Biomass Harvesting from Salvage Clearcuts on Young Eucalypt Stands and Post-Wildfire Pine Thinnings with Fixteri FX15a Feller-Bundler in Spain
Round 1
Reviewer 1 Report
In the review of the manuscript titled Biomass harvesting from salvage clearcuts on young eucalypt stands and post-wildfire pine thinnings with Fixteri FX-15a feller-bundler in Spain. The authors have provided a good description and the methodology is also fine. Some questions as follow;
What were the main factors identified as explanatory variables for the productivity of salvage clearcuts in Eucalyptus globulus stands after wildfire and Gonipterus attack?
In the context of thinning in a dense, Matsococcus affected Pinus pinaster stand regenerated after a wildfire, what factors, in addition to unit weight, were found to explain productivity?
How was the productivity of salvage clearcuts and thinning operations quantified in the study?
What type of equipment was used for the salvage clearcuts and thinning operations in this study?
In the context of biomass collection, what was the economic outcome in the Gonipterus affected plantation, and under what conditions did the cost reach a zero balance?
What were the economic implications of biomass harvesting in the pine stand that had undergone restoration efforts?
For the burned eucalypt plantation, what condition would be necessary to achieve a zero cost according to the study's findings?
Besides productivity, what other conclusions or recommendations were drawn from the detailed time-studies regarding the performance and utilization of the Fixteri FX-15a equipment?
Author Response
In the review of the manuscript titled Biomass harvesting from salvage clearcuts on young eucalypt stands and post-wildfire pine thinnings with Fixteri FX-15a feller-bundler in Spain. The authors have provided a good description and the methodology is also fine. Some questions as follow;
Thank you very much for your review, we hope it does contibute to improve the manuscript. We are proud to receive your overall positive judgment.
What were the main factors identified as explanatory variables for the productivity of salvage clearcuts in Eucalyptus globulus stands after wildfire and Gonipterus attack?
In both cases, the explanatory variable was the unit weight, oven dried kg per tree, as explained in the summary (L 16-17), being different the dependence in function of the reason for the clearcut felling: we found lower productivities for the wildfire affected stand, as depicted in Figure 1 and discussed in L. 462-467 of the corrected manuscript.
In the context of thinning in a dense, Matsococcus affected Pinus pinaster stand regenerated after a wildfire, what factors, in addition to unit weight, were found to explain productivity?
In this case, as it was a selective thinning with different intensity in different zones, the intensity of the treatment, in terms of percentage of the initial basal area extracted, was an aditional factor. We have tried to clarify this aspect adding the meaning of the variable ExtBA below the Equation 3 in the corrected manuscript (L. 348).
How was the productivity of salvage clearcuts and thinning operations quantified in the study?
In both cases, the stand were inventoried, in Catalonia before and after the treatment. The DBH distribution was used as a basis to apply biomass weight equations from different sources depending on the species. In the Galician plantations, the detailed equations allowed substracting the weight of the fractions lost because of the wildfire or the pest attack (leaves and small branches). Where we could weigh the biomass uncollected - left on the ground -, it was substracted from the total estimated standing biomass; the exception was the Galician pest-affected plantation, where it was not possible to measure the collection efficiency because they mulched the debris before we could weigh them. We have tried to explain it more clearly in L. 187-196 of the corrected manuscript.
What type of equipment was used for the salvage clearcuts and thinning operations in this study?
If you mean the machinery,in both cases it was the feller-bundler Fixtery FX15a, fllowed by different forest forwarders, as explained in L. 69-76 of the corrected manuscript. If you refer to the equipment for the time-study, besides the authomatic recording of weight and time by the machine, using the software Nexus 2, we combined the stopwatching in situ methodology - time frequency sampling - with some recorded videos which we analyzed afterwards in the laboratory.
In the context of biomass collection, what was the economic outcome in the Gonipterus affected plantation, and under what conditions did the cost reach a zero balance?
The economic outcome was negative, -125 € per hectare (L. 410), while the alternative without collecting the biomass would have been much more costly. the zero balance would be achieved for a unit weight (oven dried kg per tree) of 33 kg (L. 399-400, Figure 4), not so far from the average actual value (17.5 odkg, Table 1)
What were the economic implications of biomass harvesting in the pine stand that had undergone restoration efforts?
The operational cost on a per hectare basis was 265 € per hectare, in front of a cost of the treatment without extracting the biomass of 2,400 € per hectare, accordingly with the tarifs developed by the Spanish main public forest enterprise (L. 418-419 of the corrected manuscript). This means that the result is very positive in terms of the surface that can be treated with a certain budget.
For the burned eucalypt plantation, what condition would be necessary to achieve a zero cost according to the study's findings?
The zero balance would only be achieved for a unit weigth slightly greater than 80 odkg per tree (L. 401-402, Figure 4), very far of the observed range (average actual value of the unit weight was 12.8 odkg, Table 1)
Besides productivity, what other conclusions or recommendations were drawn from the detailed time-studies regarding the performance and utilization of the Fixteri FX-15a equipment?
The bottleneck in the studied case was the limited speed of the feeding-bundling unit compared to the feller-buncher head. Also we found limitations regarding the steep slopes due to the high cdg of the bundling unit when forming the bundles. A possble soluction for salvage clearcuts would be using a wider machine - more stable - carrying a faster bundling unit - less limtations if compared to the felling-bunching unit-.
Thank you once again for your review, we expect having answered properly to your questions and having clarified some aspects that could be unclear in the original manuscript.
Reviewer 2 Report
Thank you very much for giving me the opportunity to evaluate this article. The purpose of the article is interesting and very practical.
As far as the content is concerned, the paper has a clearly stated and unambiguous aim, with clear and concise presentation of data. It has a proper study design. In addition, its results respond to the aim of the study and the conclusions are supported by the result. References are related.
However, I would suggest the following corrections:
I believe that a large part of the section's “Introduction” (L63-90) belongs to the “Material and Methods” section, please, subtitle study area for L63-78.
(L99), explain why the plots in the first Galician eucalypt plantation have a smaller radius (4m).
L128), "The detailed time-study was performed for 18.5 hours in the Galician plantations" how many time-study were performed separately in each of the plantations in Galicia?
Fig. 1 and Fig.2 are indiscernible
(L240), undern equation 3, there is no explanation (Ext BA %?, …)
(L247), add in brackets (BA), after the phrase ….extracted basal area.
(L274) (…∙bundle-1, should become exponent -1).
There are in many places long and difficult sentences which need to be rephrased (L10-15, L70-74, L91-94, L105-109).
Author Response
Comments and Suggestions for Authors
Thank you very much for giving me the opportunity to evaluate this article. The purpose of the article is interesting and very practical.
Thank you for the review, we think that it has permitted to improve the manuscript
As far as the content is concerned, the paper has a clearly stated and unambiguous aim, with clear and concise presentation of data. It has a proper study design. In addition, its results respond to the aim of the study and the conclusions are supported by the result. References are related.
Thank you once again, we are proud to receive your positive judgments
However, I would suggest the following corrections:
I believe that a large part of the section's “Introduction” (L63-90) belongs to the “Material and Methods” section, please, subtitle study area for L63-78.
We have moved this part to "Material and Methods" as sugested
(L99), explain why the plots in the first Galician eucalypt plantation have a smaller radius (4m).
We have explained in the manuscript, the plot size is much smaller because the first Galician plantation was denser and much more homogeneous than the other two stands.
L128), "The detailed time-study was performed for 18.5 hours in the Galician plantations" how many time-study were performed separately in each of the plantations in Galicia?
It has been included in the manuscript, the first plantation was time-studied during 11,9 hours and the second (wildfire affected) during 6,5 hours
Fig. 1 and Fig.2 are indiscernible
We think that both Figures should remain separated, because they describe very different treatments with different dependent variables (productivity on work machine hour and scheduled machine hour basis, respectively) and different explanative variables (in the Galician case, only the unit weight, in the Catalonian stand, also the percentage of extrated basal area). We think that combining those Figures cound be confusing.
(L240), undern equation 3, there is no explanation (Ext BA %?, …)
It has been corrected accordingly
(L247), add in brackets (BA), after the phrase ….extracted basal area.
It has been corrected accordingly
(L274) (…∙bundle-1, should become exponent -1).
It has been corrected accordingly
Comments on the Quality of English Language
There are in many places long and difficult sentences which need to be rephrased (L10-15, L70-74, L91-94, L105-109).
The mentioned parragraphs have been rephrased, trying to improve their redaction and clarify their meaning.
Thank you once again for your wise comments.
