Global Change and Forest Disturbances in the Mediterranean Basin: Breakthroughs, Knowledge Gaps, and Recommendations

Round 1

Reviewer 1 Report

This is a review of the effects of anthropogenic change on Mediterranean forests and is generally clear, comprehensive and up to date.  While there are some small text edits and clarifications which I think would be useful, I do not think these should be a large barrier to publication.

Major comments.

• The introduction of the paper could do with a clearer definition of Mediterranean forests. There are some mentions of tree – grass dehesa ecosystems in the main body of the text but I am not sure if the authors intend these to be considered as well – there is important distinction between these open systems and more closed forests. A clarification or during the introduction would be very useful and a figure showing the distribution (even if just around the Mediterranean basin) would be even more so.
• Secondly, as the introduction talks about forests across the entire Mediterranean biome (and references regarding functional processes in these systems cover other regions), but most of the management examples are of the Mediterranean basin, some statement of the explicit coverage of this part of the review would be useful.
• I am not sure what the bolding of certain phrases is meant to signify, of if it is intentional.
• There are frequent mentions of recruitment limitations in some marginal forest ecosystems in the literature (e.g. Carnicier 2013, for a Mediterranean species). Are these of relevance (in interaction with) the effects in this species. This could work as an expansion to section 2.4
• Forest’s author policy specifies that “Latin binomial nomenclature and authority should be provided after each common name the first time referred to in the text.”. I appreciate that this is less important and potentially disruptive for a review, but I hope the authors have made this choice deliberately and it is acceptable to the editor.
• Reading the reference list I found several typographic mistakes – e.g ref. 42 – ‘precipitaytion’, 53 - semiàrid, 54 – ì 98 – carbon, 132 – crossdtalk, 234 – od a. The authors must check the reference list fully and ensure it is accurate.

Minor comments:

• Does Forests require an authority on species names? Admittedly there are many in this review so stylistically I think it looks better without.
• L58 : what is a ‘current legacy?’. The future state as predicted from the current state?
• L67: Despite what? I suggest this be phrased something like ‘Between 2010 and 2015, forests in the Mediterranean Basin have… but the level of forest degradation has also increased…’
• L77: I do not understand what the authors mean here – what does ‘except for the low water content’ mean in relation to fertility?
• L81: Are there any evidence that forest growth / C pools are also increasing?
• L84: The EU CAP was not in existance for most of the last 100-150 years. Suggest a rephrasing here.
• L97 – ‘protection against soil erosion’ by enzymes seems somewhat teleological and probably unintentional. Perhaps these two arguments (roots – erosion / fertility / water) and (enzymes – fertility) could be split to avoid confusion.
• L135 – what can be insufficient? I don’t understand this sentence.
• L138 – perhaps ‘nutrient losses’ could be expanded on. Is this N losses expected, perhaps leading to (as in other works by the authors) – N:P imbalances?
• L161 – perhaps rephrase ‘earlier taken up’ – this is a little confusing as this terminology can be used for nutrients as well with a very different meaning.
• L187 – is there any evidence that the aforementioned CO2 fertilization could raise these limits? (although maybe this is beyond the scope of this paper)
• L292 – this reference [132] does not link as the others in the review copy, and contains a typo: ‘crossdtalk’
• L340 – for some readers, a clarification as to which Sierra Nevada this refers to be would be useful
• L407 – a sentence elaborating on the links between fire, rain and erosion would be good.
• L583 – is this the definition of appropriate management, or something which can occur alongside appropriate management. Rephrasing would clarify this.

Author Response

Editor

Forests

                                                                                          Barcelona, May 3^st, 2021

Dear Editor:

We submit the revision of our manuscript No. forests-1182332 entitled “Global change and forest disturbances in the Mediterranean Basin: Breakthroughs, knowledge gaps and recommendations” after incorporating the comments and suggestions of the referees. Many thanks for your consideration and help. We hope that this study can now be published in Forests

Responses to reviewer 1 comments

1.Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style

Response: Thanks for the positive evaluation of our study.

2.Comments and Suggestions for Authors. This is a review of the effects of anthropogenic change on Mediterranean forests and is generally clear, comprehensive and up to date.  While there are some small text edits and clarifications which I think would be useful, I do not think these should be a large barrier to publication.

Response: Thanks to the reviewer for her/his favorable general evaluation of our study. We have further worked on it to solve all the edits and clarifications suggested by the reviewer (see below responses one-by-one to the reviewer’s comments).

3.Major comments. The introduction of the paper could do with a clearer definition of Mediterranean forests. There are some mentions of tree – grass dehesa ecosystems in the main body of the text but I am not sure if the authors intend these to be considered as well – there is important distinction between these open systems and more closed forests. A clarification or during the introduction would be very useful and a figure showing the distribution (even if just around the Mediterranean basin) would be even more so.

Response: Done. In fact, we considered Dehesas as agro-forestry ecosystems and are considered as within Mediterranean forest in this Mediterranean context, in fact most of them, if not human managed, tend to convert into forest ecosystems.

The revised text now reads:

“The increase in forested area in the last 100-150 years is mainly due to both the European Common Agriculture Policy and forest regeneration in rural areas following abandonment, as in several Mediterranean countries, and more recently it is also due to the European Common Agriculture Policy (as in Spain) [18,25]. Remote-sensing studies focusing on the overall Mediterranean Basin region have more recently indicated that the area of forests in the Mediterranean region has remained stable or slowly increased in the last few decades (see the “Depopulation and abandonment of rural areas” section below). A stable or increasing forest area, as defined by the FAO, though, tells us nothing about forest degradation [10]. To all these circumstances we must add in Mediterranean forested areas the long-term influence of certain extensive use of forests to obtain several products such as food, cork, wood among other products at once [18,25]. For example, the dehesas are agroforestry systems that have been long-term managed by humans endeavoring several activities such as raising pigs, bulls and goats, or growing cereals coexist with an open forest dominated frequently by evergreen oks, mainly Quercus robur L., Quercus pubescens Willd., Quercus ilex L. and Quercus rotundifolia Lam. [10,18]. These systems mostly occupy locations that without human intervention would mostly become evergreen holm oak forests, which would increase the risk of great and frequent fires [10]. These areas occupy 17.7% of the Mediterranean region [10] and are currently threatened by human abandonment and agricultural intensification which drives them to an uncertain future [10].”

4.Secondly, as the introduction talks about forests across the entire Mediterranean biome (and references regarding functional processes in these systems cover other regions), but most of the management examples are of the Mediterranean basin, some statement of the explicit coverage of this part of the review would be useful.

Response: We simply in the beginning of the first paragraph situated the Mediterranean climate and its areas, but we immediately focused the study in Mediterranean Basin. In fact, from the first sentence in the abstract we refer explicitly to Mediterranean Basin. To leave this clearer we have changed the title of the manuscript from:

“Global change and forest disturbances in the Mediterranean: Breakthroughs, knowledge gaps and recommendations”

To:

“Global change and forest disturbances in the Mediterranean Basin: Breakthroughs, knowledge gaps and recommendations”

and the title of the first section of the manuscript from:

“Background. Mediterranean forest: A system shaped by water, nutrient limitations and human management.”

To:

“Background. Mediterranean forest: A system shaped by water, nutrient limitations and human management. The Mediterranean Basin case.”

5.I am not sure what the bolding of certain phrases is meant to signify, of if it is intentional.

Response: We have removed the bold type.

6.There are frequent mentions of recruitment limitations in some marginal forest ecosystems in the literature (e.g. Carnicier 2013, for a Mediterranean species). Are these of relevance (in interaction with) the effects in this species. This could work as an expansion to section 2.4

Response: We have now commented the recruitment limitation in the chapter 2.5. (High diversity at risk) because this effect has been observed to be asymmetrical observed among distinct species being a clear threaten for biodiversity in Mediterranean forest. This now reads:

“Biodiversity in Mediterranean areas has been widely monitored and quantified, so identifying species indicative of different levels of diversity is feasible in Mediterranean landscapes [261]. Moreover, current warming has had positive effects on angiosperm Mediterranean forests and negative effect on gymnosperms Mediterranean forest as observed in Spain due to hydraulic traits and reproductive success [262,263].”

New references

262.Carnicer, J.; Coll, M.; Pons, X.; Ninyerola, M.; Vayreda, J.; Peñuelas, J. Large-scale recruitment limitation in Mediterranean pines: the role of Quercus ilex and forest successional advance as key regional drivers. Global Ecol. Biogeogr. 2014, 23, 371-384.

263.Carnicer, J.; Barbeta, A.; Sperlich, D.; Coll, A.; Peñuelas, J. Contrasting trait syndromes in angiosperms and conifers are associated with different responses of tree growth to temperature on a large scale. Front. Plant Sci. 2013, 4, 409.

7.Forest’s author policy specifies that “Latin binomial nomenclature and authority should be provided after each common name the first time referred to in the text.”. I appreciate that this is less important and potentially disruptive for a review, but I hope the authors have made this choice deliberately and it is acceptable to the editor.

Response: Thanks for make us notice of this and to avoid editorial problems we have added the authority to Latin binomial nomenclature in the first mention of the species in the text throughout the text.

8.Reading the reference list I found several typographic mistakes – e.g ref. 42 – ‘precipitaytion’, 53 - semiàrid, 54 – ì 98 – carbon, 132 – crossdtalk, 234 – od a. The authors must check the reference list fully and ensure it is accurate.

Response: Checked and corrected.

9.Minor comments: Does Forests require an authority on species names? Admittedly there are many in this review so stylistically I think it looks better without.

Response: We leave this in the editor hands.

10.L58 : what is a ‘current legacy?’. The future state as predicted from the current state?

Response: No, the current situation due to pass history. we have now clarified it. The revised text now reads:

“The current legacy of Mediterranean forests has nevertheless been modulated by historical socioeconomic pressures, leading to several unsustainable forest practices and frequently to the neglect of forested land by human society [8].”

11.L67: Despite what? I suggest this be phrased something like ‘Between 2010 and 2015, forests in the Mediterranean Basin have… but the level of forest degradation has also increased…’

Response: Thanks. Changed to now read:

“Between 2010 and 2015, forests in Mediterranean Basin have increased their cover by 2%, but the level of forest degradation, and the vulnerabilities to climate change, population expansion, wildfires and aridity have also increased [11].”

12.L77: I do not understand what the authors mean here – what does ‘except for the low water content’ mean in relation to fertility?

Response: Clarified to now read:

“Apart from the low water content during most of the year, Mediterranean soils often suffer from nutrient deficiencies, especially of nitrogen (N) and phosphorus (P) [18,20-23].”

13.L81: Are there any evidence that forest growth / C pools are also increasing?

Response: The information is contradictory. All kind of results  have been reported, whereas it seems that crop abandonment can slightly increase soil organic carbon (For example observed by Bell et al., 2021 in Spain) in general most reports observed a clear trend to loss of soil fertility and carbon in non-agricultural lands of the Mediterranean Basin (as reported in Sardans and Peñuelas 2013). Regarding to the current accumulation of carbon linked to forests in the Mediterranean Basin it is difficult to make an overall quantification. Certainly, in the course of crop abandonment and secondary succession to forest a net gain of Carbon in stand biomass has been observed in long chronosequences in the Mediterranean Basin (Badalamenti etal. 2019). Average of carbon sequestration capacity has been estimated in 4.6 Mt y^-1 in all Mediterranean forests in 2005 and this value can change between 3.3 to 5.97 Mt y^-1 depending the future socioeconomic scenarios in 2050 (FAO 2018). According with this last information we have added new information into the revised version of the manuscript. It now reads:

“Anyway, Mediterranean forest are a global sink of carbon [10]. In 2005 Mediterranean Basin forest accumulated 4.6 Mt y^-1 and this value can change between 3.3 to 5.97 Mt y^-1 in 2050 depending on the future socioeconomic scenarios [10].”

Badalamenti, E., Battipaglia, G., Gristina, L., Novara, A., Rühl, J., Sala, G., Sapienza, L., Valentini, R., La Mantia, T. Carbon stock increases up to old growth forest along a secondary succession in Mediterranean island ecosystem. PlosOne, 2019, 14, e0220194.

Bell, S.M., Terrer, C., Barriocanal, C., Jackson, R.B., Rosell-Melé, A. Soil organic carbon accumulation rates on Mediterranean Abandoned agricultural lands. Sci. Total Environ. 2021, 759, 143535.

14.L84: The EU CAP was not in existance for most of the last 100-150 years. Suggest a rephrasing here.

Response: Rephrased. It now reads:

“The increase in forested area in the last 100-150 years is mainly due to forest regeneration in rural areas following continuous abandonment, as observed in several Mediterranean countries, and more recently it is also due to the European Common Agriculture Policy (as in Spain) [18,25].”

15.L97 – ‘protection against soil erosion’ by enzymes seems somewhat teleological and probably unintentional. Perhaps these two arguments (roots – erosion / fertility / water) and (enzymes – fertility) could be split to avoid confusion.

Response: Rewritten clearly and split in two sentences:  

“For example, increasing the allocation of resources to roots facilitates the  capture of soil nutrient and water from deep soil layers and protect against soil erosion [18]. This together with high translocation and resorption of foliar nutrients and large contents of recalcitrant compounds provide to Mediterranean plants a high drought stress resistance by a high conservative and efficient use of soil resources [18].”

16.L135 – what can be insufficient? I don’t understand this sentence.

Response: Clarified. It now reads:

“For example, a long-term (20 years) climatic manipulation in a holm oak (Quercus ilex) forest has produced a continuously lower availability of soil water like that projected for the near future and has demonstrated that the capacity of the trees to adapt to this level of drought is higher than previously expected [46]. Most species of tall evergreen shrubs, however, have increased in coverage and biomass more than has Q. ilex [47,48]; and forest structure can be transformed into shrubland structure under more frequent intense heatwaves and droughts [10,18,46,49].”

17.L138 – perhaps ‘nutrient losses’ could be expanded on. Is this N losses expected, perhaps leading to (as in other works by the authors) – N:P imbalances?

Response: Yes, this is a good point to be commented in this frame; torrential rainfall and moments with extreme soil water content and high run-off can have an asymmetrical impacts on soil nutrients, for instance affecting stronger to more mobile elements as N and less to more immobile elements such as P, driving thus to nutrient imbalances. This has been now clarified in the new version of the manuscript that reads as:

“To complete this scenario, we must consider that the Mediterranean climate has frequent torrential rains [50] that are projected to increase [51] and thus produce larger nutrient losses in the near future. In this context the rise in drought periods together with more frequent extreme rain events can exert a strong impact on Mediterranean soil C:N:P ratios due to the different cycling and solubility/volatilization of these three elements [18]. This can in turn also have asymmetrical effects favoring more some species than others [18].”

18.L161 – perhaps rephrase ‘earlier taken up’ – this is a little confusing as this terminology can be used for nutrients as well with a very different meaning.

Response: Ok, now changed to:

“However, the livestock pressure is decreasing very fast in large parts of the northern Mediterranean basin, to such an extent, that herbivory has fallen to levels unnaturally low [119].”

19.L187 – is there any evidence that the aforementioned CO2 fertilization could raise these limits? (although maybe this is beyond the scope of this paper)

Response: This is already commented in the next paragraph that we have now amended to clarify this point:

“Forests thus tend to be replaced with shrubland and even steppe vegetation as projected in climate models for scenarios of rising atmospheric CO₂ concentrations [81] (Figure 2).”

20.L292 – this reference [132] does not link as the others in the review copy, and contains a typo: ‘crossdtalk’

Response: Corrected typos.

21.L340 – for some readers, a clarification as to which Sierra Nevada this refers to be would be useful

Response: Clarified. It now reads:

“…ungulates is high, as in Sierra Nevada mountains (South Spain), where..”

22.L407 – a sentence elaborating on the links between fire, rain and erosion would be good.

Response: Thanks for making us notice this. the revised text now reads:

“Forest fires in areas with Mediterranean climates greatly degrade the soil, mainly due to an increased erosion on steep slopes from torrential rain [214,215]. Fire is a driver of desertification that is linked to a continual positive feedback of higher frequency and intensity of torrential rainfall (associated to climatic change) with an increase of soil erosion, which in turn leads to a loss of soil fertility and thus plant cover. These can also be aggravated by human activities such as excessive livestock pressure, and by increasing the frequency and extend of fires [18].”

23.L583 – is this the definition of appropriate management, or something which can occur alongside appropriate management. Rephrasing would clarify this.

Response: Rephrased to clarify it.

Management practices after reforestation or afforestation are also important for increasing the probability of success [304]. Periodic reduction of vegetation, such as shrubs and grasses, can improve the survival and growth of planted trees [304]. Appropriate forest management, with a good combination of forest patches of different sizes and successional stages together with other ecosystems, such as cropland, is also an adequate tool to improve the capacity to store C [305]. Appropriate management is also necessary to maintain natural Mediterranean forests in their current structure and areas [306]. An adequate level of thinning a few years after a fire can enhance forest regeneration and allow control of fuel load for possible future forest fires, both by seeder species such as P. halepensis and by resprouter species such as Q. ilex [307].

We very much thank the consideration and very helpful comments of the referee.

Best wishes

Prof. Josep Peñuelas and Prof. Jordi Sardans

Global Ecology unit CREAF-CSIC-UAB

CREAF, Edifici C, Facultat de Ciències

Universitat Autónoma de Barcelona

Author Response File: Author Response.docx

Reviewer 2 Report

Review of manuscript “Global change and forest disturbances in the Mediterranean: Breakthroughs, knowledge gaps and recommendations” submitted by Josep Peñuelas and Jordi Sardans to the Forests (Manuscript Number “forests-1182332”)

General comments

In the conditions of a changing world, natural disturbances will be an increasingly common factor which determines the dynamics and structure of forest formations. Increasing drought and high variability of precipitations in the Mediterranean put on the agenda pending questions about sustainable forest management. Similar articles like this would contribute to “fill in” knowledge gaps, which is why I welcome such articles. Even though, I find the manuscript interesting, I have some major critiques. I do believe my suggestions could improve the paper.

Major points:

1. The abstract needs to be rewritten in terms of clearly pointing out the goals of the review. What is the exact focus of the review? What criteria has been used for the review and in what framework has it been put?  
2. In part 1. Present and future aridity: The larger threat: There are some unnecessary things in this part. There is also duplicated information in the introduction/background.
3. In the manuscript there are no comments on the possibility of occurrence of insect outbreaks, windthrows or floods! It sounds as if these types of natural disturbances do not exist in the Mediterranean Basin. In fact, they are a direct result of climate change and historical legacies (and/or disturbance legacies). Disturbance legacies may either increase or decrease the ecosystem resistance to a second disturbance and it is necessary to take into account in the human management.
4. I would recommend for you to illustrate on a map figure which exact regions of the Mediterranean Basin are discussed in the reference articles (Geographic Scope of the Review). This would help to specify whether the review concerns the whole Mediterranean Basin or only individual parts of it.
5. Summary part: In the manuscript there are single parts where the forests of Northwest Africa are mentioned. However, they are not sufficient enough to make a conclusion for their condition. It must be taken into account that the ecosystems, the socioeconomic conditions, the governmental policies and the long-term human influence are radically different than these in Southern Europe. I doubt that there could be a generic approach in the solving of future problems.
6. It is not clear what “knowledge gaps” are the writers discussing.

Minor remarks:

Line 2-3: the heading in this format does not correspond to the contents of the text.

Line 11: what is meant by “recent literature”. It is a good idea to indicate a time interval for the used reference article.

Line 13: some of the discussed factors are a result of the increasing drought as fire and pest expansion, they are even commented on as such a few lines below (at causes ii).

Line 16-17: this sentence is in the foundations of your review and it should be accented on.

Line 28: this reason has more of a general significance. It can include both the anthropogenic impact on the soil as a result of agricultural (or livestock) and forestry policies, as well as the intense management of water resources, the depopulation of rural areas, etc.

Line 39: some of the key words are not discussed in the text and they should eventually be excluded as such.

Line 89-90: I fully agree with this statement. It is very important to take into account not only the area of forests, but also structure and degradation.

Line 155: the word “dehasas” should be explained in order to make clear that it has been referred to the Spanish agroforestry farming system.

Line 152-164: these statements should be referred to a separated part, regarding the grazing in the conditions of increasing drought, temperature and torrential rains.

Line 175: it is more correct to write the whole name Atlantic multidecadal oscillation (AMO)

Line 187-189: this statement must be supported with proof. There is a scenario for migration of species to the north. In several South-European countries there are projects which model the migration of species in the condition of climate changes. You have even pointed it out in line 317-318.

Line 209-215: it is a good idea to move this part in another section concerning wildfires.

Line 226-267: these three paragraphs are unnecessary in this part.

Line 331: “…“inland” forest populations…” the use of such terms is incorrect. Usually, there types of forests are located in the border of their ecological plasticity, respectively the edge of their areal. This is what makes them highly sensitive to changes.

Line 335: I do not understand the use of bold to emphasize this part of the sentence. Following this pattern, there are other significant statements in the article that should be bolded.

Line 369-370: I cannot agree with you that Celtis australis and Robinia pseudoacacia are highly invasive species without specific proof. In your next statement, you cite that they do not have the potential in forest areas. Even Ailanthus altissima meets difficulties coping with the competition of local species out of urban territories. And yet, if we can define the tree of heaven as an invasive species, it is hardly likely that is the case for the whole Mediterranean Basin.

Line 381-382: see note for Line 335

Line 489-491: this is a very important statement which need more attention. Many authors wrongly refer to new forest and forest as the same terms.

I hope my comments are useful and will help the authors to improve the manuscript.

Author Response

Please, see the attached file. 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The abstract has been significantly improved.  The purpose of the review is now clearly defined and the obtained results are briefly and accurately stated.

 The added new data and the rewriting of some of the chapters has significantly improved the overall structure of the manuscript as well. The authors ‘answers are comprehensive and accurate.

 I only have some small notes and comments:

1. It is not yet clear what is meant by "recent literature". It is stated that it is being referred to the last twenty years. For this purpose, the following sentence is inserted:

“We have conducted a throughout review of recent literature (2000-2021) that clearly indicates large direct and indirect impacts of increasing drought conditions on the forests of the Mediterranean Basin.”

However, I did not find such a sentence in the text.

2. Line 163: a remaining reference to Figure 1. has been missed, probably whilst working with both versions of the manuscript. In the final version of the manuscript it should not be in this sentence. The authors most probably mean Figure 2.

I find the amplifying of some of the paragraphs very appropriate, thus introducing additional clarifications on a number of issues.  For example, the insertion of a new paragraph (lines 148-154) relating to the possible transformation of tall woody vegetation into shrubbery and the additional clarification in the next paragraph (lines 157-160).

Author Response

Editor

Forests

                                                                                          Barcelona, May 7^st, 2021

Dear Editor:

We submit the revision of our manuscript No. forests-1182332 entitled “Global change and forest disturbances in the Mediterranean Basin: Breakthroughs, knowledge gaps and recommendations” after incorporating the comments and suggestions of the referees. Many thanks for your consideration and help. We hope that this study can now be published in Forests

Responses to reviewer 2 comments

1.(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
( ) English language and style are fine/minor spell check required
(x) I don't feel qualified to judge about the English language and style

Response: Thanks for the general positive evaluation of our manuscript

2.Comments and Suggestions for Authors

The abstract has been significantly improved.  The purpose of the review is now clearly defined and the obtained results are briefly and accurately stated.

 The added new data and the rewriting of some of the chapters has significantly improved the overall structure of the manuscript as well. The authors ‘answers are comprehensive and accurate.

Response: Thanks again for the favorable comments now regarding to the text improvements in the last revision of the manuscript.

 I only have some small notes and comments:

3.It is not yet clear what is meant by "recent literature". It is stated that it is being referred to the last twenty years. For this purpose, the following sentence is inserted:

“We have conducted a throughout review of recent literature (2000-2021) that clearly indicates large direct and indirect impacts of increasing drought conditions on the forests of the Mediterranean Basin.”

However, I did not find such a sentence in the text.

Response: Sorry be the leave of this detail in the manuscript. Now has been incorporated. See the new version of the abstract of the manuscript.

4.Line 163: a remaining reference to Figure 1. has been missed, probably whilst working with both versions of the manuscript. In the final version of the manuscript it should not be in this sentence. The authors most probably mean Figure 2.

Response: Corrected.

5.I find the amplifying of some of the paragraphs very appropriate, thus introducing additional clarifications on a number of issues.  For example, the insertion of a new paragraph (lines 148-154) relating to the possible transformation of tall woody vegetation into shrubbery and the additional clarification in the next paragraph (lines 157-160).

Response: Thanks again for the favorable comments now regarding to the text improvements in the last revision of the manuscript.

We very much thank the consideration and very helpful comments of the referee.

Best wishes

Prof. Josep Peñuelas and Prof. Jordi Sardans

Global Ecology unit CREAF-CSIC-UAB

CREAF, Edifici C, Facultat de Ciències

Universitat Autónoma de Barcelona

Author Response File: Author Response.docx