Effects of Non-Industrial Wood Ash (NIWA) Applications on Soil Chemistry and Sugar Maple (Acer saccharum, Marsh.) Seedling Growth in an Acidic Sugar Bush in Central Ontario
Round 1
Reviewer 1 Report
I find the manuscript original and well prepared. Moreover, it addresses an important area in which useful current research results are lacking the usage of non-industrial wood ash as a forest soil amendment to counteract soil acidification.
I have only a few minor comments.
The Method section is difficult to study. It would be easier if authors divided it into shorter parts e.g. The study site, Experimental Design like in The Results sections.
L120-123 a little confusing explain better.
The abbreviation EC has two meanings: exchangeable cations (Table2) and electrical conductivity (L 168). It may be confusing.
Table 3 What does the abbreviation OM mean?
L 411-412 NASM is used only in Table 2 and in line 411-412 so it’s better to write the complete name.
Author Response
Reviewer 1
I find the manuscript original and well prepared. Moreover, it addresses an important area in which useful current research results are lacking the usage of non-industrial wood ash as a forest soil amendment to counteract soil acidification
Reply: We thank the reviewer for the enthusiastic comments about our manuscript.
I have only a few minor comments.
The Methods section is difficult to study. It would be easier if authors divided it into shorter parts e.g. The study site, Experimental Designlike in The Results sections.
Reply:We appreciate this suggestion of the reviewer.We divided the methods into shorter parts (page 3, line 106; page 3, line 119; page 4, line 146; page 4, line 191).
Line 120-123 a little confusing explain better.
Reply: We revised this sentence. Now we say, “The plots were chosen based on the following characteristics: dominated by sugar maple seedlings, far from roads and major urban locations to eliminate any road salt effects and relatively flat slope to avoid runoff of ash immediately after application, given there is a precipitation event.”(page 3, lines 121-123).
The abbreviation EC has two meanings: exchangeable cation (Table2) and electrical conductivity (L 168). It may be confusing.
Reply: We thank the reviewer for this observation. The abbreviation EC in Table 2 was incorrectly described and is now revised to mean electrical conductivity (Table 2, line 261).
Table 3 What does the abbreviation OM mean?
Reply: The abbreviation OM means “organic matter content”. We revised the Table 3 heading to clearly explain the abbreviations used in the table. We now say, “pH, electrical conductivity (EC), organic matter content (OM)…”(Table 3, lines 310-311).
L 411-412 NASM is only used in Table 2 and in line 411 -412 so it’s better to write the complete name.
Reply: This specification has been done.
Reviewer 2 Report
The abstract clearly presents the importance, methods, results, and conclusions of the study. Because the authors state that this study could inform regulations of ash application, I wonder how these applications will affect other species besides sugar maple. As Long et al. 2011 in the Can. J. For. Res. show, soil fertilization (using lime in their study) increased sugar maple growth compared to control plots. However, they found no differences in the growth of American beech, and black cherry had decreased growth rates and increased mortality.
41: After ‘are’ there seems to be a word missing.
42: Change ‘owing to’ to because of’.
47: Replace ‘due to the’ to ‘because wood ash has’.
80: Something to consider for the Discussion: Is NIWA economically feasible on a commercial scale?
84: See my word of caution about making it seem like the application of these materials is positive for all tree species. Please consider adding a word of caution about using NIWA like you did with the heavy metal concentration concerns.
Methods: One sugar bush and treatments applied to 20, 2 x 2 m plots. This begs the question of whether or not pseudo replication is an issue. Only one sugar bush is evaluated. At best, the authors should cite this as a study limitation in the Discussion – that is, inference is only about the effects at this one sugar bush.
437-442: It seems like you are repeating the results here without much discussion. I found this to be true of some paragraphs after this. Try to minimize blocks of text that just repeat the results.
Author Response
Reviewer 2
The abstract clearly presents the importance, methods, results and conclusions of the study. Because the authors state that this study could inform regulations of ash application, I wonder how these applications will affects other species besides sugar maple. As Long et al. 2011 in the Can. J. For. Res. show, soil fertilization (using lime in their study) increased sugar maple growth compared to control plots. However, they found no differences in the growth of American beech, and black cherry had decreased growth rates and increased mortality.
Reply:We thank the reviewer for the enthusiastic comments about our manuscript. Further study is needed to evaluate the responses of tree species other than sugar maple to non-industrial wood ash addition.
41: After ‘are’ there seems to be a word missing.
Reply: We revised this sentence. Now we say, “While some studies have suggested that signs of soil recovery from acidification are emerging…” (page 1, line 41).
42: Change ‘owing to’ to ‘because of’.
Reply: This specification has been done.
47: Replace ‘due to the’ to ‘because wood ash has’.
Reply: This specification has been done.
80: Something to consider for the Discussion: Is NIWA economically feasible on a commercial scale?
Reply: This is a valid point. According to Azan (2017) in FACETS, there is enough non-industrial wood ash produced in Ontario to treat approximately 4500 ha of acidified forests in Muskoka per year. Ash from non-industrial sources alone is likely not feasible on a commercial scale, however implementing a wood ash recycling program that combines ash from industrial as well as residential sources could be a more feasible option that has yet to be considered. Currently, a non-industrial wood ash recycling program is underway in Muskoka (https://ashmuskoka.ca/about-hatsoff/) and the organization in charge of this program, ASHMuskoka, hopes to eventually expand this initiative beyond that of a local scale in areas where wood burning is common. The non-industrial wood ash recycling program is substantial and adds ash to sensitive areas (targeted) on an ongoing basis. These considerations have been added to the discussion (page 16, lines 402-407)
84: See my word of caution about making it seem like the application of these materials is positive for all tree species. Please consider adding a word of caution about using NIWA like you did with the heavy metal concentrations concerns.
Reply: We added a word of caution about using NIWA on tree species other than sugar maple (page 19, line 605).
Methods: One sugar bush and treatments applied to 20, 2 x 2 m plots. This begs the question of whether or not pseudo replication is an issue. Only one sugar bush is evaluated. At best, the author should cite this as a study limitation in the Discussion – that is, inference is only about the effects of this one sugar bush.
Reply: Thank you for your concern. Due to the difficulty in acquiring non-industrial wood ash for our study at the time, we were only able to find enough for 20, 2 x 2 m plots. We believe the study site was a good representation of soils typically found in central Ontario (see Watmough et al. 2014 in Env. Poll.) and are aware that the experimental design would have been stronger if additional sites were used. We have added this limitation to the discussion (page 17, lines 480-482), however the results are likely transferable across large parts of the region.
437-442: It seems like you are repeating the results here without much discussion. I found this to be true of some paragraphs after this. Try to minimize blocks of text that just repeat the results.
Reply: We thank the reviewer for this observation. We removed text from the discussion that seemed to repeat the results (page 17, line 466; page 17, line 483; page 18, lines 552; page 19, line 583).
