly between native and non-native species. Figure 2 is helpful, but I think it would be clearer to separate out some of the information in this single panel into multiple panels. For example, one panel for hexazinone and one for tebuthiuron and/or one panel for native species and one for invasive species.
Figure 2: Are standard deviations or standard errors depicted in this figure? Also what does ohia1, ohia2, and ohia3 mean? Why was ohia measured at different life stages?
Figure legends: These need to present more information so as to be ‘standalone’. It is not clear from the legends what terms like C, H1, H2, etc. mean.
Lines 205-206: Is it considered ‘residue’ if it is measured immediately after application? Also, the information in this subsection (3.2) would be clear presented as a table or figure.
Lines 224-225: This is confusing. You say that results were lost to feral deer and goats, but then that there was less than 10% mortality.
Overall, how was mortality due to residual herbicide distinguished from mortality due to other causes (like feral hogs and goats)?
Tables 1 and 2: Are these mean values? Are there standard deviations or standard errors to report?
Conclusions:
The conclusion should also describe the impacts of the herbicides on non-target native species.
General:
Overall, this manuscript would benefit from thorough editing for language and grammar.
Please use either Latin names or common names of species throughout the report. Switching back and forth leads to confusion.
Author Response
1. This report describes an applied study of the impacts of two herbicides on target invasive species and non-target native species in two Hawaiian ecosystems. Certainly, invasive species are a significant ecological issue and their management could benefit native species and help to restore native systems. While potentially informative to land managers within the context of invasive species control and native plant management, the research design was not comprehensively described, data do not appear to have been analyzed statistically, and the results were difficult to discern from more speculative discussion of those results.
ANS: Thank you very much for your comments. I will revise the manuscript as suggested.
Abstract
2. ‘Hawaii’s delicate…ecosystem’ is redundant in the first two sentences.
ANS: As suggested, ‘Hawaii’s delicate…ecosystem’ has been deleted.
3. Lines 21-21: This assessment is confusing because first you saw that the herbicides were not effective on the species tested, but then you say that they did affect the non-native species included in your study.
ANS: The herbicides were effective on the species tested, and they didn’t affect the non-native species in the study. It is wrong word “ineffective” and it was corrected as “effective”.
4. It would be helpful for the abstract and/or keywords to contain names of species included in the study so that they would be searchable by other researchers and land managers interested in those species. And it should be made very clear which species are non-native and which were native. Without this basic information, this isn’t clear.
ANS: Thanks for your comments. As suggested, these basic information about non-native and native species have been added to abstract parts.
5. Line 23: Was transplantation a part of your study? Or were species previously transplanted? This isn’t clear. Was this mortality caused by the herbicide? What reasons do you have to suspect the list of potential causes listed in line 24?
ANS: Transplantation was a part of the preliminary study. Six months after treatment, native plants were transplanted into each plot and observed for injury from residual herbicides.
Introduction:
6. The first paragraph of the introduction starts very broad. I think that it would improve the manuscript to narrow the scope of the first paragraph. I would suggest a quicker introduction to the focus of the research.
ANS: As suggested, I has corrected the first paragraph.
Was there a reason to think that the herbicides would potentially impact native species differently than invasive species? Was the research hypothesis driven? Or only exploratory?
ANS: Thanks for your comments. The herbicides have different impact between native and invasive species after field tests. Some studies have reported the difference.
Materials and Methods:
7. In subsection 2.1 on ‘Study Sites’ could you provide specific information about the presence of the various species in each of the sites (both native and invasive species) in terms of percent cover or relative abundance? Without this information, it is difficult to envision the sites. In addition, could you provide temperature data for each site? Also, information about soils?
ANS: As suggested, these species at each have been listed. Average temperature was 20-28 °C in study sites.
8. Line 90 is confusing. Was average rainfall 1651 mm or 1092 mm?
ANS: Average rainfall was 1651 mm.
9. Line 113: How many plots were located in each site? How were plot locations within each site determined?
ANS: Thanks for your comments. The procedures followed at both sites were identical. Detailed plot information and experiment design have been added. There were a total of 14 large plots in each site. The large 10x10 m plots were separated by a 5 m buffer. Each large plot was equally divided to two treatments. Each treatment had 4 replicates.
10. Line 115: Manufacturer locations should be provided in parentheses.
ANS: As suggested, Manufacturer locations have been given in manuscript.
11. Line 118: How does hand spreading ensure uniformity of application? Wouldn’t equipment ensure more uniform application? And what does ‘in four increments’ mean? If each application covered half of the plot, why were there four applications instead of two?
ANS: It was a statement error. Four increments have been deleted from manuscript.
12. Line 119: Why were these herbicide application rates used? Were there replicate plots? Or was there only one plot per application rate?
ANS: The application rates were based on experiment tested in the lab. Each application covered an half plot and two applications were perpendicular to the other two. There were a series of applications for comparison.
13. Lines 119:121: Why did evaluation occur a full year after herbicide application? Would defoliation still be expected at that time?
ANS: We selected 12 months as an evaluation period to observe how long the effective control would last. Such information would be useful for practical management of invasive plant species in Hawaii.
14. Line 124: Were ‘plots’ from which soil was collected the same ‘plots’ are used for the herbicide application? If so, why were there so many more plots for soil sampling than for herbicide application?
ANS: For comparison study, the same four plots were used for a series of herbicide application. We collected soils from four study plots.
15. Overall, in both subsections 2.2 and 2.3, it is difficult to figure out how many plots, subplots, replicates, etc. were used in the experimental design. Information is needed to clarify the experimental design.
ANS: The subsections 2.2 and 2.3 have been revised to further clarify the experiment designs.
16. Line 136: What were the ‘outplantings’ specifically? Did these differ from transplants? Why were only two individual plants used per plot? Is this enough for robust experimental design?
ANS: As suggested, outplantings was replaced by transplants. We selected two represented plant species as testing sample in per plot. Finally, the study result will apply to multiply species evaluation.
17. Line 143: Where were these ‘various parts of Kauai’ exactly? Detail in methods should provide for the ability to replicate the experiment.
ANS: Each plot was 10 m x 10 m in 4 replicates. To test the efficacy of hexazinone and tebuthiuron on invasive species not present in the large plots or poorly represented there, a series of preliminary trials were also conducted in Kauai. In these trials, targeted weeds in 5 m diameter circular plots were treated with 0, 1, 2 and 4 kg ha-1 of hexazinone or tebuthiruon and evaluated for susceptibility to the treatments.
18. Were results analyzed statistically? For example were differences in defoliation percentages (as a dependent variable determined for herbicide type, application rates, and species origin (native vs. non-native)? This information needs to be included in the methods section.
ANS: Thank you very much for your comments. Each experiment included three replicates in this study. SD was also listed in the figures as the results were statistically analyzed. Different herbicide types, application rates, and species origins were evaluated for defoliation percentages.
Results:
19. Overall, discussion of results needs to be presented separately. As written the Results section contains much discussion and this makes it difficult to ascertain the results of the research from more speculative information that is presented. If this section is intended to be a ‘Results and Discussion’, then I would still suggest that results be presented first in paragraphs and then discussed later in those paragraphs to help distinguish between what was studied and what was speculated.
ANS: We have kept this section as “Results and Discussion” As suggested, we have separated results from discussion.
20. It is very difficult as a reader to see the results in an organized way when they are all presented in text that goes quickly between native and non-native species. Figure 2 is helpful, but I think it would be clearer to separate out some of the information in this single panel into multiple panels. For example, one panel for hexazinone and one for tebuthiuron and/or one panel for native species and one for invasive species.
ANS: Thanks for your comments. The manuscript has revised to improve its readability.
21. Figure 2: Are standard deviations or standard errors depicted in this figure? Also what does ohia1, ohia2, and ohia3 mean? Why was ohia measured at different life stages?
ANS: It was standard deviations in this figure. They represented different life periods such as ohia 1 (<3months), ohia2 (4-8 months), and ohia3 (> 9months). It was to observe how long the field control efficacy would last.
22. Figure legends: These need to present more information so as to be ‘standalone’. It is not clear from the legends what terms like C, H1, H2, etc. mean.
ANS: As suggested, additional information has been added in Figure legends.
23. Lines 205-206: Is it considered ‘residue’ if it is measured immediately after application? Also, the information in this subsection (3.2) would be clear presented as a table or figure.
ANS：Yes, it was measured immediately after application.
24. Lines 224-225: This is confusing. You say that results were lost to feral deer and goats, but then that there was less than 10% mortality.
ANS: As suggested, the part has been revised in the manuscript. The revised text: “The results of sensitivity of replanted natives in Site II were somewhat affected by feral deer and goats because enclosure of the site was not feasible. Approximately less than 10% mortality was observed for out-planted native species after three months treatment (3 MAP), indicating the native species showed less injury in the early period of transplant (Figure 4).”
25. Overall, how was mortality due to residual herbicide distinguished from mortality due to other causes (like feral hogs and goats)?
ANS: Thanks for your comments. Mortality was mainly due to herbicide. Damages by feral hogs and goats were apparent and differed from mortality caused by the herbicides.
26. Tables 1 and 2: Are these mean values? Are there standard deviations or standard errors to report?
ANS: They are mean values and there were no standard deviations.
Conclusions:
27. The conclusion should also describe the impacts of the herbicides on non-target native species.
ANS: As suggested, the conclusion has included the impacts of the herbicides on non-target native species.
General:
28. Overall, this manuscript would benefit from thorough editing for language and grammar.
ANS: As suggested, the language and grammar have been thoroughly revised.
29. Please use either Latin names or common names of species throughout the report. Switching back and forth leads to confusion.
ANS: As suggested, they have been given in manuscript.
Reviewer 2 Report
The manuscript “Practical Measure for Control of Alien Plants in Delicate Island Ecosystem of North Pacific Ocean” relates to the use of herbicides for the control of invader plants in two different ecosystems in Hawaii. This is a relevant matter, as the invasion of small islands by introduced species is one of the major threats to their natural ecosystems.
However, this contribution has several serious shortfalls and needs a profound revision.
The main points that should be address are:
- The objectives of the work must be clearly explained, and the results and conclusion should be according to them.
- The methodology should be improved; the description of the procedures is not clear.
- A suggestion: please use always the scientific name of plant species (although common name can be also included); to readers not familiar with the Hawaiian flora the common names are difficult to follow.
- Although I'm not an English-speaking native, I think that the English language and style need some improvement.
Abstract:
Ln 22 – ‘Result showed that broadcast applications of hexazinone granules and tebuthiuron pellets within 5m diameter circular plots seemed ineffective on the species tested.’ – later (Ln. 113) 10 m plots are referred. Check this.
Ln 24 – ‘indicating fertilizer, fungicide, insecticide applications and remediation of herbicide may be required to start native plants.’ – I don’t understand how this conclusion can be drawn.
Ln 27 – ‘Efficacy [of Koa – Leucaena - to tebuthiuron] can be improved by grid application which would probably offer more protection to non-target species and therefore be more practical in forest management.’ – Above (Ln. 22), 5 m diameter plots are referred. The abstract should be understood even without reading the complete manuscript.
Introduction
Ln 40 – ‘are all not satisfied ‘- Check this sentence. Also, isn’t it in contradiction with Ln 42, concerning the success of herbicides use?
Ln 41 – ‘penology’ – replace by ‘phenology’
Check specie names in a recognized data base (e.g. Tropicos). Some examples:
Ln. 66 ‘Leucaena leucocephalla’ – replace by ‘Leucaena leucocephala’
Ln. 70 ‘Pinus elliotii’ – replace by ‘Pinus elliottii’
Ln. 76 ‘Acacia KOA’ – replace by ‘Acacia koa’
Ln 98 – ‘paspalum urvillei’ - replace by ‘Paspalum urvillei’
Ln 82 – ‘efficacy of hexazinone and tebuthiuron on major invasive forest weeds were also investigated.’ – replace by ‘other major invasive weeds’? I think that weeds in the two main sites (I and II) are also important weeds.
Ln 90 – ‘Average rainfall was 1651 mm but only 1092 mm, …’ – Check this sentence.
Ln 95 – ‘The soil was described by Nakamura [25].’ – Give some detail about the soil; as it is latter discussed, soil characteristics are important to the analysis of the results.
Figure 1 could be improved
Ln 106 – ‘average rainfall of 536 mm during 1999 and 2000.’ Average rainfall values using two years makes no sense.
Also, in Ln 108 – ‘Rainfall here was seasonal, with annual dry seasons in the summer months.’ – Check this sentence (it seems incorrect).
Climate characterization of both sites (I and II) needs to be improved.
Material and Methods:
When where the essays made?
Ln. 113 - How many plots were set? In Ln. 142, 28 plots are referred but previously this number was not mentioned.
Plots 10 m? Which is the area of each one (10 x 10 m?).
L. 126 – ‘located about a quarter mile east of the Kalalau lookout in Kokee State Park of Kauai’ – this should be referred in point 2.1 (study site).
Ln. 134 - aalii (D. viscosa) – include the full name.
Ln. 135 – ‘Each plot was planted to two plants of each species except for D. rhytidosperma with four plants in each plot.’ – This number seems too small. And why four plants in the case of D. rhytidosperma?
Ln. 136 – ‘Out-plantings’ – What is the meaning?
Ln. 141 – ‘2.5. Efficacy of hexazinone and tebuthiuron on major invasive forest weeds, gives the wrong idea that the other weeds are not major invasive’. Consider adjust this title (2.5. Efficacy of hexazinone and tebuthiuron on other major invasive forest weeds)
Results:
Ln. 152 – If the date of the trials is not referred, the reader will not understand the reference to the hurricane in 1992.
Ln. 163 – ‘demonstrated a rate response to tebuthiuron.’ - What is “a rate response”?
Ln. 170 – No control plot concerning M. faya?
Ln. 185 – In Fig. 2 and 3 error bars have values above 100%. I think that this is not possible.
Ln 194 ‘Ironwood (casuarinas) was moderately susceptible to hexazinone and tebuthiuron although the control was almost as severely injured.’ – Is this the 'casuarina' in Fig. 3? The same name should be used.
Ln. 202 – Figure 3 - Were methods different in site II? In x-axis it is ohia 3, 4-8, >9 months, while in Figure 2 it is ohia 1, 2, etc…
Check Figure 3 in relation to text. It seems that some of the results pointed does not fit the figure (e.g. Ln. 188 - ‘Overall, injury at 12 months was greater than at 6 months.’; ‘At 12 months, the smallest class size of ohia (7.5 cm or less) showed a response to…’ (?);
Ln. 192 - ‘In the larger class sizes of ohia (10 to 20 cm and 23 cm or larger)? – This is the first time size values are referred. How do they match with to the ohia 1, ohia 2, etc…?
Ln 206 – Without reference values it is not possible to know if the residue levels are low or high and if they are comparable (those of tebuthiuron and hexazinone). Perhaps include some note about this.
Ln 211 to 215 - A figure with the values of residue perhaps would be better than the descriptive presentation made in these lines.
Ln. 231 – ‘The response of out-planted native species suggested that fertilizer, fungicide, insecticide applications and remediation of herbicide may be required to start native plants [30, 31].’ – What does this mean? I don’t understand how this conclusion can be drawn (as above, in the abstract).
Ln. 238 – ‘schizachyrium trials’ – ‘Schizachyrium trials’
Ln 246 to 249 - Is not clear why results with herbicides not used in present work are referred.
Ln 251 - ‘so would be useful in establishing the native koa if koa is also tolerant to tebuthiuron.’ – check English.
Ln. 257 - In Table 1 (and in Table 2), as well in text, use scientific names.
Ln. 261 – explain why they ‘were unexpectedly tolerant’.
Ln. 261 to 267 - The discussion about the type of application (plot, grid, spot-gun) was not in the objectives and needs to be situated within the context of the developed work.
Point 3.4 is difficult to follow, as different matters are mixed. Also, there are several mentions that should be contextualized. Improvement is needed.
Conclusions
Ln. 284 – ‘Broadcast applications of hexazinone granules and tebuthiuron pellets within 5 m diameter circular plots…’ - This procedure was only used in trials with other invasive forest weeds (point 2.5). And the other trials? If the reader only reads the conclusions, he will not have any idea about which the main conclusions are. This point needs to be much improved.
Author Response
1. The manuscript “Practical Measure for Control of Alien Plants in Delicate Island Ecosystem of North Pacific Ocean” relates to the use of herbicides for the control of invader plants in two different ecosystems in Hawaii. This is a relevant matter, as the invasion of small islands by introduced species is one of the major threats to their natural ecosystems.
ANS：Thanks for your comments. I will revise the manuscript based on your comments.
2. However, this contribution has several serious shortfalls and needs a profound revision. The main points that should be address are:
ANS：Thanks for your comments. I will revise the manuscript based on your comments.
3. The objectives of the work must be clearly explained, and the results and conclusion should be according to them.
ANS: As suggested, the objectives of the work has been listed in introduction parts and conclusion also be updated based on the objectives.
4. The methodology should be improved; the description of the procedures is not clear.
ANS：As suggested, the description of the procedures has been updated in the manuscript.
5. A suggestion: please use always the scientific name of plant species (although common name can be also included); to readers not familiar with the Hawaiian flora the common names are difficult to follow.
ANS: As suggested, the scientific name of plant species has been listed in the manuscript.
6. Although I'm not an English-speaking native, I think that the English language and style need some improvement.
ANS: Thank you very much for your comments. The manuscript has been thoroughly revised.
Abstract:
7. Ln 22 – ‘Result showed that broadcast applications of hexazinone granules and tebuthiuron pellets within 5m diameter circular plots seemed ineffective on the species tested.’ – later (Ln. 113) 10 m plots are referred. Check this.
ANS: As suggested, those were errors. Those errors have been corrected in the manuscript.
8. Ln 24 – ‘indicating fertilizer, fungicide, insecticide applications and remediation of herbicide may be required to start native plants.’ – I don’t understand how this conclusion can be drawn.
ANS: I have deleted the sentences
9. Ln 27 – ‘Efficacy [of Koa – Leucaena - to tebuthiuron] can be improved by grid application which would probably offer more protection to non-target species and therefore be more practical in forest management.’ – Above (Ln. 22), 5 m diameter plots are referred. The abstract should be understood even without reading the complete manuscript.
ANS: The abstract has been thoroughly revised/rewritten.
Introduction
10. Ln 40 – ‘are all not satisfied ‘- Check this sentence. Also, isn’t it in contradiction with Ln 42, concerning the success of herbicides use?
ANS: As suggested, the first sentence has been deleted and the second sentences has been deleted.
11. Ln 41 – ‘penology’ – replace by ‘phenology’
ANS: As suggested, it has been corrected.
Check specie names in a recognized data base (e.g. Tropicos). Some examples:
12. Ln. 66 ‘Leucaena leucocephalla’ – replace by ‘Leucaena leucocephala’
ANS: As suggested, it has been corrected.
13. Ln. 70 ‘Pinus elliotii’ – replace by ‘Pinus elliottii’
ANS: As suggested, it has been corrected.
14. Ln. 76 ‘Acacia KOA’ – replace by ‘Acacia koa’
ANS: As suggested, it has been corrected.
15. Ln 98 – ‘paspalum urvillei’ - replace by ‘Paspalum urvillei’
ANS: As suggested, it has been corrected.
16. Ln 82 – ‘efficacy of hexazinone and tebuthiuron on major invasive forest weeds were also investigated.’ – replace by ‘other major invasive weeds’? I think that weeds in the two main sites (I and II) are also important weeds.
ANS: As suggested, it has been corrected.
17. Ln 90 – ‘Average rainfall was 1651 mm but only 1092 mm, …’ – Check this sentence.
ANS: As suggested, it has been corrected.
18. Ln 95 – ‘The soil was described by Nakamura [25].’ – Give some detail about the soil; as it is latter discussed, soil characteristics are important to the analysis of the results.
ANS: As suggested, some information have been added in this manuscript.
19. Figure 1 could be improved
ANS: As suggested, figure 1 has been updated.
20. Ln 106 – ‘average rainfall of 536 mm during 1999 and 2000.’ Average rainfall values using two years makes no sense.
ANS: As suggested, it has been corrected.
21. Also, in Ln 108 – ‘Rainfall here was seasonal, with annual dry seasons in the summer months.’ – Check this sentence (it seems incorrect).
ANS: As suggested, the sentence has been deleted.
22. Climate characterization of both sites (I and II) needs to be improved.
ANS: As suggested, it has been added in the manuscript.
Material and Methods:
23. When where the essays made?
ANS: As suggested, detailed information of study sites have been listed in manuscript.
24. Ln. 113 - How many plots were set? In Ln. 142, 28 plots are referred but previously this number was not mentioned.
ANS: As suggested, they have been updated.
25. Plots 10 m? Which is the area of each one (10 x 10 m?).
ANS: yes, the plot size was 10 m x 10 m.
26. L. 126 – ‘located about a quarter mile east of the Kalalau lookout in Kokee State Park of Kauai’ – this should be referred in point 2.1 (study site).
ANS: As suggested, it has been updated in this manuscript.
27. Ln. 134 - aalii (D. viscosa) – include the full name.
ANS: As suggested, the full name has been added in the manuscript.
28. Ln. 135 – ‘Each plot was planted to two plants of each species except for D. rhytidosperma with four plants in each plot.’ – This number seems too small. And why four plants in the case of D. rhytidosperma?
ANS: This was a preliminary study. The number of native plants was very limited for us to do the experiments. The manuscript was revised according.
29. Ln. 136 – ‘Out-plantings’ – What is the meaning?
ANS: Out-plantings was transplant.
30. Ln. 141 – ‘2.5. Efficacy of hexazinone and tebuthiuron on major invasive forest weeds, gives the wrong idea that the other weeds are not major invasive’. Consider adjust this title (2.5. Efficacy of hexazinone and tebuthiuron on other major invasive forest weeds)
ANS: As suggested, it has been revised.
Results:
31. Ln. 152 – If the date of the trials is not referred, the reader will not understand the reference to the hurricane in 1992.
ANS: The confusing sentences have been deleted.
32. Ln. 163 – ‘demonstrated a rate response to tebuthiuron.’ - What is “a rate response”?
ANS: “rate response” has been revised to “dose-dependent response”.
33. Ln. 170 – No control plot concerning M. faya?
ANS: Yes, we had a control plot in each trials for efficacy comparison.
34. Ln. 185 – In Fig. 2 and 3 error bars have values above 100%. I think that this is not possible.
ANS: I checked all original data and error bars didn’t exceed 50%.
35. Ln 194 ‘Ironwood (casuarinas) was moderately susceptible to hexazinone and tebuthiuron although the control was almost as severely injured.’ – Is this the 'casuarina' in Fig. 3? The same name should be used.
ANS: As suggested, the name in Fig. 3 has been corrected.
36. Ln. 202 – Figure 3 - Were methods different in site II? In x-axis it is ohia 3, 4-8, >9 months, while in Figure 2 it is ohia 1, 2, etc…
ANS: The method was the same between the two sites. Fig. 3 has been corrected.
37. Check Figure 3 in relation to text. It seems that some of the results pointed does not fit the figure (e.g. Ln. 188 - ‘Overall, injury at 12 months was greater than at 6 months.’; ‘At 12 months, the smallest class size of ohia (7.5 cm or less) showed a response to…’ (?);
ANS: Fig. 3 has been corrected. The text has been revised.
38. Ln. 192 - ‘In the larger class sizes of ohia (10 to 20 cm and 23 cm or larger)? – This is the first time size values are referred. How do they match with to the ohia 1, ohia 2, etc…?
ANS: As suggested, for readers to easily understand the trials, I deleted the sentences.
39. Ln 206 – Without reference values it is not possible to know if the residue levels are low or high and if they are comparable (those of tebuthiuron and hexazinone). Perhaps include some note about this.
ANS: In L225-227 of the revised manuscript, A couple of sentence have been inserted: “It is noteworthy that there was no documented record that any herbicides were previously used in the two study sites, so that the background concentration of both hexazinone and tebuthiuron would be undetectable.”
40. Ln 211 to 215 - A figure with the values of residue perhaps would be better than the descriptive presentation made in these lines.
ANS: As suggested, I has added more detailed information to the part for the values of residue.
40. Ln. 231 – ‘The response of out-planted native species suggested that fertilizer, fungicide, insecticide applications and remediation of herbicide may be required to start native plants [30, 31].’ – What does this mean? I don’t understand how this conclusion can be drawn (as above, in the abstract).
ANS: This sentence has been revised to: “The response of out-planted native species suggested that fertilizer application, pest control (e.g., fungi and insects) and remediation of herbicide residues may be required to regrow native plants at the sites [30, 31]”.
41. Ln. 238 – ‘schizachyrium trials’ – ‘Schizachyrium trials’
ANS: As suggested, it has been corrected.
42. Ln 246 to 249 - Is not clear why results with herbicides not used in present work are referred.
ANS: The herbicide was picloram, whereas the herbicides used in the present study was hexazinone and tebuthiuron.
43 Ln 251 - ‘so would be useful in establishing the native koa if koa is also tolerant to tebuthiuron.’ – check English.
ANS: This sentence has been revised to improve the clarity: “It was preliminarily observed that Formosan koa was tolerant to tebuthiuron and so would be useful in establishing the native koa if the native Hawaiian koa (Acacia koa) is also tolerant to tebuthiuron.”
43. Ln. 257 - In Table 1 (and in Table 2), as well in text, use scientific names.
ANS: As suggested, they have been revised in the manuscript.
44. Ln. 261 – explain why they ‘were unexpectedly tolerant’.
ANS: The word “unexpectedly” has been revised to “very”.
45. Ln. 261 to 267 - The discussion about the type of application (plot, grid, spot-gun) was not in the objectives and needs to be situated within the context of the developed work.
ANS: This section of the text has been revised.
46. Point 3.4 is difficult to follow, as different matters are mixed. Also, there are several mentions that should be contextualized. Improvement is needed.
ANS: As suggested, it has been improved.
Conclusions
47. Ln. 284 – ‘Broadcast applications of hexazinone granules and tebuthiuron pellets within 5 m diameter circular plots…’ - This procedure was only used in trials with other invasive forest weeds (point 2.5). And the other trials? If the reader only reads the conclusions, he will not have any idea about which the main conclusions are. This point needs to be much improved.
ANS: As suggested, conclusion has been revised/rewritten.
Round 2
Reviewer 1 Report
Overall, I think that it is improved, but I find many of the authors responses to significant comments by both myself and the other reviewer to be minimal. In general, I felt that the authors explained their rationale and actions better in their responses to my comments than they did in the revised manuscript. Because readers are likely to have questions similar to mine when reading the manuscript, I would suggest that the authors explain their rationale and actions in the manuscript itself as well (i.e., justify their methods, explain their methods). I also think that the figures (especially Figure 1) still merit significant revision for clarification in accordance with my original comments. The figure and table legends also should be made much more descriptive as I originally suggested. And it is not clear why Table 1 doesn't include SD or SE values if the values presented are means and replicates were used in the experimental design. With these changes, I think that the manuscript could be made publication worthy.
Author Response
Overall, I think that it is improved, but I find many of the authors responses to significant comments by both myself and the other reviewer to be minimal. In general, I felt that the authors explained their rationale and actions better in their responses to my comments than they did in the revised manuscript. Because readers are likely to have questions similar to mine when reading the manuscript, I would suggest that the authors explain their rationale and actions in the manuscript itself as well (i.e., justify their methods, explain their methods). I also think that the figures (especially Figure 1) still merit significant revision for clarification in accordance with my original comments. The figure and table legends also should be made much more descriptive as I originally suggested. And it is not clear why Table 1 doesn't include SD or SE values if the values presented are means and replicates were used in the experimental design.
Response:
The entire methods section has been further clarified. Additional information in sampling, sample processing and shipping have been added in lines 153-163 of the revised manuscript.
All Figures and Tables have been revised. All Figure and Table legends have been made much more descriptive.
Standard deviations (SD) for the data listed in Tables 1 and 2 were not calculated because the experiments were quite preliminary. Drought and pest damages compromised some of the trials, so that SD were difficult to get. The information has been described in the text (e.g., line 224 of the revise manuscript).
With these changes, I think that the manuscript could be made publication worthy.
Many thanks. We highly value your comments and we have thoroughly revised the entire manuscript.
Reviewer 2 Report
Many thanks for the revisions. However, I still have some questions.
The main is, again, the use of common names. It is very difficult to understand the text using both types of names (even in the tables different criteria were used).
The scientific name should be always used (the common name is only a complement). E.g. in lines 268 – 269 the text: “It was preliminarily observed that Formosan koa was tolerant to tebuthiuron and so would be useful in establishing the native koa if the native Hawaiian koa (Acacia koa) is also tolerant to tebuthiuron.” is really confuse. A careful review of this matter is essential to avoid mistakes like that in line 276 (Formosan koa (Formosan koa) or in line 166 (Olea europaeus - Olea europaea). All the scientific names must be checked!
In the abstract the species referred for the first time cannot be abbreviated (Ln. 37-38 - The mortality of H. distans, D. rhytidosperma and A. lynchnoides).
The procedures are still confuse: e.g. Ln. 129 - Two large 10x10 m plots (i.e., 4 5x10 m); I didn’t find information about the soils (contrarily to the referred in the letter).
In Fig. 1 the two images should be separate (e.g. use an inset) since they are at completely different scales.
Concerning M. faya control plot, I asked because it is missing in Figure 2.
Check and correct typos such as: Ln. 31 hexainone – hexazinone; Ln. 299 stoleniferous – stoloniferous.
A new thoroughly and carefully review should be done.
Author Response
1、Many thanks for the revisions. However, I still have some questions. The main is, again, the use of common names. It is very difficult to understand the text using both types of names (even in the tables different criteria were used).
ANS: As suggested, I will update all names using same criteria.
2. The scientific name should be always used (the common name is only a complement). E.g. in lines 268 – 269 the text: “It was preliminarily observed that Formosan koa was tolerant to tebuthiuron and so would be useful in establishing the native koa if the native Hawaiian koa (Acacia koa) is also tolerant to tebuthiuron.” is really confuse. A careful review of this matter is essential to avoid mistakes like that in line 276 (Formosan koa (Formosan koa) or in line 166 (Olea europaeus - Olea europaea). All the scientific names must be checked!
ANS: As suggested, I deleted the sentences for reader easily understood. Other place has been updated to the scientific names.
3、In the abstract the species referred for the first time cannot be abbreviated (Ln. 37-38 - The mortality of H. distans, D. rhytidosperma and A. lynchnoides).
ANS: As suggested, they have been corrected in the manuscript.
4、The procedures are still confuse: e.g. Ln. 129 - Two large 10x10 m plots (i.e., 4 5x10 m); I didn’t find information about the soils (contrarily to the referred in the letter).
ANS: As suggested, soil information has been added to manuscript.
5、In Fig. 1 the two images should be separate (e.g. use an inset) since they are at completely different scales.
ANS: As suggested, it has been updated.
6、Concerning M. faya control plot, I asked because it is missing in Figure 2.
ANS: As suggested, I carefully the figure 2. M. faya control plot values was too small comparison with other control values.
7、Check and correct typos such as: Ln. 31 hexainone – hexazinone; Ln. 299 stoleniferous – stoloniferous.
ANS: As suggested, they have been corrected.
8、A new thoroughly and carefully review should be done.
ANS: As suggested, the manuscript has been revised wholly based on your comments.
