Interactive Effects of Intertidal Elevation and Light Level on Early Growth of Five Mangrove Species under Sonneratia apetala Buch. Hamplantation Canopy: Turning Monocultures to Mixed Forests
Round 1
Reviewer 1 Report
When I first read the abstract of the manuscript, I could not figure out why anyone would want to study this manipulation. But n the introduction, the authors did a magnificent job of explaining the problem with Spartina, the use for Sonneratia to shade it out, and then the need to replace Sonneratia with native species.
The novelty of the current work seems to be the direct consideration of canopy cover and perhaps its interaction with tidal position. Otherwise, there seem to have been many studies of a similar nature and there is a great deal here which seems to be only confirmatory. Some of the present result seems also to contradict previous studies. For example the disappearance of K. candela's and R. stylosa after 10 year in the study by Ren et al (L56) seems to contradict the conclusion that the 5 native species could replace Sonneratia (L346).
But there are definitely some parts of the paper that I find problematic. The paper could be re-written to make the novel aspects more clear and to clarify the author's thoughts.
For example, the introductory paragraph at L52ff is very confusing and my initial though was, how is all this related? As it is, it seems a disjunct set of thoughts with no unification. Or... the objective of the study (L72ff) was to investigate two hypotheses neither of which is ever stated. Again, re-write.
Materials and methods ... something should be said of the actual light levels under the three treatments, and about the possibility of wave action influencing the results. OK, actually this is covered at the start of the Results, but the light levels do not make sense... 6211 µmol m-2 s-1 is about 3x full sunlight intensity usually. Wave action should also be clarified in the results because, at least as far as my experience shows, it takes very little wave action to dislodge young mangroves. This could certainly be a complicating factor in the low intertidal zone.
With respect to relative growth rates, the authors seem to have taken a good deal of data they never used (L114 ff). In the end, they don't report proper RGRs at all, just the average for the full year despite the fact that growth rates seem clearly to have changed over that period.
Results - overall I found these very confusing, or at least so difficult to read that I couldn't concentrate on the story. The results could be separated out to make the story more clear and easier to follow. The figures are too busy and the data embedded in the text is far too complex. The organization of the Discussion is better.
One of the things that comes up too often is the conclusion that something is more or less shade-tolerant or flooding-tolerant. This is the habitat in which these plants grow naturally, and growth will unquestionably be affected by microhabitat, and it has nothing to do with some nebulous and undefined "tolerance". Indeed, at L328, the authors refer to the adaptability of the different species.
So in conclusion, there seem to be some interesting results here but they are difficult to see. The paper needs to be re-written and the figures re-done so that someone not as embedded in the study as the authors are - perhaps someone involved in mangrove restoration - can find a story worth reading and some real suggestion on how to put the study into practice in other mangrove forests.
Author Response
Point 1: When I first read the abstract of the manuscript, I could not figure out why anyone would want to study this manipulation. But in the introduction, the authors did a magnificent job of explaining the problem with Spartina, the use for Sonneratia to shade it out, and then the need to replace Sonneratia with native species.
Response 1: I added the research background to the front of Abstract: The introduced Sonneratia apetala plantations has occupied more than 3800 ha in China, and its prevalence, fast growth rate and high seed production have raised concerns about the risks of threatening native mangrove habitats. Efforts are needed to change these introduced monocultures to mixed or native forests.
Point 2: The novelty of the current work seems to be the direct consideration of canopy cover and perhaps its interaction with tidal position. Otherwise, there seem to have been many studies of a similar nature and there is a great deal here which seems to be only confirmatory. Some of the present result seems also to contradict previous studies. For example the disappearance of K. candela's and R. stylosa after 10 year in the study by Ren et al (L56) seems to contradict the conclusion that the 5 native species could replace Sonneratia (L346).
Response 2: This study only examined the survival and growth of seedlings within the first year, and it couldn't infer the succession of S. apetala plantations in the future. Therefore, I deleted "Finally, S. apetala will be replaced eventually by the five native mangrove species in mangrove plantations in the next few decades. (L346)"
Point 3: But there are definitely some parts of the paper that I find problematic. The paper could be re-written to make the novel aspects more clear and to clarify the author's thoughts.
For example, the introductory paragraph at L52ff is very confusing and my initial though was, how is all this related? As it is, it seems a disjunct set of thoughts with no unification. Or... the objective of the study (L72ff) was to investigate two hypotheses neither of which is ever stated. Again, re-write.
Response 3: (1) I rewrite L52ff: For example, Spartina alterniflora began to invade in the Qi’ao Island in the early 1990s [9], and expanded its coverage up to 227 ha by 1995. In 1999, S. apetala was introduced to control S. alterniflora invasion, and eventually eradicated S. alterniflora in 2011 (only 0.63 ha remained for experimental purpose) [10, 11]. However, S. apetala has occupied in approximately 600 ha in Qi'ao Island by 2008 [7]. Such a large area of S. apetala plantation, and its prevalence, fast growth rate and high seed production has raised the concern whether the introduced species threatens the survival and development of native mangrove species [12].
(2) I rewrite L72ff: Therefore, the objective of the present study was to compare growth and physiological responses of five native mangrove species seedlings at different light levels and intertidal elevations.
Point 4: Materials and methods ... something should be said of the actual light levels under the three treatments, and about the possibility of wave action influencing the results. OK, actually this is covered at the start of the Results, but the light levels do not make sense... 6211 µmol m-2 s-1 is about 3x full sunlight intensity usually. Wave action should also be clarified in the results because, at least as far as my experience shows, it takes very little wave action to dislodge young mangroves. This could certainly be a complicating factor in the low intertidal zone.
Response 4: We did not measure the waves and tidal inundation time. It was reported the effects of (tidal inundation time [18] and wave [19]) on young mangrove species across the intertidal zone were different, and the impacts were more significant in the low intertidal zone.
I added the measurement methods in Experimental design: We determined the canopy closure using fisheye lens camera at the intersection of diagonals of the plot, used illumination temperature recorder to measure the irradiance level at 5 points on the diagonals of every sample plot. The irradiance level were 2536 ± 246, 1642 ± 133, and 872 ± 94 μmol m-2 s-1 in the understory of S. apetala plantations at 30%, 60%, and 90% canopy closure. The effects of wave action (tidal inundation time [18] and wave [19]) on young mangrove species across the intertidal zone were different, and the impacts were more significant in the low intertidal zone. We measured the intertidal elevation with Global Positioning System (GPS), and the average elevation were 0.42 m and 1.17 m in low and high tide beach, respectively.
I added explanation of the possibility of wave action influencing to the Result: The number of A. corniculatum and A. marina seedlings that survived decreased rapidly in the low intertidal elevation, which may be dislodged by wave action. The number of R. stylosa seedlings that survived decreased rapidly in every habitat during 180–240 days (Fig. 2)
Point 5: With respect to relative growth rates, the authors seem to have taken a good deal of data they never used (L114ff). In the end, they don't report proper RGRs at all, just the average for the full year despite the fact that growth rates seem clearly to have changed over that period.
Response 5: I deleted "and separated into leaf, stem, and root components" (L122-124ff): At the end of the trial, seedlings were collected, and then dried at 65 ℃ to a constant mass to determine the biomass. I measured RGRs of the total biomass to discuss the adaptability to light levels and intertidal elevations of five native mangrove species.
Point 6: Results - overall I found these very confusing, or at least so difficult to read that I couldn't concentrate on the story. The results could be separated out to make the story more clear and easier to follow. The figures are too busy and the data embedded in the text is far too complex. The organization of the Discussion is better.
Response 6: I revised the sentences in the Results.
(1) The survival rate of B. gymnorrhiza was highest in each habitat, and the second was K. obovata seedlings at low intertidal elevation. Conversely, the survival rate of A. marina, A. corniculatum and R. stylosa were lower at low intertidal elevation than at high intertidal elevation. (L150-152ff)
(2) We found that the stem height of B. gymnorrhiza, A. corniculatum, and A. marina under 30% canopy closure in high tide beach was lower than that under 60% canopy closure low tide beach, respectively. Conversely, the stem height of R. stylosa under 30% canopy closure was higher than under 60% canopy closure. (L180-184ff)
(3) B. gymnorrhiza and R. stylosa at high intertidal elevation generally had relatively high leaf numbers, whereas K. obovata and A. marina showed a reverse tendency, respectively. (L220-222ff)
Point 7: One of the things that comes up too often is the conclusion that something is more or less shade-tolerant or flooding-tolerant. This is the habitat in which these plants grow naturally, and growth will unquestionably be affected by microhabitat, and it has nothing to do with some nebulous and undefined "tolerance". Indeed, at L328, the authors refer to the adaptability of the different species.
Response 7: I changed my expression.
(L270-272ff) Overall B. gymnorrhiza performed best in low intertidal position and low light irradiance condition during the all stages of both experiments.
(L286-289ff) In the present study, the RGR of K. obovata, A. corniculatum, and A. marina was significantly affected by the low light level regardless of the intertidal elevation, indicating light level was the main limiting factor affecting the early biomass accumulation of seedlings.
(L313-314ff) A previous study in Hong Kong showed that K. candel had stronger resilience to high intertidal elevation than B. gymnorrhiza [33].
(L322-323ff) The results showed that the survival of all five species studied and the growth of three species (A. corniculatum, A. marina, and R. stylosa) were high under adverse conditions, B. gymnorrhiza showed the best performance to the six interactive treatments.
Point 8: So in conclusion, there seem to be some interesting results here but they are difficult to see. The paper needs to be re-written and the figures re-done so that someone not as embedded in the study as the authors are - perhaps someone involved in mangrove restoration - can find a story worth reading and some real suggestion on how to put the study into practice in other mangrove forests.
Response 8: I rewrite "Conclusions".
Adaptability to light levels and intertidal elevations of five native mangrove species in China was explored in a 12-month field experiment. Although seedlings of all five native species survived better at high intertidal elevation, the stem height of all species at low intertidal elevation was higher than that at high intertidal elevation, and it was the highest under 30% canopy closure. The relative growth rate (RGR) was the highest at low intertidal elevation, and it was promoted by high light level. The survival rate and growth rate of B. gymnorrhiza was the highest in averaged across intertidal elevations and light levels. B. gymnorrhiza was the acclimated best native species in S. apetala plantations in the study area. Simultaneously, periodical thinning canopy openness artificially in the dense canopies of S. apetala plantations is an effective measure. In addition, increasing the planting density of seedlings would promote establishment and growth of native species especially at low intertidal elevations.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This manuscript examine the effect of elevation and light intensity on growth and survival of native species, which is important for future restoration of mangroves. Therefore, manuscript is timely and can be accepted for publication. Although authors need to do some minor and major corrections in the manuscript. Authors need to check English and spelling of words lot of minor mistakes in text.
Kandelia obovata but lot of places Kandelia obovate in text need to correct these minor mistakes.
Authors need to include some physiological aspect of mangrove species in introduction and discussion part such as some characteristics such as specific leaf area, leaf nitrogen, photosynthesis activity etc. It would be easy to explain results based on physiological and growth characteristics.
Authors have included only F values and significant values in tables, it would be better to include values with standard deviation and in bracket authors can show F values.
See my specific comments for each section.
Abstract
Line 15-17 Why All species survived better under 30% than 60 and 90 canopy closer? Authors need to add explanation here.
Line 18 – 21 = Add both results together
Line 28 = change intertidal levation to intertidal elevation
Introduction
Line 41 – 43 = mangrove area recovered to 22000 ha, its not clear from the sentence that total area of mangrove in China became 22000 ha or in 1990, only 15000 ha mangrove area was remain so 7000 ha of plantation was done. Rewrite the sentence.
Line 47-48 = Please check the number it doesn’t match with my previous comment if the total area of mangrove in China was 22000 ha.
Line 62 = change Plant/hm to plant/ha
Line 72 = two hypothese but I do not see any hypothesis rather than it is more likely normal objective or examining. Authors need to either add hypothese or delete this word.
Material and methods
Line 84 Authors need to check correct annual rainfall value. It seems very high as compared to global average value and other subtropical areas.
Line 86 Average sea water salinity is quite low. Authors need to clearly state is it sea water or soil pore water salinity?
Line 88 and 90 Be consistent with species name like Kandelia candel or Kandelia obovata. Initial name was K. Candel and after Siu et al. 2008 paper species name changed to K. obovata in China and Japan.
Line 94 to 98 The seeds of A. corniculatum and A. marina, and the hypocotyls of K. obovata, B. gymnorrhiza, and R. stylosa were collected from under the canopy.
The length of propagules (n = 50) of K. obovata, A. corniculatum, and B. gymnorrhiza was 19.32 ± 2.72, 28.46 ± 3.48, and 15.49 ± 1.32, respectively, and their wet weight was 14.67 ± 3.75, 19.44 ± 2.83, and 22.37 ± 4.23 g, respectively.
A. Corniculatum have seed no propoagules according to first sentence but in next sentence average length of propagules of K. obovata, A. corniculatum, and B. gymnorrhiza. This is typo mistake and authors need to change A. corniculatum with R. stylosa.
109-110 Hypocotyle, seeds and propagules…. Authors need to be consist with reproductive terminology of each species. Rewrite this sentence
Results
Line 133 How irradiance level and intertidal elevation were measured? Authors need to explain in methodology section.
Line 156 Form or from
Line 182 130.21% authors need to check this value
Table 3 R. stylosa HL 30% CC statistical difference letter is missing
Discussion
Line 258 – 261 Rewrite sentence. Results are from this study or some other published study need to be clear.
Line 270 – 284 please refer to Leaf phenological traits and leaf longevity of three mangrove species (Rhizophoraceae) on Okinawa Island, Japan. 2012, Journal of Oceanography, for discussion with reference to shade tolerant behavior of B. gymnorrhiza among K. obovate and R. stylosa based on specific leaf area in subtropical region.
Author Response
Abstract
Point 1: Line 15-17 Why All species survived better under 30% than 60% and 90% canopy closer? Authors need to add explanation here.
Response 1: We planted seedlings randomly and equidistantly in the S. apetala plantations. Some of the seedlings were difficult to get enough sunlight due to their special location in every sample plots. In the habitats of 60% and 90% canopy closure with less light penetration, the impact was even more serious, causing these seedlings gradually withered and died.
I re-adjusted the sentence: All the species had higher survival rates under 30% canopy closure than under 60% and 90% canopy closure.
Point 2: Line 18 – 21 = Add both results together
Response 2: I re-adjusted the sentence: Although seedlings of all five native species survived best at high intertidal elevation, relative growth rate (RGR) was the highest at low intertidal elevation, and it was promoted by high light level.
Point 3: Line 28 = change intertidal levation to intertidal elevation
Response 3: I had change intertidal levation to intertidal elevation
Introduction
Point 4: Line 41 – 43 = mangrove area recovered to 22000 ha, its not clear from the sentence that total area of mangrove in China became 22000 ha or in 1990, only 15000 ha mangrove area was remain so 7000 ha of plantation was done. Rewrite the sentence.
Response 4: In the early 1990s, China launched a 10-year mangrove reforestation program in degraded mangrove areas, through which the mangrove forest areas have recovered to 22,000 ha.
Point 5: Line 47-48 = Please check the number it doesn’t match with my previous comment if the total area of mangrove in China was 22000 ha.
Response 5: I deleted "accounting for 10.5% of the total mangrove area", because I did not find the related statistics of national mangroves area in the 2008.
Point 6: Line 62 = change plant/hm to plant/ha
Response 6: I had change plant/hm to plant/ha
Point 7: Line 72 = two hypothese but I do not see any hypothesis rather than it is more likely normal objective or examining. Authors need to either add hypothese or delete this word.
Response 7: I deleted "investigate the two hypotheses by": Therefore, the objective of the present study was to compare growth and physiological responses of five native mangrove species seedlings at different light levels and intertidal elevations.
Material and methods
Point 8: Line 84 Authors need to check correct annual rainfall value. It seems very high as compared to global average value and other subtropical areas.
Response 8: The annual rainfall is 1964.4, is not 11964.4. The date comes from “Eradicating invasive Spartina alterniflora with alien Sonneratia apetala and its implications for invasion controls”
Point 9: Line 86 Average sea water salinity is quite low. Authors need to clearly state is it sea water or soil pore water salinity?
Response 9: The annual mean salinity of the sea water is 18.2 ‰, is not soil pore water salinity.
Point 10: Line 88 and 90 Be consistent with species name like Kandelia candel or Kandelia obovata. Initial name was K. Candel and after Siu et al. 2008 paper species name changed to K. obovata in China and Japan.
Response 10: I have unified the species name to Kandelia obovate.
Point 11: Line 94 to 98 The seeds of A. corniculatum and A. marina, and the hypocotyls of K. obovata, B. gymnorrhiza, and R. stylosa were collected from under the canopy.
The length of propagules (n = 50) of K. obovata, A. corniculatum, and B. gymnorrhiza was 19.32 ± 2.72, 28.46 ± 3.48, and 15.49 ± 1.32, respectively, and their wet weight was 14.67 ± 3.75, 19.44 ± 2.83, and 22.37 ± 4.23 g, respectively.
A. Corniculatum have seed no propoagules according to first sentence but in next sentence average length of propagules of K. obovata, A. corniculatum, and B. gymnorrhiza. This is typo mistake and authors need to change A. corniculatum with R. stylosa.
Response 11: I had change A. corniculatum with R. stylosa
Point 12: 109-110 Hypocotyle, seeds and propagules…. Authors need to be consist with reproductive terminology of each species. Rewrite this sentence
Response 12: I rewrite this sentence: In April 2017, the hypocotyls of K. obovata and B. gymnorrhiza were planted, and the seeds of A. corniculatum, A. marina, and the hypocotyls of R. stylosa were planted in June in each plot.
Results
Point 13: Line 133 How irradiance level and intertidal elevation were measured? Authors need to explain in methodology section.
Response 13: I added the measurement methods in Experimental design: We determined the canopy closure using fisheye lens camera at the intersection of diagonals of the plot, used illumination temperature recorder to measure the irradiance level at 5 points on the diagonals of every sample plot. The irradiance level were 2536 ± 246, 1642 ± 133, and 872 ± 94 μmol m-2 s-1 in the understory of S. apetala plantations at 30%, 60%, and 90% canopy closure. The effects of wave action (tidal inundation time [18] and wave [19]) on young mangrove species across the intertidal zone were different, and the impacts were more significant in the low intertidal zone. We measured the intertidal elevation with Global Positioning System (GPS), and the average elevation were 0.42 m and 1.17 m in low and high tide beach, respectively.
Point 14: Line 156 Form or from
Response 14: It is “from”.
Point 15: Line 182 130.21% authors need to check this value
Response 15: It is 30.21%.
Point 16: Table 3 R. stylosa HL 30% CC statistical difference letter is missing
Response 16: I have added in the text.
Discussion
Point 17: Line 258 – 261 Rewrite sentence. Results are from this study or some other published study need to be clear.
Response 17: I rewrite sentence: The survival rate of four mangrove species, namely, A. marina, B. gymnorrhiza, Ceriops. tagal, and R. stylosa, were higher at high intertidal elevation than at low intertidal elevation, irrespective of the light level, and survived better in light gaps than under the canopy within the high intertidal position.
Point 18: Line 270 – 284 please refer to Leaf phenological traits and leaf longevity of three mangrove species (Rhizophoraceae) on Okinawa Island, Japan. 2012, Journal of Oceanography, for discussion with reference to shade tolerant behavior of B. gymnorrhiza among K. obovata and R. stylosa based on specific leaf area in subtropical region.
Response 18: Specific leaf area for B. gymnorrhiza (71.0 ± 2.8 cm2 g-1) were significantly different from that for R. stylosa (45.4 ± 1.0 cm2 g-1) and K. obovata (48.6 ± 0.8 cm2 g-1), which may be related to the fact that B. gymnorrhiza could tolerate more shaded conditions than the others[35].
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Much improved and the authors have paid specific attention to the reviewers comments. However, I am still concerned about two aspects of the M/M. First, no one who has done any serious light measurements will believe at all the irradiances reported here. They are ridiculously high and a measurement with these units that purports to represent an entire year of study will be considered silly. Just settle for saying 90%, 60% and 30%. Second, unless the authors have a truly serious GPS setup (and if so they should report it), there is no way a GPS can distinguish elevation differences of the size they are reporting, unless they wish to include the +/- 10 m part of the measurements.
Author Response
Point 1: Much improved and the authors have paid specific attention to the reviewers comments. However, I am still concerned about two aspects of the M/M. First, no one who has done any serious light measurements will believe at all the irradiances reported here. They are ridiculously high and a measurement with these units that purports to represent an entire year of study will be considered silly. Just settle for saying 90%, 60% and 30%. Second, unless the authors have a truly serious GPS setup (and if so they should report it), there is no way a GPS can distinguish elevation differences of the size they are reporting, unless they wish to include the +/- 10 m part of the measurements.
Response 1: I revised the sentences of the M/M: We measured the canopy closure using fisheye lens camera (Nikon D750 & SIGMA 8mm F3.5 EX DG FISHEYE) at the intersection of diagonals of the sample plot, and selected the plots with 30%, 60% and 90% canopy closure. The effects of wave action (tidal inundation time [18] and wave [19]) on young mangrove species across the intertidal zone were different, and the impacts were more significant in the low intertidal zone. We measured the water levels of the low tide zone and the high tide zone by water level logger (HOBO U20-001-0x) at high tide, and calculated the average elevation difference of the tide zone was 0.87±0.26 m.
Author Response File: Author Response.docx
Reviewer 2 Report
Revised manuscript quality have been increased. Please follow below minor comments
Point 11: Line 94 to 98 The seeds of A. corniculatum and A. marina, and the hypocotyls of K. obovata, B. gymnorrhiza, and R. stylosa were collected from under the canopy.
The length of propagules (n = 50) of K. obovata, A. corniculatum, and B. gymnorrhiza was 19.32 ± 2.72, 28.46 ± 3.48, and 15.49 ± 1.32, respectively, and their wet weight was 14.67 ± 3.75, 19.44 ± 2.83, and 22.37 ± 4.23 g, respectively.
A. Corniculatum have seed no propoagules according to first sentence but in next sentence average length of propagules of K. obovata, A. corniculatum, and B. gymnorrhiza. This is typo mistake and authors need to change A. corniculatum with R. stylosa.
Vegetative and reproductive phenology is important for the growth of mangroves following that Propagule size need to be taken in account for rehabilitation of mangroves. Refer following article in discussion part for propagule length (Md. Kamruzzaman, A. Osawa, K. Mouctar and S. Sharma (2017) Comparative reproductive phenology of subtropical mangrove communities at Manko Wetland, Okinawa Island, Japan. Journal of Forest Research, 22: 118-125)
Point 18: Line 270 – 284 please refer to Leaf phenological traits and leaf longevity of three mangrove species (Rhizophoraceae) on Okinawa Island, Japan. 2012, Journal of Oceanography, for discussion with reference to shade tolerant behavior of B. gymnorrhiza among K. obovata and R. stylosa based on specific leaf area in subtropical region.
Response 18: Specific leaf area for B. gymnorrhiza (71.0 ± 2.8 cm2 g-1) were significantly different from that for R. stylosa (45.4 ± 1.0 cm2 g-1) and K. obovata (48.6 ± 0.8 cm2 g-1), which may be related to the fact that B. gymnorrhiza could tolerate more shaded conditions than the others[35].
Citation 35 is wrong please correct the reference (S. Sharma, A.T.M.R. Hoque, M. Kamruzzaman, and A. Hagihara (2012) Leaf phenological traits and longevity in three mangrove species (Rhizophoraceae) on Okinawa, Japan. Journal of Oceanography, 68: 831-840).
Author Response
Point 11: Line 94 to 98 The seeds of A. corniculatum and A. marina, and the hypocotyls of K. obovata, B. gymnorrhiza, and R. stylosa were collected from under the canopy.
The length of propagules (n = 50) of K. obovata, A. corniculatum, and B. gymnorrhiza was 19.32 ± 2.72, 28.46 ± 3.48, and 15.49 ± 1.32, respectively, and their wet weight was 14.67 ± 3.75, 19.44 ± 2.83, and 22.37 ± 4.23 g, respectively.
A. Corniculatum have seed no propoagules according to first sentence but in next sentence average length of propagules of K. obovata, A. corniculatum, and B. gymnorrhiza. This is typo mistake and authors need to change A. corniculatum with R. stylosa.
Vegetative and reproductive phenology is important for the growth of mangroves following that Propagule size need to be taken in account for rehabilitation of mangroves. Refer following article in discussion part for propagule length (Md. Kamruzzaman, A. Osawa, K. Mouctar and S. Sharma (2017) Comparative reproductive phenology of subtropical mangrove communities at Manko Wetland, Okinawa Island, Japan. Journal of Forest Research, 22: 118-125)
Response 11: I added to Discussion: R. stylosa, B. gymnorrhiza and K. obovate survived better than the other two species at the first two months, which may be related to their bigger hypocotyls [24]. (L267ff)
I added to References: 24 Kamruzzaman, M.; Osawa, A.; Mouctar, K.; Sharma, S. Comparative reproductive phenology of subtropical mangrove communities at Manko Wetland, Okinawa Island, Japan. J. Forest Res. 2017, 22, 118-125.
Point 18: Line 270 – 284 please refer to Leaf phenological traits and leaf longevity of three mangrove species (Rhizophoraceae) on Okinawa Island, Japan. 2012, Journal of Oceanography, for discussion with reference to shade tolerant behavior of B. gymnorrhiza among K. obovata and R. stylosa based on specific leaf area in subtropical region.
Response 18: Specific leaf area for B. gymnorrhiza (71.0±2.8 cm2g-1) were significantly different from that for R. stylosa (45.4±1.0 cm2g-1) and K. obovata (48.6±0.8 cm2g-1), which may be related to the fact that B. gymnorrhiza could tolerate more shaded conditions than the others [35].
Citation 35 is wrong please correct the reference (S. Sharma, A.T.M.R. Hoque, M. Kamruzzaman, and A. Hagihara (2012) Leaf phenological traits and longevity in three mangrove species (Rhizophoraceae) on Okinawa, Japan. Journal of Oceanography, 68: 831-840).
Response 18: I correct the reference: Sharma, S.; Kamruzzaman, M.; Rafiqul Hoque, A.T.M.; Hagihara, A. Leaf phenological traits and leaf longevity of three mangrove species (Rhizophoraceae) on Okinawa Island, Japan. J. Oceanogr 2012, 68, 831-840.
Author Response File: Author Response.docx
