Profitability of the First Commercial Thinning, a Simulation Study in Northern Finland

Round 1

Reviewer 1 Report

The paper addresses an important topic of the forest management agenda in Finland, namely the effectiveness of the first commercial thinning.

My overall impression is good, but I would also mention some critique points to consider before accepting the paper.

1. The title looks too wordy. The punctuation also needs some correction. Would you please consider the reformulation? In my opinion, it is possible to not mention private forest owners and contractors.
2. Despite the topic of the paper is quite narrow, it is necessary to extend the context of international literature on similar forest policies issue, i.e. in Russia, Canada and other boreal forest countries.
3. L36—41. Some statistical figures would be nice to read.
4. L112—113. What methodology is used for simulation? 
5. Formula 1 and 2 are poorly designed. What is the sense of denominators? Why there are some powers that are not described in the text? Unfortunately, it is not possible to reproduce the results, as the formula are not in a common mathematical representation. 
6. L189—191. Do we really need such notes? Might their be included in the text.
7. It seems that Methods and Results section are confused in many parts of the text. It is necessary to decide, what content should be included into Methodology description, and what is needed in the Results.

Author Response

The paper addresses an important topic of the forest management agenda in Finland, namely the effectiveness of the first commercial thinning.

My overall impression is good, but I would also mention some critique points to consider before accepting the paper.

1. The title looks too wordy. The punctuation also needs some correction. Would you please consider the reformulation? In my opinion, it is possible to not mention private forest owners and contractors.

Our response: This is true. We have now changed the title into “Profitability of the first commercial thinning, a simulation study in northern Finland”

 

2. Despite the topic of the paper is quite narrow, it is necessary to extend the context of international literature on similar forest policies issue, i.e. in Russia, Canada and other boreal forest countries.

Our response: We only agree this argument partially since we consider that although there are international, scientific papers tackling with first commercial thinnings (to name a few, Kanninen et al. 2004, Karlsson et al. 2015,Novak et al. 2017, Witzell et al. 2019, Gailis et al. 2020, Thiffault et al. 2020) their scopes fluctuate too much with respect to this study scope. In other words, we focus here on the financial incentives associated with multiple participating actors (private forest owner and a contractor) of the first commercial thinning (FCT), while majority of the papers focus on different issues than financial performance of the FCT or examine the financial performance only from the private forest owner’s viewpoint (thus leaving the question of other actors’ financial incentives open). Further, most of the existing literature deal with other tree species, often a short-rotation tree species with a considerably different management regime than that applied in boreal forests. In brief, we do not see any rationale referring to those international papers, which eventually have another kind of focus, let alone in most cases different trees species. Thus, we wrote in the revised manuscript (Introduction) the following:   

“Further, we consider that the scope of this study (to discover financial incentives related to participating actors of FCT) is eminently country-specific due to e.g. different legal and operational practices between countries (see [18], [24]) facing seemingly similar FCT problems. Thus, the primary goal is to find out the financial incentives associated with FCT country-wise, and only after compare the results between countries.”

 

However, if the reviewer feels discomfort of our response, we are - of course - ready to change our response and the text in the revised manuscript.

 

References applied in this response:

Gailis et al., 2020.Effect of breeding on income at first commercial thinning in Silver birch plantations. Forests 2020, 11,327; doi:10.3390/f11030327; Kanninen et al., 2004. Intensity and timing of the first thinning of Tectona grandis plantations in Cost Rica: results of a thinning trial. Forest ecology and management 203:89-99; Karlsson et al., 2015. Development of Scots pine stands after biomass thinning with implications on management profitability over rotation. Scandinavian journal of forest research 30(5): 416-428; Novák et al., 2017. Importance of the first thinning in young mixed Norway spruce and European beech stands. Journal of Forest Science, 63: 254–262; Thiffault et al., 2020. Managing plantation density through initial spacing and commercial thinning: yield results from a 60-year-old red pine spacing trial experiment. Canadian journal of forest research, 51:181-189; Witzell et al., 2019. Variable corridor thinning – a cost-effective key to provision of multiple ecosystem services from young boreal conifer forests ? Scandinavian journal of forest research 34(6): 497-507.

 

3. L36—41. Some statistical figures would be nice to read.

Our response: we have now added absolute values of growing stock and annual removals into the first two sentences in Introduction, revised manuscript.

 

4. L112—113. What methodology is used for simulation? 

Our response: With regard to stand projections after the first commercial thinning we applied Motti stand simulator which is described in lines 141-150.  Motti has been widely applied in similar studies and growth conditions, and over 80 international peer-reviewed articles has been published with Motti being the main analysis tool. Then with regard to the first commercial thinning the five options were based on productivity models and cost parameters of logging linked with the forest data (i.e. stand characteristics, see Table 1). The productivity models which were used in this article, enabled to carry out cost comparison of the logging systems in different type of working conditions. In this study a static spreadsheet-based calculation approach was applied, which meant that the fluctuation of interactions in cutting and forwarding were not considered. The statistic model does not take random impacts into consideration and therefore might yield more optimistic results than the dynamic simulation model. As a background information we’d like to emphasize that in Finland the majority of annual timber supply is based on standing sales (trees are bought according to stumpage sale) whereas in this study we also applied sale at delivered price since one objective of the study was to discover the financial incentive from the contractor’s point of view at the first commercial thinning. The bottleneck in Finland is precisely the low rate of conducted first commercial thinnings and reasons for that are still partly open.   

 

5. Formula 1 and 2 are poorly designed. What is the sense of denominators? Why there are some powers that are not described in the text? Unfortunately, it is not possible to reproduce the results, as the formula are not in a common mathematical representation. 

Our response: Unfortunately, something went technically wrong during the process of submission. We have now corrected the formulas (equations 1,2) in the revised manuscript. In brief, there was no denominator other than the correct one, “1-b^t_T”. Thus, this (the false placing of endogenous variables) is purely a technical fault occurred during the process. Then, all powers are explained in the main text. For instance, in the denominator of Eq. [1] stand age t^Trefers to the time for clearcut, i.e. rotation length) and b being the discount factor, b= 1/1+r), where r is the interest rate. However, as mentioned earlier we have corrected the equations in the revised manuscript by noting a bit differently (in order to avoid any technical problems). Then, the notations are commonly used in forest economics, see, e.g. Tahvonen et al. 2013, pp. 720 (Tahvonen et al., 2013. On the economics of optimal timber production in boreal Scots pine stands. Can. J. Forest Res. 43: 719–730), Pihlainen et al. 2014, pp. 1093 (Pihlainen et al., 2014. The economics of timber and bioenergy production and carbon storage in Scots pine stands. Can J. Forest Res. 44(9): 1091-1102) and Parkatti et al. 2019, pp. 56 (Parkatti et al., 2019. Economics of boreal conifer species in continuous cover and rotation forestry. Forest Policy Econ. 100: 55-67).

 

6. L189—191. Do we really need such notes? Might they be included in the text.

Our response: we are not 100% sure where the reviewer is exactly pointing with this question (?). If she/he is referring to the text inside the brackets (starting with “[Note that there are…”) we consider that the information in brackets belongs there within the brackets within the main text.  

 

 

7. It seems that Methods and Results section are confused in many parts of the text. It is necessary to decide, what content should be included into Methodology description, and what is needed in the Results.

Our response: We agree that some parts of the Methodology section might belong to Results section. Thus, in the revised manuscript we have now moved some text (a few sentences) and Table 2 related to logging costs into Results section. Further, we added an extra sentence in Material and Methods section to describe how the logging costs were eventually calculated. These changes are easily seen in the revised manuscript since we applied track changes feature of Word. Finally, the Results section is now constructed so that we first present the logging costs results, then simulated tree growth (i.e. stand projections) and finally the financial performance - which makes the Results section chronologically logical.

Reviewer 2 Report

The issue of investment in young stands is relevant to readers.

Pre-commercial thinning or the first commercial thinning is critical to successful stand development. This paper addresses the subject matter with a simulation. This reviewer would have preferred an actual side-by-side field study of FCT across the six stands with real logging contractors. The modeling approach makes many assumptions on all the inputs. I can only assume the authors did their due diligence on the inputs before entering them into the “black box”. The authors need to be more transparent in their methods. Throughout the paper, they repeatedly expect the reader to refer to other papers to understand their methods.

The results are not surprising. The highest value wood product will be sawtimber. Thereafter, the values drop precipitously. I believe the introduction of clean chips for papermaking would make a good contrast to lower value energy chips. I am not sure if loggers in Finland can produce a clean chip on the landing. In my region, it is fairly common and quite profitable. Due to the low price of natural gas, the price of energy chips has dropped and only economical when markets are very close to minimize trucking costs.

Minor comments:

L45 – may want to include reduction in mean annual increment

L55 – how does the pre-commercial thin fit in? Do they occur in Finland?

L77 – forewest?

L84 – profit?

L114 – clarify that industrial is roundwood and energy wood is fuel chips; whole tree means 100% chipping for energy chips? Are there markets for pulp grade (clean) chips?

L196 – need to make clear that logging contractor is paying for the stumpage

L205 – of what?

L207 – of what?

L208 – function of 49 applied? The authors repeatedly expect the reader to refer to other papers to understand their methods.

L214 – not clear of all logging costs are included such as overhead, set up and best management practices

L222 – if logging contractor is paying stumpage, why are logging costs so similar when the stumpage rate is 8 versus 3?

 

Figure 2 – difficult to visually decipher FCT across the five options

Table 3 – clarify delivery sales for energy wood; does this include transportation costs?

Table 4 – the two categories of “ongoing” and “future” are not clear; why is “future” relevant?

Author Response

REVIEWER 2#

The issue of investment in young stands is relevant to readers.

Pre-commercial thinning or the first commercial thinning is critical to successful stand development. This paper addresses the subject matter with a simulation. This reviewer would have preferred an actual side-by-side field study of FCT across the six stands with real logging contractors. The modeling approach makes many assumptions on all the inputs. I can only assume the authors did their due diligence on the inputs before entering them into the “black box”. The authors need to be more transparent in their methods. Throughout the paper, they repeatedly expect the reader to refer to other papers to understand their methods.

Our response: We find it challenging to reply to the text above – since there are no explicit questions addressed. However, we try our best to answer to some of them and clarify the study setting. First, this paper does not show any results on pre-commercial thinning. We focus on the first commercial thinning. Then, “The modelling approach makes many assumptions on all the inputs” needs to be clarified. Background: studies focusing on simulations are bound to have assumptions, this is the status quo – this is a known fact among experts of the field. The relevant question is whether these assumptions hold. We reckon our assumptions hold, and further we show all the crucial inputs and assumptions applied as well as the results obtained in our manuscript – see, Table 1, 2, 3 and 4, and Figure 2 and 3. Readers familiar with forest management in boreal zone can easily judge whether our assumptions and further the results are credible. Finally, if needed the reviewer could pinpoint the supposedly hazy text in the manuscript item by item so we can correct them in detail.        

The results are not surprising. The highest value wood product will be sawtimber. Thereafter, the values drop precipitously. I believe the introduction of clean chips for papermaking would make a good contrast to lower value energy chips. I am not sure if loggers in Finland can produce a clean chip on the landing. In my region, it is fairly common and quite profitable. Due to the low price of natural gas, the price of energy chips has dropped and only economical when markets are very close to minimize trucking costs.

Our response: This is only partially true. Sawtimber does not explain the ranking fully – since in the first commercial thinning there is not much sawtimber to be procured in any option 1-5. Further, for a private forest owner’s point of view (see Eq. [1] and [2]) the profitability (expressed as MaxNPV) is defined by taking into account the ongoing rotation as well as the future generations (management regime obtained through stand-level optimization). The rationale was first to find out the best performers among the five options introduced, and then to discover whether the different options (1-5) would financially diverge with respect to ongoing and future generations. Future generations were needed in the analysis since the rotation length of the ongoing rotation varied between options (this was already explained in the original manuscript in detail, lines 80-182). The ranking between the options is better explained by the fact that in options 1 and 2 a bit more of pulpwood is procured in the FCT (compared to other options 3,4 and 5 – see Table 4). This combined with the fact that pulpwood price is much higher than the energy wood price (for a private forest owner!) results in that options 1 and 2 are the best financial performers for a private forest owner (Figure 3a). [Note that Table 4 shows the FCT cutting removals associated with option 1-5, and it also represents the total cutting removals for the ongoing and future generations]. Then, with regard to contractor’s point of view (Figure 3b) the explanation is different – since now we take into account also the cutting costs (presented in Table 3 in the revised manuscript) and we focus solely on the FCT. However, the ranking remains the same as for a private forest owner, mostly because this time the sawtimber removal makes the difference for options 1 and 2, compared to options 3,4 and 5 (no sawtimber procured). To avoid further confusion, in the revised manuscript we have now added the average sawtimber removals associated with FCT in option 1 and 2, Table 3. Finally, one should note that price of energy wood for the contractor (see Table 2 in the revised manuscript) is different than the price of energy wood for a private forest owner (€3 or €8 m^-3, see Chapter 2.2. Simulations). This due to the difference between standing sales (private forest owner) and delivery sales system applied in the Finnish roundwood markets.     

Minor comments:

L45 – may want to include reduction in mean annual increment

Our response: In the revised text we have added “…a reduction in a mean annual increment and… “

L55 – how does the pre-commercial thin fit in? Do they occur in Finland?

Our response: This is a good question. We do apply PCT in Finland (e.g. Huuskonen et al. 2020), but in this study the original stands were selected particularly because of the lack of early management (e.g. PCT) and due to the delay in the timing of first commercial thinning. For instance, in the Material and Methods section we write “ The chosen stands belong to specific clusters of postponed FCTs”. The big question in Finland right now is “What can we do with stands facing delayed FCT” ?  

Reference applied in this response:

Huuskonen, S., Haikarainen, S., Sauvala-Seppälä, T., Salminen, H., Lehtonen, M., Siipilehto, J., Ahtikoski, A., Korhonen, K.T. and Hynynen, J. 2020. Benefits of juvenile stand management in Finland – impacts on wood production based on scenario analysis. Forestry: An international journal of forest research. https://doi.org/10.1093/forestry/cpz075

L77 – forewest?

Our response: in the revised manuscript we have corrected this into “forest”.

L84 – profit?

Our response: If reviewer refers to term “optimal solution”, one could say profit. However, since the stand management was optimized we prefer the term “optimal solution”

L114 – clarify that industrial is roundwood and energy wood is fuel chips; whole tree means 100% chipping for energy chips? Are there markets for pulp grade (clean) chips?

Our response: In brief, industrial roundwood is pulpwood and sawn timber. The former (pulpwood) is peeled and further chipped (as clean chips) for pulp industry, the total amount in 2019 was around 42 million cubic meters in Finland. Then energy wood is fuel chips for heat production made of either stems or mixture of stems, foliage and branches by chipping them (the mixture is usually referred as whole-tree energy wood). Fuel chips always include bark, which makes them unsuitable for pulping. In the manuscript we wrote ”…Further, in options 2), 4) and 5) 30% of foliage and branches was assumed to be left on site after thinning, and in option 3) all, i.e. 100%.” This means that in options 3 only stems for energy were procured while in options 2, 4 and 5 70% (i.e. 100%-30%) of foliage and branches was procured for energy. This is a common practice in Finland and Sweden: to leave some part of the foliage and branches on a site to secure nutrient substances for tree growth of remaining trees.

L196 – need to make clear that logging contractor is paying for the stumpage

Our response: This is not correct: contractor does not pay for the stumpage (see Eq. 3) ! In Finland and Sweden the system is that forest company pays for the stumpage for a private forest owner and the forest company also hires the contractor for procuring. In brief, the primary financial incentive for a contractor stems from the fact that logging costs are kept below the revenues (cutting incomes according to roadside prices). Then, markets eventually define whether the stumpage prices paid for private forest owners and logging tariffs (note that logging tariffs diverge from the revenues !) paid for contractors are in relation to the profits achievable for a forest company (stumpage prices and logging tariffs represent costs for a forest company !). Before the markets can even function/operate we need to assess whether there are financial incentives for private forest owners and contractors to participate to the process in the first place. In other words, we first need to reveal whether a contractor can operate in FCT, given the calculated logging costs and revenues determined according to roadside prices. Further, a private forest owner simply tries to maximize NPV according to Equation [2].

L205 – of what?

Our response: Due to the technical design of Forests the references in the main text are depicted by numbers in brackets. Number [21] refers to Laitila, J.; Väätäinen, K. Hakkuutyön tuottavuus metsävarustellulla  turvetuotantotraktorilla karsitun aines- ja energiapuun korjuussa  [The cutting productivity in integrated harvesting of pulpwood and delimbed energy wood with a forestry-equipped peat harvesting tractor]. Suo – Mires and Peat 2013, 64, 97–112

L207 – of what?

Our response: See our response above. Number [48] refers to Nurminen, T.; Korpunen, H.; Uusitalo, J. Time consumption analysis of the mechanized cut-to-length harvesting system. Silva Fenn. 2006, 40, 335–363 and number [49] to Laitila, J.; Asikainen, A.; Nuutinen, Y. Forwarding of whole trees after manual and mechanized felling bunching in pre-commercial thinnings. Int. J. For. Eng. 2007, 18, 29–39.

L208 – function of 49 applied? The authors repeatedly expect the reader to refer to other papers to understand their methods.

Our response: First, we slightly disagree when the reviewer states that “The authors repeatedly expect the reader to refer to other papers..”. Our argument is that there are only three papers referred: [21] for cutting productivities (i.e. time consumption models), [48] for forwarding productivity and [49] for forwarding productivity when tree tops (i.e. foliage and branches) are procured. We do not see that these three references correspond to term “repeatedly”.

Then, in lines 207 and 208 we refer to the original study of Laitila et al. 2007 (reference number [49]), and also illustrate the assumptions related to load sizes which are relevant to be presented for readers familiar with logging costs. Readers can verify and confirm the assumptions and applied equations by checking the logging costs results in Table 2. In other words, are they realistic or not. Had we presented all the original equations (shown in the three articles), this would have taken a major space of the manuscript. Instead, we present only the relevant assumptions by numbers and refer to articles where the original models are, and then readers can check their reliability by looking the logging cost results shown in Table 3 (revised manuscript). For us this is not a question of methodology per se – rather we apply the existing time consumption and productivity models (by referring them in the main text) relevant for this study to obtain logging costs for further analyses.

L214 – not clear of all logging costs are included such as overhead, set up and best management practices

Our response: We state (and write) that only logging costs derived from the three models (and based on the assumptions described in the main text) are applied in this study. Thus, overhead, set up costs, etc. are excluded from the analyses.  

L222 – if logging contractor is paying stumpage, why are logging costs so similar when the stumpage rate is 8 versus 3?

Our response: see our response related to “L 196 – need to make clear that logging contractor is paying for the stumpage”. It seems that reviewer 2 has somewhat misunderstood our study scope. In brief logging costs do not include stumpage (the reason is explained in former response and can also be seen in Equation 3). 

 

Figure 2 – difficult to visually decipher FCT across the five options

Our response: We agree. In the revised manuscript we have added the following sentence into Figure legend:” FCT conducted at the stand age between 54 and 59 years, depending on the option.” Note that we already wrote in the 2.2. Simulations Chapter the following: “The timing and intensity of the first commercial thinning according to the above-mentioned options (1-5) were obtained through a stand-level optimization”.

Table 3 – clarify delivery sales for energy wood; does this include transportation costs?

Our response: The original phrasing was misleading. In the revised manuscript we have corrected the text above the Table “…and price of energy wood…Price of energy wood is at roadside.”  

Table 4 – the two categories of “ongoing” and “future” are not clear; why is “future” relevant?

Our response: The future generations are needed to be taken into account due to the fact that ongoing rotation length varies between options 1-5 (see Figure 2 and Table 4 “Ongoing”). This is also written in the Material and Methods section (between Eq.[1] and [2]), stating: “ Since the time horizon might vary among simulated management regimes of the ongoing rotation, the discounted maxLEV (Eq. 1) was included into the financial analysis to commensurate to the management regimes (see [26] for technical details)”.

Reviewer 3 Report

1. This article is well prepared and exercised. But I have several questions and suggestions to be considered.

2. What is the criteria for the FCT? Does Catagory in the Finnish system or tree age work for the FCT basis? According to the results of simulations, option 1(Traditional) is the best for the private owners as well as the contractors. If this is true why the exercises of the first commercial thinning are delayed. Is this a result from timing mismatch between biological and economical thinnings?

3. Why do option 1 and 2 outperform the other options for the private owners as well as contractors? I think the prices might cause the different performances. With the same silvicultural costs and the similar logging cost the higher price will make more profits to private owners and contractors. To see this more clear it is recommended to solve the problem with analytical approach and have optimal conditions in this paper. This is a personal recommendation.

4. In option 4 and 5, what prices are they? Prices of energy(116-117), prices of energy wood(229), or stumpage price of energy wood(220)?

5. Since the prices in equation [2] and [3] are different, the notations of two prices should be different.

Author Response

REVIEWER 3#

 

1. This article is well prepared and exercised. But I have several questions and suggestions to be considered.
2. . What is the criteria for the FCT? Does Catagory in the Finnish system or tree age work for the FCT basis? According to the results of simulations, option 1(Traditional) is the best for the private owners as well as the contractors. If this is true why the exercises of the first commercial thinning are delayed. Is this a result from timing mismatch between biological and economical thinnings?

Our response: The criteria for FCT in general is described in the Finnish silvicultural recommendations (Äijälä et al.2014; in brief, the timing for FCT is determined according to a basal area limit for a particular dominant height), but in this study we applied a framework where the six stands (see Figure 1, Table 1) were derived from “specific clusters of postponed FCTs” (lines 97-98, original manuscript). Thus, the stands can be considered to be already late for traditional FCT. The rationale was to discover how to manage the stands which are delayed for conventional FCT. For this end we introduced five options (described in lines 112-129, original manuscript). In other words, our results apply only for cases when the FCT is postponed. We wrote in the Material and Methods section the following:”

The stands were selected according to: i) the stand has passed the juvenile development phase but is not yet a mature stand (technically representing category 2 or 3 in the Finnish system) and ii) an FCT had been suggested to be conducted in the stand within the past five years….”. To our opinion these sentences itself clarify that we are dealing with at least somewhat delayed FCT.

Finally, there is a timing mismatch between biological (growth and yield) and economical thinnings also in Finland… This discrepancy has been demonstrated in several stand-level optimizations, see e.g. Ahtikoski and Hökkä 2019.

References applied in this response:

Ahtikoski, A. and Hökkä, H.2019.Intensive forest management – does it financially pay off on drained peatlands ? Canadian Journal of Forest Research, vol. 49:1101-111. 

Äijälä O, Koistinen A, Sved J, Vanhatalo K, Väisänen P. (Editors)(2014) Metsänhoidon suositukset Silvicultural recommendations]. The Forestry Development Centre Tapio. Helsinkin, Finland. [In Finnish].186 p.

   

 

3. Why do option 1 and 2 outperform the other options for the private owners as well as contractors? I think the prices might cause the different performances. With the same silvicultural costs and the similar logging cost the higher price will make more profits to private owners and contractors. To see this more clear it is recommended to solve the problem with analytical approach and have optimal conditions in this paper. This is a personal recommendation.

Our response: That is true, to some extent. Sawtimber, however does not explain the ranking fully – since in the first commercial thinning (FCT) there is not much sawtimber to be procured in any option 1-5, and in the financial assessment for a private forest owner we also take into account the rest of the ongoing rotation as well as future generations (see Eq. [2]). (One detail: MaxNPV is valued at stumpage, excluding logging costs since > 85% timber supply in Finland is based on standing sales). The ranking between the options is better explained by the fact that in options 1 and 2 a bit more of pulpwood is procured (compared to other options 3,4 and 5 – see Table 4). This combined with the fact that pulpwood price is much higher than the energy wood price (for a private forest owner !) results in that options 1 and 2 are the best financial performers for a private forest owner (Figure 3a). Then, with regard to contractor’s point of view (Figure 3b) the explanation is bit different – since now we take into account also the cutting costs (presented in Table 2), and we focus solely on the FCT. However, the ranking remains the same as for a private forest owner, mostly because this time the sawtimber removal makes the difference for options 1 and 2, compared to options 3,4 and 5 (no sawtimber procured). Then, we cannot apply an analytical approach which would clarify the problem of price effect. This is simply due to the fact that this study focused on numerical stand-level optimization and further extending the analyses into analytical framework would be beyond the original scope of the study. Good and relevant recommendation, altogether. Finally, the rationale in this study (see lines 296-309 in the original manuscript, lines 314-327 in the revised manuscript) was to discover whether the best financial option(s) among the options 1-5 for a private forest owner also assures that a contractor can profitably conduct the FCT (which is included into the optimal management regime !). If not, then there is a conflict between actors – if yes, then there is a win-win situation. Further, since there is a massive amount of delayed FCTs in Finland, we focused on finding out the underlying reason(s) for that grievance.

 

    

4. In option 4 and 5, what prices are they? Prices of energy(116-117), prices of energy wood(229), or stumpage price of energy wood(220)?

Our response: (some background first; since we applied a stand-level optimization, the two prices needed to be fed before the simulation started. They were variable values which endogenously affected during optimization – with two different price levels we could find out the effect of energy wood price on optimal management regime and thus on financial performance). Then, for option 4) energy price was €3 m^-3 and for option 5 it was €8 m^-3 . This is written in the original manuscript, lines 116-117. Then, in line 220 (original manuscript) there is an unfortunate foul in the text below the Table. In the revised manuscript it is corrected: “ ³⁾stumpage price of energy wood 8 € m^-3.” In other words, a superscript “³⁾” was missing, which hindered reading… Finally, in the revised manuscript we have clarified the terminology related to prices (see Table 3) so that reader now can easily see the different prices applied for a private forest owner and a contractor.

 

5. Since the prices in equation [2] and [3] are different, the notations of two prices should be different.

Our response: This is correct. In the revised manuscript we have now denoted the prices for a contractor (Eq. [3]) by p_k’. See lines 211-213 in the revised manuscript.

Round 2

Reviewer 1 Report

I am satisfied with a job made by the authors.